The Green Building Handbook Vol 7- Materials and Technologies - Alive2green

The Green Bulding Handbook

T A M South Africa Volume 7

Materials and Technologies

ISBN 9-780620-452403 07

9

780620 452403

R150.00 incl. VAT

&TECH

ONE EARTH. ONE PAINT.

ONLY PLASCON.

formulation and trusted performance is complemented by its pioneering environmental approach that results in the most groundbreaking green paint products on the market.

You see, green is not just a colour to us, which is why Plascon’s decorative coatings are

Our industry-first extended guarantees of

lead-free, low VOC and ECOKIND .

15 years on interior paints and 12 years on

TM

exterior paints ensure that the environmental At Plascon, we don’t merely innovate, we

footprint of our paints is even greener.

ECOVATE. New Water-based Velvaglo

Of course, it’s not just our products that are

is just one such example. Another is the

green – so is our approach to manufacturing

ion technology of Silver Protect™, which

with all of our South African plants accredited

transforms Double Velvet and Cashmere

with ISO 1 4001certification.

into smart coatings that actively inhibit the growth of harmful bacteria. The result is

To find out more about what

fresher, cleaner, and more hygienic walls

Plascon is doing to keep our planet

for a guaranteed 15 years.

green, contact the Plascon Advisory Centre on 0860 20 40 60, email

The cutting-edge formulation of Nuroof Cool

tradeadvice@plascon.co.za or

is smart enough to decrease the emission

visit plascontrade.co.za

of greenhouse gasses, and the Direct to Substrate™ feature of Velvaglo Enamel combines a primer and topcoat into one coat, making it gentler on the planet.

13805 IDEA ENGINEE ® S

Plascon’s 125 year history of leading quality assurance, superb

www.corobrik.co.za | info@corobrik.co.za

Rainwater & Wastewater Solutions Filter

Rainwater harvesting

Pump

Municipal switch-over www.kyasol.co.za

Supply filter *

• Professional rainwater harvesting systems for domestic and commercial applications • Complete package solutions with single tank capacities of 4,800 L and 6,500 L • Multiple tanks can be connected • Suitable for drive way installations • Automatic switch-over between tank and municipal supply

* on the tank

filter • Anaerobix is the new low-cost PVC mesh cleaning system, replacing standard septic tanks • The bio-reactor, filled with PVC mesh material, increases the cleaning performance of a standard septic tank several times over • The large surface of the bacteria friendly, recyclable plastic carrier material allows the bio film responsible for the cleaning process to cover a larger area Anaerobix filter kit

Anaerobix - Septic Tank

one2clean - Wastewater System • • • •

Up to 99% cleaning efficiency Immediate wastewater treatment prevents odours Low power consumption Long sludge removal intervals Water Infiltration Tunnels • 300 L capacity per element • Multiple elements for larger volumes • Vehicle loading upto 3.5 t/m2

6

+27 (0) 11 840 0840 info@kyasol.co.za www.kyasol.co.za

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

The Green Building Handbook

South Africa Volume 7

Materials and Technologies

EDITOR Llewellyn van Wyk

PROJECT LEADER Louna Rae

CONTRIBUTORS Llewellyn van Wyk, Coralie van Reenen, Vernon Collis, Prof Mark Alexander, Kyle Wickins, Tobias van Reenen, Ivor Jones, Wim Jonker Klunne, Andy le May

ADVERTISING EXECUTIVES Charity Musiyanga Tendai Jani

PEER REVIEWER Naalamkai Ampofo-Anti, Llewellyn van Wyk LAYOUT & DESIGN Nicole Kenny DIGITAL MARKETING MANAGER Marcus Matsi DISTRIBUTION Edward Macdonald

CHIEF EXECUTIVE Gordon Brown DIRECTORS Gordon Brown Andrew Fehrsen Lloyd Macfarlane EDITORIAL ENQUIRIES LvWyk@csir.co.za PUBLISHER

HR ASSISTANT Leslie-Rae Webber CLIENT LIASON MANAGAER Eunice Visagie

www.alive2green.com

The

The Sustainability Series Of Handbooks PHYSICAL ADDRESS: Alive2green Cape Media House 28 Main Road Rondebosch Cape Town South Africa 7700 TEL: 021 447 4733 FAX: 086 6947443 Company Registration Number: 2006/206388/23 Vat Number: 4130252432

Sustainability and Integrated REPORTING HANDBOOK South Africa 2014

ISBN No: 978 0 620 45240 3. Volume 7 first published February 2012. All rights reserved. No part of this publication may be reproduced or transmitted in any way or in any form without the prior written consent of the publisher. The opinions expressed herein are not necessarily those of the Publisher or the editor. All editorial contributions are accepted on the understanding that the contributor either owns or has obtained all necessary copyrights and permissions.

IMAGES AND DIAGRAMS: Space limitations and source format have affected the size of certain published images and/or diagrams in this publication. For larger PDF versions of these images please contact the publisher.

DISTRIBUTION AND COPY SALES ENQUIRIES distribution@alive2green.com INTERNATIONAL FRANCHISE ENQUIRIES info@alive2green.com PRINTER FA Print ADVERTISING ENQUIRIES sales@alive2green.com

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

7

The

Sustainability and Integrated REPORTING HANDBOOK South Africa 2014

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

9

LEAVE BEHIND A LASTING LEGACY

Natural clay brick - the benchmark for quality construction

The Pietermartzburg City Hall is the largest clay brick building in the southern hemisphere

South Africa needs a safe and long lasting public infrastructure of schools, hospitals, prisons, workplaces and homes.

Alternative lightweight “quick fix” building solutions are not cheaper, are expensive to maintain and have a short lifespan compared with clay brick.

A clay brick structure is a long term investment that will protect & serve cost effectively for 100 years or more.

INSIST ON CLAY BRICKS FROM AN ACCREDITED SUPPLIER 011 805-4206 | www.claybrick.org.za

EDITOR’S NOTE

Llewellyn van Wyk Editor

T

he launch of this Green Building Materials and Technologies Handbook marks a significant step in the effort to develop and disseminate information with regard to sustainability and resilience building. While many worthwhile initiatives exist to promote sustainability and green building, transformation will be driven forward when technologies exist that are able to significantly enable the implementation of new sustainable and resilient solutions.

Chhaya Bhanti, a brand strategy and sustainability consultant based in New York, made the observation that “we cannot continue to manage what we have failed to manage thus far: we must design our way out”. The word ‘design’ is the key word in the sentence, and I am reminded of the comment Steve Jobs made that “design is not just what it looks like and feels like: design is how it works”.

In conceptualising the content of this Handbook, consideration is not just given to the new. Too often we view new technologies as the only technologies worthy of consideration, whereas there are traditional and established technologies which

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

11

Bulkmatech Waste Minimization Equipment Specialists Tel: 0861-782-358 Web: www.bulkmatech.co.za

E-mail: info@bulkmatech.co.za

SAVE WASTE COSTS AND REDUCE YOUR CARBON FOOTPRINT!

What is Compaction?

Compaction basically refers to an increase in density of a material. This usually results from pressing together of particles under the influence of their own weight.

WASTE PROBLEMS????

Call us to solve it!!

The high compressing capacity enables you to save transport costs of up to 80%. Low operating and minimal maintenance costs are the best conditions for a profitable and environmentally friendly refuse collection.

Bulkmatech supplies a comprehensive range of waste compaction equipment suitable to handle the different volumes and type of waste generated.

We offer our compactors and balers as “FULL MAINTENANCE RENTALS”.

Contact us for a solution.

Tel: 0861-782-358

EDITOR’S NOTE

have been forgotten about but which are still effective, such as the use of wetlands for waste water treatment.

In addition, this Handbook will not tout technologies as the saviour of our time: I am too well aware that technology is but one instrument to use in the movement toward sustainable and resilient communities.

Leadership and human behaviour are equally important.

What this Handbook therefore sets out to do is to expose readers, decision-makers, designers and those interested in sustainability to as full a range of technologies and materials as is possible. In doing so this Handbook will not endorse any one technology or material, but will strive to share technology and material development and, wherever possible, support this with research and case studies.

I trust that this Handbook will add value to those involved in the support and development of sustainability and resilience-building.

Sincerely Llewellyn van Wyk Editor

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

13

FOREWORD

T

he South African Institute of Architects (SAIA) is in support of sustainable design and construction, a fundamental component of which is the specification of materials and technologies, and as such SAIA is happy to provide this foreword for the Green Building Materials and Technologies Handbook.

This peer reviewed publication is a further contribution to the overall body of knowledge on the subject of sustainable design, and we have no doubt that it will be of value to our members and indeed to all specifiers and decision-makers grappling with the technical and often conflicting sustainability arguments presented by suppliers.

We hope you will find this publication beneficial in your architectural practice.

Yours faithfully

Obert Chakarisa Chief Executive Officer On behalf of SAIA

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

15

CONTRIBUTORS LLEWELLYN VAN WYK

Llewellyn van Wyk graduated in 1980 from the University of Cape Town with a Bachelor of Architecture degree. He opened his practice in 1984 completing building projects throughout Southern Africa. He joined the CSIR in 2002 and is currently a Principal Researcher in the Built Environment Unit.

ANDY LE MAY Andy is the founder of two organisations, EWIZZ and icologie, that are bringing about positive sustainable social change in SA. EWIZZ is providing zero emission transport solutions and icologie is bringing about sustainable inspiration, motivation and education.

CORALIE VAN REENEN Coralie van Reenen is a professional architect, currently working as a researcher in the CSIR Built Environment Unit. She has a career background in innovative building technologies and is a Green Star Accredited Professional. She has studied environmental law and also lectures architecture students at the University of Pretoria, having a passion for the interface between humankind and the environment.

KEN STUCKE Ken Stucke has had extensive training and experience in green buildings and sustainability in England, France, Botswana and South Africa. In 2001 Ken founded his firm Environment Response Architecture (ERA Architects) with a primary focus on green architecture. Ken has more than 15 years teaching experience at both Wits University and University of Johannesburg where he has been promoting Sustainable Development and “Green Architecture� in carefully formulated courses.

KYLE WICKINS Kyle Wickins has a BSC Masters in Civil Engineering. His thesis included the recycling of construction and demolition waste as an aggregate replacement.

16

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

CONTRIBUTORS

PROF MARK ALEXANDER

Mark Alexander is Professor of Civil Engineering at UCT. His research is in cement and concrete materials engineering, specifically relating to design and construction. He is part

of the leadership of CoMSIRU at UCT, where work is being done on concrete durability and aggregate replacement.

TOBIAS VAN REENEN Tobias van Reenen is a senior researcher with the Council for Scientific and Industrial Research (CSIR). After serving a decade as a mechanical engineering consultant designing industrial cleanrooms and bio-safety laboratories internationally, he works today primarily on researching the role of buildings in airborne disease transmission and perceptions of indoor comfort.

VERNON COLLIS Vernon Collis is an Engineer-Architect specialising in integrated and sustainable systems design for the built environment. His praxis includes the investigation of recycling construction waste using appropriate technologies. He is also an HRA at UCT Civil Engineering.

WIM JONKER KLUNNE Wim Jonker Klunne is a renowned energy expert with an academic background in Civil Engineering and Management. His extensive experience in renewable energy projects, from a technical, financial and socio-economic perspective, provides him with a solid background for technical assistance in this field. Currently Wim is working at the Council for Scientific and Industrial Research (CSIR) in South Africa as senior researcher and involved in a large portfolio of renewable energy and energy efficiency projects.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

17

CONTENTS 1

What are green materials and technologies?

Llewellyn van Wyk, Principal Researcher, CSIR

24

2

Green building materials and technologies in the context of the Green Star rating tool Coralie van Reenen, Researcher, CSIR

42

3

Use of recycled construction waste in concrete Vernon Collis, Mark Alexander, Kyle Wickins

4

Green HVAC systems Tobias van Reenen, Senior Researcher, CSIR

54 68

54

24

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

19

adhesion Sw/009/14/e

www.swartland.co.za

Our new application will take the frustration out of fenestration.

Introducing SpecNet, a free online application designed by professionals, for professionals, to make specifying windows and doors easy.

SpecNet gives you access to accurate, intelligent Revit families and ArchiCAD objects (SmartXA ready) of our Cape Culture range, with their corresponding U-values and SHGC values, ready for use.

Easy-to-use DRAG & DROP function.

1

Smart-XA ready ArchiCad objects, Revit families and intelligent schedules with product data.

2

Product documentation and certification, training and information sharing.

3

Instant price estimate and submit for quote function.

4

A discussion forum with interactive expert advice.

To try this free application visit www.swartland.co.za/specnet or call us on 0861 10 24 25

5

Product catalogues and images for all our ranges.

CONTENTS 86

78

5

Application of a wetland to treat sanitation in an urban setting Ken Stucke, Architect

78

6

Solar electricity for buildings Wim Jonker Klunne

86

7

Infrastructure for clean transport in South Africa Andy le May

98

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

21

PROFILE

Insulate and save Dylan Miller, from leading wooden windows and doors supplier, Swartland, offers some advice on how to best insulate your doors and windows.

When it comes to heat loss, windows and doors are generally the biggest culprits, as by default, they are designed to open the inside of your home to the outdoors.

Why is insulation so important?

Simply explained, heat flows naturally from a warmer to a cooler place. As such, in winter, the heat will move directly from a heated living space to the colder areas. During the summer, any heat will move from the hot outdoors into the cooler interior of our homes, making air-conditioners work that much harder to keep the interior cool.

Insulation acts as a barrier to this natural flow of heat. It can be described as any product that limits or blocks the transfer to heat from heated areas to cooler areas, helping to keep your home warmer in the winter and cooler in the summer.

Double-glazing “The best way to ensure the windows throughout your home are well-insulated is to replace them with double-glazed models. Double-glazing substantially reduces and regulates thermal loss from the inside and solar heat gain from the outside and it is also environmentally-friendly.”

Double-glazing could easily reduce the energy spent on regulating the temperature by as much as 50%. “Recent independent tests on a Swartland window has shown that it had one of the lowest tested U-rating of all tested windows in South Africa, while our solar heat gain rating was also the lowest. Tests completed on Swartland’s double-glazed windows achieved a U-value of U-1,86 – this is lower than the accepted SANS204 default U-value for timber, which is U-5,6.”

Our Cape Culture Collection product data is now available on SpecNet, Swartland’s online specification tool designed by professionals for professionals.

SpecNet revolutionises your window and door buying experience SpecNet is a fantastic, free online specification tool designed to make specifying windows and doors easy. Dylan Miller from leading wooden window and door manufacturer, Swartland, explains: “The system, accessible via www.swartland.co.za/specnet or www.swartland.co.za will give specifiers, architects or builders access to accurate, intelligent ArchiCAD objects and Revit

PROFILE

families. From sketch design, through to reality, Swartland windows and doors are freely available to all registered users.”

The benefit of using the SpecNet application is that it has been designed by professionals, for professionals, and it aims to really simplify the specification process and save industry professionals time and money. Also – since all the information on the SpecNet system is accurate, there is less of a margin for error on the professional’s side. All the data has been provided

by Modena and LARGEarchitecture Group and can be saved at no cost into your own personal online library.

Each SpecNet drawing comes with its own individual U-values and SHGC-values ready to fit into your plans to ensure that they meet all the SANS 10400-XA National Building requirements.

These regulations relate to energy usage in buildings and it is mandatory by law to meet them.

Getting proportions and sizing right when it comes to fitting doors and windows is crucial.

Currently, you can peruse Swartland’s full Cape Culture range of wooden windows and doors on SpecNet – using it for inspiration or to find the specific products that are best suited to the project you are working on. In the near future, Swartland will include its full Winsters Collection on SpecNet as well.

SpecNet allows users access to: • Smart-XA™ ready ArchiCAD objects, Revit families and intelligent schedules with product data • A specification tool, as well as a drag and drop function • A discussion forum with interactive expert advice • True supplier content for an informed design concept • Product documentation and certification • Product catalogues • A price estimation system • Training and information sharing • Product images for all ranges

GREEN MATERIALS AND TECHNOLOGIES

1

WHAT ARE GREEN MATERIALS AND TECHNOLOGIES?

Llewellyn van Wyk

24

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

1

GREEN MATERIALS AND TECHNOLOGIES

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

25

GREEN MATERIALS AND TECHNOLOGIES

26

1

Introduction

Background

The potential impact of climate change and global warming is without doubt one of the most life-threatening challenges that face humanity. Central to this challenge is our dependence on fossil fuels as the primary source of energy – the major contributors of greenhouse gases (GHGs) including carbon dioxide (CO₂) – and the extensive use of non-renewable resources.

