Steiner School Report

Steiner School, Belfast City Centre

Conceptual Design Booklet

Authors Noel Hughes Anthony Kelly Chris McGeough Daniel Roe Produced in conjunction with: Queen’s University, Belfast MSc. Sustainable Design

The aim of this project was to design a school in a unique city centre location in Queens Street, Belfast. The school is to follow the ethos of Steiner Education developed by Rudolph Steiner, where the focus is on student interaction with nature as opposed to more mainstream educational methods. With this it was decided to implement sustainability and holistic construction as the core of the design process.

A sustainability checklist was developed to ensure sustainability was examined in every aspect of the building’s design. Following on from this, a number of precedents were examined and their conformity with our sustainability checklist was evaluated.

With all this information at hand, a project brief was created as a guide to the design process stating clearly what issues any possible design must address.

A sketch design was shaped to adhere to our sustainability checklist and project brief. The resulting design is hoped to address all the main issues ranging from recycling of the initial site to the performance of the structure once completed.

Introduction

1

2

Contents

• • • • • • • • • • • • • • • • • • • • • • • • • • •

Sustainability Checklist Precedents

Precedents

Precedents

Project Brief

Area Analysis

Site Analysis

Site Analysis

Building Approach Basement

Ground

First - Fourth

Roof

Building Form Water

Heating

Electrical

Access

Structural Frame Facade and Insulation Ventilation

Lighting

Flexibility

Student Involvement Impact on People Impact on Place Appendix

Contents

04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 31

3

Sustainability Checklist The Sustainable Checklist identifies resources and saving opportunities within any project. The checklist focuses on sustainability in energy and water use, waste management, procurement and carbon management, among others. All the tasks are designed to promote or develop sustainable policies and action within any building or structure.

1.

Structure Type Determine whether to use a frame or cellular approach. If a basement area is necessary and how it should be constructed.

5.

2. Materials • Recycling of Current Site • Materials used for the main structure to reduce embedded carbon • Glazing Area to use of natural light while reducing solar gains • Insulating materials 3.

Open Spaces/Green Roof • In following a sustainable approach to the scheme it is important to consider a space which can easily adapt their function, thus extending their lifespan of the scheme.

• The limited access to green open space in urban environments is a concern to the education development of children in the Steiner School system. It is important that we provide an external green open space for the children and therefore we will be implementing a living green roof within our structure.

4. Heating/Ventilation Our approach will examine the possibilities of heating strategies for an urban multi-storey structure. We shall explore the efficiencies of a verity of technologies and methodologies to reduce the energy requirement and environmental impact of the heating requirements of the building.

4

Sustainability Checklist

Water Recycling With an ever increasing focus on water usage in buildings we believe water recycling as well as water usage reduction should be incorporated into our design. Aside from obvious financial reasons to cut water consumption from the mains, the unsustainable use of water at present cannot continue. Using water treated to drinking quality for activities such as irrigation and flushing toilets cannot continue. Aside from the obvious waste of water, considerable energy consumption is associated with the treatment and delivery of potable water.

6. Access/Transport Examine how people access the site and provide sustainable solutions.

7.

Local Community Use/Education

8.

Whole Life Design • Maintenance • Flexible Spaces • Disassembly

9.

Student Involvement: Considering the structure is to be used as a Steiner school, we decided from the outset that student learning and involvement should be incorporated into as many of the sustainable technologies as possible. We hope to enable staff to use the final design to incorporate sustainability into the curriculum.

Holywood Steiner School, Belfast Steiner education is an alternative method of education to more mainstream methods.

It was developed by Rudolph Steiner who applied his concept of anthroposophy to education to provide a creative learning environment. Steiner has its own particular style of architecture with softer corners and the use of rounder forms with a focus on ergonomics.

Hollywood Steiner School Although not effectively a precedent as it contains few of the characteristics required on our sustainability checklist we thought it may be of use to study an existing Steiner School here in Belfast.

The school caters for students from kindergarten all the way up to class 11. The classrooms were all designed to ensure good acoustical qualities which most of the teachers we spoke with believed worked well. Good use of natural lighting is evident in the main building.

Requirements The school principle believes that if a second Steiner school were to be built in Belfast it would ideally act as a feeder school acting as a Kindergarten for the existing school. She also believes it would be beneficial if certain facilities could be shared by the two schools and with the school lacking a number of facilities the new school could provide these. The existing hall is inadequate so a new sports hall with provisions for a stage for drama etc was high on her list of priorities as well as a green area for the kindergarten class.

Performance against Checklist Obviously due to the nature of the school it compared extremely poorly with our sustainability checklist however the visit and subsequent study did enable us to create a clearer and more specific brief.

Precedents

5

Kingsmead Primary School Northwich, Cheshire Kingsmead Primary School located in Cheshire was designed by White Design Associates and completed in July 2004. With sustainably sourced wood being used for the timber frame and cladding the building has a low embodied energy. Recycled glass has been used as insulation.

Lighting and Ventilation Ventilation is by natural means via roof lights at the back of the classrooms.

Passive solar design was executed extremely well on the project and lights are rarely needed in the classrooms.

With all classrooms north facing it was possible to use tall walls and allow as much sunlight as possible in with the roof lights boosting light levels towards the back of the classrooms. Automated blinds on the roof lights allow solar gains when needed and block it when not.

Sustainable Technologies A water harvesting system collects rainwater from the sloping roof which cuts water use by approximately 32%.

Heating comes from a biomass boiler backed up by a gas boiler however problems with the biomass boiler led to complete reliance on the gas boiler initially. PV’s and solar thermal panels were also included to contribute towards electricity and hot water usage.

6

Precedents

Student Involvement A building management system allows the rainwater harvesting system and PV array be used as an environmental teaching tool and can be incorporated into maths and geography lessons.

Also a transparent downpipe allows students see the rainwater being collected.

Other Key Characteristics Bike racks and a short access road hope to encourage walking and cycling to school. Sustainable materials and construction methods were used wherever possible and the possibility of dismantling and recycling building materials was considered in the design Performance against Checklist Interior concrete walls aren’t structurally important giving the building the flexibility to adapt to any future needs and low embodied energy ensures it rates highly on matters of whole life design and materials. Ventilation, water recycling, access, and student involvement are all well addressed however a number of factors have led to poor performance on the heating and electricity front however these should be rectified in the future.

Holywood Steiner School, Belfast Steiner education is an alternative method of education to more mainstream methods.

It was developed by Rudolph Steiner who applied his concept of anthroposophy to education to provide a creative learning environment. Steiner has its own particular style of architecture with softer corners and the use of rounder forms with a focus on ergonomics.

Hollywood Steiner School Although not effectively a precedent as it contains few of the characteristics required on our sustainability checklist we thought it may be of use to study an existing Steiner School here in Belfast.

The school caters for students from kindergarten all the way up to class 11. The classrooms were all designed to ensure good acoustical qualities which most of the teachers we spoke with believed worked well. Good use of natural lighting is evident in the main building.

Requirements The school principle believes that if a second Steiner school were to be built in Belfast it would ideally act as a feeder school acting as a Kindergarten for the existing school. She also believes it would be beneficial if certain facilities could be shared by the two schools and with the school lacking a number of facilities the new school could provide these. The existing hall is inadequate so a new sports hall with provisions for a stage for drama etc was high on her list of priorities as well as a green area for the kindergarten class.

