The Housing A to Z of G to A
Energy Performance Certification of Dutch Housing FACULTY OF ARCHITECTURE
Technical University of Delft april 2008
SMART & BIOCLIMATIC DESIGN Elective course within the Masters Program (code: AR0530)
by:
ALBERT RICHTERS
(1169513) 4th year architecture student at TUDelft
Contact
E-mail: alberttrichters@hotmail.com Skype: alberttrichters
TUTORS
dr.ir. Andy van den Dobbelsteen Specialist in climatology & Sustainability
Ing. Ann Karina Lassen
Specialist in climatology & Sustainability
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INTRODUCTION 1 LEGISLATION
1.1 Europe 1.1.1 Minimum EP- requirements 1.1.2 Certification procedures 1.1.3 Inspection of boilers and air conditioning systems 1.2 EPBD in the Netherlands 1.2.1 calculation procedures 1.2.2 Informing the public
2 THE ENERGY LABEL
2.1 Energy Index 2.2 Class arrangement on the certificate 2.3 Reporting the Energy Perfomance Certificate 2.3.1 EP-database 2.3.2 Information flow of EP-data 2.4 A brief look abroad
3 EI DETERMINATION
3.1 Standard conditions 3.1.1 Standard weather conditions 3.1.2 Standard values for user behavior 3.2 Standard energy saving measures 3.3 Physical and technical constituents of the EI 3.3.1 General data 3.3.2 Architecture 3.3.3 Construction 3.3.4 Appliances
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24 25 26 26 28 29 33
3.4 EI determination (EI-software) 3.4.1 Size and shape 3.4.2 Types 3.4.3 Façade openings and orientation 3.4.4 Special spaces 3.4.5 Age and improvements
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4 SOLUTIONS TO A HIGHER EI
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AUTHOR’S NOTES REFERENCES
80 81
36 37 41 45
58 4.1 Insulation 58 4.1.1 Advantages and disadvantages 59 4.1.2 Costs and savings 60 4.2 Glazing 60 4.1.1 Advantages 61 4.1.2 Costs and savings 63 4.3 Central heating 63 4.3.1 Costs and savings 64 4.4 Heat pumps and heat pump boilers 64 4.4.1 What is it? 65 4.4.2 Points of importance 66 4.4.3 Heat pump boiler 4.4.4 Combination heat pumps 67 69 4.4.5 Collective heat pump systems 71 4.5 Solar heating systems 71 4.4.1 What is it? 71 4.4.2 Points of importance 72 4.5.3 Systems 74 4.5.4 Supporting techniques 76 4.6 Ventilation & Air quality 76 4.6.1 Saving energy 77 4.6.2 Balanced ventilation with heat recovery 78 4.6.3 Ventilation on demand
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Campaign image of Ministry of Housing Spacial Planning and Environmet (VROM)
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INTRODUCTION
On the fourth of January 2003 the “Energy Performance of Buildings (EPDB)” directive was adopted, with the overwhelming support from Member States of the European Parliament. The EPDB is now considered to be a very important legislative component of energy efficiency activities of the European Union designed to meet the Kyoto commitment* and respond to issues in the “Green Paper”** on security of energy supply. The EPDB forms an outline in which member states of the EU develop their own specific legislation and measures to monitor and improve their own energy consumption. As other member states, the Netherlands has been concerned about the issue of energy use and since the late 90’s has already been implementing measures to build energy efficient buildings. But the EPDB has also stimulated the research and improvements that have to be made in the field of older existing buildings. This finally led to the certification of existing buildings concerning their energy consumption. Since the 1st of January of 2008 a house with an age older than ten years which is put on the market must be certified with a so called Energy Label. This system is similar to * **
the way appliances like washing machines, refrigerators and cars are certified. Next to the legislative side of the Energy Label this manual will mainly focus on the criteria upon which a house is certified. How is the certification set up? Once these criteria have been discussed, it is possible to look at how the house size, age, and orientation can influence the outcome of the label. Also the location of the house within a housing block can influence the outcome. This will be done by the use of special software that normally is used by experts or inspectors who hand out the label. By specifying certain standards of housing in the software, conclusions can be made based on the input in combination with outcome. After looking at the label outcome, measures to improve this outcome will be researched. Which measures to improve the energy effectiveness of a house have the greatest effect on the outcome and what are the costs concerning certain methods?
Kyoto commitment: http://en.wikipedia.org/wiki/Kyoto _ Protocol Green Paper: http://ec.europa.eu/energy/green-paper-energy/index _ en.htm
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1 LEGISLATION
1.1 EUROPE After adopting the Performance of Buildings Directive (EPBD)in 2003 an EC Action Plan for Energy Efficiency has been set up in 2006. This action plan identifies energy efficiency in the building sector as a top priority giving a key role for the EPDB which specializes in this sector. By improving energy consumption in this sector a reduction of 28% is estimated in turn reducing the total EU energy use to around 11%. To improve the energy performance of buildings the EPBD states requirements to be implemented by the Member States. These reguirements are arranged into five main themes: 1 Minimum EP-requirements 2 Certification procedures 3 Inspection of boilers and air conditioning systems 4 Requirements for experts and inspectors 5 Calculation Procedures On the 4th of January 2006 the 25 Member States had to transpose the EPBD into national law. Due to a lack of qualified experts and inspectors the certification and inspection procedures haven’t been
transposed into law yet by all 25 Member States. For housing this has been done in the Netherlands on the 1st of January 2008. Certification of other housing corporations and other sorts of buildings will follow quickly. The EPBD is a measure that concerns a large number of parties. From tenants and owners to designers, architects and providers of building appliances. Throughout all these levels the EPBD will greatly affect awareness of energy use of buildings. It should tackle the great challenge of pushing the European building sector towards energy efficiency and the use of renewable energy resources. 1.1.1 Minimum EP-requirements (articles 4,5 & 6 of EPBD) The minimum energy performance (EP) requirements can differ throughout the Member States. There may be a distinction between the requirements for the new buildings and that of existing buildings and other categories. The setting of the EP-requirements is based on certain strategies. They should take into account themes like: indoor climate conditions, building types and the exemption of certain types from these requirements and requirements
The EPBD Buildings Platform (EU-initiative): http://www.buildingsplatform.eu The EPBD directive: http://www.buildingsplatform.eu/cms/index.php?id=13
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for major renovations. Furthermore these requirements should be comparable to measured and/or calculated data and benchmarks. This makes it possible to to set up a rating such as the energy label. The guidelines for the minimum EP-requirements are stated in articles 4, 5 and 6 of the EPBD. Articles 5 and 6 respectively state guidelines for new and existing buildings. 1.1.2 Certification procedures (article 7 of EPBD) Certification of buildings happens not only for newly built buildings but also for the existing buildings. First of all it is a method to collect data about the energy performance of buildings. To do this properly, the quality of the certificate must be monitored as well. So the certification procedures also comprise the assurance of the quality of tools handled for the certification. They also focus on the public acceptance by informing about costs, benefits and energy saving recommendations. The “Energy Performance Certificate” also is described in article 7 of the directive.
1.1.3 Inspection of boilers and air conditioning systems (articles 8 & 9 of EPBD) In its “considerations”, the EPBD states that “regular maintenance of boilers and of air-conditioning systems by qualified personnel contributes to maintaining their correct adjustment in accordance with the product specification and in that way will ensure optimal performance from an environmental, safety and energy point of view”. It also asserts that “an independent assessment of the total heating installation is appropriate whenever replacement could be considered on the basis of cost-effectiveness”. The EPBD states that inspection should not only happen with regard to energy consumption, but also with regard to the reduction of CO2 emissions. Inspections and assessment of systems should be the base for appropriate advice on improvement or replacements of heating and cooling systems. Article 8 deals with boilers and article 9 deals with air conditioning.
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1.1.4 Requirements for experts and inspectors (article 10 of EPBD) Article 10: “Member States shall ensure that the certification of buildings, the drafting of the accompanying recommendations and the inspection of boilers and air-conditioning systems are carried out in an independent manner by qualified and/or accredited experts, whether operating as sole traders or employed by public or private enterprise bodies.� This article deals with quality assurance, criteria for accreditation, code of practice, insurance and liability.
It includes assessment of: -EN (CEN) and EN ISO* standards (under mandate nr. 343) -implementation of these standards at national level -quality assurance of calculation methods -distinction between calculation methods for new buildings and for old buildings. -legal aspects -simplicity and practicability (but with accuracy) -methodology for innovative technologies *ISO (=International Standardization Organization). As CEN is for Europe, the ISO is an globally aimed organization.
1.1.5 Calculation procedures Calculation procedures for the EP are specified in article 3 of the EPBD. The EPDB gives general guidelines for calculation procedures. For more precise calculations a mandate (nr. 343) has been given to the CEN(=European Committee for Standardization ; French abbreviation) which takes the responsibility to develop appropriate calculation methods. In doing this it also supports the individual Member States in the national application of article 3. Papers on standardization by CEN: http://www.buildingsplatform.eu/cms/index.php?id=181#c733 European Commitee for Standardization: http://www.cen.eu
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Performance of Buildings’ (in Dutch: ‘Regeling energieprestatie gebouwen’ REG) The BEG deals with the law and REG is concerned with the implementation of the specifications stated in the BEG.
1.2 EPBD in the Netherlands As mentioned in the text earlier Member States of the European Union were obliged to transpose EPBD requirements into national law in 2006. Of course, so was the case in the Netherlands. Ongoing developments finally led to the implementation of the ‘Decree Energy Performance of Buildings’(in Dutch: ‘Besluit energiepresatatie gebouwen’ BEG) and the ‘Regulation of Energy
The implementation of the EPBD in Netherlands falls under the responsibility of the Ministry of Housing, Spacial Planning and Environment (in Dutch abbreviated as: VROM). At this moment Netherland already complies with a large amount of requirements stated by the EPBD. But, as other Member States, the Netherlands was unable to meet the requirements for the certification and inspection of buildings before the original deadline of January 2006 given by the European Government. Since this deadline has been postponed to January 2009 the Netherlands is implementing certification and inspection requirements step by step. Thus, since the 1st of January 2008, it is now obligatory to have an energy label for housing. This step will be followed one year later by housing companies which will certify their whole building stock in the coming year. Also public buildings will be permanently certified starting January the 1st 2009.