It is now widely recognised that the climate systems are warming: there is also medium confidence that other effects of regional climate change on natural and human environments are emerging, although many are difficult to discern due to adaptation and non-climatic drivers. Global GHG emissions due to human activities have grown since pre-industrial times, with an increase of 70 per cent between 1970 and 2004. Anthropogenic warming could lead to some impacts that are abrupt or irreversible, depending upon the rate and magnitude of the climate change, including severe species loss.

Nevertheless, a wide range of adaptation options is available, although a more progressive rate of adaptation than is currently evident is required. Given an increase in adaptation rates, many impacts can be reduced, delayed or avoided. There is thus a causal relationship between climate change mitigation and sustainable development: sustainable development can reduce vulnerability to climate change by enhancing adaptive capacity and increasing resilience.

The construction and maintenance of the built environment has a fundamental role to play in this challenge: green materials and technologies for new and existing buildings could considerably reduce CO₂ emissions while simultaneously improving indoor and outdoor air quality, social welfare, energy security, and ecological goods and services.

The built environment is where the majority of the world’s population now reside: one out of every two people live in a city (UN 1996). Global population has expanded more than sixfold since 1800 and the gross world product more than 58-fold since 1820.

As a result, the ecological footprint (EF) of humanity exceeds earth’s capacity by about 30 per cent. If we continue on the same development trajectory, by the early 2030s two planets will be required to keep up with humanity’s demand for goods and services.

In 2013, the global building stock was 138.2 billion m², of which 73 per cent was in residential buildings (Bloom & Goldstein 2014:2). It is forecast that the commercial and residential segments will experience compound annual growth rates (CAGRs) in the next 10 years of 2,1 per cent and 2,2 per cent respectively (Bloom & Goldstein 2014:3).

Overall it is projected that the total building stock will grow to 171.3billion m² at a GAGR of 2,2 per cent over the next decade (Bloom & Goldstein 2014:3).

Most of the growth is expected to occur in China, where nearly 2.0 billion m² are added to the commercial and residential building stock every year. However, North America and Europe are each likely to make a significant contribution to the total building stock (Bloom & Goldstein 2014).

Interestingly enough, Bloom & Goldstein claim that commercial, residential, and industrial buildings are responsible for 47 percent of global greenhouse gas (GHG) emissions and 49 percent of the world’s energy consumption (2014:1).

As stated earlier, the construction industry plays a critical role in the growth of the economy through its creation of immovable fixed assets. Because of this role Government has declared the construction industry a national priority (Cidb 2012:10).

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

1

According to StatisticsSA Gross Domestic Product, Quarter 1, 2014 (Statistical release P0441), the construction industry expanded R4 billion to R31 billion from the Q4: 2013 to Q1: 2014 (2014:4). Were this to continue at current rates investments in construction works should reach R124 billion by Q4: 2014.

Gross Fixed Capital Formation (GFCF) for the residential sector fell -2,2 percent year-on-year in Q4: 2011 based on constant 2005 prices, from R24,83 bn to R24,29 bn.

The non-residential sector fell by 1,3 percent year-on-year in Q4: 2011, to R37,08 bn from R37,56 bn in Q4: 2010. GFCF in construction works rose 2,3 per cent year-on-year in Q4: 2011, the highest growth rate over the past seven quarters with investment in construction works increasing to R110,36bn in Q4: 2011 from R107,89bn in Q4: 2010 (Industry Insight 2012:18).

The total GDP for South Africa in 2013 was approximately R3,3 trillion of which the non-residential sector contributed 1,41 per cent directly, 1,55 percent indirectly, and 2,39 percent induced (SAPOA 2014:51).

During 2013 the real estate sub-sector contributed R1,32 billion to the fixed capital stock of South Africa, while the gross fixed capital formation added R97,856 million to this figure over the same period, representing 20,9 percent and 14,95 percent respectively of the whole economy (SAPOA 2014:15). Of this capital formation, R69,697 million or 71,2 percent, is attributable to non-residential buildings (SAPOA 2014:15).

It is also a significant consumer of resources especially materials, energy and water: globally the construction industry is responsible for about 50per cent of all materials used, 45 per cent of energy generated to heat, cool and light buildings and a further 5per cent to construct them, 40 per cent of water used (in construction and operation), and 70 per cent of all timber products that end up in construction

GREEN MATERIALS AND TECHNOLOGIES

(Edwards 2002). In South Africa, buildings account for 23 per cent of electricity used, and a further 5 per cent in the manufacturing of construction products (CIDB 2012).

The construction industry has traditionally been a slow adopter of new technologies in general, mainly due to the perceived associated risks (Woudhuysen and Abley, 2004). The building sector in particular is reluctant to adopt new technologies due to potential buyer resistance (Woudhuysen and Abley, 2004).

Thus, the sector undertakes most of its work with conventional technologies.

Green technologies really came into consideration with the emergence of the formal green building movement lead by the British Research Establishment (BRE), and Professors’ Feist and Adamson in the late 1990s. This saw the release of green building systems such as British Research Establishment’s Environmental Assessment Method (BREEAM), and the Passivhaus concept respectively. Since then a number of new green building systems have emerged, including the Green Star® system as adopted by the Green Building Council of South Africa (GBCSA).

The introduction of these systems has heightened interest in green building, and in the technologies they use. While much of the technology remains conventional to meet some of the performance requirements, green technology is required.

High Performance Green Building

Because buildings are often used for centuries, the rapid pace of development increasingly means that it is impossible to imagine the demands that future uses will place on buildings. Consequently, products and systems should be chosen that make adaptation easier. While aesthetic appeal will always be a component of building

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

27

1

design, the real challenge is to create built environments that are durable and flexible, appropriate in their surroundings and provide high performance with less detrimental impacts.

In response to this challenge, a global initiative launched by the World Business Council for Sustainable Development (WBCSD) and supported by over 40 global companies aims to “transform the way buildings are conceived, constructed, operated and dismantled” to achieve zero energy consumption from external sources and zero net carbon dioxide emissions while being economically viable to construct and operate. Included in the initiative is the identification of the full range of present and future opportunities with regard to “ultraefficient building materials and equipment”.

Additionally, this aim is enhanced by using the “cradle-to-cradle” concept of producing, using and later re-using building materials, a design evolution needed to achieve sustainability for buildings.

The current generation of‘green’ buildings already offer significant improvements over conventional buildings inasmuch as they consume less energy, materials, and water; provide demonstrably healthier living and working environments; and greatly enhance the quality of the built environment, including the neighbourhood.

However, these improvements are offered through the use of existing materials and products, design approaches, and construction methods. Because of this conventional approach to design and construction, it remains difficult to incorporate truly innovative technologies into current construction practice.

Good design is fundamental to sustainable construction. Decisions made at the initial design stage have the greatest effect on the overall sustainability impact of projects. The issues to be faced by radical

GREEN MATERIALS AND TECHNOLOGIES

high-performance “green” buildings favours construction products and methods that are flexible, light and durable: it is here that green materials and technologies emerge as a material-driven construction system capable of achieving the prerequisite performance standards.

Prudent use of natural resources results in both greater industry efficiency and a restricted usage of natural materials.

Practices such as materials recycling, waste minimisation, local product resourcing, land decontamination, and construction- and demolition-waste disposal make sound business sense and encourage good construction housekeeping. Application of the principles of ‘lean construction’ and life-cycle assessment is equally important.

The characteristics of high-performance green building as suggested by Fujita Research (2000) include: 1. Optimal environmental and economic performance; 2. Integrated processes, innovative design and increased efficiencies to save energy and resources; 3. Satisfying, healthy, productive, quality indoor spaces; 4. Employing lean construction methodologies and tools to improve waste management and reduce the environmental impact of construction waste; 5. Increasing the emphasis, at R&D stage, of whole-building design, construction and operation over the entire life cycle; 6. Fully integrated approach including teams, processes and systems; 7. Renewal engineering methods; 8. Management and business practices; 9. New standards, open buildings, advance jointing and assembly techniques, process engineering;

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

29

We know that every drop of water and every watt of power saved helps preserve the environment. Which is why we stock a wide range of eco-friendly products and energy efficient heat pumps. Perfect for eco-warriors!

086 123

ON TAP 66 827

ontapsa

OnTapSA

On Tap www.ontapsa.co.za

Eastern Cape: East London & Mthatha, Jeffrey's Bay, Port Elizabeth. Western Cape: Cape Town, Malmesbury, Paarden Eiland, Paarl, Tableview, Vredenburg, George, Mossel Bay, Stilbaai. Limpopo: Tzaneen. Gauteng: Greenstone, Woodmead Kwa-Zulu Natal: Ballito, Durban, Durban North, Hillcrest, Pietermaritzburg, Pinetown, Queensburgh.

1

10. Materials and systems: new function integrated building components, durability, repairability, and retrofitability of components.

In High Performance construction, the key issue is how the choice of construction products and methods can create scope for reducing burdens.

Green Materials

The market for building materials is predicted to grow steadily into the foreseeable future. The primary driver for growth by sheer volume is the ongoing government investment in new buildings and other physical infrastructure in developing countries such as South Africa. At the same time, the demand for building materials is shifting towards environmentally preferable or “green” materials due to consumer demand; and an ever growing number of mandatory environmental regulations and standards.

Green materials use is predicated on the replacement of future flows of conventional building materials with “green” materials.

From an environmental perspective, “green”

GREEN MATERIALS AND TECHNOLOGIES

materials would need to be those materials with the least “embodied effects”, where the word embodied refers to attribution or allocation in an accounting sense as opposed to true physical embodiment. In the building community, the tendency is to refer only to “embodied energy” (Trusty and Horst, 2006). However, as implied by the comprehensive list of effect categories (Table 1) typically investigated in a Life Cycle Assessment (LCA) study, all the extractions from and releases to nature are embodied effects, and there are also embodied effects associated with the making and moving of energy itself (known as pre-combustion energy).

Until the 1970s, the construction industry sector made little attempt to establish objective and comprehensive methods for environmental assessment and improvement of buildings. The concept of Sustainable Construction which is “The creation and operation of a healthy built environment based on ecological principles” (Kibert, 1994) was first mooted in the wake of the 1987 Brundtland Report and the 1992 Rio Accords. Starting with the launch of the Building Research

Inputs (extractions from nature)

Outputs (release to the environment)

Outputs (release to the environment)

Acidification

Land

Climate change

Materials

Eutrophication

Water

Eco-toxicity Human toxicity Photo-chemical oxidant formation Stratospheric ozone depletion Table 1: Embodied effects typically investigated in a Life Cycle Assessment.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

31

GREEN MATERIALS AND TECHNOLOGIES

1

Establishment Environmental Assessment Method (BREEAM) in 1990, a large number of building rating systems have been developed around the world to provide the basis for putting sustainable construction into practice.

However, rating tools are not underpinned by robust science. The environmental improvements suggested are not benchmarked against empirical data (Reijnders and van Roekel, 1999). There is a lack of credits dealing directly with the environmental problems (embodied effects) of concern to society (Zimmerman and Kibert, 2007). These deficiencies are most notable in the case of materials selection

32

which is generally informed by prescriptive easy-to-follow directions, for example, use materials with recycled content (Blom, 2006; Trusty, 2007).

Green Technologies

Green technologies in the building sector can be defined as those technologies which reduce the environmental impact of building on the environment. These technologies would either reduce environmental impact through the development of more environmentally sustainable materials and products, or through the generation and/ or conservation of resources such as energy and water.

Technology

Description

Green characteristics

Green characteristics

High performance building envelopes, generally modular and light-weight

Reduced embodied energy Reduced energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Reduced material mass Self-cleaning Lower maintenance More durable Recyclable Reusable

Chilled beams

Type of convention heating, ventilation and air conditioning system using a heat exchanger to heat or cool space

Reduced energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Greater efficiency

Co-generation and tri-generation

Generation of electricity and heat mainly from gas

Generation of electricity and heat mainly from gas

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

1

GREEN MATERIALS AND TECHNOLOGIES

Demand-controlled ventilation

Provides the correct level of heating/ cooling for the actual occupancy

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Improved efficiency Improves thermal comfort for occupants

Dual-wall facades

Combination of two or more high performance walling systems

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Improves thermal comfort for occupants

Heat pumps

Provides heat energy from a source of heat to a destination called a heat sink

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

Electrochromic glass

Changes light transmission in response to voltage, light or heat applications thereby controlling the amount of light and heat transmitted

Changes light transmission in response to voltage, light or heat applications thereby controlling the amount of light and heat transmitted

Fuel cells

Converts chemical energy from a fuel into electricity through a chemical reaction with an oxidising agent

Reduces fossil-fuel derived energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

Geothermal systems

Uses geothermal energy for heating or cooling applications

Reduces fossil-fuel derived energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

33

GREEN MATERIALS AND TECHNOLOGIES

34

1

Green infrastructure

Includes a range of technologies that mimic natural systems to collect, treat, handle water and sanitation

Uses natural systems and process (e.g. bioretention) Reduced reliance on chemical processes Reduces greenhouse gas emissions Reduced energy consumption Reduces water consumption associated with fossil-fuel derived electricity production Enhances natural processes Enhances ecological goods and services

Innovative building technologies (IBTs)

Includes a range of building systems that are generally lightweight using light steel section frames with insulated core and clad externally and internally

Reduced material mass Reduced embodied energy Reduced chemical content Lower toxicity Improved energy efficiency in use Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

Radiant heating/ cooling

Heats and cools surfaces rather than air which then radiate into the occupied space

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Improves occupant health Improves occupant comfort

Smart and intelligent systems

Uses sensors and actuators to respond to predetermined inputs

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Improves occupant health Improves occupant comfort

Solar absorption chillers

Uses solar thermal energy to drive air conditioners

Eliminates fossil fuel consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

1

GREEN MATERIALS AND TECHNOLOGIES

Solar energy

Uses sun energy to either heat a medium (solar water heaters) or to generate electricity (photovoltaic panels)

Reduces fossil-fuel derived energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

Thermal energy storage

Allows excess energy to be collected for later use through mediums such as water, ice, and earth

Reduces fossil-fuel derived energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production

Passive ventilation

Uses non-mechanised ventilation systems to ventilate buildings

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Improves occupant health Improves occupant comfort

Underfloor air distribution

Relies on air displacement techniques

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Improves occupant health Improves occupant comfort

Wind turbines

Uses wind energy to generate electricity

Reduces energy consumption Reduces greenhouse gas emissions Reduces water consumption associated with fossil-fuel derived electricity production Table 2: A Selection of Green Technologies.

Conclusion The construction industry sector is the largest documented user of materials by weight. The market for building materials is predicted to grow steadily into the foreseeable future driven by ongoing investments in built infrastructure and the consumer demand for “green” products.

Sustainable materials use is thus predicated on the replacement of future flows of conventional with innovative building materials which have the least embodied effects where the “effects” in question are flows of key natural resources – energy, land, materials and water; and emissions to air, land and water.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

35

GREEN MATERIALS AND TECHNOLOGIES

1

The results of previous building-related LCA studies

As undertaken by CSIR (Ampofo-Anti 2011), used here as illustrative examples, and limited mostly to energy cases because of a dearth of other data, suggest that a transition to sustainable materials use would require at least: • The integration of LCA-based tools into “green” building material assessment and rating. The literature suggests that this is already happening in the case of LEED (USA), Green Star (Australia) and BREEAM (UK).

• Substitution of toxic with environmentally benign building materials. The literature and the results of previous studies indicate that toxic substances are frequently included in the formulation of building materials with devastating consequences for human and ecological health. A step change would entail possibly mandatory provisions in respect of testing, certification and labelling; and

36

a chemical policy – to exclude inherently toxic materials such as PVC. • Design for disassembly or deconstruction to facilitate maximum reuse of discarded building materials, elements and components. This would be the “cornerstone” of the sustainable materials framework, stemming the flows from and to nature and resulting in the avoidance of potential embodied effects associated with those flows. This aspect may need to be supported by mandatory extended producer responsibility (EPR).

• Design with durability or service life in mind. The results of previous LCA studies emphasis the need for designers to either choose long life interior finishing materials; or to select shorter life materials provided the latter can be led back into EPR scheme. Building designers would need access to a comprehensive service life database on building types and building materials and components to support implementation of this aspect.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

1

GREEN MATERIALS AND TECHNOLOGIES

References • Ampofo-Anti, N., 2011. “Life Cycle Assessment and its role in sustainable materials use”, Pretoria, CSIR. • Blom, I. 2006. “Environmental assessment of buildings: bottlenecks in current practice.” In ENHR International Conference, Ljubljana, July 2006.

• Bloom, E., and Goldstein, N., 2014. “Global Building Stock Database”, Boulder, Colorado, Navigant Consulting, Inc. • Cidb 2012., “Annual Report 2011/12”, Pretoria, Construction Industry Development Board.