Performance against Checklist Obviously due to the nature of the school it compared extremely poorly with our sustainability checklist however the visit and subsequent study did enable us to create a clearer and more specific brief.

Precedents

7

Brief The proposed new Steiner School on Queens Street Belfast shall provide a creative learning environment for children between the ages of 3-7. This school shall encourage imagination and creative flair, while growing intellectual development. The building must also reflect the Steiner education mentality which adapts to every child’s strengths and aptitudes, and thus dispelling any forms of inequality.

At present, no such facility exists within Belfast City which offers this form of anthroposophical learning. A Steiner school exists in Holywood, around 20 minutes outside of Belfast, however despite offering a relative case study, is completely contrasting to our proposed compact and urban site.

• • • • • • • • • • •

8

Project Brief

Multifunctional Hall, which shall provide performance and sporting needs.

Reading Rooms.

Outdoor facilities.

Garden(s)/ Vegetation.

Art Room.

Efficient storage space.

Acoustically sound and bright rooms/ spaces.

Administration/ Teacher offices.

Meeting Room.

Children’s Library. (If needed on site) Canteen/ Eating/ Water Facilities, in each classroom.

The focus of the project will be on the creation of rooms and spaces with can adapt to the varying facilities provided by the Steiner Education.

Integration of thinking, making and doing to the design is crucial. Educate through movement and physical interaction.

• Reception area.

• Multifunctional Hall, which shall provide performance and sporting needs.

• Reading Rooms.

• Outdoor facilities.

• Garden(s)/ Vegetation.

• Art Room.

• Efficient storage space.

• Acoustically sound and bright rooms/ spaces.

• Administration/ Teacher offices.

• Meeting Room.

• Children’s Library. (If needed on site) • Canteen/ Eating/ Water Facilities, in each classroom.

The focus of the project will be on the creation of rooms and spaces with can adapt to the varying facilities provided by the Steiner Education.

Area Analysis An area analysis of Belfast city centre (the local catchment area for the proposed Stiener School) has identified the following community assets/amenities and number of urban shortcoming in relation to the development of a new school.

Local Amenities

• Extensive Shopping (Victoria Centre, Castlecourt)

• Office Space

• Two area of Private Green Space

• Event Venues (Waterfront, Odyssey)

• Civil Centre (Belfast City Hall)

Lack of Amenities

• Public Activities Area (Parks, Swimming pools etc)

• Community Area (Community Hall, Meeting Area)

• Sport Grounds

• Children’s Play Zone

• Community Anchor

Area Analysis

9

Site Analysis Analysis of vehicular and pedestrian traffic across the site. In addition to the prevailing meteorological conditions.

10

Site Analysis

Site Analysis Analysis of various environmental conditions affecting the site.

Site Analysis

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Front Aerial Elevation

12

Building Approach

Basement Gym A two storey space to accommodate the physical education requirements of the school and greater community. The gym is half buried, which an entrance at basement level.

Store Room This area connects to the gym to store the associated equipment Plant Room The central for all the building heating and plumbing mechanics Access Corridor A combination of the building circulation space and a natural ventilation stack.

External Ground Works This zone is external to the building and located under the buildings proposed playground. Here is where the proposed heat pumps boreholes and holding tanks for the rainwater catchment systems will be located.

Basement

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Ground Office Space This area will contain the reception and greeting area. It will also house the office space for the various members of staff within the school.

Gym A two storey space to accommodate the physical education requirements of the school and greater community. The gym is half buried, which an entrance at basement level.

Access Corridor A combination of the building circulation space and a natural ventilation stack.

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Ground

First - Fourth Classroom / Multi-Use Space These areas will provide a space for the school to educate in. The spaces and structure will be design to be able to adapt to multiple usage. Will semipermanent wall and open plan layout Access Corridor A combination of the building circulation space and a natural ventilation stack.

First - Forth

15

Roof Roof Garden The proposed roof will be a living garden with a high hedge line around the perimeter to act as a wind screen.

The area will provide an education area and planting patch for the building, it will also act as a catchment area for a rainwater harvesting system.

Solar Panels An area of the roof space dedicate to the housing of both a PV and thermal solar panel system. The area will be covered in rapeseed and will be separated from the rest of the roof space. This is for security, safety an ease of access for maintenance reasons.

Access Corridor A combination of the building circulation space and a natural ventilation stack.

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Roof

Rear Aerial Elevation

Building Form

17

Water Conservation System Rainwater Harvesting System • Used to collect store and recycle rainwater usually from roof area • Incorporated into roof gardenSome plants would help filter rainwater however would significantly reduce collected volumes of water • With an 850mm per annum of rainfall and a 350m2 roof, 300,000l of water is available for collection • However a sedum roof can capture 75% of rainwater meaning only 75,000l but this is still a significant reduction in the needless use of potable water.

Greywater Recycling System • Wastewater collected from hand basins etc is treated, stored and recycled to the same systems or for irrigation when required • New systems refill cisterns directly from basin run off (reduces energy & storage requirements) • Must be collected from >80% of fittings to comply with BREEAM

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Water

Combining Both Systems • Combination of both to meet BREEAM requirements of collection of 50% of predicted toilet and urinal flushing (BREEAM, 2010) • Better economies of scale leading to reduced payback period • However unless separate tanks are used rainwater must be needlessly also treated to same level as greywater.

WC’s/Taps • Dual flush cisterns which incorporate low volume technologies to reduce the water needed to 4l and 2.6l per flush for solids and liquids respectively (Waterwise, 2010) • Waterless urinals using either fan or deodorizing pads to eliminate odours • Sensor operated spray taps can reduce consumption by up to 80% over conventional taps (Green Building Stores, 2010)

Heating Management Systems

Heating Generation Systems

Technologies • Heat Zoning • Adjustable Room Settings • Under-floor Heating • Passive Solar

Technologies • Gas Boiler • Air Source Heat Pump • Ground Source Heat Pump

Heating Zoning • Isolate zones by the usage and requirements • Provides a more efficient system of heating the structure

Gas Boiler • Efficient and low running costs • Existing City supply line • Relatively low emissions • No need for fuel storage on tight city site

Adjustable Room Settings • Allow for individual control of rooms and spaces.

• Provides for a more comfortable heating environment Under-floor Heating • Creates a more stable internal temperature.

• Provides for the heating requirements for after school activities more efficiently that radiators • More compatible with hat recovery systems Passive Solar • Maximum the heat gains of natural daylight

Air Source Heat Pump • Ability to use proposed roof space to recover exhaust heat • Reduces heating generation requirements of the structure Ground Source Heat Pump • Use of required external play ground space to generate heat • Reduces heating generation requirements of the structure Solar Thermal Panels • Ability to use proposed roof space to generate hot water.