For EU country reports on EPBD check: http://www.buildingsplatform.eu/cms/index.php?id=178 Dutch country reports on EPBD: http://www.buildingsplatform.eu/cms/index.php?id=118&publication _ id=2904 Also check ISSO-publication 82.1
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Like the European Union, the Dutch government actively implements policy to minimize the administrative costs of the Dutch citizen. Therefore, costs for the certification of buildings are kept to a minimum. 1.2.1 Calculation procedures Concerning Article 3 of the EPDB (the Adoption of a Calculation Methodology) the Netherlands meets the requirements. For new buildings this is made possible through of the Energy Performance Standard (Dutch abbreviation: EPN): new buildings should comply with these standards. For the existing building stock a similar calculation procedure is used called the Energy Performance Advice (EPA): based on certain benchmarks and requirements advice is given to improve the performance of existing buildings. Through the EPN the Netherlands also complies with the requirements stated in article 4 (Minimum EPrequirements). These requirements also apply for major renovations (area >/=1000m2). 1.2.1a Certification of new buildings An important method to monitor the energy performance of new buildings and major renovations
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is the calculation of the Energy Performance Coefficient (EPC). A lower the EPC-value means a better performance. This method has been in use since 1995. Throughout the past decade the requirements for a certain EPC-value have changed in accordance with new (technical) developments leading to a sharper EPC-requirement. At this moment the EPC-value of new buildings may not exceed 0,8. 1.2.1b Certification of existing buildings For existing buildings a similar method is maintained. Using a value called the Energy Index. The EI-value is based on requirements for thermal insulation and ventilation. The certification of existing buildings is based on the EI-value which leads to a certain grade in the Energy Label. As mentioned earlier guidelines for building certification are stated in the ‘Decree Energy Performance of Buildings’(BEG) which are implemented through the ‘Regulation of Energy Performance of Buildings’ (REG).
Mandatory certification apartment blocks offices schools hospitals hotels & restaurants sport complexes retail- & wholesale-trade buildings
No mandatory certification monuments religious buildings free standing buildins <50m2 caravan/trailer lodging buildings (e.g. hikers hut) industrial buildings
Table 1.1: building types
An EP-certificate is strictly related to the part or section of a building which is put on the market to be let or sold. In the case that a part of the building is supplied by a central heating system of the whole building the certificate of the whole building suffices. The certificate is valid for a maximum of 10 years. The BEG and REG state that a certificate may only be handed out by a licensed inspector. Often advisors and inspectors work through a company which specializes in handing out the certificate. The company must be accredited and licensed.
To maintain the quality of inspections inspectors should work according to specific building directives set up by the so called KBI: institute for the quality control of the installation sector for buildings. The building directive ‘BRL9500’ specifies the requirements to be met by inspectors, and inspecting companies. Also the inspection process and methods have to meet requirements stated in this directive. A second directive, ‘BRL9501’, specifies requirements for EP-calculation: e.g. which tests should be done and reference values for testing.
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The ISSO-institute specializes in informing specialists and public on developments in appliances and installations for buildings. The institute publishes guides (â&#x20AC;&#x2DC;ISSO-82â&#x20AC;&#x2122; for housing) that specify procedures to be followed by inspectors on how to certify buildings. The following diagram (figure 1.1) clarifies the relations mentioned above. government: law & regulation
BEG
Buildings built after 1997 do not need a certificate based on the Energy Index. Since these buildings were built after the introduction of the EPC-calculation method. In this case an official copy of the EPC-calculation will suffice if the building is not older than 10 years of age.
KBI requirements & qualitycontrol
BRL 9500
ISSO 75
utility buildings
ISSO 82 housing
REG BRL 9501
Fig. 1.1: relations involved in EP- certifictation
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ISSO resources
ISSO 54
The total certification structure is shown in this diagram (figure 1.2):
RvA
KBI licence agreement
CCvDI
accreditation
Certification
institution
BRL-9500
Certificate administrator (EPA-advisor)
inspectors
inspectors
certificate
inspectors
inspectors inspectors
Fig. 1.2: total certification structure
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1.2.1c Explanation of figure 1.2 The certification administrator is the link between the legislation an the clients. On one hand, the administrator should comply with the requirements stated in BRL9500 and on the other hand it gives information and security to the client. The CCvDI (Dutch abreviation for a central board of experts in the installation sector) represents a number of parties representing different sectors of the market: clients buying the certificate, suppliers handing out certificates and experts (e.g. with technical know-how). The board deals with: -keeping certification requiremenst up-to-date -defining the amount of checkups of certifying institutes -defining the qualification of certificatying personel -informing clients on new developments The CCvDI is responsible for the BRL 9500. A certifying institute must have a license to make use of the BRL 9500. RvA (abreviation for Accreditation Counsel). The counsel secures and monitors the quality of the certifying institution.
1.2.2 Informing the public The public is generally informed through campaigns set up by the Ministry of Housing, Spatial Planning and Environment (VROM). Since the end of 2007 there is an emphasis in informing the public on the certification of their house with the Energy Label. This mainly happens through papers, television and radio ads. For more in-depth and technical information about the implementation of the EPBD and certification of buildings SenterNovem plays an important role. SenterNovem is an agency of the Dutch Ministry of Economic Affairs (Dutch abbreviation: EZ). It promotes sustainable development and innovation, both within the Netherlands and abroad. SenterNovemâ&#x20AC;&#x2122;s core business consists of implementing the Dutch governmentâ&#x20AC;&#x2122;s policy concerning sustainable development. With its experience and expertise the agency is capable to inform on these themes. VROM, EZ and SenterNovem are large constituents of the ISSOinstitute. As mentioned before, the institute specializes in informing specialists and public on developments in appliances and installations for buildings.
VROM website on Energy Label: http://www.vrom.nl/pagina.html?id=31994 SenterNovem English site on EPBD: http://www.senternovem.nl/impact/index.asp SenterNovem site on the Energy Label: http://www.senternovem.nl/energielabelgebouwen/index.asp ISSO: http://www.isso.nl/ KBI: http://www.kbi.nl/
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2 THE ENERGY LABEL
The Energy Label is officially known as the Energy Performance Certificate. The outlook of the certificate is very similar to that of energy labels for white goods (e.g. refrigerators or washing machines), light bulbs and cars. The energy efficiency is rated in terms of energy efficiency classes A to G. With A being the best rating and G the worst. Each product type has its own value upon which a class is based. For white goods, for example, this is kWh (per cycle) and for motor vehicles the performance is based on carbon dioxide emissions. For homes the rating is based on the so called ‘energy index’ (EI).
2.1 Energy Index A lower EI, means a better performance. To determine the EIvalue standard circumstances are used. This makes it possible to compare different houses with each other. Since the label is made to inform people that are purchasing a house, this is very important. Standard circumstances are standard weather and user behavior. This will be discussed in chapter 3. The formula: EI=Qtot/(155*Ag+106*Aloss+9560) Qtot=total energy consumtion of the house under standard circumstances (MJ) Ag=user area (m2) Aloss=sum of areas of elements dividing the exterior from the interior in regard to the amount of expected heat loss through transmission. (m2) In ISSO-publication 82.3 ‘formula structure for the EP of houses’. Formulas used to calculate the total energy use and are explained in detail.
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2.2 CLASS ARRANGEMENT ON THE CERTIFICATE Class A++ A+ A B C D E F G
Energy-index limits </=0,5 0,51-0,7 0,71-1,05 1,06-1,30 1,31-1,60 1,61-2,00 2,01-2,40 2,41-2,90 >2,90
A
B
Table. 2.1: EI-limits
D
2.2.1a The label A: classification of the testcase B: the different classes and the values they represent C: Energy Index D: -Address and city -date of inspection -date that validity of certificate expires (10 years after inspection) E: EPBD control mark F: Advising company data
E
F Fig. 2.2: example of the Energy Label
On the backside of the label the inspector should precisely specify which software has been used to determine the energy index and the final classification. Also a list of feasible solutions is given to improve the energy performance of the house.
For certified advisors on the Energy Label check: http://www.vrom.nl/pagina.html?id=34304
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C
2.3 REPORTING THE ENERGIE PERFORMANCE CERTIFICATE As mentioned in chapter 1, the EPBD is legally stated in the REG (regulation of energy performance) (figure 1.1) coordinated by the VROM ministry (housing, special planning, environment). Article 3 of the REG stated that an inspector should report the EP certificate to the government. By doing this an EP data-base is created. 2.3.1 EP-database The database has 3 main reasons: 1 monitoring: implementation and results of the EPBD are monitored to report to the national and European government. 2 maintaining and supervising the presence of the certificate 3 quality control. The database helps inspectors to maintain the quality of the certificates.
should provide all information on calculations and their results. Like this it is possible to monitor the certification system. D: The results provided are checked and an approval is sent back with a serial number that should be filled in on the certificate. Only then the certificate is official. E: The land registry may look at results and at any moment F: Implementation organization supplies information to the VROM ministry. G: VROM in turn supplies information to the EU every 2 years. I: Certificate administrator supplies the applicant with calculation information.
2.3.2 Information flow of EP-data (see figure 2.1) A: certification of administrating companies by certification institutes and checking of calculations A2: additional information to be supplied by certificate administrating companies. B: Admitted companies and results of checks. C: Certificate administrators
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EU G:monitoring reports
VROM
-set up of monitoring reports -adjusting EPBD F:monitoring reports
land registry
E: information
Applicant (house owner)
implementing organ
-B: admission/ inspection results -results sample
Certification institutes
-certifying administrators -checking calculations
-C: calculation information -D: reaction
-A: inspection -A2: additional information
Fig: 2.1: information flows of EP-certificate results
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H: calculations
Certification administrator (companies)
2.4 A brief look abroad Among other countries in the European Union France and the United Kingdom are actively participating to improve energy use. In these countries the energy label for housing has already been implemented and is compulsory. An important diffence with the label in the U.K. and France is that these also include a label for CO2 emissions. So in this sense France and the U.K. have a lead as opposed to the Netherlands. In france regulations are specified in the so called RT2005 An important organization in France is ADEME. In the U.K. the ‘Code for Sustainable Homes’ is an environmental impact rating system for housing setting new standards for energy efficency and sustainability above those in current building regulations. These are not mandatory under current building regulations but represent important developments towards limiting the environmental impact of housing. France has a similar code which certifies houses with a ‘Haute Qualité Environmentale’ (HQE). Although Portugal does not yet have a compulsory label for housing there is also development on a similar front as the Code Sustainable Homes called ‘LiderA’ Main criteria of these different codes are:
-Energy and CO2 Emissions: Operational Energy and resulting emissions of carbon dioxide to the atmosphere -Water: The consumption of potable water from the public supply systems or other ground water resources -Materials: The environmental impact of construction materials for key construction elements -Surface Water Run-off: The change in surface water runoff patterns as a result of the development -Waste: Waste generated as a result of the construction process and facilities encouraging recycling of domestic wast in the home -Pollution: Pollution resulting from the operation of the dwelling -Health and Well Being: The effects that the dwelling’s design and indoor environment has on its occupants. -Management: Steps that have been taken to allow good management of the environmental impacts of the construction and operation of the home. -Ecology: The impact of the dwelling on the local ecosystem, bio-diversity and land use The U.S. and Canada have ‘the Leadership in Energy and Environmental Design’ (LEED) But this system still focusses a lot on fossil fuels instead of sustainable energy sources.