• Edwards, B., 2002. “Rough guide to sustainability.” Royal Institute of British Architects, London.

• Industry Insight 2012. “State of the South African Construction Industry, 2nd Quarter 2012”, Johannesburg, Industry Insight.

• UNEP/CIDB 2012. “South African Report on greenhouse gas emission reduction potentials from buildings.” Pretoria, UNEP/SBCI/CIDB. • Fujita Research 2000. “What is sustainable construction?” Accessed www.fujitaresearch.com/ • Kibert, C.J., Sendzimar, J. and Guy, B. 2000. “Construction ecology and metabolism: natural system analogues for a sustainable built environment.” Construction Management and Economics, 18(2000): 903-916.

• Reijnders, L. and Van Roekel, A. 1999. “Comprehensiveness and adequacy of tools for the environmental assessment of buildings.” Journal of Cleaner Production, 7(3), 221-225.

• SAPOA 2014. “The Economic Impact of the Commercial Real Estate Sector on the South African Economy”, Sandton, South African Property Owners Association.

• StatisticsSA 2014. “Gross Domestic Product, Quarter 1, 2014”, Statistical release P0441, Pretoria, Statistics South Africa.

• Trusty, W.B. 2007. “Separating process and prescriptive measures from building performance.” Accessed http://www.athenasmi.org/ • Trusty, W.B. and Horst, S., 2006. “LCA tools around the world”, Building Design and Construction.

Accessed www.bdcnetwork.com/ • UN 1996. “Istanbul Declaration on Human Settlements”, New York, United Nations Human Settlements Programme.

• Woudhuysen and Abley, 2004. “Why is building so backward?” England, Wiley Academy.

• Zimmerman, A. and Kibert, C.J. 2007. “Informing LEED’s next generation with the natural step.” Building Research and Information (2007) 35(6), 681-689.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

37

GREEN STAR RATING TOOL

2

PRINCIPLES OF MATERIAL CHOICE WITH REFERENCE TO THE GREEN STAR SA RATING SYSTEM Coralie van Reenen

42

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

2

GREEN STAR RATING TOOL

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

43

GREEN STAR RATING TOOL

A

2

ccording to the South African Constitution’s Bill of Rights, every citizen, including in future generations, has the right to a safe and healthy environment, and to have the environment protected. In response to this right, the South African government as well as each citizen have the responsibility to ensure the protection of the environment.

This right, and the associated obligation to protect the environment, is translated into the built environment by the promotion of green, or sustainable, buildings.

The concept of green buildings is in response to the built environment’s high negative environmental impact, including its contribution towards greenhouse gas emissions and the resultant climate change.

At its core, the green building movement strives to create buildings that are designed, constructed and operate in such a way as to reduce the direct and indirect negative impact of development on the environment and its inhabitants.

The Green Building Council of South Africa (GBCSA) was established to promote and guide green building design and defines green building as follows: “Green building incorporates design, construction and operational practices that significantly reduce or eliminate the negative impact of development on the environment and people. Green buildings are energy efficient, resource efficient and environmentally responsible.” [1] The Green Star SA rating system was developed by the GBCSA as a means of assessing and scoring a building’s level of transformation from the conventional (traditional) way of building construction and management to a more environmentally responsible solution. There are Green Star SA rating tools available for various building types as well for interiors (currently in Pilot).

Issues pertaining to the environmental

44

impact of a building are addressed in categories under which various credits are available for factors that potentially improve a building’s environmental performance [1].

Significant value in terms of credits available is placed on the choice of materials, which has a dedicated category.

However, it is almost impossible to address any component of a building without considering the material aspects associated with it and therefore some credits falling under other categories must be also be considered in the choice of materials for a green building.

When viewed with reference to the GBCSA definition of green buildings, the following principles regarding material choice can be identified: materials are to be assessed according to their impact in all stages of a buildings life—design, construction and operation (including endof-life); materials are to be assessed with regard to their energy efficiency, resource efficiency and environmental responsibility.

Energy efficiency

The energy efficiency of a specific material can refer to the energy efficiency of its production (pre-installation) or the energy efficiency of its performance (post-installation). The Green Star SA rating system only recognises a material’s energy efficiency in its pre-installation phase.

This is relevant when looking at materials individually, though the designer should also consider the energy efficiency of the building as a whole during operation.

1.1 Embodied energy Development and manufacturing processes pose a risk to the environment in the way that they damage or alter ecosystems at ground level and—arguably, more significantly—in the way that they lead to greenhouse gas emissions, which in turn lead to climate

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

2

change. The construction process as well as the extraction, manufacture, transport and disposal of building materials require energy, usually in the form of carbon-based fuel. This amounts to the embodied energy of a product, which is directly proportional to the environmental impact as the burning of fuel releases greenhouse gasses. Although the quantification of the embodied energy of materials is not required in the Green Star SA rating tool, there is recognition for reducing the use of identified materials that have high embodied energy (eg. cement).

This is achieved through the reduction, reuse or recycling of such materials.

1.2 Local sourcing Part of the embodied energy of a material product is contributed by transport emissions. This is specifically addressed under the Materials: Local sourcing credit.

The reduction of transport emissions by using materials and products that are sourced within close proximity to the site is recognised and encouraged in an effort to lower the embodied energy of a building.

In the Green Star SA Interior Pilot tool, the use of products manufactured within the country is recognised, with additional merit where products are also extracted, harvested and processed in the country.

On a finer scale, the other Green Star SA rating tools award merit where 20% or 10% of the building materials are sourced, from extraction to dispatch, within 400km or 50km of the site respectively.

Resource efficiency

The concept of resource efficiency is aimed at limiting the amount of virgin material used in construction to mitigate the environmental impact and resource depletion. Resource efficiency can be achieved through reduction of material use, reuse of materials or recycling of materials.

GREEN STAR RATING TOOL

2.1 Material reduction In mitigating the exploitation of virgin materials, the Green Star SA rating tool encourages the reduction of the amount of material, and the reduction of the damaging components of a material.

2.1.1 Dematerialisation The Materials: Dematerialisation credit addresses resource efficiency by encouraging designing for less material.

This credit addresses good design more than choice of materials and is crucial for the responsible designer to consider. This Green Star SA rating identifies specific areas that can be considered to achieve dematerialisation: • Designing to achieve the building’s structural requirements and integrity with 20% less steel, concrete or timber.

• Designing ventilation with little or no ducting.

• Designing space efficiently to lower the ratio of gross floor area to usable area.

• Minimising the application of finishing materials, leaving the structure exposed.

• By making use of dual function cladding (eg. photovoltaic panels serving as cladding).

• By reducing piping through, for example, the use of water-free toilets.

Although not recognized by the rating tool, a responsible designer will also design efficiently to reduce the amount of unusable off-cuts of products on site.

2.1.2 Substitution When an environmentally damaging material cannot be avoided, it is sometimes possible to reduce the harmful component by substituting it with an alternative. This is the case with concrete. The Materials: Concrete credit recognises the reduction and substitution of Portland cement in

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

45

PROFILE

NATURAL DAYLIGHTING (SOLATUBE AUSTRALIA) Solatube tubular daylighting devices, or TDDs for short, are affordable, high-performance lighting solutions that bring daylight into interior spaces where traditional skylights and windows simply can’t reach. Sometimes referred to as “tubular skylights,” Solatube Daylighting Systems have become the ideal solution for lighting interiors in a cost-effective, energy-efficient and eco-friendly way because they significantly reduce the need for electricity while keeping people connected to the outdoor environment.

Solatube Daylighting Systems are the superior choice because they are the only high-performance daylighting devices that utilize global best patented optical technologies to significantly improve the way daylight is captured and delivered to interiors.

Solatube Daylighting Systems are modular and easy to connect to ceiling systems. Unlike traditional skylights, they are designed to control the problematic aspects of sunlight. They reduce glare and inconsistent light patterns. They also screen infrared rays that can overheat interiors as well as ultraviolet rays that can fade furniture and fabrics.

Aside from their functionality, Solatube also promotes creative architectural expression. They can be designed to achieve specific lighting effects such as wall washes and soffit lighting. They even can provide illumination for special applications such as living walls and aquariums.

Solatube is the best-known brand in the industry for a reason.

Our daylighting systems use the best materials, the most advanced technologies, and the most progressive engineering to create products that deliver the highest quality daylight at the greatest Natural Daylighting (Pty) Ltd output. In fact, millions of units have been installed in residential , Ground Floor Lobelia Park, 670 Lobelia Street, Moreleta and commercial buildings to date and we install more each day.

Park, 0044, Pretoria And we do it because we believe everyone deserves to T: +27 12 993 2775 experience the benefits that bright, beautiful and free daylight E: zurcom@zurcom.net has to offer. That’s why designing high-performing, cost-effective www.solatube.co.za and affordable daylighting systems that reduce electricity use and www.solatube.com.au energy costs is not only our job, it’s our passion.

2

concrete, which has a very high embodied energy. The Portland cement content can be reduced by making use of a percentage of acceptable industrial waste substitutes (such as fly ash) or using oversized aggregate. This needs to be carefully engineered to ensure that strength is not compromised, requiring more structural elements as this would be counter the goal of material reduction.

2.2 Reuse Perhaps the most effective way to reduce virgin material usage is to rather reuse existing materials. The reuse of materials and buildings is encouraged by the rating tool as a means of mitigating resource depletion. Reuse of materials should be used in preference to recycling of materials.

2.2.1 Building reuse The Green Star SA Materials: Building reuse credit acknowledges two levels of building reuse—either by reusing the structure (or part thereof ) and stripping the façade, or by reusing the structure and the façade (or part thereof ). The benefit of reusing a building is not only and efficient use of materials but also of land and finances.

2.2.2 Material reuse Materials: Designing for disassembly facilitates the reuse of materials. Elements such as framework, cladding or roofing can be reused in future projects if they are detailed in such a way that they can easily be removed without damage. This reduces demolition waste as well as emissions associated with demolition and removal.

For this to be practical, the end-of-life must be considered at the design and detailing stage. Instructions for disassembly must be included in the building’s Operations and Maintenance Manual and elements must be marked with their date of manufacture and inherent properties to enable correct reuse.

GREEN STAR RATING TOOL

The Green Star SA Interiors Pilot rating tool credits the reuse of furniture, assemblies, walling coverings and flooring, where there is also creative opportunity to reuse demolished structural elements in furniture and fittings.

The Materials: Steel credit encourages the reuse of structural steel that is extracted from the building and put to a new use.

Steel elements that remain in the building being refurbished fall out of this credit and into the credit for Materials: Building reuse, while non-structural elements, such as roof sheeting, that are reused will fall under the Materials: Reused and recycled materials credit. Timber structural elements may be best reused in cabinetry or other interior fittings, or re-milled and used in the structure or cladding, as recognised under Materials: Timber. The Materials: Concrete credit does not recognise reuse, but rather recycling.

However, it would still be good practice to reuse concrete elements wherever possible, such as precast lintels or pavers.

2.3 Recycling When choosing building materials to specify, both the recycled content and the recyclability of the material waste should be considered in terms of its environmental impact.

2.3.1 Construction materials Of the commonly used building materials —concrete, timber and steel—all can be recycled to some degree and points are awarded for the recycling of these materials specifically. Recycling is distinguished from reuse in that recycled materials are remanufactured, having been deconstructed (crushed, chipped or melted) and processed to produce an entirely new product.

Under the Materials: Concrete credit, the use of recycled aggregate is recognised.

Processed concrete waste can be used as

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

47

GREEN STAR RATING TOOL

2

fill, aggregate or concrete fines, depending on its structural capacity as determined by a suitably qualified engineer.

The Materials: Steel credit encourages the use of steel with a certain percentage of post-consumer recycled content. This needs to be verified by the supplier and includes structural steel as well as concrete reinforcing. Please do note that postconsumer content refers to content that has been returned from the end-user and not content that is waste from within the processing plant. The recycling of timber (Materials: Timber) is recognised, although this must be used with caution as recycled timber is most often in the form of particle board, the use of which is discouraged under the IEQ: Formaldehyde credit.

2.3.2 Construction waste reduction The recycling of material is also addressed in the Management: Waste management credit, encouraging the minimisation of construction waste going to disposal.

Points are awarded where demolition and construction waste is reused or recycled. In this case, the specification of materials that can be recycling is merited, though the material may not contain recycled content.

Environmental responsibility

The environmentally responsible material is one that does not cause harm to the environment or to people. Three factors that are to be considered here are sustainability of materials and hazardous content.

3.1 Sustainability Although in some cases the reduction of virgin material use is difficult to achieve, the impact can at least be reduced if the resource is sustainable. Sustainability essentially means that a natural material

48

resource is able to be maintained at a certain level by renewal, preventing depletion. The means of extraction should also not cause unnecessary, avoidable damage to the environment. Timber is the only renewable resource acknowledged by the Green Star SA rating tool.

The Materials: Timber credit encourages the renewal of depleted resources, requiring all timber used to be certified by the Forest Stewardship Council (FSC), meaning that it is sourced from a sustainable forest. This applies to all timber used on a project including structure, cladding, joinery, furniture (for Interior tool) and formwork.

3.2 Hazardous content Apart from the impact of materials exploitation and production on the greater environment, the green building movement is also concerned with the health of the indoor environment and its occupants. The removal and minimisation of materials with hazardous content is dealt with in various credits of Materials and Indoor Environment Quality (IEQ) due tohuman health risks.

3.2.1 Hazardous materials The IEQ: Hazardous materials credit is mostly applicable when old buildings are reused, since most hazardous materials are no longer used in modern products.

A hazardous materials survey should be carried out in an existing building and all identified hazardous materials should be removed and disposed of according to the relevant standards for that material. The materials specifically identified in the Green Star SA rating tools are asbestos, lead and Polychlorinated Biphenyls (PCBs). Each of these materials has known adverse health effects for humans.

Asbestos is a strong, insulating, heatresistant mineral that was commonly

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

2

used in roofing, cladding, pipes, insulation and many other building products. The asbestos fibers can be breathed in causing potentially fatal lung diseases such as asbestosis, mesothelioma and lung cancer [2]. Although the fibers are only released when the product is worked (cut, sanded, drilled, etc.) the health risk is high enough to warrant a total ban on the use of asbestos in many countries.

Lead in buildings is most commonly found in paints. It can be absorbed into the body by breathing in paint chips or dust [3] and can cause health problems as it inhibits the transport of oxygen and calcium in the body. Lead-based paint has now been largely phased out of use.

Polychlorinated Biphenyl (PCB) is a man-made organic chemical used in many industrial and commercial applications. It has good electrical insulating and dielectric properties, making it useful in transformers, capacitors and heat transfer fluids. It was commonly used in fluorescent light fixture ballasts, which the Green Star SA rating tool identifies and condemns.

The United States Environmental Protection Agency views it as a probable human carcinogen and there are strong indications of effects on the immune system, reproductive system and nervous system [2].

PCBs accumulate in the body and health risks thus increase with exposure.

If discovered to be present in a building it must be removed in accordance with the Department of Water Affairs and Forestry: Minimum requirements for handling, classification and disposal of hazardous waste. Since reuse of buildings and materials is promoted by the Green Star SA rating system, it is important to ensure that no such hazards are inherited in a building.

GREEN STAR RATING TOOL

3.2.2 VOCs Volatile Organic Compounds (VOCs) are carbon-based products that off-gasses at room temperature [4] and include a wide range of chemicals used in the manufacture of various materials, such as paints, paint strippers, solvents, wood preservatives and detergents. The chemical emissions vary in toxicity and may cause membrane irritations, headaches, nausea or damage the liver, kidneys or central nervous system [5]. Because of their toxicity, the use of materials containing them is limited under the IEQ: VOCs credit of the building rating tools of Green Star SA and under the IEQ: Pollutants credit of the Interior Pilot tool.

The Green Star SA rating tools address engineered wood products (only in Interior Pilot tool), paints, adhesives and sealants, and carpets and flooring. VOC limits are specified and the use of materials that boast low VOC emissions or are VOC free is encouraged.

It is important to note that this requires acutely detailed specifications to ensure that a good choice of material is not compromised by a poor of specification of paint, adhesives or sealants to be used with the material.

3.2.3 Formaldehyde The IEQ: Formaldehyde credit specifically deals with formaldehyde, although it is a VOC. Formaldehyde is a chemical produced from methane that is used widely in glues, resins, laminates, cleaning agents, dyes, ink, disinfectants and many other products [6]. It is a colourless chemical that is a gas at room temperature with a pungent odour.

In a poorly ventilated area, the effects of formaldehyde gas on humans range from respiratory effects (eg Asthma) to eye, nose and throat irritations, skin irritation

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

49

GREEN STAR RATING TOOL

2

and fatigue and is classified as a probable human carcinogen [5].