• Reduces the thermal energy requirements of hot water of the structure

Heating

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Electrical Management Systems

Electrical Generation Systems

Technologies • Electrical Zoning • Smart Meters

Technologies • Helix Wind Turbines • PV Solar Panels

Electrical Zoning • Isolate zones by the usage and requirements • Reduces the building electrical requirement • Provides a more efficient use electricity dictated by the activity of a space • Invisible technology, no maintenance

Helix Wind Turbines • Proven Technology • Helix form has an advantage over Axis turbines in the chaotic urban wind environment • Income generated by providing energy to the grid • Attractive feature on street front elevation • Promotes buildings character and focal point for the community

Smart Meters • Proven to reduce the electrical use of any building through changing peoples habits • Educational tool • Income generated by providing energy to the grid • Invisible technology, no maintenance

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Electrical

PV Solar Panels • Open access to east to west direct south sunlight • Limited obstruction of sunlight at city roof level • Income generated by providing energy to the grid • Reduces the buildings energy requirements and carbon footprint • Roof layout provided for easy maintenance access • Educational tool

There currently exists a network of access to the site. There are bus stops located either side of Queen Street, no more than 50m from the site entrance, and there is a pedestrian crossing where Queen Street meets College Street.

This proposal will specify bike racks/ sheds on site and propose a new pedestrian crossing at the Queen Street - Castle Street junction.

Proposal A

Proposal B

Early on it was identified that due to the age of the children attending the school that there would be a large number of students being dropped and collected at the school by car. As the site of Queen Street is a busy area this issue needed to be addressed by the site.

Proposal B suggests a drop off location cut into the existing footpath. The footpath outside the site is wide enough to support this solution and there is already an example of this outside one of the neighbouring sites. The benefits are that the basement can be used for its original purpose, it’s a much simpler solution to the problem and it is easily accessible and visible for parents.

The primary problem would be that of planning permission and also making the area large enough to accommodate as many cars as possible.

Proposal B is the preferable.

Proposal A was to utilise the basement space as a drop off area. The site provides ample area for this action.

The benefit of this is that it is all done on site. The problems are that of maintaining constant flow of cars, and also sufficient ventilation in a basement location with running vehicles.

Access

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The existing site is a tarmacadam car park with an estimated 150mm tarmac covering 1.5m of hard core. The tarmac cannot be recycled but the hard core can be re-used as hard core for under the basement or cleaned and graded and used as aggregate. To re-use it as hard core is the cheaper option.

It was decided that a basement would be needed to house plant, gym and potential access. On a tight inner city site the easiest method of construction is interlocking bored concrete piles, to form a wall. As concrete was already being utilised it was decided to continue the concrete structure up to first floor level. This has many advantages (Appendix). The concrete will be specified to use a percentage GGBS and recycled aggregates to minimise environmental impact.

The roof will be constructed flat to house a green roof over two-thirds of the area, with the remaining third housing solar panels and a small area for services. The green roof poses many advantages over a plain flat roof, even more so considering a basement will be constructed for the bulk of the plant.

Continuous bored pile wall

Timber Super-structure

Several solutions were looked at for the superstructure, but in order to reduce the embedded carbon of the structure it was decided that timber would be the primary structural material (Appendix).

In order to achieve the height and spans required glulam would be needed.

In addition the floor structures will be constructed from timber-concrete composite (Appendix).

Concrete Sub-structure

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Structural Frame

Timber-Concrete composite floor

As the main elevations of the building are east-west orientated care must be taken to allow sufficient natural light but also have solar shading, as a lot of the light will be low angle.

N

Therefore the exposed façades on the East and West of the building will be a mix of solid and glazed façade. The only south facing elevation will have increased glazing area but opaque to reduce solar gains but maintain natural light.

Cellulose fibre is a grey coloured cellulose fibre insulation made from recycled newsprint. It has been treated with inorganic salts to provide pest and fire-resistance and is non-irritant to handle and touch. The salts give it the fire rating required and cellulose fibre can absorb and release moisture without significant loss of thermal resistance.

The atrium will be a mix of clear and opaque glazing.

The solid façade area will be highly insulated panels, and the glazed areas will be kept low to avoid undue heat loss in winter and heat gain in summer.

Current building regulations have the glazed area no more than 40% of façade area, for unprotected glass.

Atrium

When looking at insulation, several criteria were important to the selection; environmentally friendly materials and thermal conductivity.

Also semi-transparent insulation types were considered to optimise light, such as Kalwall.

The various contenders were compared (Appendix) and what was chosen was cellulose fibre.

Photo of opaque and clear glass façade house

by Wiel Arets Architects

Cellulose Fibre Insulation

Façade and Insulation

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What currently exists for specification of ventilation in the construction of schools in the UK is that of Natural ventilation for classrooms and offices etc and mechanical ventilation for W.C and kitchen areas.

Noise Reducing Intake Vent

A

B B

For this project the same basic principles will be used, Natural ventilation for classrooms, offices etc and mechanical for W.C, kitchen areas, basements and gym.

The natural ventilation will be achieved using buoyancy driven effect in an open atrium, running the length of the building. The solution of the atrium was chosen as it also helps utilise natural light.

CO2 sensors will be used in winter and temperature sensors in summer to regulate air intake.

As noise is an issue with natural ventilation, and the proposed site is beside a main road, care must be taken to avoid undue noise from entering the classrooms. Also pollution from car fumes is an issue close to a road.

To mitigate this, specialised vents will be used at the intake in each classroom.

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Ventilation

A

In addition to this, the option of a mechanical solution could be put in place for classroom areas, to be utilised during the winter months to avoid heat loss. This option is a possible addition and not chosen for the scheme due to cost.

A

Natural Ventilation using the atrium for buoyancy driven effect

B

In order to maintain the issue of sustainability, natural light will be utilised as much as possible. Natural light is also more preferable for a better indoor environment for the occupiers.

To optimise daylight in the building the east-west elevations of the building will have sufficient glazing, coupled with solar shading due to low angle light.

The atrium, orientated north-south, will also be utilised to increase the volume of natural light entering the building.

Artificial lighting will have to be used in the building. The specifications for the type of lamp would ideally be LEDs but due to cost this might not be feasible.

Alternatively compact fluorescent lamps could be used. For this build LEDs will be specified due to their increased design life (Table 1)

Fibre optic lighting was an option to further the penetration of natural light into the building but not a feasible option for this site. Light wells were also examined

Table1: Comparison of light types Light Incandescent Halogen Fluorescent LED Blennerhassett (2010).

Life (hours) 1000 1500 8000 50,000

Efficiency (lumen/watt) 15 20 70-100 50-100

Light Well

Lighting

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Open Spaces & Flexibility

Gym

Semi-Permanent Wall Panels These are prefabricated vertical panels suspended concealed, side guides. They are usually slid or clipped into place. They are a simple means of divide Common Rooms, Lecture Theatre, and as long as they have properly sized storage space they have little impact on the space when closed.

Retractable Seating Flexible seating is required to allow the building to cater for much larger sporting events, lectures, concerts and any graduation ceremonies which may occur there. The rows would be spaced in a 610mm by 840mm grid with safety railings (fixed or removable options).

This would create a uniform look and an efficient storage unit.

Folding Wall Panels Similar in construction to a semi permanent wall panel. A panel hung from lightweight aluminium track, without the need for floor track or guides. The main difference is these fold out were semi permanent panel are either slid on a track or clipped into place.