Ademe: www.ademe.fr Code for Sustainable Homes: http://www.planningportal.gov.uk/england/professionals/en/1115314116927.html HQE: www.assohqe.org LiderA (in english): http://www.lidera.info/Lidera _ ingles.html LEED for homes: http://www.usgbc.org/DisplayPage.aspx?CMSPageID=147
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3 EI-DETERMINATION This chapter will deal with determining of the ranking of a house by using the Energy Index. After giving an explanation on the standardized values that are used for the calculation of the EI, the elements of a house that have an effect on the EI will be discussed. This is made possible by the use of special EI-software which calculates the EI and shows the ranking. With the software it is possible to illustrate the effect of house size, orientation, age and appliances on the final ranking of the house. In order to do this, an explanation on how the housing types are determined will be given before looking at the results.
3.1 STANDARD CONDITIONS The user behavior has influences the energy consumption of a household a lot. One of the most important aspects of the Energy Label is that it gives the possibility to compare different houses with each other. This of course is essential for consumers if they choose a house based on its energy performance. To cancel out the influence of user behavior the calculation of the EI is based on standard conditions. Standard conditions are based on standard values for weather and standard values for user behavior. 3.1.1 Standard weather conditions The so called Test Reference Year (TRY: 1964-1965 and sometimes 1994 as a reference for relatively warm year) of de Bilt (location of Dutch headquarters for meteorology) is used for data upon which standard weather values are based. In this year the heating season starts on October 1st ending on April 30th. (See table 3.1) The orientation of the vertical plane and shade influences the amount of sunlight entering faรงade openings:
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Heating season length Average outside temperature Accumulated sunshine during heating season on an outdoor vertical plane with southern orientation Accumulated sunshine on an outdoor vertical plane with southern orientation including window frame factor (fc=0,75)* correction factor for pollution and lace curtains (fIV=0,95) Accumulated sunshine on an outdoor vertical plane suncollectors and photovoltaic cells
212 days 5,64=oC 1200MJ/m2 855MJ/m2 2800MJ/m2
*windowframe factor: ratio of glass area and gross window area Table 3.1: meteorological data used for EI-calculation
Fig. 3.1: Dutch weather* Royal Dutch Meteorological Insitute: www.KNMI.nl Weather graph (figure 3.1): http://www.bbc.co.uk/weather/world/city _ guides/results.shtml?tt=TT004040
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Orientation South Southeast Southwest East West Northeast Northwest North Horizontal
Orientation Light reduction Accumulated sunlight on factor factor caused vertical faรงade openings* (MJ/ by shade m2) 1,00 0,90 770 0,85 0,80 581 0,85 0,80 581 0,56 0,90 431 0,56 0,90 431 0,38 0,95 309 0,38 0,95 309 0,33 1,00 282 0,89 1,00 761
*855MJ/m2 (see table 3.1 p.21) multiplied by the orientation and light reduction factor of shade Table 3.2: influence of orientation on faรงade openings
As visible above certain orientations have more shade than others. In the north orientation there is no light reduction from shade since there is no direct sunlight. The horizontal plane has direct sunlight permanently without any notable obstruction of light. For the orientation of sun-boilers a southern orientation with an inclination of 45o as a reference point with a value 1,00. Other orientations lead to these orientation factors (table 4):
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Fig. 3.1: top: sun boiler; down: PV-cells
Orientation South Southeast Southwest East West Northeast Northwest North
Inclination(o) 0 15 0,88 0,97 0,88 0,93 0,88 0,86 0,88 0,78 0,88 0,77 0,88 0,79 0,88 0,88 0,88 0,94
30 1,01 0,95 0,82 0,67 0,64 0,68 0,85 0,95
45 1,00 0,93 0,77 0,56 0,52 0,58 0,80 0,95
60 0,94 0,87 0,70 0,48 0,42 0,50 0,75 ,90
75 0,85 0,78 0,62 0,42 0,36 0,44 0,66 0,81
90 0,71 0,66 0,54 0,37 0,33 0,38 0,57 0,69
60 1,33 1,22 0,98 0,72 0,58 0,75 1,03 1,26
75 1,19 1,09 0,87 0,63 0,50 0,66 0,92 1,13
90 1,00 0,93 0,75 0,54 0,45 0,57 0,79 0,97
Table 3.3: orientation factors for sun-boilers
For the orientation of photovoltaic cells a vertical 90o position is maintained as a reference point with value 1,00. Orientation South Southeast Southwest East West Northeast Northwest North
Inclination(o) 0 15 1,24 1,36 1,24 1,31 1,24 1,21 1,24 1,12 1,24 1,08 1,24 1,13 1,24 1,23 1,24 1,33
30 1,42 1,34 1,16 0,97 0,90 0,99 1,19 1,36
45 1,41 1,31 1,08 0,83 0,72 0,86 1,12 1,34
Table 3.4: orientation factors for PV-cells
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3.1.2. Standard values for user behavior These aspects determine the standard user behavior used to calculate the EI: -inside heating temperature of 18oC -specified number of occupants (see point A) -adjustments made for local heating and/or kitchen water heating (see point B) -ventilation according to NEN5128 with correction factor 1,0 -internal heat production of 6w/m2 -annual electricity use for lighting of 6kWh/m2 -specified annual netwarmth requirements for tap water (see point A) 3.1.2a: Standard amount of occupants The standard amount of occupants is based on the floor area for a living function These values are used to define the specified annual net-warmth requirements for tap water:
Floor area for living (m2) <50 50 - 75 75 - 100 100 - 150 >/= 150
Number of occupants 1,4 2,2 2,8 3,0 3,2
Table 3.5: number of occupants
3.1.2b: Adjustments made for local heating and/or kitchen water heaters Adjustment type Local heating (oil, gas, electricity)
Kitchen tap water heating
EI-calculation method -seen as individual central heating with normal efficiency -(piping)inside thermal envelope -individual usage-meter -no thermostat -combination boiler with normal efficiency -inside thermal envelope -limited piping length
table 3.6: adjustments for local heating and/or kitchen water heating
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3.1.2c: extra standardization Extra adjustments to simplify the EI determination are: -all glass is set within the thermal envelope. Meaning that it divides the inside air from the outside air -permanent presence of a shower -no water saving showerhead -no dishwasher -AC ventilators -no ideal arrangement of heating -normal conventional efficiency boilers are not connected to a pump. Whereas the higher en high efficiency boilers are.
3.2 STANDARD ENERGY SAVING METHODS The Energy Label also indicates a list of cost-effective energy saving measures mostly with a cost recovery time of less than 5 years. The measures given on the certificate are the result of data from the standard user behavior discussed in the past section. Because of this the measures advised by the Energy Label are strictly indications. If an owner is truly planning to take measures to heighten the efficiency of the house then it is advised to have a special custommade recommendation for energy saving measures. This recommendation can be given by the same certified advisors that hand out the Energy Label and is also based on specifications(ISSOpublication 82.1) set up by the ISSO-institute (see 1.2.2b).
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This is the list of standard measures indicated by the Energy Label: -floor insulation (improvement) -roof insulation (improvement) -faรงade insulation (improvement) -High efficiency glazing -Insulation of piping for room heating -High efficiency boiler -High efficiency combination boiler -Pump for heating -Insulation of tap water piping -Heat pump for warm tap water -Heat recovery for balanced ventilation -Sun boiler -Photovoltaic cells -Sealing of cracks In chapter 4 some important measures will be discussed in greater detail.
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3.3 PHYSICAL AND TECHNICAL CONSTITUENTS OF THE EI To determine the EI of a house there are many elements that should be taken into account. These elements can be divided into 4 groups: 1 General data 2 Architecture 3 Construction 4 Appliances 3.3.1 General data 3.3.1a building age The age of the building affects the energy performance of the building mainly because of the materials and the technique used to construct the buildings. This changes through time thanks to technological development and improvement of building techniques 3.3.1b house type - one-family house also including houses connected to other functions (e.g. shops, offices) -more-family house: two or more houses or living areas above each other -detached house (also including houses connected to each other by a storage or garage)
-corner house/two houses sharing one roof -terraced house (row house in between two identical or mirrored houses) -flat in an apartment block (or tower) using communal entrance ways either opened to outside or closed (e.g. (open-)corridors, central entrance hall) -multi-story house on upper floor with individual or communal entrance at street level either open to outside air or closed. 3.3.1c orientation The orientation of the house is based on the orientation of the front door. 3.3.1d amount of floors per house These are floors with a living function: living, sleeping, kitchen and sanitary units. 3.3.1e roof type -flat roof (gradient <15o) -gabled roof When there are two roof types on one house, the type with the largest area is chosen. Roof vaults may be ignored. 3.3.1f functional area of floor with living function A living function meets the following requirements:
-enough penetration of outdoor light -enough height -walls, floors and ceilings should be finished The following aspects do not count as functional area: -areas with a net-height of 1,5m with exception of areas under staircases, slopes etc. -openings in (for stair, lifts etc.) larger than 4m2. -load bearing walls -a detached construction or shaft with a horizontal section larger than 0,5m2. -there should be a fixed staircase with a wall to divide stairwell and rooms. 3.3.1g presence of an unheated attic (no living function) 3.3.1h presecne of a conservatory The conservatory only counts as such if it isnâ&#x20AC;&#x2122;t permanently open and thus forms a thermal buffer between the inside of the house and the outdoors. It is also placed outside of the thermal envelope. 3.3.1i height of conservatory If the height is larger than 0,7m it is seen a double-level conservatory.
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3.3.1j preheating ventilation air through conservatory Preheated air is used to ventilate the house. This only counts if the air is mechanically ventilated (e.g. small ventilator in conservatory) The opening of doors and window doesn’t suffice. 3.3.1k orientation of the conservatory 3.3.1 Balcony/arcade shutters Like the conservatory the shutters can function as a thermal buffer outside the thermal envelope of the house. Also the sort of glazing on the façade of the house should be taken into account (single glazing or double glazing) 3.3.1m preheating ventilation air through conservatory (see 3.3.1j) 3.3.2 Architecture When looking the architectural aspects of a house the only relevant theme is the area of the thermal envelope. To determine the thermal envelope there should be a clear difference in temperature on either side of the envelope during the heating season (see 3.1.1). Such temperature difference exists between the inand outdoors and heated and unheated spaces like a garage. So walls
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and floors dividing two houses do not apply to this rule. Within a house, different sorts of spaces can be distinguished: -heated spaces: directly heated by a heating element or indirectly by other heated spaces. -special spaces: attic, conservatory, garage and basement (see figure 3.3) -unheated attic: seen as an extra large cavity construction like a cavity wall The area of the thermal envelope consists out of these elements: -closed façade (see 3.3.2a) -openings in the façade including windows and panels (see 3.3.2b) -roof -floors 3.3.2a Closed façade area The closed façade consists of parts of the façade that have nothing to do with windows, panels. This means that window frames do not count as closed areas. Areas that are finished with a certain covering and prefab façade elements are seen as closed. The sides of roof vaults also count as closed areas in the case that
For houses on upper floors the faรงade measurement starts at the underside of the lowest floor and ends at the underside of the floor of the house above or roof. See figure 3.4.
thermal envelope
A G
B
Co.