In terms of building products, formaldehyde is most commonly found in the binding resins of composite wood products and in glues. While formaldehyde is present in numerous building products, the Green Star SA rating tool singles out composite wood products and discourages their use, regardless of whether the product is exposed or concealed. This includes applications in interior fittings and furniture, such as cupboards, flooring and paneling.

While the Green Star SA tool condemns the use of formaldehyde in the form of composite wood products, the effects can be minimised by ensuring good ventilation or specifying a lower formaldehyde content product. Different kinds of formaldehyde compounds contain varying levels of the toxin. Urea-formaldehyde releases formaldehyde more readily than melamineor phenol-formaldehyde. It is therefore preferable to use pressed wood products that contain phenol-formaldehyde, for example softwood plywood and orientated strand board, that are intended for exterior construction, than those containing ureaformaldehyde, such as medium density fibreboard [7].

3.2.4 PVC Materials: PVC minimisation is in response to the known health risks associated with the manufacture and use of PVC products.

Polyvinyl chloride (PVC) is a plastic used in pipes, conduits, carpets and backings, vinyl flooring and cladding, window frames, cable coatings and many other products.

It contains chlorine, which results in the

50

release of dioxins during manufacture, and often contains phthalates (to make it softer or more flexible) or Bisphenol. These three chemicals respectively are known to carry health risks and thus the use of PVC in buildings is discouraged. PVC products should be replaced with alternatives, for example, PVC window frames could be replaced with timber or aluminium. Great care must be taken to consider all factors together so as not to replace one hazardous material with another as many alternatives may contain VOCs.

Conclusion

It is evident from this paper that the choice and use of materials for construction and operation has a high impact on the environment. The principles extracted and discussed give guidance regarding material choice and are to be considered simultaneously when choosing a green material. While the Green Star SA rating tool credits certain material choices, there is no single material that can check all the boxes. However, these principles will enable the designer to analytically motivate an environmentally responsible decision.

One should also bear in mind that the major portion of a building’s embodied energy as a whole is contributed by the operational phase of the building, implying that although a material may have a high environmental impact in its manufacturing phase, its performance during the operation of the building could outweigh the benefits of an alternative material. The chart in Figure 1: Material choice decision questions is a collection of questions to answer when making a choice of materials.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

2

Is there an alternative with lower embodied energy?

Can existing material be reused?

Can material content be reduced by design?

Does operational perfomance outwiegh manufacturing impact?

Does the material carry a health risk?

GREEN STAR RATING TOOL

Can material be sustainably sourced?

Can the product be locally sourced?

Can recycled products be used?

Figure 1: Material choice decision questions.

References

• Green Building Council SA, “Green Building Council SA,” 2012. [Online]. Available: www.gbcsa.org.za.

[Accessed 15 July 2014].

• United States Environmental Protection Agency, “EPA,” 2014. [Online]. Available: http://www2.epa.gov/ asbestos/learn-about-asbestos#effects. [Accessed 26 July 2014].

• Natrual Resources Defence Council, “NRDC,” 2000. [Online]. Available: http://www.nrdc.org/health/ effects/flead.asp. [Accessed 26 July 2014].

• J. Hirshberg, “Green Building Supply,” 2014. [Online]. Available: www.greenbuildingsupply.com.

[Accessed 15 July 2014].

• United States Environmental Protection Agency, “EPA Indoor Air,” 2012. [Online]. Available: http://www. epa.gov/iaq/voc.html#Sources. [Accessed 26 July 2014].

• V. Lovekar, “Buzzle Formaldehyde uses,” 2013. [Online]. Available: www.buzzle.com/articles/formaldehyde-uses.html. [Accessed 15 July 2014].

• United States Environmental Protection Agency, “EPA Indoor Air,” 20 June 2012. [Online]. Available: www.epa.gov/iaq/formaldehyde.html. [Accessed 15 July 2014].

• “Build direct learning centre,” [Online]. Available: http://learn.builddirect.com/flooring-info/health/formaldehyde-emissions/. [Accessed 18 July 2014].

• American Chemistry Council, “Formaldehyde Facts,” 2014. [Online]. Available: http://www.formaldehydefacts.org/applications/common_uses/. [Accessed 26 July 2014].

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

51

RECYCLED CONSTRUCTION WASTE IN CONCRETE

3

USING RECYCLED CONSTRUCTION WASTE IN CONCRETE A Sustainable Approach to Conserving Concrete Aggregates through the Use of Excavated Sand, Recycled Bricks and Concrete.

Vernon Collis, Prof Mark Alexander, Kyle Wickins

54

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

3

RECYCLED CONSTRUCTION WASTE IN CONCRETE

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

55

3

T

here’s a life-threatening contradiction between our resource-hungry, wastegenerating cities and the need to reduce CO2 emissions to stem climate change. It is increasingly vital to safely and efficiently recycle our waste, specifically construction and demolition waste, with the goal of a self-cleaning city. Giving these materials value would reduce carbon production and provide clear environmental and social benefits. At present less than half of Cape Town’s construction and demolition waste is recycled (Wickins 2013).

This article is the result of more than 15 years of research into why building materials, deemed perfectly acceptable during construction, are deemed to be waste when taken down years later. This inquiry includes excavated material as well as the waste generated during construction.

What has provided added impetus is that, at current building rates, natural building sand, within a 80 km radius of the City, will only be available until 2030 (Walker 2013).

The core laboratory for this investigation was the building site. Although all materials were studied, what follows is confined to solutions for aggregate replacements using site-won sand and brick aggregates.

On almost every project we found limited perspectives on waste usage by owners and builders, a lack of the scientific data, building regulations which failed to encourage or allow recycling and limited perspective by banks and the NHBRC. Architects ,as project leaders, on most building projects lacked the knowledge and confidence to promote the process. Generally, they relied on structural engineers who are naturally risk averse and rely on conventional materials guaranteed by the industry. Innovation was also limited by the JBCC contract, which is geared to measuring standard materials and not recycling old ones. And unless there’s a financial reward for the time and effort, why

RECYCLED CONSTRUCTION WASTE IN CONCRETE

would a builder recycle when it’s far easier to cart away old materials and buy new ones?

This submission will focus on the Cape Peninsula’s site-won sands and recycled brick aggregate, as it is here that most of our team’s innovation has taken place. Our intention is to share some of the innovative output, including research conducted with Professor Mark Alexander, a concrete materials expert and head of the Concrete Materials and Structural Integrity Research Unit at UCT’s Civil Engineering Department.

At the time of writing, this research is being prepared for publication and will be converted into booklets and CPD courses for architects, engineers and contractors. The plan is to disseminate this research to leaders and policy makers in the industry, including relevant government departments.

Writing this article is a way to share the work and to encourage a deeper and more critical reflection of the topic by architects, engineers and the industry. The hope is also to raise further funding to complete the research and make it accessible in formats for wider audiences.

Definitions of Recycling

Figure 2: Maximising labour and skills transfer

by recycling and down-cycling clay bricks

The term ‘recycling’ in the construction industry applies to the reprocessing of any material regarded as waste. It is generally believed that if anything is recycled then good work has been done for the

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

57

PROFILE

THE LEGACY OF CLAY BRICK Throughout South Africa, clay brick buildings shape our architectural heritage. The Castle of Good Hope in Cape Town, built between 1666 and 1684, has withstood the Cape of Storms for over three centuries and is the oldest surviving building in South Africa. The very first clay bricks in South Africa were fired in 1656; since then this unrivalled building material has been used to beat our blistering heat, torrential rain, hail, frost and lightning storms.

Can any material really compare to clay brick?

New alternative materials and systems are always presenting themselves as “the next big thing” in construction technology, and claiming to be “as good as clay brick”. Although some materials can match clay brick on one or two measures, none can offer the full range of benefits across the spectrum. Some innovative construction materials were eventually proven to be killers. Lead, asbestos and PVC are all building components commonly used in the past that have been shown to release toxins.

The rise in chronic diseases like asthma are being linked to many materials built into our homes and workplaces. Unlike lightweight fibre cement panels that release silica dust when cut or damaged, clay brick releases no pollutants or toxins and clay bricks can be recycled. A clay brick house can stand as collateral for a bank loan, and when the grandchildren arrive, a brick house can be extended, or re-mortgaged based on its continually increasing value.

Not just safe, but energy efficient Clay bricks are one of the most cost effective ways to include thermal mass in buildings.

They absorb and store heat throughout the day, and then slowly release it at night. This moderate internal temperatures, leading to lower energy consumption, and reduced costs for heating and cooling. “South Africa’s public sector infrastructure backlog is pressuring the government to focus on speed of erection

The Bell Tower at the Castle of Good Hope in Cape Town – South Africa’s oldest building – has braved the Cape of Storms since 1684.

rather than the essential aspects of safety, security, maintainability, investment value and lifespan,” explains At Coetzee, executive director of the Clay Brick Association of South Africa. “Public Works departments experiment with novel, alternative building systems but it is brick and mortar that are the mainstay of our country’s long lasting infrastructure - the proven method of building that has endured the test of time.” concludes Coetzee.

For further information: The Clay Brick Association of South Africa Website: www.claybrick.org.za Editorial & Advertising Contact: Dianne Volek InterComm South Africa Tel: (011) 453-5229

3

environment. But this is not always the case. Indeed much damage can be done unintentionally and/or opportunities lost.

It is therefore important to define what we mean by the following terms.

Down-cycling: Reuse of a material to perform a function that is less than its potential or how it was used originally.

An example would be the lifting of top quality FBX paving bricks and crushing them to make aggregate. Apparently this occurred when the old Cape Town stadium was demolished. Considering the carbon footprint to produce FBX bricks and that the old ones had to be carted away to a crusher, it would have been more environmentallyfriendly to reuse those pavers as pavers (recycling) or as face bricks.

Re-cycling: Reuse of a material to perform a function that is equal to or similar to how it was used originally, like the reuse of paving bricks as paving bricks or face bricks.

Up-cycling: Reuse of a material to perform a function that is more than its potential or to how it was used originally.

If a percentage of the paving bricks in the example above were broken during lifting and could not be used as half bricks, then they can be crushed on site to form a superior aggregate. Thus a potential waste which would normally be down-cycled as fill is up-cycled into a fine aggregate, the carbon footprint being potentially less than a mined and imported aggregate.

Additionally, employment has been created in the process.

The objective then is to be thorough during the auditing stage and to up-cycle as much as possible. Apart from bricks, this also applies to sands. One could assume that because the sand on site has been re-cycled, environmental work has been done. But, again, this is not always the case.

For example, some site sands are poorly graded and cause ‘stiff’ and unworkable

RECYCLED CONSTRUCTION WASTE IN CONCRETE

concrete. The uninformed builder adds water to get around the problem; the more informed builder adds water and cement to make the mix more workable. The first will result in a much weaker concrete and the second a concrete unnecessarily high in cement content. A calculation would thus be required to establish the trade-off between additional cement (usually the highest contributor of CO2 in concrete) and transport plus environmental damage to cart away the old sand and bring in new.

So reusing site sand without a laboratory study is inadvisable.

The Site Research Process

Many projects over a 15 year period have been investigated for this study, from renovations to new builds. These have varied in scale from economic to upmarket houses. Typologies range from a mine to a road and bridge, and from rural to urban environments. My roles varied from architect and engineer using conventional contractors, to architect or engineer where I was the builder. The ideal opportunity presented itself, allowing for full research and innovation, when I was an owner or builder.

On all undertakings, an important objective was to investigate how much waste a project could absorb from other projects, the industry and the site itself. If excess waste was generated, it was reused on another project or sold. The aim was not for zero waste, but for the project to become a net waste absorber and/or materials supplier without emitting excessive carbon to achieve it. Demolition and new build was required to maximise labour and skill transfer. Finally, any new build had to be designed to make the construction easier to deconstruct if required.

This process required a study of how buildings were assembled and

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

59

RECYCLED CONSTRUCTION WASTE IN CONCRETE

3

Figure 3: Mapping resource flow BEFORE a project commences (above) informs both the material choice and the design process to create a more holistically sustainable project .

‘deconstructed’ and how demolition waste (as well as suppliers’ waste) entered and moved through the city waste stream.

This process is referred to as Mapping.

The potential to reduce a project’s carbon intensive activities (red arrows) and improve

60

social, economic and environmental criteria (green arrows) is shown is Figure 3 above.

Recycled concrete for aggregate has not been covered here since significant research has already been conducted by others and is well known.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

3

The Research Process In 2002 Professor Alexander and I created a research initiative to investigate the reutilisation potential of the materials under investigation. Alexander consulted on the performance of the aggregate replacements in my projects where the boundaries were being pushed by civil engineering thesis and masters students. To date there have been 14 such studies, six of which have been Master’s theses.

Material 1: Excavated Sand as a Fine Aggregate Replacement in Concrete Most excavated material is carted away to landfill which is generally about 40 km from the centre of Cape Town. This includes rock, sand, clay and silt as well as a mixture of all these. New sand and stone is imported from

RECYCLED CONSTRUCTION WASTE IN CONCRETE

a similar distance to make concrete on site, if ready-mix is not used. The energy waste, resource inefficiency and infrastructural road damage for these activities is obvious.

This is illustrated in Figure 4.

Sands are generally a reflection of the geology and weathering process that have taken place in a region. Site-won fine material (4.75 to 0.075 mm in size) in the Cape Peninsula is typically made up of ‘dune’ sand as well as various sands containing some clay and silt. Clay and silt particles are referred to as micro-fine materials less than 0.075 mm. We are in the process of mapping Cape Town’s site-won sand in various locations around the Peninsula.

Typical sands were plotted with the help of Frank du Plessis (Geotechnical engineer with Kantey and Templer). The goal is to enable

Figure 4: Map shows the movement of landfill facilities further and further from Cape Town. This can be slowed if materials such as site-derived material, shown in the photographs, are recycled and reused.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

61

End To End Building Solution

Concept

Building Design +Pre Engineered

FRAMECAD Cold Rolled Steel Profiles

Performance Process

Fire, Acoustics + Composite Thermal Building

Contact : Andre Schlunz | Mobile +27(0) 72 647 2533 | Email Andres@Framecad.com High Performance Alternative Building Solutions Andre@rbtafrica.com

3

an architect and engineer to understand the area they’re developing and know the potential of saving by reusing excavated material. Once identified, consultants can undertake a step-by-step process to scientifically verify the reuse potential and provide a specification to the contractor.

This process and potential is best explained in these examples.

Phillipi Project—Tsoga Environmental Centre: The site sand was tested and found to have identical qualities to commercially available Phillipi sand supplied from a nearby quarry. This sand contained minimal organic material which was removed by sieving. Upon discovering the reuse of the site sand, the building inspector stopped the project. Eventually the City accepted the process when the background and principles were explained and underwritten by the author. On this project, no extra sand was imported for building work. The site sand was of very good quality and, coupled with the geotechnical engineer’s

RECYCLED CONSTRUCTION WASTE IN CONCRETE

local knowledge, only minimal testing was required. A large portion of the Cape Flats is underlain by this high quality dune sand which is being carted away daily to landfill when an area is developed.

Aandblom Street Houses, Vredehoek: The sand/stone matrix in this area contains a small percentage of clay. Conventionally, sand with any clay is rejected because engineers fear it will expand. However lab testing of concrete cubes (the best way to test a material) revealed strengths 15% above the target design. This suggests that a relatively high percentage of some clay types, compared to SANS recommendations, can increase the compressive strength of the mix due to increased packing density (fine-filler effect) of the concrete matrix and secondary chemical reactions (O’NeillWilliams 2012). This is validated by the data shown in Figure 5. The sand was sieved on site and blended with 50 per cent imported sand. The stones were set aside for use in the concrete works.

Figure 5: Research shows that increased clay quantities in site-derived sands can lead to increased concrete strength (O’Neill-Williams 2012). It is noted that SANS1083 recommends cay content of below 2% for sands to be used in concrete.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

63

RECYCLED CONSTRUCTION WASTE IN CONCRETE

3

Swimming Pools: An excellent source for investigation and sand mapping is the excavation of swimming pools. This process is illustrated in Figure 6. In Tokai, excavated sand carted away was found to be better than the imported material brought in.

Some of the site-won sands met the SANS requirements, but most did not. The building inspector on the Phillipi site, for example, quite reasonably pointed this out.

But we found that many of the commercially supplied sands also did not meet the SANS requirements (O’Neill-Williams 2012, Wickins 2010). The deviation of commercial and site won sands from recommended grading limits is shown in Figure 7. This required a rethink of the SANS requirements and a study of the performance of commercial sands against site sands. It also raised a question about the rejection of site sands.