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Flexibility

The Rainwater Harvesting System • Design similar to the precedent study of Kingsmead school to include a transparent downpipe which runs collected rainwater through building to storage tanks below • Allows students see the system in operation • An electronic display incorporated into the system will allow students record levels of rainwater being collected during year Exposed Wall Cavity • Promotes understanding by allowing students see a cut away section of wall and insulation used

Roof Garden • Kindergarten children in existing Steiner school allowed plant in school garden • Roof Garden would allow students do this and gives them their own space • Can also be used by community after school hours and during Summer Sustainability in the Curriculum • Technologies such as those mentioned above for the rainwater harvesting system and PV cells will allow teachers introduce sustainability

PV Cell Meters • Would allow students see how much electricity was being generated • Incorporate into maths lessons for older students Smart Meters/ Educational Light Switches • Will encourage more responsible energy use by both students and staff • Educational light switches such as those used in Birchensale Middle School creates better awareness among students on how to cut energy usage

Student Involvement

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Impacts on People Our centre shall reach out and offer its services to the local community. This shall allow the building to integrate with the community in a positive way, while also allowing the building to be more sustainable by using the building out of school hours. These design features shall also contribute greatly to the area as it shall offer local society the chance to further education and develop their own personal development.

Adult Learning The Steiner School shall offer the opportunity for adult education centre for Belfast city centre. Using the versatile open spaces and multi functional aspect of the design, the building shall adapt in the evening time, to facilitate adult learning. The centre shall provide individual and group tuition in reading, writing and spelling for adults with reading and writing difficulties. The school shall offer the elderly the chance to learn from current students of the school. Classes teaching the basics of the internet and the learning of new technologies shall be offered, enabling the elderly learn modern skills, while allowing students develop teaching skills. This aspect of the building shall improve social relations and offer a viable community learning facility.

After School Club This feature of the design shall enable the buildings aspects be used beyond the standard schooling hours, while offering a safe place for school children to come study and interact. Using the building after hours shall add greatly to the sustainable nature of the building... It shall also address a problem which affects the site currently, that of anti social behaviour. Offering a safe and inspiring place for children to come after school, enables working parents to work longer hours and peace of mind.

Community Education Our design has focused on allowing the building to be used by both the students of the school and the local community. Multi function rooms and spaces shall provide ideal teaching facilities for adult and communal learning. The design shall benefit all aspects of society, catering and including both young and old generations.

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Impact on People

Impacts on Place Our design shall provide not just for the people of the area but also provide new attractions and facilities currently needed.

Social Centre The building shall act as the main community space for the area, and will allow a wide range of disparate activities. In the evenings the school shall become a centre for local activities and provide a place of support networks for minority groups and the community.

Gym in Basement The gym in the basement shall be multi- functional space for sports education, theatrical performances, lectures, social gatherings, conferences, exhibitions and public/ private meetings. This new asset to the community shall easily manipulate to suit both the needs of the school and the needs of the wider community.

Impact on Place 29

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Appendix Contents

•

General

33

•

Electrical

39

•

Heating

47

•

Technology

57

•

References

66

Appendix

31

32

Appendix

General

Appendix

33

Renewable Energy Facts •

•

•

Combining solar collector with a wood burning stove provides an ideal year-round renewable energy heating solution. A solar collector system can provide around 60% of your annual hot water needs for free (80 to 90% in summer).

Simple Passive Solar Design techniques can make a big difference to energy consumption in the home. Just by facing a house south to capture the maximum daylight energy bills can be reduced by 30%.

Transmission of light through windows (passive solar heating) can reduce heating costs - could you allow for passive solar heating in the design of a new home? What about integrating a solar water heating system onto a south facing roof?

•

Adding an unheated conservatory or sun-space to the south face of your house increases passive solar gains and provides an insulating effect.

•

Space and water heating account for over 70% of energy used in the home, so switching to clean; renewable energy (e.g. wood fuel, solar energy or heat

34

Renewable Energy Facts

pump systems) makes a big reduction in the environmental impact of your home.

•

Wood is a renewable fuel you can use without producing the harmful greenhouse gas emissions of fossil fuels.

Instead of coal or peat, throw on a log onto a fire. Whereas peat and coal take hundreds of thousands of years to form, wood is a renewable fuel that grows in just 3-70 years.

•

Using renewable sources of energy like wood and solar energy to heat our homes reduces our reliance on polluting, imported fossil fuels like oil and coal.

•

If you recycle glass and paper, you save on a great deal of energy, raw materials and pollution.

•

Ground source heat pumps, which collect solar energy stored in the ground, are ideally suited to the Irish climate and can provide year round space and water heating for the fraction of the costs of a conventional system.

•

A modern wood burning stove can achieve efficiencies of up to 80% compared to only 20-30% for a traditional open fire.

Lighting A building’s lighting system is one of the major contributors to its electrical consumption. Luckily, it is an easy area to improve efficiency. This part of chapter will look at ways of how to reduce electrical consumption is of lighting.

Natural Daylight Before you even consider electric lighting make sure you make maximum use of all available natural sunlight. Daylight provides a healthier indoor climate, can provide higher standards of visual comfort and makes for more enjoyable interiors. And that is apart from the energy savings and environmental benefits.

•

Rooms should be furnished to allow daylight in and activities for which daylight or sunlight is essential should be positioned near windows.

•

Furniture and other obstacles should not obstruct daylight penetration of the room. Net curtains hamper daylight penetration of a room.

•

Paint the surfaces of rooms, including ceilings, with colours of high reflectance to maximise the day lighting opportunities (and also the effectiveness of artificial light). Light colours can reflect up to 80% of incident

light while deep / dark colours might reflect less than 10% of incident light.

•

Dirt on vertical windows can reduce performance by 10% and even more if the dirt is allowed to build up on rooflights.

Natural Daylight

35

Construction / Insulation The advantage of having a concrete substructure is that it allows the super structure of timber to achieve more stories. Timber construction is limited to about four stories but if you utilise concrete in the substructure, as it was already used for the basement construction, one can achieve greater heights with the timber. Also, a proposed solution to having a “Drop off” area was to put it in the basement, with traffic running through the basement a much more impact stable material would benefit over timber.

Timber as the main material was chosen due to its better embodied carbon value than the other main structural frame materials of steel and reinforced concrete, Table 1. It has a higher embodied energy value per weight but when you factor in the weight of a timber structure Compared to a concrete or steel structure it performs much better. Also timber frame has no thermal bridges.

Timber-concrete composite floors are a relatively new idea derived from a very old one. Using it in commercial settings is rarely done but when using a glulam frame the addition of the concrete makes the section perform better (Natterer, 2002). The system also adds thermal mass.

36

Construction / Insulation

Insulation chosen was cellulose fibre due to several reasons. It’s made from recycled materials, newsprint, it has a good thermal conductivity value, and it is lighter than sheep’s wool (Table 2).

Weight is a big factor when dealing with timber construction. It is always good to keep dead loads to a minimum (McKenzie, 2007).

Table 1: Embodied energy of building materials.

Material Weight kg/m3 Embodied Energy MJ/kg Recycled Steel 8000 9 Reinforced Concrete 2400 1.5 Glulam Timber 550 16.5 Berge. B (2009), “The Ecology of Building Materials”, 2nd Ed. Architectural Press, Oxford UK.