A=attic G=garage B=basement Co.=concervatory
A G
B
Co.
fig. 3.3: special spaces
The attic is used as a living space. The walls of a cellar or basement are also seen as closed faรงade areas unless these spaces are not heated.
3.3.2b faรงade openings including window frames and panels Openings in the faรงade consist of frames within which either glazing or panels are set. Openings should divide indoor from outdoor air, heated from unheated spaces, and house and conservatory. Window frames is a description of every that has to do with the window, such as latticework, locks, handles, panes, etc. The only thing that needs to be specified for EIcalculation is the material. 3.3.3 Construction Within the thermal envelope there are objects that should be determined in detail. In the last section the quantity was discussed and in this section it is about the qualitative characteristics of the faรงade, windows, panels, roofs and floors. The determination of these qualities is specified in ISSOpublication 82.1. This is done by means of flow-charts (see figure 3.5 for example) that lead to the
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inner wall
including frame
open
closed
middle measurement
corner measurement
open
floor measurement
closed
Fig. 3.4: specification of open and closed faรงade areas and floor height
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use of certain tables showing the value quantifying the Rc-value (warmth resistance in m2.K/W) of faรงades, panels roofs and floors and the U-value (heat-penetration coefficient in W/m2.K) and ZTAvalue (ratio: amount of sunlight hitting window/sunlight entering window)of windows. When looking at the thermal envelope of the house there are two groups: -faรงades, panels, roofs and floors -windows 3.3.3a Determining faรงades, panels roofs and floors In figure 3.5 a flow chart is shown with the steps that need to be taken to determine the Rc-value of facades. This same kind of chart is also used for the panels, roofs and floor. But of course, for these elements, other tables are used. 3.3.3b Determining windows For windows the U-value and ZTAvalue are based on: -type of frame (material) -glass type (e.g. high efficiency glass, double glazing, single glazing)
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Determination Rc-value of faรงade
no
is there insulation?
yes
unknown
building year: <1965?
no
yes
yes
building year: <1965?
no
see tabel 3.7a
insulation thickness <40mm?
no
yes
presence of air cavity: yes, no or unknown
presence of air cavity: yes, no or unknown
see tabel 3.7d
insulation thickness in centimeters
no
yes
presence of air cavity: yes, no or unknown
see tabel 3.7a
is insulation thickness known?
see tabel 3.7d
see tabel 3.7b
see tabel 3.7c
Fig. 3.5: example of flowchart; in this case to determine faรงade qualities
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cavity
Rc-value (m2K/W) unknown/ (preventive) missing insulation insulation 0,36 0,86
unknown/ 0,19 no cavity
0,69
Table 3.7a: no/unknown insulation
Rc-value (m2K/W) insulation cavity no cavity/ thickness unknown 10mm 0,61 0,44 20mm 0,86 0,69 30mm 1,11 0,94
thickness Rcin mm value (m2K/W)
40 50 60 70 80 90 100 110 120 130 140
1,36 1,61 1,86 2,11 2,36 2,61 2,86 3,11 3,36 3,61 3,86
building period
Rc-value (m2K/W)
1965-1975 1975-1983 1983-1988 1988-1992 >/= 1992
0,43 1,3 1,3 2 2,53
Table 3.7d: no or unknown insulation & building period >/= 1965
Table 3.7b: insulation less than 40mm thick
Table 3.7c: insulation =/>40mm thick
3.3.4 Appliances Houses can contain appliances for heating of rooms and tap water, ventilation, and the production of electricity with PV-cells. To define these appliances, once again, flowcharts are used according to ISSO-publication 82.1.
chosen and the number of houses making use of these systems can be defined. Secondly the sort of heating appliance is chosen. (See table 3.8)
3.3.4a Room heating Heating can be collective of individual. This is the first specification that should be made when defining the heating system. In a collective system one or two heating appliances can be
Fig. 3.6: HR boiler
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Local heating oil/gas Local electrical heating Central heating (individual or collective) -gas boiler with conventional efficiency -improved efficiency boiler (Dutch: VR-boiler); choose electrical or gas ignition -high efficiency boiler (Dutch: HR-boiler); only has electrical ignition HR100,HR 104 or HR107 Electrical heat pump (individual or collective): -ground -groundwater -air Power plant (heat and electricity) for entire building Heat supply by third party Table 3.8: heat appliances
All these heating systems have there own efficiency coefficient. Also appliances and piping can be in- or outdoors. This of course has an effect on the total efficiency of the system. A final important subject in the defining of heating systems is the heating temperatures. These can be grouped in the following way:
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1 2 3
T</=35oC 35oC< T</=55oC 55oC>T
1 Is used for a system strictly using radiators 3 Is used for a floor heating system 2 Is a combination of the above given systems 3.3.4b tap water heating The different appliances: Kitchen boiler Bath Boiler Combination boiler with direct heating -conventional efficiency -improved efficiency boiler (VR) -high efficiency boiler (HR) HR100,HR 104 or HR107 Combination boiler with hot water storage (heat exchange) -conventional efficiency -improved efficiency boiler (VR) -high efficiency boiler (HR) HR100,HR 104 or HR107 Electric boiler Gas boiler Heat pump boiler Collective heater Table 3.9: tap water heat appliances
Like with the heating system tap water heating can also be an individual or collective system. Furthermore, there should be looked at the presence of a closein boiler. This is a small boiler (</=20litres) which is used as a second appliance that can satisfy the use in the kitchen. The main boiler then only needs to heat bathroom water and, if necessary, washbasins. Other aspects that influence the energy consumption for heating tap water are: -presence of a bath -length (L) of piping from appliance to tap (L</=5<L) -the presence of (insulated) circulative piping in the case of collective heating for more-family housing -presence of a sun boiler (type, inclination and orientation)
3.3.4c Ventilation & infiltration Types: Totally natural ventilation Natural supply/ mechanical exhaust Ventilation on demand* Mechanical supply and exhaust without heat recovery Mechanical supply and drainage with heat recovery * supply is regulated by grates and drainage is mechanically controlled through oulets in kitchen, toilet and bathroom. This control is based on carbon-monoxide detection and pressure differences Table 3.10: ventilation/infiltration appliances
Next to the choice of these types the efficiency and the presence of crack sealing should also be taken into account.
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3.4 EI DETERMINATION (SOFTWARE RESEARCH) This section will discuss the way EI is determined mainly through the use of EI-software. This special software is a key tool for inspectors when assessing a house. The past sections already show that many factors have an influence on the final EI. In this section no speciefic types will be shown. Since there are many different types of houses. The goal behind this section is to get an understanding on which factors have what impacts. To give a sense of the influences of different factors on the EI, this section will show certain inputs into the software and there outcomes. These inputs are based on house size, shape, house type, orientation and age. Next to this the software gives the possibility of looking at the appliances used and the appliances that can be used to improve the energy performance. In figure 3.7 we can see which part of the EI-formula corresponds to which elements. EI=Qtot/(155*Ag+106*Aloss+9560) Aloss=section A* Qtot= section B**
A*
B**
*A: transmission of thermal envelope: façades (=‘gevel’) floors (=‘vloer’) roof (=‘dak’) concervatory (=’serre’) **B: energy consumption of heating and ventilation appliances Fig. 3.7: EI-software screenshot of constituents
Software is courtesy of DGMR consultants for industry, traffic, environment and software http://www.dgmr.nl/en/
36.
3.4.1 Size and shape The software sets up the size of the house based on measurements of: -the thermal envelope (faรงade, windows, roof and floors -the living area Within these two criteria different factors can possibly affect the Energy Performance of the building. For instance, a relatively small living area can be combined with a relatively large envelope area; if the story height of a building is high the ratio of faรงade area (thus envelope area)/living area is greater that that of a house with lower story height. But a same
ratio can also be accomplished with a house that has a more complex shape: a house with extra corners, niches or bays has more faรงade area than a simple rectangular house with the same living area. Certain building heights can contain a different amount of stories. Since the roof area is approximately the same as that of the floor area this also means that for instance a tall house, has a larger faรงade/roof surface ratio than that of a lower house. This also may affect the performance of a building since a the roof and floor have different insulation factors than that of the faรงades. (see figure 3.8)
Fig. 3.8: more floors within same volume; more living area
37.
3.4.1a constant factors With this information, different models representing different sizes can be fed into the software. Since this first research is about size and proportions, data about installations should be the same for each different size. The software automatically uses a standard set of installations: -heating (for air and tap water) is supplied by an improved efficiency combination boiler with radiators (55oC>T). -there is no mechanical ventilation and there is no use of sun boilers or PV-cells). Next to these constants other factors should be constant throughout all models as well: -Rc-values of external walls: 1,30 -glazing type: uncoated double glazing. -amount of faรงade openings: 30% of faรงade area. In the front faรงade where the front door is situated the front door is included as a part of that 30%. -there is a flat roof. -no special spaces (unheated attic, basement or conservatory) The type of house specified in the software as a standard is a terraced house with neighbors on
38.
both sides. Other housing types will be discussed later on in this chapter. 3.4.1b setting up the models To create a set of models the models are based on: -footprint -house height -number of stories Floor areas and roof can be based on the footprint. The combination of footprint and height determine the size and dimensions. Finally the number of stories gives a certain amount of living space. As mentioned earlier, it is possible that there can be different numbers of stories per height. For these factors standard values have been set up. -footprints: 50m2, 80m2 and 160m2. -house height: 2,3m; 4,6m; 9,2m; 15,8m -nr. of stories: 1 to 4 A story hieght of 4,6 is of course extreme, just as a footprint area of 160m2. This is not realistic, but these values are used for the sake of the resaearch. To be able to compare the models. The specifications above the following models.:
bring
heights
footprints 50m2 80m2 2,3m 1 st. 1 st. 4,6m 1 st. 1 st. 2 sts. 2 sts. 9,2m 2 sts. 2 sts. 3 sts. 3 sts. 4 sts. 4 sts. 15,8m 4 sts. 4 sts.
160m2 1 st. 1 st. 2 sts. 2 sts. 3 sts. 4 sts. 4 sts.
-nr. of stories; st.=story; sts.=stories Table 3.11: different models/sizes nr.