Figure 6: Comparison of conventional pool excavation – dig and dump to an ‘up-cycled’ pool – hand dig and reuse.

Figure 7: Data showing the deviation of commercial and site derived sand from the recommended

particle size limits defined by SANS 1083:2006 (O’Neill-Williams 2012).

64

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

3 Material Two: Crushed bricks as a course aggregate replacement in concrete As with sand, many of the bricks, as brick rubble, are carted away from building sites.

Although cleaning bricks for reuse is on the increase, the recycling of bricks (both cement and clay bricks) for coarse aggregate is generally avoided. This is because of negative perceptions around the strength and durability of the material in concrete.

This is largely due to the rubble being mixed up during demolition. Bricks, plaster and mortar are broken up and piled together, resulting in a low quality, mish-mash which is usually good only for fill.

Thus separation of this material is critical.

Photographs of separated clay brick and concrete that has been processed into 19 mm aggregates by small mobile crusher and then tested and used as coarse aggregate are shown in Figure 8. This research found that by wetting clay brick aggregate, this moisture supply reduced the concrete shrinkage when compared to concrete using conventional by internal hydration processes (Wickins 2013). Thus the concrete had an additional water source to the one supplied from the ‘outside’ if cured correctly.

Compared to clay brick, commercial coarse aggregates have negligible water absorption potential. Thus fully fired claybrick aggregate, if correctly selected and

RECYCLED CONSTRUCTION WASTE IN CONCRETE

prepared, will produce a better concrete than conventional materials and may assist to reduce the risk of poorly cured concrete (on the outside) on site.

The key to the success of brick recycling lies is the investigation and identification of the bricks BEFORE they are demolished.

Rigorous testing procedure is followed to identify the material properties and use potential. This process is best explained by example. The two following projects below zero waste was achieved.

Phillipi Tsoga Project: About 30 per cent of the bricks needed for the project were sourced from a burned-down local beerhall. Women from the community were employed to clean the clay bricks (NFX and FBX mix) achieving more than a 75 per cent recovery rate. The broken bricks were hand crushed to 30 mm aggregates for the foundations, ground slabs and reinforced cavity work. The removed mortar was added to the layer-works under the ground slab.

Aandblom Street Project: An old and failing clay brick and plastered house was ‘deconstructed’ by hand. Before this, the old house structure was exposed and the quality of materials audited and tested. This informed both the manual deconstruction strategy for maximum recovery and how and where the materials were to be used for the new house. There were two types of bricks—engineering fired bricks (NFX) and

Figure 8: Down-cycled concrete and NFX clay brick aggregates (left). Laboratory testing (right) of concrete cubes made with these two aggregate types (Wickins 2013)

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

65

RECYCLED CONSTRUCTION WASTE IN CONCRETE

3

Figure 9: Collis & Associate’s projects that have achieved 100per cent recycling rates using excavated and recycled brick

under-fired plaster bricks (NFP) which can lose strength if exposed to moisture. Over 90 per cent of the bricks were cleaned for reuse. The NFP broken bricks were hand crushed for use in lower strength concrete – internal ground slabs, mass concrete stairs and internal cavity fill – where the concrete would be in a permanently dry environment after construction. The NFX engineering brick aggregate was mixed with the stone sieved from the excavated sand and used in the higher strength structural elements.

25MPa cubes yielded almost 30MPa when crushed at UCT using the clay-sand blend and the stone-NFX blend. On site clay aggregate was soaked in water before being added to the mix.

Conclusion

Recycling reduces environmental damage, landfill pressure, resource depletion, damage to roads and CO2 emissions. It’s also labour-intensive creating employment. Yet less than half of Cape Town’s construction waste* is recycled and building regulations and codes exclude the recycling of rubble.

This urgently needs to change. As a contribution to rethinking this problem, this article focused on replacement of concrete aggregates using site-won sands and recycled bricks.

66

The first problem is that there’s no inclusive best practice on how to evaluate, deconstruct, test and specify construction waste. Without this, architects are limited when informing clients or projects where recycling is possible. No similarly rigorous methodology exists for engineers.

For the past 20 years this consultancy has sought solutions to this problem, investigating a ‘cradle-to-cradle’ process using construction waste and maximising on site labour. With associates, we have provided the professional service on projects in the Western and Eastern Cape, Indonesia and West Africa. On occasion we have acted as contractor, allowing for maximum research and innovation. What we’ve developed are processes that can be applied anywhere in the world. We are fine-tuning and documenting our findings for publication and CPD presentation.

The site innovations have been supported by UCT Civil Engineering with four Masters and 10 undergraduate theses under the supervision of Professor Mark Alexander and myself for over a decade.

Some findings in the Peninsula include the discovery that: • within 80 km of Cape Town sufficient concrete building sand resources are available until 2030. It is estimated that

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

3

•

• •

•

the remaining quality natural sands will just fill Cape Town Stadium. the industry’s perception that ‘all claysands for concrete must be rejected’ is incorrect some clay-sands perform better than conventional sands in concrete some fired engineering bricks make for better aggregate than commercial stone in certain applications some site sands were better than commercial sands when used in concrete

RECYCLED CONSTRUCTION WASTE IN CONCRETE

• some commercial sands do not conform to SANS requirements • sometimes recycling causes more environmental damage than conventional building methods.

The correct recycling of construction waste reduces carbon emissions and saves resources. However, it is essential that potential materials be fully investigated to inform the design process and manage risk. * Construction waste is excavated sand and rock, demolition material and building rubble.

References UCT Fine Aggregate Replacement Research • Bodley, M. 2010, Durability and Dimensional Stability of Concrete Incorporating Clayey Fine Aggregates.

BSc Civil Eng. Thesis UCT. • Hainana, G. 2009. Effects of Clay Minerals on Concrete. BSc Civil Eng. Thesis UCT. • Jarrett, N. 2008. The Usage of Clayey Soils, Found On-site, as Fine Aggregate for Concrete. BSc Civil Eng. Thesis UCT. • O’Neill-Williams, B. 2009. Rammed Earth for Construction in the Cape Town Metropolitan Area. BSc Civil Eng. Thesis UCT. • O’Neill-Williams, BSc 2012. The Use of Natural Site Derived Materials as Concrete Aggregate. MSc Civil Eng. Thesis UCT. • Scott, A. 2006. A Comparative Study of Two Building Foundations – A foundation built on sustainability principles vs one built in the conventional method. BSc Civil Eng. Thesis UCT. • Thuysbaert, J. 2012. Suitability of Rammed Earth Construction in the Cape Town. MSc Civil Eng. Thesis UCT. • Walker, B. 2013. The Availability of Natural Aggregates in Cape Town. MSc Civil Eng. Thesis UCT. • Wickins, K. 2010. The Use of Site-derived Sand in Concrete. BSc Civil Eng. Thesis UCT.

UCT Coarse Aggregate Replacement Research – crushed bricks • Kiewet, S. 2009. The Use of Site Derived Stone for Construction Purposes in the Cape Town Area. BSc Civil Eng. Thesis UCT. • Mwatile, N. 2008. Design for Deconstruction of Concrete Based Materials and Structures. BSc Civil Eng. Thesis UCT. • Smallbones, D. 2009. Site Derived Stone in Construction – The application of site derived coarse aggregate in concrete in the Cape Peninsula. BSc Civil Eng. Thesis UCT. • Walker, B. 2010. Deconstruction of Concrete Structures. BSc Civil Eng. Thesis UCT. • Wickins, K. 2013. The Use of Construction & Demolition Waste in Concrete in Cape Town. MSc Civil Eng. Thesis UCT.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

67

GREEN HVAC SYSTEMS

4

DISPLACING THE NORM IN ROOM AIR DISTRIBUTION

Tobias van Reenen

An introduction to displacement ventilation as an energy efficient ventilation strategy.

68

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

4

GREEN HVAC SYSTEMS

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

69

GREEN HVAC SYSTEMS

4

This article discusses an alternative room air distribution strategy for South Africa.

Displacement ventilation, or stratified room air distribution, is a ventilation strategy that is worthy of two points according to the Green Star SA Office design rating tool. Unfortunately these same points are available for demonstrating a ventilation effectiveness index of >95 per cent (ASHRAE 129) for conventional mechanical

“

We strongly recommend that the spirit of this new frontier be revived throughout Rehva, particularly with regard to exchange of technical information as a means of spreading practical knowledge.

system design are encouraged to consult the Rehva Guidebook #1 Displacement Ventilation in Non-Industrial premises, available at www.rehva.org.

Displacement Ventilation in a nutshell

Displacement ventilation is a room air distribution model in which cool air is introduced into an indoor space at low level and is extracted at high level. Displacement ventilation relies on buoyancy forces developed by temperature differentials as the air is heated by the internal heat sources.

This drives the air upward through the room.

As the air rises through the room it cools the room and carries contaminants into the upper room, from where it is extracted.

This air distribution model fills the room with conditioned air from below, like water, displacing the older room air upwards (Figure 1).

“

-Livio De Santoli Chairman of Rehva technical Committee, Professor at University of Rome, La Spaienza (Displacement Ventilation in Non-Industrial Premises: Rehva Guidebook #1)

ventilation systems. Since these two points could be more easily achieved using ceiling fans, this rating tool offers little incentive to pursue the comparatively complex displacement ventilation strategy. Also, the tool’s minimum acceptance criteria for displacement ventilation may not guarantee effective systems under all conditions. This article therefore intends to present a more compelling reason to consider displacement ventilation as a viable alternative to the status quo, while giving an overview of displacement ventilation design for nonindustrial spaces. Designers interested in learning more about the strategies and methodologies of displacement ventilation

70

Figure 1: Buoyancy driven displacement venitaltion The principles of displacement ventilation (DV) had been understood and utilised for many years in passively ventilated buildings before the advent of mechanically driven mixing ventilation. More recently these systems have been well studied, developed and used, mainly in Scandinavian countries.

Somewhat oddly, displacement ventilation has been largely ignored by the rest of the world. The Federation of European heating

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

4

and Air-conditioning Associations (Rehva), however, now strongly recommends the “spirit of this new frontier” throughout Rehva (Mundt et al, 2004).

As the design of a displacement ventilation system makes demands of the architectural design, these systems are not readily suited to retrofitted buildings where there is insufficient ceiling height (<2.4m) or space for vertical air ducts. It is also imperative that the ventilation system designer work in close collaboration with the architect from the earliest stages of the architectural design process.

The benefits of applying a displacement ventilation strategy for room air distribution are: • lower annual energy consumption; • reduced air-conditioning system sizes; • better indoor air quality for the same airflow; and • better ventilation effectiveness than available through ideal mixing.

(Lin et al, 2005; Mundt et al, 2004) Under South African climatic conditions, where buildings require mainly cooling, the only significant draw back to the implementation of DV is that the design of these systems requires what is currently a relatively scarce technical skill set. This will remain true while few ventilation engineers are bold enough to venture into this field.

Vertical Temperature gradient in the room

With stratified room air distribution, the air levels of contaminants and temperatures increase with height in the room. This is contrasted against mixing ventilation regimes, where the room temperature and contaminant levels remain constant throughout the room.

For purposes of evaluation of the temperature gradient, a dimensionless

GREEN HVAC SYSTEMS

temperature can be described for points on a vertical plane running up through a room.

This dimensionless air temperature near the floor is given by: κ=

(θf-θs ) (θe-θs )

-Equation 1 (Mundt et al, 2004).

Where: θf =temperature at floor θs =supply air temperture θe =extract air temperature In order to maintain occupancy comfort, the temperature gradient in the lower room needs to be kept relatively low. Figure 2 shows the relative vertical temperature

Figure 2 Relative temperature gradients gradients with heat sources in upper room vs that with heat sources in lower room.

Where heat sources are predominantly in the lower portion of the room (from people and equipment) the vertical temperature in the lower zone will be steeper than in the upper part of the room. Similarly, where heat sources are predominantly in the upper part of the room (ceiling and lighting) the temperature gradient in the upper part will be higher than that in the occupied zone.

It follows that, where heat sources are in the upper part of the room, displacement ventilation will be very efficient at cooling the occupied zone.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

71

PROFILE

KNAUF AMF For decades, Knauf AMF has been one of the leading European manufacturers of ceiling systems. As a member of the Knauf Group, the company develop and produce innovative ceiling solutions. The products are marketed in more than 90 countries worldwide.

Product range The comprehensive range of systems from Knauf AMF ranges from concealed, visible and free-spanning ceiling constructions to ceiling rafts and wall absorbers. The range consists of the strong brands THERMATEX®, HERADESIGN ®, VENTATEC® and DONN® , with which Knauf AMF offers complete, sophisticated solutions for a wide spectrum of applications in new build and refurbishment of non-residential buildings: From administrative buildings to educational institutions and healthcare facilities – Knauf AMF develops optimum solutions for many different room situations whilst fulfilling the highest functional requirements.

The extensive THERMATEX range includes special acoustic and fire protection solutions as well as hygiene ceilings to reduce pollutants or particles. Aesthetic requirements are met with a wide variety of materials and surface variations. These range from elegant, white fleece-coated surfaces to various perforation patterns, fine wood and metal decors. With the two grid systems VENTATEC and DONN, Knauf AMF offers a particularly, extensive range of systems, for which numerous fire tests are available based on current European standards.

The VENTATEC grid system is tested in combination with the comprehensive product group AMF THERMATEX and all relevant soffit types and offers a wide variety of high-quality, co-ordinated constructions for technical fire protection. The range is complemented by the DONN grid system that has been successfully tested in combination with all major ceiling tiles from different manufacturers. With the product brand Heradesign, Knauf AMF offers high-quality, wood-wool acoustic ceilings for optimum sound absorption and sound attenuation. All products from Knauf AMF are developed and produced using sustainable materials and technologies.

Production Across production sites in Grafenau, Viersen, Ferndorf (Austria), Dreux (France), Peterlee (England) and Antwerp (Belgium), the overall plant production capacity is around 65 million square metres of ceiling tiles and 220 million linear metres of grid. Currently, the company employs approximately 600 employees worldwide.

Service In addition to the extensive product range, Knauf AMF offers excellent service. The strong sales team is well known for its high level of advisory expertise and is a reliable partner to architects, contractors and developers.

Worldwide, there are 30 sales offices and representatives.

Knauf AMF Southern Africa P.O. Box 85, Ruimsig 1732 - Roodepoort, Gauteng Tel.: +27 11 768 4373 Fax: +27 11 768 4373 E-mail: motlhathudi.thabo@knaufamf.co.za http://www.amfceilings.com

4

Thermal Comfort When compared with mixing ventilation, maintaining thermal comfort is admittedly more technical.

This is due to the risk of creating cold drafts near the floor or exceeding the recommended vertical thermal differences between occupants’ heads and feet (ASHRAE, 2013).

To mitigate these risks the designer needs to take account of the location and magnitude of thermal sources, understand thermal plume development and appropriately position supply diffusers. In order to do this successfully, the ventilation engineer must collaborate closely on architectural design decisions.

Air Distribution and Quality

Air that rises in the convection current in the room is displaced by the supply air from below. This creates a stratification of cold to warm and fresh to “polluted” air from the lower to upper zones in the room.

Displacement ventilation can therefore provide something approaching piston flow and, as a result, increased ventilation efficiency and reduced ventilation load when compared with mixing ventilation.

The contaminant concentration in the occupied zone is always lower under displacement ventilation than with mixing ventilation for the same volumetric airflow.

Studies have shown that for the same air quality, displacement ventilation requires an approximately 25per cent lower supply air volume compared with a conventional mixing ventilation system.

The total temperature difference, together with the volumetric airflow rate (air removed from the space) gives the rate of heat removed from the space. The dimensionless temperature near the floor can be determined with the following:

GREEN HVAC SYSTEMS

1

κ= -3 q ∙10 ρ∙c (1/αr +1/αcf )+1 v p

-Equation 2 (Mundt, 1990) Where: κ. =dimensionless temperature near floor (Equation 1) αr =heat transfer coefficient due to radiation αcf =heat transfer coefficient at floor due to convection A =floor area qv=volumetric air flow rate ρ =air densitycp=specific heat capacity of air Thus, the temperature differences between the vertical levels of the room and the thermal plumes develop the buoyancy forces which drive the ventilation rate.

As a first approximation, the “50per cent rule” can be assumed. This applies to rooms with standard ceiling heights using normal displacement diffusers. The 50per cent rule states that the temperature near the floor is approximately half of the difference between the supply and extract air temperatures (see temperature gradient line in Figure 3).

Figure 3 Room with various heat sources in the lower room.