Table 2: Insulation comparisons.

Insulation Type Thermal Conductivity W/mK Bonded EPS Board 0.038 Rock Wool 0.04 Urea Formaldehyde Foam 0.04 Cellulose Fibre 0.035 Sheep’s Wool 0.039 ‘Green Book- Meath VEC, 2009’

Density kg/m3 12 18 10 14.8 19

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38

Electrical

Appendix

39

Artificial Lighting Artificial light consumes a lot of energy but worthwhile savings can be made by sensible use of efficient electric lighting. Simply put, lights should remain off as long as there is sufficient daylight and the lighting should be as efficient as possible to meet the household requirements.

Artificial lighting levels should be kept as low as the activity permits. Generally the more intricate the task, the greater the lighting level required. On this basis rooms where activities are performed, typically require about twice the lighting level of hallways. Studies need even more. Having several independently switched lights in a room allows the appropriate lighting level to be selected to suit the activity.

Use task lighting (e.g. desk or reading lamps) when required for locally high levels of light. A desk located away from a window may need additional artificial lighting while a desk near the window may often have more than sufficient daylight.

40

Artificial Lighting

Filament Bulbs vs. CFLs There are many types of lighting available for use in the home today.

Lighting choices have improved a lot in recent times and now offers us the following alternatives: All light bulbs are now labelled for efficiency in a similar way to kitchen appliance labelling (though generally it is printed directly onto the product packaging) so you can always check how efficient your chosen product is before purchase. The label will also allow you to check on other important lighting information which will help to inform your purchase, including the average rated lamp life. For most people the choice will be between the conventional incandescent and CFLs. And while an individual CFL may be more expensive, they last significantly longer (up to 10 times, or in some cases even more) meaning they actually cost less to purchase in the long run and they use only one fifth of the energy.

What Can You Save?

Replacing 3 x conventional light bulbs with CFLs can save a building saves up to €37 per annum and if every building in Ireland did the same it would save €24m nationally, with CO2 savings of over 115,000 tonnes per year.

In some situations the use of strip fluorescent lighting may be appropriate.

If this is the case then be sure to use the 26mm tubes which are 10-15% more efficient than their 38mm counterparts.

•

•

Compact Fluorescent Lamps (CFLs) use 80% less electricity and last up to 10 times longer than ordinary light-bulbs.

Dirt can reduce lamp efficiency by 20-25%.

Filament Bulbs vs. CFLs

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Electrical Zoning Electrical Zoning is when a building is divided into a number of areas, each with its own individual electrical properties. It works on the same principle as heating zoning.

Different areas of the building are set out because of the similar energy need. This allows for specific electrical properties to be applied to an individual zone. For example the lighting in each zone can be programmed to turn off at an appropriate time, based on its usage.

The benefits of electrical zoning, is that it’s allow for the prevention of energy wastage when an area of a building is no long in use (i.e. at weekends, evenings etc).

The drawback of such intelligent electrics systems is that it requires a modern electric grid in a building and may not be feasible in older structure.

It is advisable to consider such electrical system, if new wiring is going to be installed in any building.

The drawback of such intelligent electrics systems is that it requires a modern electric grid in a building and may not be feasible in older structure.

It is advisable to consider such electrical system, if new wiring is going to be installed in any building.

Electrical Zoning

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Energy Monitor / Smart Metres A home energy monitor provides prompt, convenient feedback on electrical or other energy use. These devices can also display the cost of energy used, and estimates of amount greenhouse gas emissions produced in real time.

Upon getting into the coalition government in 2007, Eamon Ryan, the Green Party Minister for Communications, Energy and Natural Resources, pledged to introduce smart meters for every home in the country within a five year period.

Various studies have shown a reduction in home energy use of 4-15% through use of home energy display. Electricity use may be measure with an inductive clamp placed around the electric main, via the electric meter (either through an optical port, or by sensing the meters actions), by communicating with a smart meter, or by direct connection to the electrical system.

The display portion is remote from the measurement, communicating with the sensor using a cable, power line communications, or using radio.

They provide a possible means to reduce household energy consumption, as these monitors display real-time feedback to the building’s occupants, so they can change their energy using behaviour.

Recently, low-cost energy feedback displays, such as The Energy Detective, Eco-eye, Wattson, Power Watch, or Cent-a-meter, have become available.

Energy Monitor / Smart Metres

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Electrical Appliances Electrical appliances use a lot less electricity than they did 20 years ago. This can be attributed to the fact that manufacturers have made technological developments that meet the demands of an increasingly discerning market who are better informed by energy labelling. But even today there can be substantial differences in energy consumption between different models. Even small reductions in the amount of electricity consumed daily can add up to significant savings over the lifetime of the appliance which could be as long as 10-15 years.

Energy labelling of appliances was first introduced in Ireland in 1995 under EU legislation. The legislation currently covers washers, dryers, combination washer dryers, fridges, freezers, fridge-freezers, dishwashers, ovens and air conditioners as well as lighting.

Appliances are labelled to indicate energy consumption and are rated from A-G, with A being the most efficient.

Energy efficient appliances will save you money on your energy bill and are less harmful to the environment.

Energy labelling of appliances helps you to make a more informed choice when buying an appliance by allowing you to easily compare the energy consumption of different models.

In addition, other performance Electrical Appliances

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information allows you to choose the best appliance for your individual needs.

In some instances, the indicative range on labels has been adjusted or adapted as a result of either legislative or market led interventions. These include: •

On the basis of the significant improvements in efficiency of refrigeration appliances since the introduction of energy labelling, the EU introduced a Minimum Standards Directive so that all such appliances are now only in the A – C range.

•

On foot of a voluntary agreement among the majority of large appliance manufacturers / suppliers in Europe some years back, most washing machines available in retail outlets will fall in the A – D range.

Energy Saving Tips •

Compact Fluorescent Lamps (CFLs) use 80% less electricity and last up to 10 times longer than ordinary light-bulbs.

•

Dimmers allow you to only use what level of lighting you require at any time and so control the amount of energy you use. Dimmers cannot always be used with CFLs so check the product packaging or manufacturers details before use.

•

Movement sensors, time delay switch etc are all available to improve lighting efficiency, but good manual operation of lighting in a building is always vitally important.

•

Always turn off lights when you leave a room.

•

Dirt can reduce lamp efficiency by 20-25%.

•

Configure your computer to “energy saving” mode in which it will automatically change to the state of low consumption when not in use.

•

Switching off the screen can save even more than just letting the screen saver run.

•

Remember you should turn off your computer whenever you are not going to use it for more than an hour. Turning your computer off at night instead of leaving it on will save on average 25% of its annual energy bill.

Energy Saving Tips

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46

Heating

Appendix

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Boilers The majority of modern conventional boilers should achieve efficiencies of a maximum efficiency of 84% regardless of what type of fuels they burn.

Typically, any oil or gas boilers over 15 years old are unlikely to achieve efficiencies greater than 70% Increasing the operational efficiency of your boiler by this amount represents an actual fuel saving of more than 25%. In other words, by replacing an older, low efficiency boiler with a new, high efficiency boiler, you can cut your fuel bills by a quarter.