Each model uses a rectangular plan with width:depth ratio 1:2. SEE DIAGRAM!!! -The façade area is calculated in this manner: A=X*Y with X=√(F/2) A=area (m2); X=width (m) Y=house height (m); F=footprint (m2) -Glazing area=30% of façade area -Roof area=footprint (F) -Floor area of floor within thermal envelope=footprint (F) -The living areas for the models is 90% of the footprint (because of wall thickness) and in the presence of stairs 3m2 of floor opening per story. Of course the ground floor doesn’t have an opening for stairs. So for houses with 2 or more stories this means: Living Area=(F*Sn*0,90)-(3*Sn-1) F=footprint (m2); Sn= # of stories footprints (m2) # of stories 50m2 80m2 160m2 1 45m2 72m2 144m2 2 87m2 143m2 285m2 3 124m2 210m2 426m2 2 2 4 171m 279m 567m2
Fig. 3.9: model set up
Table 3.12: living area
39.
3.4.1c Results
footprint: 160m2
footprint: 80m2
footprint: 50m2
footprint _ height _ #of stories 50 _ 2300 _ 1 50 _ 4600 _ 1 50 _ 4600 _ 2 50 _ 9200 _ 2 50 _ 9200 _ 3 50 _ 9200 _ 4 50 _ 15800 _ 4 average
EI 1,58 1,65 1,66 1,77 1,68 1,61 1,72 1,67
Label C D D D D D D D
80 _ 2300 _ 1 80 _ 4600 _ 1 80 _ 4600 _ 2 80 _ 9200 _ 2 80 _ 9200 _ 3 80 _ 9200 _ 4 80 _ 15800 _ 4 average
1,67 1,73 1,63 1,72 1,63 1,55 1,65 1,65
D D D D D C D D
160 _ 2300 _ 1 160 _ 4600 _ 1 160 _ 4600 _ 2 160 _ 9200 _ 2 160 _ 9200 _ 3 160 _ 9200 _ 4 160 _ 15800 _ 4 average
1,69 1,74 1,58 1,66 1,55 1,48 1,56 1,61
D D C D C C C D
Table 3.12: results
40.
3.4.1d Conclusions The first conclusion that can be made from these results, is the fact that more or less all models have the same rating. The average of each footprint improves slightly if the footprint is larger. An interesting conclusion is that the floor height has a positive effect on the EI. The lower the floor the better the performance. This is visible when looking at the values for a height of 4600mm and 1 story, which is the highest story height and that of a height of 9200 with a story height of 9200/4=2300mm. The lowest story height in the models. Not only this the story height plays a role, but also the amount of stories. So, the more low height stories, the better. For a 50m2 footprint the results are slightly different. This might have to do with volume. At some point a small volume has a different effect. These results are of course logical. A higher story height means more transmission area per unit of living area which means there is more heat loss per unit of area. Thus, a lower EI-value. A larger amount of floors helps contain the heat more. The conclusions meantioned above
are based on the rectangular models. Described in 3.4.1b. But conclusions can also be made for buildings with other shapes (except round). The software does not use the amount of stories but the amount of living space. This means that the software looks at the amoun t of facade area as opposed to the amount of living area. This means that a heigher story height actually is the same as a shape with more corners, nishes or bays. This type of shape has a worse performance than a rectangular shape since the faรงade area is relatively larger: more heat loss per unit of livings space. living area: 1 higher EI
:
1 lower EI
1 : 1,5 faรงade area: Fig. 3.10: Faรงade and living area ratio
In the end, this simply follows the EI-formula shown in chapter 2. The formula relates transmission area to the living area.
3.4.2 Types As now known from the previous section 3.4.1 on size and shape the area of the thermal envelope has an effect on the EI (also visible in the EI-formula shown in chapter 2). In essence the type of house also has to do with this aspect. A corner house, for instance, has more faรงade area than that of a terraced house. By looking at the formula, it is to be expected that a corner house has a higher EI than that of a terraced house. None the less it might be interesting to test this influence with the software to see how large the effect of difference in types actually is. 3.4.2a models As explained in section 3.3.1b there are many different types of houses. Basically, this section will look at 5 main types: -detached home -semi-detached home/corner home -terraced house (on ground floor)
note: some models set up in this section wil be used in following sections for further investigation. They will be refered to according to footprint height, # of stories and living area.
41.
-multi story house on level floor
-two story flat (no roof)
To test the difference in energy performance of the types a two story house with a height of 4600mm was chosen (See 3.4.1). There are different reasons for this. As visible in table 3.12. A one story house has a different progression of values when looking at different building footprints: the larger the footprint the higher the EI. Houses with at least two stories have a more constant progression: the larger the footprint the lower the EI. This is also shown in table 3.12 This can be crucial for the outcome of the results. So a two story house is more representative. Furthermore two stories is also not too big either. This is a good choice when it comes to, for instance, a flat. With the chosen types of houses there will be looked at the influence of volume (based on the
42.
footprints of 3.4.1). Of course, a footprint of 160 m2 is extremely large, but as explained in 3.4.1 this extreme value is for the sake of the research, although not realistic in practical sense. Also the aspect of age will be tested in combination with the types. Since age has to do with developments in insulation this will have an effect on the EI. The aspect of building age is going to be calculated in a standard way by the software. As explained in section 3.4.5 about age and appliances, different ages have different standards as insulation values. By specifying the age in the building data. The software knows which insulation value to use. For the test three ages are chosen: 1910 (before 1965), 1975 (shortly after 1965) and 1997. 3.4.2b Constant factors -Height 4,6m -Two stories -Heating (for air and tap water) is supplied by an improved efficiency combination boiler with radiators (55oC>T) -There is no mechanical ventilation and there is no use of sun boilers or PV-cells -There is a flat roof. -No special spaces (unheated attic, basement or conservatory)
3.4.2c Results 3,00
1910
2,50
2,00
1975
1,50
1,00
1997
detached
semi detached/corner 50m^2: 1910 80m^2: 1910 160m^2: 1910
terraced 50m^2: 1975 80m^2: 1975 160m^2: 1975
on upper level
two story flat
50m^2: 1997 80m^2: 1997 160m^2: 1997
Fig. 3.11: influence of age and footprints
43.
Detached
Two story flat
Age
On upper level
2,99; G 1,90; D 1,52; C
2,75; F 1,80; D 1,45; C
2,43; F 1,66; D 1,35; C
2,35; E 1,53; C 1,31; C
1,87; D 1,47; C 1,37; C
Age
Semi detached/ Terraced corner
2,94; G 1,85; D 1,46; C
2,71; F 1,75; D 1,38; C
2,43; F 1,63; D 1,29; B
2,33; E 1,47; F 1,24; B
1,76; D 1,39; C 1,29; B
Age
Footprints 50 _ 4600 _ 2 1910 1975 1997 80 _ 4600 _ 2 1910 1975 1997 160 _ 4600 _ 2 1910 1975 1997
2,83; F 1,77; D 1,37; C
2,64; F 1,68; D 1,30; C
2,40; E 1,58; C 1,21; B
2,29; E 1,49; C 1,14; B
1,58; C 1,27; B 1,19; B
Table 3.12: results; Energy Index
3.4.3d Conclusions Looking at the graph in figure 3.11 it is clear that age has a larger influence on the EI than volume. Looking at the aspect of volume, it is also visible that the lines are more or less parallel to eachother. This means that each type has the same influence, no matter which volume, on the final EI. In 1997 none of the models have a label higher than C, which is an acceptable label. This corresponds with the legislation in that time. After 1997 it was mandatory to have an â&#x20AC;&#x2DC;Energy Performance Coefficient calculationâ&#x20AC;&#x2122; before building a new house (see 1.2.1a).
44.
Also, it is visible that in a new house a two story flat has a slightly worse performance than that of a terraced house on an upper level. It is difficult to determine what causes this. A possible explanation could be that at relatively low EI-values, the heat of the sun plays a role. A roof heats up in the sun, and this could cause higher indoor temperatures. Less energy is then needed for heating. So it is not a question of heat loss through the neiboring house above the flat, but more a question of heat gainance in the roof.
3.4.3 Façade openings and orientation Section 3.1.1 on standard values for EI-calculation explained that the influence of orientation of a house is based on the amount of façade openings facing a certain direction. 3.4.3a constant factors For this a 2 story house will be used with a footprint of 80m2 and a living area of 210m2. Further constant factors are: -building height 9,2m -heating (for air and tap water) is supplied by an improved efficiency combination boiler with radiators (55oC>T). -there is no mechanical ventilation and there is no use of sun boilers or PV-cells -there is a flat roof. -no special spaces (unheated attic, basement or conservatory) -Rc-values of walls 1,3 3.4.3b tests Three tests will be done to see the infuence of façade openings and the orientation. 1 What is the effect of the amount of façade openings (percentage)? 2 What is the effect of the amount of glass and a cetain orientation? 3 How does a certain glass type perform in a certain orientation?
1 The house will have percentages of glass: 0%, 20% 30%, 40% 50%. Also the aspect of building age will be added to see what efect glazing has for older and newer buildings. As explained earlier, this has to do with insulation capacities of the exterior walls. 2 The second test shows in which façade it is better to have more glass. For this we use a model which has 30% of glass on one facade and 0%, 30% or 50% of glass on the opposite façade. The house is then turned to different orientations and then it visible if it is better to have more glass in a façade facing north or south. 3 The third test shows with which façade it is wiser to replace single glazing with better glazing types. Like in the previous test, two oposite façades are compared. In this case one façade has special glazing types that are compared with the opposite façade that has single glazing.
45.
3.4.3c results building amount of year 0% 20% 1910 2,51 2,47 1975 1,51 1,59 1997 1,16 1,27
2,5
glazing 30% 2,45 1,63 1,32
40% 2,43 1,67 1,38
50% 2,41 1,71 1,44
Table 3.13: amount of façade openings and building year; EI (Fig. 3.12)
opening orientation of amount(%)* tested façade S SE/ E/W SW 0% 1,63 1,62 1,62 30% 1,63 1,63 1,63 60% 1,64 1,72 1,76
NE/ NW 1,56 1,63 1,78
N 1,52 1,63 1,75
*opening amount of tested façade. The opposite façade has a percentage of 30% façade openings Table 3.15: facade opening amount and the orientation; EI (Fig. 3.13)
special orientation of façade glazing* with special glazing S SE/ E/W NE/ N SW NW double 1,77 1,81 1,81 1,80 1,76 glazing coated 1,75 1,78 1,78 1,76 1,72 double glazing HR++ 1,69 1,72 1,71 1,70 1,66 *special glazing as opposed to single glazing in the opposite façade. Table 3.14: glazing types and their orientation; EI
46.
2
1,5
1 0%
20% 1910
30% 40% 1975
50% 1997
Fig. 3.12: amount of façade openings and building year (table 3.12) 1,80 1,75 1,70 1,65 1,60 1,55 1,50 1,45 1,40 1,35 S
SE/SW 0%
E/W 30%
NE/NW
N 60%
Fig. 3.13: amount of façade openings and orientation (table 3.13)
3.4.3d conclusions In the graph of figure 3.12 based on table 3.13 it is visible that glass percentage is directly proportional to the EI-value. The lines in the graph are strait. In genereral it is not an advantage to have more façade openings, but for a house built in 1910 it is. Insulation is so poor that façade openings help warmth form sunlight get in. None the less, the EI-value is still vert high. As in figure 3.12 the graph in figure 3.13 shows that more glass means a wors performance in this case (the model is from 1975). Within the different percentages of openings in the façade. The façade with more glass will have a better performance when oriented to the south. It is interesting to see that the façade with 60% openings has almost the same perfomance as that of a house with 30% of openings when oriented to the south. Meaming, if a decision is made to make more façade openings, extra openings in the south will not worson the EP. Of course, when making façade openings smaller this should be done on the north façade to maintain the same performance.