To understand and effectively design displacement ventilation, the designer needs to have an understanding of

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

73

PROFILE

WORLD-LEADING CHEMICAL BUILDING SOLUTIONS FOR SOUTH AFRICA Mapei is the world leader in the production of adhesives, sealants and chemical products for building. Its products have been distributed in South Africa since 2007 and, in July 2009, a combination of growth potential in Africa and the growing demand in South Africa led to the opening of a fully-owned subsidiary, Mapei South Africa (Pty) LTD. Founded in Milan in 1937, the Mapei Group has 68 subsidiaries with 63 production facilities operating in over 31 countries on 5 continents.

The Group has always placed great emphasis on research and invests 12% of its total workforce and 5% of its turnover in R&D. Sustainable development is a core focus of Mapei and 70% of its R&D efforts are devoted to developing eco-sustainable and environmentally-friendly products which meet LEED* requirements.

Mapei South Africa distributes Mapei products throughout the SADEC region, offering customers the wide-ranging benefits that come from having the backing of the Group’s unparalleled knowledge, technical experts, research capabilities and product specialists. An example of Mapei’s advanced

environmentally-friendly products is the recent local introduction of a range of highly-effective form release agents, Mapeform Eco 31 and Eco 61, which comprise stable emulsions of vegetable oils, corrosion inhibitors and special admixtures that are non-toxic, do not irritate the skin or cause sensitisation, and biodegrade rapidly.

The company has launched the following product lines in the local market: • Building • Admixtures for concrete • Waterproofing • Products for underground construction • Sealants • Cement grinding additives • Concrete repair Mapei South Africa is a member of the Green Building Council of South Africa in support of the drive to ensure that all local buildings are designed, built and operated in an environmentally sustainable way. *Leadership in Energy and Environmental Design.

GREEN ENGINEERING FOR PRESTIGE PROJECTS Mapei technology has been used recently for two prestigious South African office developments: one in Cape Town and the other in Sandton, Gauteng. The 32 storey Portside building in Cape Town is destined to be the Mother City’s tallest building and South Africa’s first Green Star rated skyscraper. Mapei provided close technical service support and ensured that the unequalled technical resources of the international Group were available to help develop the most effective solutions to construction challenges. The architecturally advanced 102 Rivonia in Sandton used Mapei’s green technology to reduce the carbon footprint of the building.

Portside Building in Cape Town – South Africa’s first Green star rated building

The 4 Star Green Star SA rated building – 102 Rivonia Road Sandton

4

convection flows and the formation of thermal plumes from heat sources (or wells) in the room. The dynamics of these plumes can be determined empirically, analytically or computationally and the Rehva Guidebook #1 Displacement Ventilation in Non-Industrial Premises could be consulted for more information on this relatively technical aspect of design.

Heating modes during cold conditions will result in supply air rising rapidly from the diffusers, effectively short-circuiting and reducing ventilation effectiveness. This requires interventions such as increasing the supply air induction velocity to generate a dilution or mixing ventilation mode during winter. For this purpose, diffusers could be selected with the option of adjusting the opening aperture for heating modes.

GREEN HVAC SYSTEMS

the air terminal at low velocity and flow along the floor. Wall mounted diffusers therefore demand a zone adjacent to the diffuser, in which permanent occupancy is not recommended. Occupancy in this zone could disrupt the room air distribution and is likely to be a zone of thermal discomfort. It is the therefore the designerâ&#x20AC;&#x2122;s responsibility to define these zones together with the architect or interior planner.

Since wall mounted DV supply terminals require additional floor space, the alternative of under-floor air distribution (UFAD) could be considered. In this solution, the air is delivered through the floor via an under floor plenum. Room air delivery could be through the carpet directly or through floor mounted air terminals. Where air is delivered through the carpet, very low supply velocities can be achieved; however, the building operatorâ&#x20AC;&#x2122;s ability to maintain a high level of carpet cleanliness should be considered for sustainable air quality.

Energy Efficiency

Figure 4 Short-circuiting under heating.

Proximity of heating terminals to room occupants would require moderation of the supply air temperatures to ensure consistent comfort levels. Alternative strategies, such as reversing the supply and extract such that the air is supplied high and returned at low level could be investigated for heating modes.

Location of terminals

Displacement ventilation diffusers need to be located at or near floor level so that the cool air supplied can cascade out of

The potential to increase both supply and return air temperatures using displacement ventilation means that the latent energy demand is reduced for the same relative humidity. Under extremely humid conditions, desiccant or refrigerant dehumidifiers may be required as the raised off-coil conditions may not provide sufficient dehumidification. This could demand additional heater energy for the regeneration of the desiccant (Lin et al, 2011a).

As the supply air temperatures are higher for displacement ventilation than mixing ventilation, the annual free cooling opportunity is broadened. This is a major contributing factor toward achieving reduced energy consumption. (see Figure 5) Another energy benefit that is often quoted for displacement ventilation is the

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

75

GREEN HVAC SYSTEMS

4

to accommodate the room conditions in real time using occupancy and CO2 sensors, these sensors should be located in the occupied zone and not in the return air ducting. Sensors placed in the return ducting may not be able to consistently give a representation of variable room conditions.

Figure 5 Comparison of mixing and displacement ventilation cooling energy consumption (Lin et al., 2011b). reduced ventilation fan power required.

This benefit may only be evident where the cooling demand is not excessively high and indoor air quality is the primary driver of ventilation rates. Displacement ventilation generally requires a greater airflow for cooling than mixing ventilation.

This results from the lower air temperature differentials between the supply and room air. (see Figure 6)

Figure 6 Cooling capacity and air consumption (Fitzner, 1996).

Higher chilled water and subsequent evaporator temperatures also allow for an improved chiller efficiency, further reducing the energy demand in comparison to mixing ventilation.

For demand controlled systems, where the ventilation rates are adjusted

76

Professional Services

Building developers should realise that, similar to natural ventilation design, displacement ventilation design places an increased demand on the ventilation engineer in terms of time, level of competency and coordination with other building professionals such as architects and interior space planners.

The fruits of this additional effort include dramatically reduced energy and lifecycle costs and reduced capital cost of engineering components. Paradoxically this may also result in reduced engineering fees in accordance with gazetted fee scales, when compared with those for mixing ventilation design. The services professional’s compensation therefore becomes inversely proportional to his required effort. This may require incentivising the adoption of displacement ventilation by engineers through fees scales weighted by system performance and cost savings, and not purely by the installed equipment value.

Summary

• Air cooling delivered at floor level, flows like water and fills the room from below.

• Room air distribution driven by buoyancy, carries heat and pollutants upward to ceiling level extraction/return.

• The reduced room airflow velocity reduces the possibility for drafts, when designed correctly • Cold drafts along the floor need to be managed.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

4

• Ventilation effectiveness during heating modes must be considered.

• Large supply air terminals are required, thereby reducing ventilation induced room noise.

• Overview of ventilation effectiveness, IAQ (IEQ = quieter diffusers) and energy efficiency.

• Energy savings between 8 and 24% over constant and variable air volume systems mixing ventilation systems can be realised.

Displacement ventilation is not likely to be appropriate for spaces with: • Ceiling heights less than 2.4 m.

• Smaller single occupancy rooms.

• Rooms where overheating control dominates the determination of ventilation rate.

• Regions with high humidity and high system latent loads. Typically where descant de-humidification is required.

GREEN HVAC SYSTEMS

• Dense cool contaminants.

Displacement ventilation should be considered for: • space with high ceilings; • restaurants; • halls; • Meeting and conference rooms; • Classrooms; • Supermarkets; • Spaces where contaminants are warm and lighter than air

Conclusion

Displacement ventilation comes with great potential for significant energy savings while delivering much improved indoor environmental quality. However, together with this potential comes an increased burden of design effort from the entire professional services team as the technology is not easily accommodating of compromised solutions.

References

• ASHRAE, 2013. ASHRAE 55-2013; Thermal environmental conditions for human occupancy. Am. Soc. Heating, Refrig. Air Cond.

• Fitzner, K., 1996. Displacement ventilation and cooled ceilings, results of laboratory tests and practical installations, in: Indoor Air 1996. Nagoya.

• Lin, Z., Chow, T.T., Fong, K.F., Tsang, C.F., Wang, Q., 2005. Comparison of performances of displacement and mixing ventilations. Part II: indoor air quality. Int. J. Refrig. 28, 288–305.

• Lin, Z., Lee, C.K., Fong, K.F., Chow, T.T., 2011a. Comparison of annual energy performances with different ventilation methods for temperature and humidity control. Energy Build. 43, 3599–3608.

• Lin, Z., Lee, C.K., Fong, S., Chow, T.T., Yao, T., Chan, a. L.S., 2011b. Comparison of annual energy performances with different ventilation methods for cooling. Energy Build. 43, 130–136.

• Mundt, E., 1990. Convection flows above common heat sources in rooms with displacement ventilation, in: ROOMVENT ’90. Oslo.

• Mundt, E., Nielsen, P. V, Railio, J., 2004. Displacement Ventilation, 2nd ed. Federation of European Heating and Air-conditioning Associations, Finland, Forssan Kirjapaino Oy, Forssa.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

77

HOUSE JONES

5

HOUSE JONES Application of a wetland to treat sanitaion in an Urban setting.

78

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

Era Architects

5

HOUSE JONES

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

79

HOUSE JONES

5

Rainwater Collection Rainwater harvesting is achieved in two stages: • Roof level rainwater is collected for nonpotable use in the house; and • Paving runoff and subsoil drainage (required for founding conditions) is collected directly in the storage dam and used for irrigation.

Collected rainwater from rooftops is sent through leaf shedders and a first flush diverter before it is stored in 40 000 litres of surface storage tanks on site. The first flush diverter drains into the storage dam to be used for irrigation. The collected rainwater is filtered in three stages; a particle filter to remove solids, a carbon filter and a UV filter to kill bacteria. The filtered water is used for non-potable purposes in the house, a flow activated pump operates whenever a tap is opened to provide water pressure in the house. Low flow fittings, toilets and showers ensure that the minimum amount of water

is used in the house. The whole system has a divert switch to either completely tank supply or council supply. Council water is filtered separately, with another three filters and delivered to three “potable” taps in the house.

A borehole was sunk and the water tested. The borehole is intended to be used as sparingly as possible, and only tops up the on site storage the minimum amount possible, while waiting for the rain to fill the storage systems.

Wastewater Treatment System

All grey and black water generated in the house (except for the kitchen waste) is treated on site in a three phase anaerobic septic tank and an aerobic digester system.

Clarified water is then fed through a wetland to further polish the water before being stored in a dam and used for irrigation. A divert switch allows the clarified effluent to be sent to the municipal sewer line

Section illustrating recycled water treatment system. (ERA ARCHITECTS 2014).

80

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

5

for emergencies or during maintenance work. Nutrients in the recycled wastewater, which is used as irrigation, are used to feed the biodiversity of the site. The kitchen has been plumbed so that in future it can be included in the recycled water system with the addition of a grease trap. The client was spared the maintenance required of a grease trap for now.

All the recycled water from the wetlands and collected ground level rainwater is collected in a 60 000 litre storage dam to be used during the dry season. The borehole fills the dam to the minimum level when required. Again, waiting for the rain, the dam is designed to have its level vary from dry to wet season as the water is stored and used as required. The dam is profiled to have steps on the northern wall which are used for planting. This ensures that the dam remains an aesthetic and functioning part of the garden even during the dry months.

The landscaping was designed as a natural ecosystem. The water strategy on

HOUSE JONES

the site calls for wetlands and cascading rock waterfalls to oxygenate the water while it is being treated and recycled. A circulation pump powers the oxygenation strategy, indigenous plants and fish were introduced to kick-start the ecology.

Frogs and birds began discovering the natural system and colonising it immediately.

The planting has been designed to create many areas where various animals, birds and insects can make a home. The variety of environments in terms of plant species and climatic factors make for many different characteristics of ecosystems and micro-climates where much biodiversity can flourish.

Garden landscaping species were chosen for water treatment, low-maintenance and encouraging biodiversity by providing plants that either: • Attract insects; • Provide nesting materials; • Produce Fruit and seeds.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

81

1.

The planted screens around the house create their own individual microclimates. These vary in quality and characteristic slightly, depending on what planted species are used. This also leads to more diversity of ecology and environment, further encouraging a variety of different species to come and make the house their home.

The irrigation strategy doubles as an external micro-climate evaporative cooling strategy in the planted green bubbles during summer.

This building has five different sources of water; collected rainwater off rooftops, collected rainwater from ground runoff, recycled water, municipal water and borehole water.

Integrating all of these sources into the building for various uses creates a very complex system.

The nature of the different water sources, treatments and uses also means lots of pumps are used to move water around the site. The lowest energy consuming pumps were specified but because of the way pumps operate, they create a large initial spike on the electrical supply system. For this reason, batteries were not used in the project as they would need replacing regularly. Instead, a photovoltaic system meets the houseâ&#x20AC;&#x2122;s needs during the daytime; any excess energy is fed into the national grid. Intelligent inverters control the power drawn from and fed into the national grid effectively using it as a battery.

These alternatives are all incorporated into the design of the building making the project very resilient.

2.

3.

4.

5.

1. Biodiversity photographic illustration. ERA Architects 2014.

2. Rainwater collection. Barry Goldman. 2014.

3. â&#x20AC;&#x153;LILIPUTâ&#x20AC;? aerobic digester. ERA Architects 2014.

4.Biodiversity photographic illustration. ERA Architects 2014.

5. Biodiversity photographic illustration. ERA Architects 2014.

SOLAR ELECTRICITY

6

SOLAR ELECTRICITY FOR BUILDINGS Wim Jonker Klunne

86

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

6

SOLAR ELECTRICITY

This chapter will reflect on the use of solar electricity for houses and commercial buildings and looks into the options available and how to determine what type of system is required.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

87

SOLAR ELECTRICITY

6

The Benefits There are different reasons why building users and owners might go for solar electricity, depending on the nature of the building itself, its usages and very importantly its location.

Buildings that are located in areas where grid electricity is not available might have to revert to alternative ways of providing the energy needs of the building and its users, solar electricity might be one of these options.

For buildings (already) connected to the electricity grid, solar energy might be beneficial for a number of reasons: • Reducing the costs of energy provision by generating own electricity that can be used instead of electricity bought from the utility (in the South African context either ESKOM or the local municipality); • Becoming self-sufficient and no longer depending on the availability of the grid; • Reducing the carbon footprint of electricity used; • The availability of subsidies, rebates, tax incentives, feed in tariffs etc. that make an investment in solar electricity viable.

The technology

Solar Photovoltaic cells, or PV cells in short, convert sunlight directly into electricity.

The term photovoltaic is referring to the process of converting light (photons) to electricity (voltage). This photovoltaic effect was discovered in 1954 by scientists at Bell Telephone that found that silicon (an element found in sand) created an electric charge when exposed to sunlight (Chapin, Fuller et al, 1954). Very importantly is the distinction between solar PV systems that produce electricity and thermal solar systems like solar water heaters that produce heat and no electricity.

Solar electricity is produced using PV cells. Currently PV cells are manufactured

88

from a variety of different types of materials, the most common being crystalline silicon. Apart from a wide range of more experimental materials, there are four main types of commercially available cells: • Crystalline Silicon (c-Si) – Monocrystalline • Crystalline Silicon (c-Si) – Polycrystalline • Amorphous Silicon (a-Si) Solar Cells • Thin-Film Solar Cells

Crystalline Silicon (c-Si)

Almost 90 per cent of the world’s photovoltaics today are based on some variation of silicon (Maehlum 2013). In 2011, about 95per cent of all shipments by U.S. manufacturers to the residential sector were crystalline silicon solar panels (EIA 2013). The silicon used in PV takes many forms. The main difference is the purity of the silicon.

Solar cells made of monocrystalline silicon (mono-Si), also called singlecrystalline silicon (single-crystal-Si), are quite easily recognisable by an even colouring and uniform look, indicating high-purity silicon.

The first solar panels based on polycrystalline silicon, which also is known as polysilicon (p-Si) and multi-crystalline silicon (mc-Si), were introduced to the market in 1981. A good way to distinguish between mono- and polycrystalline solar panels is that polycrystalline solar cells look perfectly rectangular with no rounded edges.

Thin-film Solar Cells

Depositing one or several thin layers of photovoltaic material onto a substrate is the basic prinicple of how thin-film solar cells are manufactured. They are also known as thin-film photovoltaic cells (TFPV). The different types of thin-film solar cells can be categorised by which photovoltaic material is deposited onto the substrate: • Amorphous silicon (a-Si) • Cadmium telluride (CdTe)

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

6

SOLAR ELECTRICITY

Figure 1 Solar cell efficiencies (NREL 2013)

• Copper indium gallium selenide (CIS/ CIGS) • Organic photovoltaic cells (OPC)

Efficiencies

Monocrystalline PV cells have efficiencies of 13–17 per cent and are the most efficient type of the three types of silicon PV cell (EvoEnergy 2012). However, they require more time and energy to produce than polycrystalline silicon PV cells, and are therefore slightly more expensive. This compares to efficiencies of 11 – 15 per cent for mass-produced polycrystalline PV cells. Amorphous Silicon PV cells have an efficiency of between 6 - 8 per cent and are typically not used in energy systems for buildings but rather for devices which require very little power, such as pocket

calculators. Thin-film modules operate at about 9 per cent efficiency. Figure 1 gives on overview of current and expected conversion efficiencies for different systems.