A building’s heating system should be efficient, not only at full load, but also at lower loads. No matter what type of what you were looking at, whether it is oil, gas or solid fuel boilers, you should ensure that the boiler complies with the EU boiler efficiency directive If you have a natural gas supply then it is likely to be the lowest cost option in terms of both boiler installation cost and running cost. If you don’t have a natural gas supply then the choice is between oil, LPG or pellet boilers. For rural areas or areas that are off the national gas grid, both oil and LPG are viable solutions.

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Boilers

Combination Boilers Combination boilers are capable of providing instant hot water and heating while saving space within a home.

The conventional arrangement in Ireland is to have a normal boiler which heats the radiators via a sealed water circuit. By “sealed” it is meant that the water is contained within the system, going around in a loop between the radiators and the boiler.

To heat the “domestic hot water” (i.e. the water that comes out of the hot taps) the storage cylinder in the hot press has a coil in it through which the “radiator water” flows.

The disadvantage with this arrangement is that if the cylinder does not have hot water in it you have to wait some time for the coil to heat it up.

A ‘combi’ boiler is a boiler which combines both a conventional boiler for radiators and an independent water heater, together in the one unit. This dispenses with the hot water cylinder in the hot press. But better still, it means that hot water is always available instantly and for as long as you need it.

Combination Boilers

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Condensing Boilers Where possible, you should consider installing the highest efficiency boiler possible. Condensing boilers have a much higher efficiency than noncondensing boilers; however there are some rare situations where installing one may not always be feasible.

Condensing boilers burns gas or oil at approximately 92% or higher efficiency.

These boilers are more costly to buy than conventional boilers but the price difference will be recovered over 10–15 years due to reduced annual running costs.

Condensing boilers are highly efficient.

They use less fuel and have lower running costs than other boilers.

Higher efficiency levels are made possible by extracting heat contained in the combustion gases, which would otherwise have been lost to the atmosphere.

These boilers, which operate at maximum efficiency when running at lower temperatures, are ideal for under floor heating systems. For radiator systems operated at lower temperatures the radiators may need to be oversized to provide the required heat output. A condensing boiler will emit a plume of water vapour to the atmosphere during operation, this is normal and harmless.

This is because both oil and gas contain hydrogen locked within chemical structure called hydrocarbons. When oil or gas is burned, the hydrogen breaks its links with the carbon atoms and instead links with oxygen in the air to form H2O (water). This water (as vapour) can be seen from the exhausts of cars on cold days. The vapour (or steam) contains about 8% of the total fuel’s energy and capturing it makes energy efficiency sense. This is exactly what condensing boilers do. They “condense” the vapour and capture the energy contained there, making modern boilers so much more efficient.

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Condensing Boilers

Fuel Types Table 1: CO2 Emissions and Cost/Unit of common Fuel Types Material Natural Gas Oil Solid Fuel* Electricity

CO2 Emissions g/kWh 227.2 290.3 389.1 896.9

(Solid Fuel = Wood Pellets*, Timber* and Peat Blocks)

Energy Costs £/kWh 0.0185 0.0769 0.0176 0.0769

* Wood Pellets are a ‘Carbon Neutral’ fuel as is timber if it comes from a sustained forest. ‘Carbon Neutral’ means all the CO2 that is given off while the pellets are being burn is offset by the CO2 absorbed by the plant as it grown. The two amounts are equal so no extra CO2 enters the atmosphere.

Solid Fuel Turf Wood Coal Oil Kerosene Gas oil Gas Natural gas LPG Electricity Day rate electricity Off-peak supply Sustainable Fuels Solar energy Wood* Wind energy * Wood fuel from managed forests

Costs The annual running costs of a heating system depend largely on the cost of the useful energy of a fuel taking account of the efficiency of the heat generator employed. The associated table for the energy costs for each fuel and at the associated efficiency at which they are used.

Environmental Issues All fossil fuels when burnt will cause emissions to the atmosphere. All these fuels will emit CO2, the main greenhouse gas which is contributing to global warming. In addition to carbon dioxide and water vapour, some fuels will also emit smoke particles, sulphur dioxide and oxides of nitrogen to the air which will reduce our air quality.

Considerations for Fuel Choice Availability Check with local fuel suppliers for convenience of supplying a particular fuel.

Storage Some fuels, i.e. solid fuel, oil, LPG, etc will require you to provide space to store the fuel. This may be bulky or unsightly or may have safety or insurance implications.

Fuel Types

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Heat Pumps Heat is widely available in the ground, air and water around your house. These natural sources of heat are constantly replenished by the sun, wind and rain.

A heat pump system will harness these free and renewable energy sources for heating your house and supplying hot water at a very low cost. The role of the heat pump is to ‘pump up’ heat from a low temperature source, for example the ground under your lawn and release it at a higher temperature into your central heating system.

There are three main types of heat pump available on the market, those that take heat from the ground, from water (rivers or wells) or directly from the air. Ground source heat pumps come in two varieties – vertical bore or horizontal loop.

Heat pumps are very economical, for every unit of electricity used to power the heat pump, 3 to 4 units of heat are generated. They work best in conjunction with low temperature heat distribution systems e.g. underfloor heating. Because they require electricity to run, they are most cost effective when they can use night rate electricity. This requires a night rate meter. A buffer store is required to maximise efficiency as this allows the heat pump to store heat on a constant basis, releasing it as and when required.

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Heat Pumps

Air-Source Heat Pump Air/Air heat pumps take the energy from the air and transfer it to a warm air heating system and Air/Water heat pumps take the energy from the air and transfer it to the heating system Water–Source Heat Pump Water source heat pumps work in a similar fashion to ground source systems and transfer the heat from your water source to the house. Water source heat pumps use an open loop collector. Underground water sources such as a well circulate the water through pipe-work that in turn transfers heat to your house.

Ground Source Heat Pumps Ground Source Heat Pumps are a system that extracts heat from the ground, upgrades it to a higher temperature and releases it where required for space and water heating.

The GSHP function can also be reversed for cooling purposes.

Pros: • Highly efficient renewable heating and cooling system • Carbon savings of 30-35% (more if the pump is powered by renewable electricity) • Life expectancy of 40+ years.

Space Heating Because GSHPs raise the temperature to around 40° they are most suitable for under-floor heating systems or lowtemperature radiators, which require temperatures of between 30° and 35°.

Higher outputs, such as to conventional radiators requiring higher temperatures of around 60° to 80° can be obtained through use of the GSHP in combination with a conventional boiler or immersion heater.

A GSHP can be a highly efficient form of space heater, particularly where deployed in conjunction with a low energy heating system such as underfloor heating. For each kW of electricity used to run the heat pump some 3-4 kW of heat are typically produced.

Water Heating The GSHP system is inadequate in itself for directly heating hot water output. Hot water for taps needs to be stored at 60° whereas for domestic GSHPs the maximum water storage temperature obtainable is 50°. A water heating strategy can be designed where the incoming water supply is preheated by the GSHP before reaching an ancillary heating source.

However, it might be determined that an immersion heater working off offpeak electricity is more economical.