Table 3.14 on glazing types als supports thathe theory that more sunlight entering the room will has a better effect on the energy performance of a home. New glazing types let less sunlight in, thus also less warmth. That is why it is better to put new glazing on the north façade in the case that only one façade is restored. But this does not mean that energy performance will worsen when all façades are restored. Of course less warmth will enter the room (through sunlight), but more importantly, the insulation performance of the house improves dramatically so warmth is kept inside. This finally leads to an improved energy peformance. This is shown in the table below: glazing type
orientation of façade N/S
double glazing coated double glazing HR++
E/W
1,63
SE/SW/ NE/NW 1,67
1,58
1,61
1,62
1,45
1,48
1,48
1,68
Table 3.15: glazing improvements to all façades; EI
47.
3.4.4 Special spaces As explained in chapter section 3.3.2 the software can also make calculations taking special spaced into account. This section will show the influence of the following special spaces on the EI: -unheated attic -garage & unheated neighboring space -heated and unheated basement -conservatory Since some spaces often are placed beside a house the tests will not only be done with a terraced house but also a detached house. This will also give an extra possibility to compare certain effects. 3.3.4a Constant factors The model used is a house from 1975: -Footprint=80m2 -Height=9,2m -Living area=210m2 -heating (for air and tap water) is supplied by an improved efficiency combination boiler with radiators (55oC>T). -there is no mechanical ventilation and there is no use of sun boilers or PV-cells -Rc-values of walls and roofs: 1,3 -Rc-values of floors: 0,52
48.
3.4.4b Unheated Attic For the unheated attic there are different types. For the tests, two types will be used: a gabled roof and a flat roof. These two types will be applied to the detached house and to the terraced house. The results will be compared to the base models for the 3 story house with a living area of 210m2 named above. In the case of the flat roof the sides of the attic can be roofing, thus it is an independent attic (fig. 3.14: D). It is also possible that the sides of the attic have neighboring rooms from the house next door (fig. 3.14: E). In this case they are not added to the EI-calculation. For both flat, as gabled roof the attic is 3m high.
has been explained in section 3.4.2. What is interesting is that attics under same roofs for either detached or terraced houses give the more or less the same improvement of the EI-value in absolute sense: 1,93-1,86=0,07 & 1,86-1,71=0,15 1,63-1,56=0,07 & 1,56-1,39=0,17
Fig. 3.14: tested attic types
detached
base model 1,93; D
gabled (A) 1,86; D
flat (B) 1,71; D
terraced
Results
base model 1,63; D
gabled (C) 1,56; C
flat (D) 1,39; C
flat 2 (E) 1,50; C
table 3.16: unheated attic under different roof types; EI
Conclusions Table 3.16 shows the obvious difference in EI for a terraced and detached house. This effect
Strangely, the attic with neigboring shared walls (fig. 3.14: E) has a higher value that that of the independent attic in (fig. 3.14: D). This could have the same reason as the one described in section 3.4.2 on house types where a flat without its own roof has a worse performance than the terraced house which has a roof. Since type D has more roof surface, there maybe is more heat gainance from the sun than heat loss, which gives a better EI since there is less energy needed for heating. None the less, the reason is not very clear. A larger surface also means a larger heat loss area. 3.4.4c Garage and other unheated spaces (see 3.1.1) In fact the garage and other unheated spaces are comparable to each other. The main difference is that a garage is a more
49.
ventilated kind of space. This can influence EI outcomes. Using the detached house, the garage and unheated space will be located either along the whole length or along the width of the house. Also orientation will be tested a what effect does a garage on the south have as opposed to that on the north. For a terraced house it is not possible to see the effect of a garage next to the house because of the neighboring house. A last test is the garage or other unheated space underneath the house. In all cases the garage and other unheated spaces are seen as 3m high additions to the house. Results detached base 1,93; D model location orientation along length
South North along South width North underneath on GF
type garage unheated room 1,89; D 1,88; D 1,83; D 1,82; D 1,92; D 1,91; D 1,90; D 1,90; D 2,05; E 1,99; D
Table 3.17: unheated spaces against a detached house; EI
50.
terraced base 1,63; D model location orientation along width
South North underneath on GF
type garage unheated room 1,61; D 1,61; D 1,59; C 1,58; C 1,80; D 1,72; D
Table 3.1: unheated spaces against a terraced house; EI
Conclusions First of all it is visible that the diffrence between a garage or anoter type of unheated space is very minimal. The extra ventilated garage has more heat loss therefore leading to a slightly higher EI. The differences between the values of position along the length and the width have to do with the wall area covered by the uneated space. Along the length this area is larger and so there is less heat loss. An unheated space actually works like a cavity wall with an extra large cavity. Improving insulating performance just like an unheated attic. The effect of the orientation of the unheated spaces simply has to do with the amount of faรงade openings. The wall area covered by, for instance, the garage does
not have windows. This means that there are less opening in that faรงade. If this faรงade is facing south it means less entry of sunlight meaning less entry of heat and thus a higher EI-value. This has been explained in 3.4.3. The location of an unheated space under the house on the ground floor has a worsening effect on the EI. In the base model the ground floor if the house is set on the ground. The ground has better insulating qualities than the air in the unheated space under a house. 3.4.4d Heated and unheated basement Results detached base 1,93; D model
terraced base 1,63; D model
unheated 1,99; D basement heated 1,90; D basement
unheated 1,72; D basement heated 1,63; D basement
Table 3.19: basements; EI
Conclusions For the same reason that an unheated space under a house gives a worse EI-value, this is also the case with an unheated basement. In this case, the air in the basement has worse insulating properties than that of the ground under the floor when there would not be a basement. A heated basement is actually seen as an extra floor surrounded by the ground. For the detached house, this has a slightly positive effect on the EI. The surrounding ground has good insulating properties. For the terraced house, the basment is flanked by basements of neighboring houses. This means less ground to hold the warm air, thus resulting in an unchanged EI as opposed to having no basement. 3.4.4e Conservatory (see 3.1.1) When it comes to the conservatory there is a difference between conservatories that preheat the incoming air an a those that do not. Also orientation plays a role. Most conservatories are higher than 0,7m (double-level; see 3.1.1i) this is the type that is used in the tests. The software is not able to specify the location of the conservatory around the house, so this will not be counted into the equation.
51.
detached
base model 1,93; D orientation no preheating S 1,89; D N 1,91; D
terraced
results
base model 1,63; D orientation no preheating S 1,57; D N 1,60; D
preheating 1,86; D 1,90; D
preheating 1,53; D 1,59; D
Table 3.20: conservatories; EI
Conclusions A preheated conservatory gives a considerable improvement in the energy performance. Certainly with a terraced house. The effect of a conservatory with a terraced house is relatively larger than that of a detached house because a detached house has relatively more faรงade area than a terraced house. This makes the percantage of faรงade covered by the conservatory larger with a terraced house. Of course a southern orientation is the best because more sun warmth can be caught. Note: the software does not give an option to determine the conservatory size and the faรงade to which it is attached.
52.
3.4.5 Age and improvements In the previous section the age of the building was used for some calculations to compare results. For instance, in section 3.4.3 on faรงade openings. Age indicates a certain performance in insulation. Because of new techniques and materials insulation has improved through the years. After 1965, for instance, exterior walls have a cavity. The EI-software can specify certain Rc-vlaues for different elements based on the building year. ISSOpublictaion 82.1 shows which Rcvalues apply for walls, floors and roof in a certain period. For houses before 1965, the presence of a cavitywall has to be specified. This is also the case for secondary insulation. For houses after 1965, only the building year has to be specified. The software will ten automatically generate a standard RC-value for that time. After researching differences in age-types, these age-types will also be used as base models to improve the EI and see which measures are needed to get to the A-class of the energy label. For a large part this has to do with the effects of different heating and ventilation appliances.
age </=1965
elements (Rc-values) façade floor roof 0,19 0,15 0,22
</=1965
0,36
0,32
0,39
</=1965
0,69
0,65
0,72
</=1965
0,86
0,82
0,89
1965-1975
0,43
0,17
0,86
>/=1992
2,53
2,53
2,53
no cavity, not insulated* cavity, not insulated*
</= 1965
For the research of age types, these are the constant factors: -Footprint=80m2 -Height=9,2m -Living area=210m2 -heating (for air and tap water) is supplied by local gas heating through radiators (55oC>T) -water will be heated by an electrical boiler -there is no mechanical ventilation and there is no use of sun boilers or PV-cells The above standards make use of appliances which have the worst energy performance. From this ‘baseline’ appliances will be changed to finally end up with an A-label.
These are the different types and the Rc-values:
>1965
3.4.5a Constant factors Like in the previous chapter the 3 story house with the 80m2 footprint will be used as a base model.
no cavity, insulated* cavity, insulated*
*this has to do with the presence of secondary insulation (applied later). Table 3.21: standard Rc-values of different elements in different building periods
3.4.5b Age types To be able to see the effects of age, the following periods have been chosen: -1910 (before 1965) -1970 (represents the period ‘75-’65) -1992 (represents age >/=1992)
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Results Based on the age-types given on the in table 3.21 the following results are given in table 3.22. For the period 1965-1975 distiction is made between windows with just single glazing and windows with secondary glazing. This is just to indicate the effect of this simple improvement. For the period after 1992, also double glazing is used as a standard. age </=1965
results EI Label 3,60 G
</=1965
3,27
G
</=1965
2,42
F
</=1965
2,28
E
1965-â&#x20AC;&#x2122; 75
2,61
F
1965-1975
2,35
E
>/=1992
1,50
C
no cavity, not insulated
</=1965
cavity, not insulated no cavity, insulated cavity, insulated
>1956
with single glazing with secondary glazing
with double glazing table 3.22: results of age-types
54.