Solar PV Terminology

The basic element of a PV system is a solar cell in which the photovoltaic principle is used to generate electricity. Typically a number of these cells are packaged and connected to form a solar panel or solar module, see figure 2. The size of a solar panel is normally expressed in terms of its electricity producing capability. The unit used for this is Wp (Watt peak), which is defined as power output under peak sunshine conditions (1 kW/m2), temperature of 25˚C and wind speed of 5 m/s. Although solar panels can be produced in any size, for

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

89

THE SMALLEST GEYSER IN THE WORLD INSTANT HOT WATER

FEATURES

ENERGY AND WATER SAVERS SAY GOODBYE…..

TO YOUR LUMPY OLD GEYSER

• • • • • •

ECO-TAPS the amazing new taps & showers that gives you HOT WATER IN SECONDS, without a GEYSER The ECO-TAP is COST EFFECTIVE, CO-RESPONSIBLE & highly advantageous as opposed to a traditional GEYSER

•

Tested and certified by the SABS, SANS IEC: 60 335 2 35 Electrically tested and certified Built-in water sensor to protect the element from overheating 100% safe for use by the whole family Compact and stylish designs Easy installation, can be installed by any certified plumber 3 years swap-around warranty

BENEFITS • • • •

No more boiling water!

No more paying too much for electricity because of a Geyser!!!

Why pay for a geyser, when all you need is hot water?

Hot water when you need it, just like that

www.ecotaps-sa.co.za 031 303 5527 0828247312 35 INNES ROAD MORNINGSIDE DURBAN info@ecotapssa.co.za

6

SOLAR ELECTRICITY

Figure 2 Elements of a solar PV system.

household and building applications typical sizes are 50 Wp, 80 Wp, 100 Wp, 150 Wp and 240 Wp. Other important components of a PV system are: • Mounting equipment: equipment to mount the panels on the roof, wall, etc.

This equipment can be used to direct the panels on the best angle to ensure maximum solar radiation.

Very importantly this mounting equipment needs to be designed to withstand wind and other forces for the full lifespan of the panels (typically 20 – 25 years).

• DC-to-AC inverters: Inverters take the low-voltage, high-current signals from the PV panels and convert them into 240 V AC, which is directly compatible with grid power.

• Utility power meters: this meter keeps track of the amount of power the PV system has delivered to the electricity grid and will be used to determine payments due to the owner of the system (if applicable).

• Batteries: solar systems that are not connected to the electricity grid or designed to power the building during power blackouts are equipped with batteries that will store electricity for periods the sun is not shining (typically the evenings). The size of the battery system depends on the electricity demand that needs to be catered for during periods that the sun is not shining, as well as for extended periods of overcast weather (this is referred to as autonomy: a three days autonomy means that the battery system is designed to store an amount of electricity needed for three consecutive days).

Solar Resource

The amount of solar energy that can be generated is dependent on the number of sun hours in a day and the intensity of the sun. Figure 3 gives an overview of the average annual solar radiation in South Africa.

The rate at which solar energy reaches a unit area at the earth is called the "solar

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

91

SOLAR ELECTRICITY

6

Figure 3 Average annual solar radiation in South Africa (based on Scholes, Fairbanks et al, 1999).

irradiance" or "insolation". The units of measure for irradiance are Watts per square meter (W/m2). Solar irradiance is an instantaneous measure of rate and can vary over time.

Properly aiming modules due north with an appropriate tilt will maximise the solar energy that the PV array collects. However, small variations of up to 15째 in orientation or tilt will not significantly affect performance.

As a general rule, a tilt angle equal to the latitude of the site will maximise yearly performance.

The solar irradiation depends on a wide range of variables like dust and cloud cover, humidity and location. Detailed databases are available online of the solar regime at specific locations. Based on the tilt angle of the system and the size of the solar system to be used, average annual electricity

92

generation can be calculated. Table 1 gives an indication of the amount of electricity that can be generated by a 1000 Wp system at various locations in South Africa.

Port Elizabeth

1558 kWh/kWp/yr

Pretoria

1700 kWh/kWp/yr

North Eastern Cape

1850 kWh/kWp/yr

Karoo

1880 kWh/kWp/yr

East London

1620 kWh/kWp/yr

Table 1 Indication of expected output of solar PV in different locations in South Africa (Dyk 2013).

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

6

Using Solar PV to Power a Building

When considering solar energy to provide power to a building some fundamental choices need to be made before a system is designed. Grid tied or not?

A totally off-grid system will need to be able to provide power to the building as and when needed, even during periods the sun is not shining. This necessitates the use of energy storage devices like batteries to store electricity when it is produced and release it again when the electricity is required.

Grid-tied systems can feed any electricity generated in excess of the demand into the grid and draw energy when the demand exceeds production.

Maximum electricity demand expected.

A good assessment needs to be made of the expected electricity demand profile of the building in order to size the PV system to be able to service that demand.

Available area for the solar system. In certain cases the available space to put the solar PV panels is limited and might determine the maximum size of system that can be installed.

AC or DC? The electricity generated by solar panels is direct current low voltage, which can be used directly by specific devices.

If you want to run standard appliances of a solar system the electricity needs to be converted to 220/240 V AC.

Designing a Solar System

The design of a solar PV system should follow a three-step approach: first, reduce the amount of energy required by implementing building designs that minimise the need for energy; second, look to using energy efficient appliances to service the energy needs that are still required; and third, design a system that can supply this resulting need for electricity.

SOLAR ELECTRICITY

Typical ways of reducing the energy requirements of buildings are optimising the orientation of the building to enhance solar gains, using overhangs to reduce heat capture by the building in hot periods (and thus minimise the amount of energy needed to cool the building), positioning spaces where people live and/or work on the north side of the building, etc. If combined with natural ventilation and the use of energy efficient building materials, the amount of energy required to keep the building within comfort levels can be minimised.

Once the building has been designed or retrofitted to reduce the energy required, any appliance used should be of high energy efficiency. The main aim is to reduce the amount of electricity needed to a minimum. Examples are the use of appliances with a high energy efficiency rating, energy efficient lighting (CFLs or LEDs), etc. After having minimised the energy requirements in the first two steps, the last step will be used to ensure that the resulting electricity demand can be met by an appropriately sized and placed solar PV system. An example on how to determine the required size of the PV system is given in the case study below.

Financial Considerations

The price of solar panels has dropped significantly over the last years, due to a combination of stagnating demand worldwide (and particularly in Europe), and over-capacity on the world market (mainly in China). The current spot-market price for PV panels is around â&#x201A;Ź 0.60â&#x20AC;&#x201D;0.70 / Wp (pvXchange 2013), resulting in a price of approximately â&#x201A;Ź 1.50 / Wp for turnkey solar installations in Europe. The recent South African Renewable Energy IPP Programme did see a price of approximately ZAR 30 / Wp for large scale grid connected systems (Breytenbach 2013).

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

93

PROFILE

You already know what we do, and how we do it.

Tel :014 736 3463 Steve Nicol Mobile: 082 441 9549 Email: steve@scarabsa.co.za Johan Carr Mobile: 082 535 4576 Email: johan@scarabsa.co.za www.scarabsa.co.za Australia www.scarabwater.com www.scarabwater.au

CONTACT

We know what we do, and we love doing it !

6

When comparing a solar system with an ordinary grid connection due consideration has to be given to the expected life span of the solar system (typically 20 â&#x20AC;&#x201C; 25 years), as well as the expected price development of grid electricity. As the major investments for a solar system are upfront, i.e. the investment needed for the systems itself and not for the running costs, financing costs and expected revenue streams in the future might be the biggest determining factors.

A clear distinction needs to be made between buildings with an existing electricity connection and new buildings.

For the latter the costs of connecting the building to the grid will be avoided when designing it as an off-grid building. In this case provision for energy storage needs to be made and no revenue can be made from feeding electricity back to the grid.

Support Mechanisms

Governments worldwide have put in support mechanisms to promote the use of renewable energy sources like solar PV for the generation of electricity. These support mechanisms range from reduced import duties and taxes to accelerated depreciation to the payment of premium tariffs for electricity delivered to the electricity grid.

A major boom for solar PV has been provided by grid feed in tariffs in a large number of countries in the world. Early 2012, 71 countries in the world and 28 states / provinces have provided some kind of feed-in tariff for renewable energy (REN21 2013). In those cases, producers of electricity by means of renewable energy technologies such as solar PV get paid a guaranteed price per kWh delivered to the grid. This tariff is normally higher than the standard tariff for power bought from the grid as an incentive towards clean production of energy. The exact price, as well as the associated terms and conditions,

SOLAR ELECTRICITY

vary per country. Unfortunately South Africa does not have feed-in tariffs at the moment, nor other support mechanisms for small scale solar PV installations, although some of the metros are currently looking into ways of accommodating feeding electricity into their grid by households / companies.

Conclusion

Currently available solar PV systems are adequately able to generate electricity for houses and commercial buildings, either as a totally off-grid building or as a grid connected building that feeds any excess electricity back into the electricity grid. With recently declining prices, solar PV systems have reached a price level that can be compared with grid based electricity and in certain cases can be deployed as an income generating technology (depending on the support systems in place).

Case Study

This case study describes the selection of a solar PV system for an office / research building in Port Elizabeth, South Africa. The building has been designed to be net zero energy: it produces the same amount of energy on an annual basis as it consumes during the same period. The building is grid connected and will feed any excess power generated during the day into the grid (which will be used by other buildings on the same premises).

STEP 1: Design the building is such way that the required energy consumption will be minimised. This was achieved by the use of passive solar design, passive heating and cooling systems and other interventions.

STEP 2: Minimise the required electricity for the needed energy services. This was achieved by selecting energy efficient appliances like CFL lights. The remaining energy requirement can be found in the table below.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

95

6

SOLAR ELECTRICITY

Expected electricity use Appliance

#

W

Hrs

Wh/Day

Lap top computers

3

140

8

3 360

Computers

4

200

24

19 200

Lamps

35

11

6

2 520

Pump

1

90

6

540

Kettle

1

1 500

1

1 500

Microwave

1

1 500

1

1 500

Fridge

1

296

6

1 776

TOTAL Allowance - System Losses

30 396 15%

GRAND TOTAL

4 559 34 955

STEP 3: Develop a solar PV system able to supply the required 35 kWh each day the building is in use. As the building will be used for experiments and exhibitions it is assumed that it is in use for 7 days per week. The panels will be placed on the roof of the building, which has been designed in such way that this roof is facing north and has the optimal solar angle of 35° (which corresponds with Port Elizabeth’s latitude of 34°).

• Wh to be generated per day = (Daily power need × days in use) / 7 • Wh / day required = (35 000 Wh × 7 days) / 7 = 35 000 Wh / day Figure 4 gives an indication of the solar

96

hours in PE for solar panels angled at 35°, from which we derived the minimum solar hours per day to be used for the PV system size calculations.

• Minimum array Wp = Wh to be generated / peak sun hours • Size of solar system required = 35 000 / 5 = 7 000 Wp The number of panels we will need for a system of 7 Wp is depending on the rating of the panels we intend to use. Having selected a panel rating of 240 Wp, the number of panels will be 30 (7000 / 240 = 29.166), which results in an area of 49.5 m2 based on the specific dimensions of the panels selected.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

6

SOLAR ELECTRICITY

Figure 4 Solar resource for Port Elizabeth for horizontal panels and panels with 35° incline.

References • BREYTENBACH, K., 2013. Keynote address: Update on the Renewable Energy IPP programme: Key milestones, achievements and preparing for challenges ahead, Africa Electricity Exhibition and Conference 2013 2013.

• CHAPIN, D.M., FULLER, C.S. and PEARSON, G.L., 1954. A New Silicon p-n Junction Photocell for Converting Solar Radiation into Electrical Power. Journal of Applied Physics, 25(5), pp. 676-677.

• DYK, E.E.V., 2013. Solar Energy resource in SA and energy yield of multi-MW photovoltaic power stations.

2013.

• EIA, 2013. Solar Photovoltaic Cell/Module Shipments Report 2012. Washington D.C.: U.S. Energy Information Administration (EIA),.

• EVOENERGY, 2012-last update, PV Comparison | Compare Solar Technology | Mono & Poly | EvoEnergy.

Available: http://www.evoenergy.co.uk/solar-pv/our-technology/pv-cell-comparison/ [December 20, 2013].

• MAEHLUM, M.A., 2013-last update, Which Solar Panel Type is Best? Mono- vs. Polycrystalline vs.

Thin Film. Available: http://energyinformative.org/best-solar-panel-monocrystalline-polycrystalline-thin-film/ [December 10, 2013].

• PVXCHANGE, 2013-last update, Price Index. Available: http://www.pvxchange.com/priceindex/Default. aspx?template_id=1&langTag=en-GB [December 20, 2013].

• REN21, 2013. Renewables 2013 Global Status Report. Paris: REN21 Secretariat.

• SCHOLES, R.J., FAIRBANKS, D.H.K., MULLER, J.L., MCKELLY, D.H., ESTERHUYSE, D., ARCHER, C., WINKLER, H., KHOABANE, K., CHOMA, M.A. and MOKALAPA, N.D., 1999. Procedures Used to Calculate the Distribution of Solar Radiation in South Africa, Chapter 3, South African Renewable Energy Database.

Procedures Used to Calculate the Distribution of Solar Radiation in South Africa. Pretoria: CSIR.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

97

INFRASTRUCTURE FOR CLEAN TRANSPORT

7

INFRASTRUCTURE FOR CLEAN TRANSPORT IN SOUTH AFRICA Andy le May

98

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

7

INFRASTRUCTURE FOR CLEAN TRANSPORT

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

99

INFRASTRUCTURE FOR CLEAN TRANSPORT

C

7

lean options for vehicles, charge points and power generation infrastructure are available now and more options are coming as the world demand and implementation of clean technology develops.

Currently, this is driven mainly by demand in Europe and America, but we are waking up to the possibilities here in South Africa. This section looks at the components of such a solution and explains how the pieces fit together to reduce not only our transport pollution but also how it supports other essential systems of our society.

There are potentially a wide range of cleaner technologies we could use for transport.

The development of bio-fuel based fuel production is good in the short term, especially when made from waste cooling oils and usage creates an emissions cycle, but it puts pressure on land used currently for food production and so is only a short term and limited use solution.

Hydrogen fuel cell systems have received a lot of money for development and the usage cycle is sustainable. However, the implementation of large scale hydrogen generation and the refueling infrastructure will be very challenging costly for transport.

In this authors opinion Hydrogen is most viable, currently, as a power storage technology and can be used to supply energy to remote areas and to balance energy demand loads on the grid.

Consequently, this article will focus on battery electric vehicles rather than other technologies, as they seem to offer the most viable current solution.

Clean transport technology is very new in the minds of many people, consequently there are many questions that need to be answered before we will engage, for example. Is it cost effective? Do we have the infrastructure to support it? What does it really cost to run? Won’t it just increase our

100

grid issues? It is reliable? What happens if I run out and where do I charge?

Cost effective

This is a major decision point in most people’s minds. I can’t give figures for all electric vehicles but I can give some insight.

In South Africa there are no subsidies for electric vehicle purchases as you find in other countries. This makes the purchase price of family electric cars, like the Nissan leaf, harder to cost justify. As a comparison a Nissan leaf in SA is around R470 000.

In the UK it is around £20 000 and in the USA around $19 000. So, immediately we have a significant cost hurdle to overcome compared to other countries.

The comparison to smaller electrics such as for electric motorbikes, electric scooters, electric golf carts (road legal) etc, where range is from 50 to 200 km is much easier. Even though there is no subsidy, the good news is there is no import duty on these vehicles. When you do a comparison to equivalent petrol vehicles the cost justification is very clear, they are around half the cost to run. For example, an EWIZZ Lightning 9 electric motorcycle doing around 20 000 km per year, or 77 km per day, will cost around R1 per km to run.