Ground Source Heat Pumps

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Heat Recovery Systems A Heat Recovery System (also known as a heat exchanger, air exchanger or air-to-air exchanger) is a ventilation system that employs a counter-flow heat exchanger between the inbound and outbound air flow. HRS provides fresh air and improved climate control, while also saving energy by reducing the heating (or cooling) requirements by exchanging the heat from the outgoing exhaust air flow to the incoming intake air stream.

Heat Recovery Systems (HRS’s), as the name implies, recover the heat energy in the exhaust air, and transfer it to fresh air as it enters the building.

HRS’s can be stand-alone devices that operate independently, or they can be built-in, or added to existing HVAC systems. For efficiency, HRS’s are designed to maximize the surface area of the wall between the two air flows, while minimizing resistance to the flows through the unit. The HRS’s performance can also be affected by the addition of fins or corrugations in one or both directions, which increase surface area but they may channel the air flows or induce turbulence into them (which may have negative effects).

Recovery Units for example have a Heat Recovery Efficiency (HRE) of up to 95%.

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Heat Recovery Systems

Heating Zoning This is a feature of modern central heating systems. From a central control system, it is capable of specify the heating condition in different rooms or area of the building.

This is a common feature in many modern heating systems. Different areas of the building are set out because of the similar heating requirements. This allows for specific temperatures and on/off times to be applied to an individual rooms and zone. For example the heating conditions a hallway are very different to that in a classroom.

The benefits of heating zoning, also allow for the heating in different areas of the building to be turn on and off at separate time than the rest of the structure. For example, a sport hall will have to have its heaters turned on long before that in the changing rooms.

Unfortunately of such intelligent heating system may not be feasible in older structure and heating systems.

It is advisable to consider such a system, when installing a new heating system in any building.

Heating Zoning

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56

Technology

Appendix

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Rainwater Harvesting Introduction Rainwater Harvesting is systems which collect run-off water from rooftops, (although inside half systems are also available). This run-off water is filtered, and then use again in appliances that don’t need purified water i.e., toilets, irrigation also baths and showers if the water is treated.

How It Works Rainwater is collected from a roof drainage system, and then passed through underground filters before heading to water storage tank.

The filters remove debris from the water and will divert about 90% of it into the storage tank. The remaining water goes to soak-away pits or storm drains in the usual manner as those to exercise alone from storage tank.

This water is then supplied on demand by pumps, through specific outlets, usually to WCs or washing plants.

These pumps are controlled by dedicated control units, which turned pumps on and off as required, thus reducing their energy consumption.

These systems are automatically topped up by mains water to prevent damage in times of drought.

Such a system could provide an estimated 30% reduction in water use for the average household.

Rainwater Harvesting 58

Payback and Maintenance Payback depends on how much a building pays in water charges; however it does count towards lowering buildings BER rating. The maintenance of this is some not is above that of maintaining a septic tank or existing roof drainage systems (down water pipes, gutters).

Greywater Recycling Introduction Greywater accounts for 50-80% of all residential wastewater. Greywater comprises of wastewater generated from all of the house’s sanitation equipment except for the septic tank (water from toilets is blackwater, or sewage).

This system requires two separate plumbing systems. The first being a greywater plumbing system, which collects wastewater from a buildings sinks, baths and laundry areas. The second collects all waste from the building’s toilets and delivers it to the septic tank or search mains.

methods to do this, namely, chemical methods or using a UV light to destroy contaminants.

Payback and Maintenance Payback and maintenance is the same as ‘Rainwater Harvesting’.

How It Works Greywater recycling systems operate on the same principles as rainwater harvesting. The only significant difference between the two is that the water harvested no longer comes from the roof but is instead harvested from an internal wastewater system which is separate from the sewage plumbing.

This system could provide similar results as Rainwater Harvesting, at 30% reduction in water usage. However, greywater systems have a higher potential risk of their water supply being contaminated by biological agents, i.e. washing detergents, soap and order chemical agents.

Grey water systems, usually contain treatment plans to remove these contaminants. There are a number of Greywater Recycling

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Hydro Power Generator Introduction Hydro power has produced mechanical energy for hundreds of years but was first used to produce electricity in the 1870’s. Most Irish installations are run of river installations. As such, hydro installations in this country are generally dependent upon precipitation and have little impact on their surrounding environment.

Hydro electricity has the greatest energy yield factor of the renewable technologies meaning the energy it produces in its lifetime greatly exceeds the amount of energy used in its manufacture, operation and eventual disposal. This is due to the reliability and long lifespan of a hydro system.

For example, a modest 20kW scheme would save 70 tonnes of CO2 being released into the atmosphere each year from fossil fuelled power stations.

How it Works The power generation from a hydro scheme is dependent upon two variables, the height the water falls, (head) and the volume of water available, (flow). Water is diverted from a given point on a river, ideally near a weir and piped through to a turbine house downstream, where the water falls through a turbine and drives a generator. The water passes through the turbine and returns to the river unpolluted. Various measures are taken to ensure fish are not directed Hydro Power Generator 60

into the channel, which feeds the turbine. These can include mesh screening and electric currents in the water to deter fish from entering. If a hydro scheme is proposed on a fish migratory route, a ‘fish pass’ is built which is designed to guide fish away from the turbine house and up a series of basin-like steps.

Installation The feasibility of a hydro scheme will depend very much upon the proposed site, as much capital is often spent on civil engineering work such as the weir, water channel and fish pass. A site such as a disused millrace may have an existing weir or water channel and this will reduce the capital per kilowatt outlay.

Communication with downstream water users is essential to unite support. Fisheries and anglers who use the river can be strong opponents and will seek assurances that their livelihoods or leisure activities will not be harmed.

Your local planning authority should be consulted at an early stage and planning permission must be sought for any hydro installation.

Wind Turbines Introduction Wind is an abundant source of energy, especially in Ireland. Largescale wind turbines are now installed around the country and off shore to provide for Ireland’s electricity needs and supplying ‘green’ electricity to consumers from the utility grid.

How it Works For residential sites that have connection to the electricity grid, the cost effectiveness of installing a wind turbine should be carefully examined.

In this situation, the annual electricity demand, wind resource and daily demand profile must be considered. If you wish to purchase electricity from a wind turbine, you may be able to sign up to a ‘green electricity’ supply tariff.

output if placed at a higher level.

Payback and Maintenance Wind turbines have a number of moving parts so annual maintenance is required and your installer can provide this. The payback period of a wind turbine is dependent on utilisation of the electricity generated, which should be off set against that taken from the grid. Payback is therefore highly variable, but could be as short as 15 years.

Small-scale wind turbines range in size from less than 1kW to 50kW. They can be cost effective in off-grid applications and wind power can be more economic than other renewable options.

Energy storage in batteries is necessary in off-grid applications. Large-scale turbines up to 3MW in size, usually installed on wind farms, are generally connected to the grid.

Installation Wind speed and direction will determine the most suitable position for a wind turbine. Wind speed increases with height, so turbines will give a greater Wind Turbines

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Photovoltaic Panels Introduction Photovoltaic (PV), which also collect sunlight, are a very different technology to solar water heating, as they use the light to generate electricity.

Today, the industry’s production of photovoltaic (PV) modules is growing at approximately 25% annually, and major programs in the U.S.A., Japan and Europe are rapidly accelerating the implementation of PV systems on buildings and connection to electricity grid networks.