3.4.5c Improvements The improvements are based on the following base models form the age-types shown in table 3.21. </=1965; no cavity, no insulation </=1965; cavity, no insulation 1965-1975; with single glazing >/=1992; with double glazing (See tables 3.22-3.25) First of all there is a distinction between houses with or without cavity walls. This is a physical aspect that cannot be changed easily. The tables in the following pages show the minimum of improvements needed to get to a higher classification. In some cases different measures are shown. This mainly has to do with the choice to use or not to use heatpumps. Heatpumps are rather large appliances and are not always easy to install. In research mainly air heatpumps are used. First of all this is because air-heatpumps are the least efficient type of heatpumps. Secondly air heatpumps can also be plaed on a level. Other heatpumps can only be placed on the ground floor. Chapter 4 will discuss heatpumps in detail, as well as other important appliances to improve the energy performance.
building period: </=1965 no cavity, no insulation A -in case of presence of heatpump: HR++glazing; combi. sunboiler 5,5m2; crystalline PV-cells 2m2 or
EI 1,04
-in case of no heatpump yet: Air based heatpump (T</=35oC); natural air supply and mechanical air drainage (ventilation); bathroom boiler B -Air based heat pump (T</=35oC); natural air supply and mechanical air drainage (ventilation) or
1,04
-HR++glazing; combi. sunboiler 5,5m2; crystalline PV-cells 2m2 C combination HR107 boiler (tap); double glazing with coating; shortend piping
1,29 1,60
secondary insulation of floor and faรงade secondary roof insulation HR100 heating and double glazing single glazing; individual local gas heating (T>55oC); electric boiler; natural vent.; no sun boiler; no PV-cells
1,88 2,40 2,83 3,60
D E F G
1,25 or
Table 3.22
building period: </=1965 cavity, no insulation A Air based heatpump (T</=35oC); heatpump boiler; natural air supply and mechanical air drainage (ventilation); combi. sunboiler 5,5m2; crystalline PV-cells 4m2 B in case of no heatpumps: HR107 combi. boiler (tap); HR++glazing; shortend piping; standard sun boiler 4,0m2 C in case of no heatpumps: added insulation of floor and faรงade D -Air based heat pump and heat pump boiler; (35oC<T<=55oC); natural air supply and mechanical air drainage (ventilation); kitchen boiler or
EI 1,05
-secondary roof insulation E combi. HR100 boiler F secondary/double glazing; ventilation on demand G single glazing; individual local gas heating (T>55oC); electric boiler; natural vent.; no sun boiler; no PV-cells
1,94 2,36 2,85 3,27
1,30 1,60 2,00 or
Table 3.23
55.
A B C D E F G
building period: 1965 to 1975 with single glazing Ground based heat pump (T=/<35oC); combi. sun boiler (5,5m2) Air based heat pump (T,/=35oC); natural air supply and mechanical air drainage (ventilation); bathroom boiler HR++ glazing; combi. HR107 boiler; ventilation on demand HR100 heating; gas boiler; shortend piping Secondary/double glazing single glazing; individual local gas heating (T>55oC); electric boiler; natural vent.; no sun boiler; no PV-cells x
Table 3.24
It is important to state that the tables mearly are an indication of the possibilities of different improvements. Of course, there are many ways to improve the energy perfomance. Clarification of phrases: -heating can happen at certain temperature levels: T=/<35oC (purely floor heating) 35oC<T<=55oC (radiator and floor heating) T>55oC (radiator heating) -shortend piping: By shortening heating pipes there is less heat loss along the length of the pipes -ventilation on demand: see section 4.6.3 in chapter 4.
56.
EI 1,04 1,26 1,59 2,00 2,35 2,61
building period: >/=1992 with double glazing A -in case of no HR++ glazing: combi. HR107 heating (tap); shortend piping; standard sunboiler or
EI 1,02 or
-in case presence of HR++ glazing: combi. HR100 heating B -HR++ glazing; shortend piping or
1,03 1,29 or 1,30 1,50
-VR heating; ventilation on demand C double glazing; individual local gas heating (T>55oC); electric boiler; natural vent.; no sun boiler; no PV-cells D x E x F x
G x Table 3.25
Conclusions It is obvious that a younger house needs much less improvements than an old house. The tables also show that a houses up to 1975 need heatpumps to get an A classification. Of course this conclusion is based on the fact that walls have standard insulation for their time. By adding insulation the an A classification might be easier to get, maybe even without the use of heatpumps. In a standard situation sometimes not only sunboilers, but also heat pumps are needed to get an A classification. Combining these two heat sources can be difficult and also takes space.
It is relatively easy to get an old house to a D classification but old houses are more difficult to get fron a D to an A. This is because the secondary insulation for old houses (from before 1965) usually is not as good as standard insulation of newer houses. Note: Interesting article of NRC Next Newspaper on tests done to 6 houses (published on the web on the 6th of march 2008): http://www.nrcnext.nl/achtergrond/ article963926.ece
57.
4 solutions to higher EI As seen in chapter 3, there are a large number of solutions that can improve the energy index. Some solutions have a greater influence on the EI than others. These are the solutions that will be discussed in the following pages. The solutions are explained in greater detail and also attempts have been made to explain costs and benefits (whether in time or not). It should be emphasized that these are purely attempts and indications since it is a difficult process to difine how much energy costs are saved as opposed to the investment costs of these solutions. There are many different factors that can influence this (see chapter 3). Also some solutions have been known for a longer time. Such as insulation techniques and glazing types. Sun boilers and PV-cells are newer techniques, so less is known about them concerning efficiency (over time) and costs. Since newer solutions have a more dynamic development there is also a lot of fluctuation in costs and benefits.
4.1 INSULATION Applying insulation are adding an extra layer of insulation can greatly improve the energy performance of a house. Adding insulation is possible in three ways: 1 external insulation layer 2 insulation in cavity of cavitywalls 3 indoor insulation 4.1.1 Advantages and disadvantages 4.4.1a External insulation Advantages: -this solution has the greatest reduction of energy -relatively low danger of moist or condense problems -fully renovated facades Disadvantages: -most costly investment in comparison two other to solutions. It takes 10 years to earn back the investment. -change of the outlook of the faรงade possibly problematic (e.g. when dealing with monumental buildings or terraced houses) -the municipality needs to allow the intervention -relatively low danger of moist or condense problems
Insulation: http://www.milieucentraal.nl/pagina?onderwerp=Gevelisolatie
58.
4.4.1b Cavity insulation Advantages: -good energy-reducing capacity -done by a certified company, there is little danger of moist or condense problems. -exterior outlook stays intact -the cheapest investment in relation to the other two solutions. It can be earned back in 3 years. Disadvantage: -a cavity wall is needed. Houses before 1965 do not always have cavity walls. 4.1.1c Indoor insulation Advantages: -fairly good performance concerning energy reduction.
-less efficient than external insulation because parts in the interior are hard to insulate (e.g. internal walls) -exterior outlook stays intact -applied yourself, it is a relatively cheap investment which can be earned back in 3 years. Disadvantages: -More risk of moisture and condense problems close to difficult connections like floors, ceilings and internal walls. -Often, adjustments should be made to electrical circuits or plugs -The work indoors can be a nuisance -When applied by professionals it is a costly investment which is earned back after more than 10 years.
4.1.2 Costs and savings type costs per m2 (by professionals) external: Rc=1,3 €112 external: Rc=2,5 €142 cavity: Rc=1,3 €18 indoor: Rc =1,3 €80 indoor: Rc =2,5 €89 indoor: Rc =1,3 €18 (D.I.Y.) indoor: Rc =2,5 €20 (D.I.Y.)
gas savings per earn back time m2 per year in years 3 11m (€7,40) 15 3 11m (€8,70) 16 3 11m (€6) 3 3 11m (€6) 13 3 11m (€7,70) 11,5 3 11m (€6) 3 3 11m (€7,70) 2,5
-savings are calculated with the price of €0,67/m3 of gas (2007 price level) -the calculation is based on standard use and standard presence people Table 4.1: Costs and Savings (indication)
59.
4.2 GLAZING As was already known from the software, there are different solutions to insulate windows: -secondary glazing -conventional double glazing -HR+ glass -HR++ glass Double glazing (or sometimes, triple glazing) has a cavity in between the glass. This cavity contains dry air or sometimes special gas. This is the case with HR+ glass and HR++ glass (HR is the Dutch abbreviation for ‘high efficiency’) which often contains argon, an inert gas with high insulating quality. The cavity can also contain a special coating, which enhances the insulation properties of the type single glazing uncoated secondary glass double glazing coated secondary glass HR+ glazing HR++ glazing
insulation value (u-value) 5,8 2,8 2,8 2 1,6 1,2
window even more by reflecting escaping heat back into the room but still letting in sun light. Table 4.2 shows insulation values of different types of glazing. 4.2.1 Advantages Looking at energy performance double and high efficiency glazing only have advantages. Energy reduction Of course, special glazing as opposed to single glazing helps reduce the energy consumption. (see tables 4.3 & 4.4) Investment Replacement of glazing is not a very expensive investment. Earn back time varies from 7 to 9 years, depending on the sort of room: either living room or bedroom. (see tables 4.3 & 4.4) gas savings per year per m2 of glass in living room 25m3 25m3 30m3 33m3 35m3
cost savings per year per m2 of glass €17 €17 €20 €22 €23
Table 4.2: insulation values and savings per glass type Glazing: http://www.milieucentraal.nl/pagina?onderwerp=Dubbele%20beglazing#Voor- _ en _ nadelen
60.
Less draft Single glazing windows loose a lot of warmth through small slits and cracks. This creates a draft which gives an even colder sensation to the room temperature which then leads to heightening of the thermostat temperature and even more energy-loss. Newer double glazing prevents heat form leaving the inside and stops draft. Important note: less draft means less ventilation and less ventilation means a worse quality due to higher moist levels of air and no flow of fresh air. This will be discussed later on in this chapter. Less condense on the inside Insulating glass has less condensation problems on the inside because the inner glass pane is warm. A drawback though, is that there is often more condensation risk on the outer pane mainly at night an in the morning. This can be annoying if the condense does not evaporate quickly. Light HR+ and HR++ glass let in 1% less light than double glazing without special coatings. This minor reduction is unperceivable.
4.2.2 Costs and savings Costs for the replacement of windows are in fact: -purchase of the window itself mostly this is including the frame. -installation (incl. painting) The lifespan of new glazing is guaranteed for 10 years. Technically the windows should function properly for over 20 years before moist problems occur in the cavity. Savings are based on less consumption of gas. The amount of cubic meters of gas that is saved after replacing glazing depends on the type of glazing chosen and the room function: living room, kitchen or bedroom. For bedrooms less heating is required. Next to this savings also have to do with presence of people. If there are less people or heating is kept on a lower level less gas is saved, speaking in absolute terms. Of course, the fact that heating is kept on a lower temperature is as saving in itself. Calculations on savings are based on an average use and presence.
61.
type HR++ glass U-value</=1,2 (cavity>15mm) HR++ glass U-value>/=1,2 (cavity 9-13mm) HR+ glass double glass uncoated secondary glass
costs per m2 average gas savings per average earn back of glass m2 of glass per year time in years 3 €148 35m (€20) 9 €148
33m3 (€19)
10
€136 €123 €119
33m3 (€19) 25m3 (€14) 25m3 (€14)
9 11 11
Table 4.3: costs and savings per type of glass for kitchen and living room
type HR++ glass U-value</=1,2 (cavity>15mm) HR++ glass U-value>/=1,2 (cavity 9-13mm) HR+ glass double glass uncoated secondary glass
costs per m2 average gas savings per average earn back of glass m2 of glass per year time in years 3 €148 35m (€17) 10,5 €148
33m3 (€15)
12
€136 €123 €119
37m3 (€15) 20m3 (€11) 20m3 (€11)
11 13,4 13
Table 4.4: costs and savings per type of glass for bedroom
62.