This includes the complete purchase and operating costs of the vehicle. An equivalent petrol bike will cost around R2 to run. This means a saving of around R100 000 over 5 years. So even if you were to be given the petrol bike you would still save money running the electric. This is an amazing reality of electric vehicles. The reason electrics are cheaper is mainly because of a reduction in fuel and servicing costs. For example the above electric motorcycle has an equivalent efficiency of 233 km/lt or 0.43 lt/100 km. This works out at R0.06 a km or about R6 to fill and only requires minimal servicing every 10 000 km. So these electrics are very efficiency and cost effective to run.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

7

Practical How far can I go? How long does it take to recharge? Where can I recharge?

On one fill, the range of battery only electrics is currently much less than most petrol and diesel vehicles. There are exceptions like the Tesla model S electric car with a 500 km range, but the majority of electrics are between 50 and 250 km.

Hybrids incorporating an ICE (internal combustion engine) and generator help to bridge this gap, but again they are expensive and are often not plug-in. Thus, all the energy to drive the vehicle has to come from petrol or diesel rather than potentially cleaner sources.

Plugging-in with on-board charging systems allow charging times roughly between 1.5 and 8 hours. The time is dependent on the power of the charger and the size of the battery pack. This time is adequate for most of us who can recharge at home or at work, but it won’t work for long distance journeys.

Faster charging systems are available though. However, these nearly always require the installation of external infrastructure needing a powerful 3-phase supply. These fast-charging units can recharge the batteries to 90% in around 30 minutes. So, imagine parking your car at a service station, plugging in and then getting a coffee, something to eat, going to the toilet and then by the time you come out, your vehicle is pretty much full again and off you go.

This focus on long range and fast charging is actually a distraction from what is mostly needed because it is not representative of the vast majority of journey’s occurring every day. In the absence of complete data for SA, I’ll make an estimate that most of us, 80%, travel between 5 to 100 km each day made up of between 1 and 4 journeys and with an average distance per journey of around 15 km. Even with a large variation in

INFRASTRUCTURE FOR CLEAN TRANSPORT

these assumptions, electrics doing between 50 and 250 km on a charge, with 1.5 to 8 hour charging and with speeds between 80 and 150 km/h practically support the majority of our transport needs. For the 20% currently outside of this envelope we can still use current ICE technology and we still drastically reduce our emissions and costs.

We now have the opportunity to rethink our transport energy supply model. The flexibility of electricity as our power source allows us think differently, we can not only generate the energy ourselves but we also remove the need to go to a special place, potentially out of our way, to get it. As we have more options for the source of the energy, we have more control over the cost of our energy and can take advantage of new energy generation technology directly.

One paradigm we can adopt is similar to the one we use for our cell phones and laptops, in that, we just plug in and top up wherever we go. Consequently, the time it takes to refill is just the time it takes to plug in. After plugging in you are away doing your business, shopping, working, relaxing etc. So, with electrics there is no more need to go to a gas station and pay increasingly high prices for transport energy. Most electrics have an on-board, built-in, charger, so just plug into any normal plug point. We have at least 45 million plug points where you could potentially recharge in South Africa at the moment.

Personally, we have an ICE diesel vehicle for longer journeys, but 95% of the time we take the electrics. As the battery technology develops and high speed charging infrastructure becomes the norm, the need for the ICE vehicle will reduce.

Pressure on our electricity grid

In SA we get blackouts because of peaks in energy demand, mainly in the evening when we all get home. Plugging in electric

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

101

Thermoshield features & benefits • Reduce inside temperature by up to 45% • Cut air-conditioning and refrigeration equipment running costs by up to 40% • Reduce ultraviolet penetration by up to 96.6% • Eliminate 80% of ‘thermal shock’ (expansion and contraction of roof sheets – the leading cause of roof wear and tear) • Greatly inhibit rust, increasing roof life • Improve working and living conditions, thereby improving productivity Natures Touch features & benefits • Fully washable wall coating • 0 VOC • No odour • Sheen finish • Ideal for baby rooms, hospitals, call centres, kitchens and shopping centres

7

vehicles at this time could increase energy demand and thus exacerbate the problem.

I say “could”, because electrics can actually help the situation. How can this be?

Electrics can take power from the grid, but they can also give it back. This is where smart home and smart grid technology comes in. What happens is that when we come home and plug-in the smart tech, rather it takes power from the car to support the home and potentially our grid. The vehicle then recharges later at night when demand reduces.

The adoption of these smart power technologies and electric vehicles means we would not need as much peaking and mid merit power production. This area of production uses hydro but mainly burns millions of litres of diesel to keep our lights on. This is both very expensive and environmentally destructive.

In SA we have about 35 GWh of spare energy capacity that could be provided at night without any change in our infrastructure. Charging vehicles at night means that our baseload power can continue running at higher efficiencies.

Currently it needs to be run down to match demand which is not efficient.

How many cars could we recharge for 35 GWh? An average electric car would

INFRASTRUCTURE FOR CLEAN TRANSPORT

use around 20 kWh of power in a day. That means we could charge around 1.75 Million cars right now at night with no increased generation capacity.

But the story actually gets better., electrics support the cost effective adoption of renewable technologies like Solar PV. Electrics plugged in during the day at work, or home, can be absorbing energy generated directly from local and large scale solar and other renewables. This means the need for storage is drastically reduced and thus it is cheaper to implement those renewables. We have some of the best areas in the world for solar power production in South Africa and rather than use it we are fighting it with fossil and nuclear fuels.

Implementing so called “clean energy” generation technologies such as nuclear will be extremely expensive. As an example, the cost to decommission two nuclear plants in the UK is estimated at £150 bn, that’s 2.7 trillion rand at the moment. The Draft IEP (Integrated Energy Plan) 2012 quoted the installation of Nuclear at R35 000 / kWh. Whereas Solar PV is quoted at R12 500 / kWh now and R5 000 / kWh by 2025. It will take 10-15 years just the build nuclear plant. The recent Solar PV installations can be implemented very quickly 1 - 2 years and these have gone in on-time and onbudget. This allows us to simply build to match demand as it develops. So, electrics help solve one the problems of solar PV and that is storage.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

103

PROFESSIONAL SERVICES • Commercial & Residential Landscapes • Multi-Award Winning Implementation • Complimentary Consultations • Professional Design Services • Living Green Walls • Precision Gabion Retaining Walls • Indigenous & Water Wise Landscapes • Environmental Restoration & Rehabilitation • Landscape Maintenance • Sub-surface drainage • Plant Sourcing & Planting

For more information please visit www.capecontours.co.za or call us on (021) 788 1202

7

Energy efficiency is very important but this is causing problems in loss of revenue for municipalities. Of course the adoption, support and promotion of electric vehicles and infrastructure means municipalities and Eskom will make more revenue from electricity sales. They will also reduce transport operating costs and reduce their transport emissions. This can be achieved without increasing energy production capability but will need some investment in smart grid and smart home distribution technology.

Emissions

Even with the way we generate our energy in South Africa, 80% coal and lignite, the emissions of electric vehicles are around half because of the efficiency of the electric drive train Project 90x2030 took health impact figures from Europe’s energy production and extrapolated them for South Africa’s energy mix. They showed that around 4 million people get minor illnesses, 65 000 serious illnesses’ and 4 000 people die every year. So, emissions are a serious problem that we are all paying for. There are two main components to fuel/energy emissions.

Upstream emissions are created in the production of energy and downstream emissions are created in usage. With ICE vehicles the downstream emissions are often quoted, but what is often overlooked are the emissions in the creation of the fuel which can be estimated at around 20%. If the fuel is created via coal (SASOL) this will most likely be worse.

Electrics on the other hand have zero downstream emissions, that is they produce no emissions in usage. So all the emissions with electrics are upstream. Hence, as we move to more renewable energy generation then our upstream emissions reduce. The adoption of electrics now not only drastically reduces our emissions but gives us a path to be completely zero emission in the future.

INFRASTRUCTURE FOR CLEAN TRANSPORT

Concusion The widespread adoption of electric vehicles has multifarious benefits for South Africa. Electrics reduce our dependence on imported fuels and support the adoption of cheaper local and centralised renewable energy generation technologies. Electrics drastically reduce emissions and will improve our health.

Electrics drastically reduce transportoperating costs and thus transport poverty.

Electrics and local renewable energy generation can bring clean cost effective transport to rural areas, thus providing opportunities and infrastructure to support more local services. Combined with smart grid and smart home technologies electrics can help balance our grid and reduce power outages. Even though electrics are much more cost effective for the vast majority of our current journeys, the provision of high speed public charging points at freeway service stations, malls and workplaces will increase operational range and remove most range concerns. Plugging in at home and at public points is a revenue generation and business opportunities for municipalities and businesses small and large. Simple public charge points in cafés, restaurants, shops, etc is something we can all do now to build charging infrastructure and it will help drive our adoption of the technology.

The price of oil is very closely linked to food prices and thus reducing the demand for oil and using cheaper transport solutions will reduce the cost of food.

The adoption of electrics in society will drive an enormous wave of investment and development and thus any limitations of this technology will quickly be overcome.

We will start to see the same acceleration in technology capability as we have seen in the computer industry that has followed Moore’s law. Electrics are quiet, smooth, low maintenance, clean, healthy and cost effective. Let’s drive the future.

THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

105

After years of experience manufacturing uPVC Windows and Doors, Magpro’s commitment to quality and investment in technical innovation and equipment has made us a market leader in our industry. We are involved in every aspect of the extrusion process, whether on the production line or in our on-site laboratory, we are there making sure that all Magpro products meet the highest quality standards. Our expert fitting solutions and after-sales service is just as important – our authorised fabricators actively ensure lasting client satisfaction.

Why use our products?

Internationally, innovations within the window and door sector have resulted in an enormous surge towards uPVC products. Magpro took it a step further – our research and development teams have devised a formulation specifically suited to the harsh South African climate.

The purest unplasticized Polyvinylchloride (uPVC) is enhanced with 15 microadditives, forming 20% of the total formula to produce a resilient product suited to our own climate.

Magpro uPVC Windows and Doors offer unparalleled advantages making your choice a simple one: Our profiles are durable: uPVC’s product life is estimated to be in excess of 25 years, which is not affected by coastal or saline environments. Impressively, installations in South Africa have been monitored over a 30-year period, and show no significant degradation. Stabilizers are added to strengthen the profiles to give it vital long-term stability.

Our profiles are UV resistant: Stabilizers are added to minimize the effect of solar radiation and changes in temperature. The addition of Titanium Dioxide (TiO2) ensures that our uPVC products retain their brilliant white finish.

Our profiles are virtually maintenance free: You no longer have to worry about painting your frames! Regular cleaning with a mild non-abrasive detergent solution will ensure a lasting finish. Should you find that you require service and maintenance, we advise that you contact your supplying fabricator or installer.

Our profiles keep the unwanted elements out: Our multi-chambered design offers maximum soundproofing, effective insulation and efficient drainage.

Our profiles have aesthetic appeal: Various modern designs are available ensuring our product is not only durable but also compliments the style of your property.

Our profiles offer added security benefits: Our uPVC windows and doors are robustly constructed for added security and peace of mind. The electro-galvanised steel reinforcement in the frame, sash and transom is extremely difficult to cut through or bend.

Our profiles do not support combustion: uPVC is very difficult to ignite via the common sources of fire (matches, blow lamps etc). In addition, uPVC does not burn once the source of heat or flame has been removed.

Our profiles are eco-friendly: uPVC provides excellent insulation in a building, thus reducing heating and cooling costs and increasing energy efficiency. In addition, uPVC replaces timber frame windows, thus aiding in the conservation of valuable hardwoods.

Complete solutions for all property owners

Residential: Magpro systems are modern, adaptable, affordable and secure – thus perfectly suited to the requirements of the residential market.

Hotels: The long-term efficiency and low maintenance requirements of the Magpro range is ideal to cope with the demands of the hospitality industry.

Commercial and Industrial: Magpro products are competitively priced and provide a robust and durable solution in commercial and industrial buildings.

Low cost housing: Magpro uPVC Door and Window systems are the cost-effective answer to the needs of the mass market in low-cost housing, with durability and easy maintenance solving numerous problems.

Our Installations: KwaZulu Natal: Bluewaters Hotel Protea Hotel Edward Elarish Restaurant & Conference Centre Sappi Saiccor-Umkomass Commercial Cold Storage Durban North Girls High School Glenwood Boys High School Huntsman Tioxide-Umbogintwini Bluff Lifesavers Club Chelsea Preparatory Shool

Johannesburg: Formula 1 Hotel in Midrand Sanria Muslim School in Mayfair Cape Town: Harbour Edge Hotel – Gordon’s Bay Island View Apartments – Milnerton St. Michaels Office Park T: 031 4016782 C: 083 779 2408 www.magpro.co.za

F: 031 401 3844 F2E : 086 512 0908 sales@magpro.co.za

Sustainable yet durable Ecosure gives you the durability and stability of using a normal emulsion with the added bonus of having a lower environmental impact.

THE PERFECT BALANCE OF SUSTAINABILITY AND PERFORMANCE.

Weâ&#x20AC;&#x2122;re all under pressure to be sustainable these days, but traditionally, using eco-paints has meant sacrificing on performance. Thatâ&#x20AC;&#x2122;s why Dulux Trade has developed the Ecosure range: the range of waterbased paints that enables you to help meet your sustainability targets and maintain a professional finish.

STANDARD BANK ROSEBANK

For further information visit www.duluxtrade.co.za or call 0860 330 111

INDEX OF ADVERTISERS PAGE

COMPANY

14

Alugro

84-85

Ashanti Trading Arcelor Mittal

116-117

Avani SA

118-121

BASF

110-111 38-41

Bluescope Steel

12

Bulkmatech

28; 104

Cape Contours

10; 58

Clay Brick Assciation Corobrik

4-5

Eco Taps

90

Evapco

18

Framecad

62 108-OBC

ICI Dulux

8

Isover Saint Gobain

IFC-1

Kansai Plascon

72

Knauf AMF

6

Kyasol Green Technologies

74

Mapei SA

106-107

Magpro Megabond Thermoshield

102

Natural Daylighting

46

Precast Cement Products

56 112-IBC

Safintra

94

Scarab Technologies

2-3

Sika

20; 22-23

Swartland Think smart built in systems

52-53

University of Johannesburg

122-123

On Tap

30 THE GREEN BUILDING MATERIALS AND TECHNOLOGIES HANDBOOK

109

www.safintra.co.za

www.S-5.com

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

PROFILE

Formed in March 2012, Johannesburg based Avani SA Consulting is a multidisciplined consultancy specialising in the management of social infrastructure and development programmes and projects.

VISION: Avani SA Consulting seeks to become a leading South African programme management service provider. Avani SA Consulting’s committed team of professionals and alliance partners apply only the highest standards of strategic, technical and operational expertise with the aim to deliver innovative and empowering end-to-end solutions across the entire spectrum of the programme delivery cycle value chain.

AVANI SA CONSULTING’S UNIQUE SKILLS PACKAGE ASSISTS CLIENTS TO R Effectively plan and manage social development and infrastructure programmes and projects, R Understand programme and project requirements from a portfolio management perspective, R Create solutions that align project deliverables to a Client’s strategic goals and objectives, R Deliver projects on time, within budget, while meeting the clients intended strategic objectives.

A team of dedicated and loyal personnel have also been at the forefront of implementing projects and programmes using Alternative Building Technologies (ABT’s), pioneering implementation models that integrate into conventional processes and respond to the needs of the social infrastructure and development sector.

A company with heart and commitment to the upliftment of people, places and communities, Avani SA Consulting ensures the participation of disadvantaged communities within some of the most rural locations in South Africa. The company passionately pursues the delivery of projects that benefit previously disadvantaged and marginalised communities, achieving this through the application of best practice project and programme management methodologies.

1 Eastgate Lane, Bedfordview, Johannesburg Tel +27 11 616 0223 | Cell +27 83 779 2404 | Fax +27 86 513 7405 info@avani-sa.com | www.avani-sa.com

PROFILEPROFILE

HANGE JUNIOR SECONDARY SCHOOL

QOLOMBANE SENIOR PRIMARY SCHOOL

J L DUBE AMPHITHEATRE

MNXEKAZI JUNIOR SECONDARY SCHOOL

Our Ecosure Range is not only low VOC and Greenstar SA rated, but is also hard wearing and durable.

We’re all under pressure to be sustainble these days, but traditionally, using “green paints” has meant sacrificing on performance. That’s why Dulux Trade has developed the Ecosure range: the range of water-based paints that enables you to help meet your sustainability targets and maintain a professional finish.

Dulux EnvironWash System The smarter way to clean-up painting tools

Dulux has launched the EnviroWash System, providing painters businesses with an environmentally responsible way of washing out painting tools, such as brushes and rollers. The revolutionary wash system converts waterbourne paint washings into clear water and solid waste, allowing for easier and safer disposal.

For further information visit www.duluxtrade.co.za or call 0860 330 111