Stand-Alone Systems Stand-alone systems produce power independently of the electricity grid network.

In some off-the-grid locations, standalone photovoltaic systems can be more cost- effective than extending existing power lines. Direct-coupled systems need no electrical storage because they operate only during daylight hours, but most systems rely on battery storage so that energy produced during the day can be used at night. Some systems, called hybrid systems, combine solar power with additional power sources such as wind or diesel generators. As well as domestic applications, stand-alone systems can be used to power traffic warnings, parking meters, emergency telephones and buildings in remote locations.

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Photovoltaic Panels

Grid-Connected Systems Grid-connected photovoltaic systems, supply surplus power back onto the grid and electricity is drawn from the grid at periods when demand in the home exceeds the PV output. Grid-connected systems are generally integrated into the structure of buildings, but can also be ground mounted. These systems remove the need for battery storage.

In some cases, utility companies allow additional metering*, which allows the owner to sell excess power back to the utility company.

Solar Thermal Heating Introduction Active solar energy systems generally incorporate a roof mounted solar collector, which receives direct and indirect sunlight and changes it into heat. This heat may be used to provide for hot water, or in a combined system, for space and hot water needs. At the end of 2003, approx. 12 million m2 of solar thermal collectors were installed in the EU. There is great potential to increase this further.

necessary. Most systems are run by an electricity-powered pump, which will cost a small amount to run per year.

Generally systems come with a 10 year warranty and their lifetime is about 25 years. For a list of suppliers, contact us (see back of booklet for details).

How it Works Solar collectors can provide 50% of the annual hot water demand of a typical home, depending on the orientation, size, mounted angle and efficiency of the collector. The most common application is for water heating, and 4m2 of solar collector can provide about 80% of hot water needs in summer and 20% in winter (when there is less solar heat available) for a typical family. The solar water system needs to be backed up with a conventional heat source to provide the remainder of the hot water needs such as an electric immersion in the storage cylinder.

Payback and Maintenance The payback period of a solar water heating system will vary depending on the cost of the fuel you are replacing and the amount of hot water you consume.

A typical correctly installed system has a payback period of between 7 and 15 years and little maintenance is Solar Thermal Heating

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Biomass Introduction The main types of Biomass are chips and pellets. Wood chips are a bulk fuel and, as such, are generally unsuitable for domestic properties. However, they are usually a cheaper fuel than pellets and are appropriate for larger buildings such as offices, public buildings or to heat clusters of domestic properties through a district heating system.

Wood pellets are compressed wood, usually sawdust or wood shavings.

They are typically 6-12 mm in diameter and 6-20 mm in length. Pellets have the advantage of uniformity in shape and composition, are easy to ignite, and are dry, create little ash and will flow freely through feeding mechanisms such as hoppers and augers. These properties make pellets ideal for automatic appliances.

range of styles, from traditional-looking wood-burning stoves to modern, minimalist designs. Good quality appliances use modern controls to ensure an efficient, clean burning fire.

Because they use thermostatic controls and fans to distribute warm air around the room they are safer than traditional stoves, which rely on radiated heat to warm the room, making the room’s temperature uneven and the body of the stove dangerously hot.

Wood fuel can be used to create both electricity and heat and is a well established renewable energy source in many countries, including the USA, Sweden, Austria and Denmark. It has a great potential for use in the country, particularly for heating.

Unlike many renewable energy technologies, with biomass you still need to buy fuel. Wood chip boilers are usually cheaper to run than oil or mains gas. Pellet prices vary, but are generally comparable with oil and mains gas. Pellets are usually available in bags or are delivered loose in bulk.

How it Works Pellets are highly suitable for houses and can be burned in either a boiler or a stove. Pellet boilers provide full central heating and hot water, with a convenience normally associated with oil or gas. Stoves provide heating for a single room. Stoves are available in a Biomass 64

Payback and Maintenance Maintenance is similar to that of conventional stoves and boilers. The ash pans of both stoves and boilers will require emptying, typically once per month for stoves and once every three months for boilers.

Ground Source Heat Pump Introduction Ground source heat pumps, also known as geothermal heat pumps, are used for space heating and cooling, as well as water heating. They operate on the fact that the earth beneath the surface remains at a constant temperature throughout the year, and that the ground acts as a heat source in winter and a heat sink in summer.

How it Works The earth’s surface acts as a huge solar collector, absorbing radiation from the sun.

In this country the ground maintains a constant temperature between 11°C and 13°C, several metres below the surface. Ground source heat pumps take advantage of this by transferring the heat stored in the earth or in ground water to buildings in winter and the opposite in summer for cooling.

Through compression, heat pumps can ‘pump up’ heat at low temperature and release it at a higher temperature so that it may be used again. A heat pump looks similar and can perform the same functions as a conventional gas or oil boiler, i.e. space heating and sanitary hot water production. For every unit of electricity used to operate the heat pump, up to four units of heat are generated. Therefore for every unit of electricity used to pump the heat, 3-4 units of heat are produced.

Payback and Maintenance The initial capital costs of installing a ground source heat pump system is usually higher than other conventional central heating systems. A large proportion of the outlay will be for the purchase and installation of the ground collector. However, the system is among the most energy efficient and cost effective heating and cooling systems available. Typically, four units of heat are generated for every unit of electricity used by the heat pump to deliver it, and the payback is typically about 8-10 years. The life expectancy of the system is around 20 years. Once installed a heat pump requires very little maintenance and anyone installing a heat pump should speak with their installer regarding a maintenance agreement.

Ground Source Heat Pump

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References Text Berge, B. (2009), “The Ecology of Building Materials”, 2nd Edition. Architectural Press, Oxford Uk Blennerhassett , Edith (2010) Lighting notes. MSc Sustainable Design McKenzie, W. M. C, and Zhang, Binsheng. (2007), “Design of Structural Timber to Eurocode 5”, Palgrave McMillon, NY Natterer, J.K. (2002) ), “New Technologies for Engineering Timber Structures”, Prog. Structural Engineering Material, v4:245-263 Hughes, N, ‘Green Book’, (2009), Meath VEC, Ireland J.R.Smith MFG. Co. (2010), Green Roof and Cool Roof Drains, Division of Smith Industries, Montgomery, Alabama, USA. May 2010.

ROCA (2010), Roca User Manual, Avda, Barcelona Spain. November 2010.

DfES (2006), Schools for the Future, Design of Sustainable Schools: Case Studies, Department for Education and Skills, CABE (2004), Case Study: Kingsmead Primary School, Commission for Architecture and the Built Environment, 1 Kemble Street, London WC2B 4AN, 2004.

CABE (2006), Case Study: Academy of St. Francis of Assisi, Commission for Architecture and the Built Environment, 1 Kemble Street, London WC2B 4AN, 2006.

White Design (2004), Case Study: Kingsmead Primary School, White Design Associates Limited, Sevier Street, Bristol, 2004 Pictures Photo of opaque and clear glass façade. Wiel Arets Architects. www.wielaretsarchitects.nl Intake Vent. IAC Building Services. www.Industrialacoustics.com/uk/building_services/duct_silence.asp Light Well, Notes from Blennerhassett , Edith (2010) Lighting notes. MSc Sustainable Design

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References

References

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