4.3 CENTRAL HEATING There are three types of boilers for central heating: -conventional boiler: with 70-80%* efficiency -improved efficiency boiler (VRboiler): 75-85% efficiency -high efficiency boiler (HRboiler): 100-107% efficiency *70-80% efficiency means that 20-30% of heat and energy is lost through exhaust air.
The 100-107% efficiency of HRboilers is possible because the boiler makes use of a condenser. This element gains heat from water damp caused by the burning type average purchase price saving in m3 per year earn back time in years (compared to conventional boiler) earnigs after 15 years CO2 savings in kg per year (compared to conventional boiler)
of gas as extra source. If the efficiency of the boiler is for example 97% and the efficiency of the condenser is 10% it makes a total of 107%. Within the boiler types discrepancies concerning cleaner burning of gas. VR- and HR-boilers have a special label stating a cleaner combustion. 4.3.1 Costs and savings Below, table 4.5 shows the costs and savings. The prices and savings are averages including the installation costs. The gas price is €0,67/m3(price level in 2007).
conventional boiler without gas label €1740
improved efficiency boiler (VR) with gas label €1740
high efficiency boiler (HR) with gas label €2410
-
60 (€40) 0
241 (€161) 4
-
€605
€1750
-
107
429
Table 4.5: costs and savings per type of central heating boilers Central heating: http://www.milieucentraal.nl/pagina?onderwerp=Centrale%20verwarming#Leeg
63.
4.4 HEATPUMPS BOILERS
AND
HEATPUMP
4.4.1 What is it? In essence a heat pump is an appliance that brings surrounding warmth to a higher more usable temperature. Liquid extracts heat from a source (air, ground, water, garbage) a compressor heightens the pressure of this liquid automatically raising its temperature which is then emitted to the surroundings. To drive the heat pump only a relatively small amount of primary energy is needed for the compressor. This can give an improvement of up to 50% as opposed to that of a boiler. The efficiency of the compressing process is the socalled Coefficient of Performance: COP (see figure 4.1). This gives the ratio of primary (electric) energy and the vested
amount of usable heat. Since surrounding warmth extracted out of the sources named above is free and exists in huge quantities, this is not included into the COP equation. Therefore the COP is always larger than 1. There is always more usable warmth than energy needed to drive the system. The higher the COP, the better. When a there is a demand for higher temperatures, as in a radiator-based heating system, the COP is lower. This is the reason that heat pumps are mainly used in combination with emission systems like floor and wall heating. A heat pump system always consists of: -a pump -a heat supply (ground, water, air, etc.) -a heat emission system
Fig. 4.1: Coefficient of Performance Heatpumps: http://www.sbr.nl/warmtepompen/default.aspx?ctid=3750
64.
Main advantages of heat pumps -sustainable energy, good for the environment -improves the value of a house -floor and/or wall heating, so called LTH (=low temperature heating) gives more comfort and the possibility of cooling through the same system. -LTH also reduces the amount of dust whirl and therefore improves the health qualities of inside air. 4.4.2 Points of importance For housing, two heating systems are available now-a-days: -heat pump boiler (exclusively for tap water heating) -electrical combination heat pump (for heating and sometimes cooling of rooms, and tap water heating) In spite of the advantages concerning heat pumps there are also points of importance which need attention when using a such a system: Price -An average combination heat pump costs around €4500,-. A groundbased heat collector costs an additional €1500,-An average heat pump boiler costs around €2500,-A heat pump is seen as a green
investment. This type f investment makes it possible to get a lower interest in the total mortgage taken out on a home When using a heat pump boiler -the house must have mechanical exhaust of air. -the installation room housing the boiler should be suitable for sound and vibrations that may be produced by the boiler. It should also be large (at least 0,6 x 0,6 m2) and high enough (1,80m) -the floor should be able to carry the weight. When using a combination heat pump -Heat pumps can only be used in combination with LTH. Preferably this means heating strictly based on floor and/or wall heating and otherwise the combination of part floor and part radiator heating. A heat pump needs its own heat source (ground, water , air, etc.) -The installation room must be suitable for sound and vibrations. A combination heat pump takes more space than a boiler (0,7 x 0,7m2). Also, the room should be accessible for maintenance Preferably heat pumps should be placed on the ground floor. This mainly applies for the ground-
65.
and groundwater based systems. Air based systems can be placed on other floors. The floors should of course be able to carry the weight, which is considerably larger than that of a boiler system. 4.4.3 Heat pump boiler As mentioned earlier, ventilation air enters the house through grates or through special soundproof inlets above windows. The exhaust air is mechanically blown out through outlets that are at least placed in the kitchen, toilet and bathroom. These outlets are connected to a central air duct. Heating of air is done by a high efficiency boiler. Heat pump boilers can be combined with two heating systems: -high temperature heating -low temperature heating 4.4.3a high temperature heating High temperature heating (55oC>T) basically means standard radiator heating. Tap water heating is covered by the heat pump boiler instead of the high efficiency boiler. The warmth of ventilation air is used to heat the water
66.
Fig. 4.1: Heat pump boiler and high temperature heating
through a heat exchanger. In this case a heat pump boiler cannot be combined with a so called ‘balanced ventilation and heat recovery’. With this system the heat in the exhaust air is ‘reused’ to preheat incoming ventilation air. This means that the exhaust air doesn’t have enough warmth to supply the heat pump boiler. With high temperature heating, the boiler has is less effective than that of a sun boiler although it
can be a good solution in the case that a sun boiler cannot be placed. In combination with ventilation on demand (using mechanically opened grates) the energy performance is improved to a level which is better than the sun boiler system. This has also been visible in the last chapter in the results of the software. The costs of a heat pump are approximately the same as that of a sun boiler. 4.4.3b Low temperature heating Combining the heat pump boiler with LTH (35oC< T</=55oC or T</ =35C), meaning floor and/or wall heating, improves the energy performance even more than the high temperature heating system. This is because the heat pump can extract more heat from the air since the warmth in the rooms is less local. This is also the reason why this system improves comfort, since the heat is emitted more evenly.
Fig. 4.2: Heat pump boiler and low temperature heating
4.4.4 Combination heat pumps Heat pumps can be combine with the following two ventilation systems (4.4.4a and 4.4.4b) 4.4.4a natural ventilation with mechanical suction of exhaust This system has been explained in the past section. Important note: this ventilation system in combination with LTH is less adequate for comfort reasons since incoming air causes more draft with this system.
67.
68.
4.4.4b Balanced ventilation with heat recovery This system has been explained in the past section. Compared to the last system this system has a better energy performance. There are two systems concerning combination heat pumps: -based on electricity -based on gas
4.4.4c Based on electricity An electrical heat pump can bring low temperature heat (around 12oC) up to about 55oC. This requires a relatively small amount of electricity. This leads to a level of COP 4. This system has very good effect on the potential energy reduction. This was also visible in the results of the software
Fig. 4.3: Combination boiler with mechanical suction
Fig. 4.4: Combination boiler with het recovery
research in the last chapter. Next to this it a this system can reduce energy consumption even more when a ground warmth exchanger is used for sustainable cooling in the summer and heating in the winter. This is the case in the ground based heat pump systems. This was also visible in the software research. Drawbacks could be the fact that extra space is needed to house such a system and the sound. 4.4.4d Based on gas This system is actually more relevant for houses that are to be built. This is because the systems of gas supply of older houses are not equipped to be adapted to a gas based heat pump system. This system has a better performance than the electrical system because there are more possibilities to lower the required heat thus lowering the energy consumption. Also it requires a smaller heat source and extra heating (to supply for peak demand) can be realized more easily. For cooling through ground heat exchange the performance is slightly lower than the electrical system because of the smaller heat source.
4.4.5 Collective heat pump systems A final system for heat pumps which has not been researched to a far extent in the last chapter with the software is the collective system. This, because of the fact that it is not very common that houses are improved collectively since the energy label currently just meant for individual systems. None the less it is good to discuss this system briefly. This system is suitable for apartment complexes or larger buildings with other functions than just living. There are three possible combinations: -Collective heat pump with distribution of heat for air and tap water. -Collective heat pump just for air heating and with separate appliances per apartment for heating of tap water -Collective source with distribution of source warmth to separate heat pumps per apartment. Points of importance: -The minimal project size is at least 50 apartments -The system is more feasible if cooled in the summer
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Fig. 4.6: collective heating with central heat pumps
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4.5 SOLAR HEATING 4.5.1 What is it? A solar heating system basically consists out of two elements: -a heat transfer circuit including fluid and means to circulate it (e.g. pump) -storage system including a heat exchanger The solar heating system can provide the heat for tap water and also be used to supply a heating system based normal radiators and/or floor heating. Nowadays 5-hydroxymethylfurfural is applied on the collectors to improve heat rejection at low wavelengths. Heat is usually stored in storage tanks filled with water. The purpose of these tanks is to cover about a two dayâ&#x20AC;&#x2122;s requirement of heat. Solar heating can reduce the energy consumption of either tap water- and/or air heating. 4.5.2 Points of importance Shade -it is not wise to use collectors in a situation in which trees or neighboring buildings obstruct the sun light.
Fig. 4.7: obstruction by buildings
Fig. 4.8: obstruction by trees
Orientation -It is important to orientate the collectors properly. An shown in section 3.1.1 a south orientation with an inclination of 30o-60o is the best.
Solar heating: SBR: http://www.sbr.nl/zonneboilers/ Milieu Centraal: http://www.milieucentraal.nl/pagina?onderwerp=Zonneboiler
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Price -an average solar collector costs at least â&#x201A;Ź3000,-Pricing is comparable to other newer energy improving appliances such is heat pumps Installation room -the boiler needs enough space (3-6m2) -the room in which the boiler is situated should be as close as possible to the collector on the roof.
4.5.3a Compact solar collector and boiler combination In this case the collector is combined with the boiler. This means that there is no storage tank inside the house. To prevent freezing an electric heating element is used. A drawback of this system is that it is that the roof should be strong enough to carry the relatively heavy weight.
Maintenance -A solar heating system requires a relatively small amount of maintenance. Check up of the system can be included in the inspection of the central heating boiler -The solar collector on the roof does not need cleaning 4.5.3 Systems In fact there are 5 main solar heating systems: 1 compact solar collector and boiler combination 2 central heating and solar heating combination 3 solar boiler with electric heating assistance 4 solar boiler with integrated gas heating assistance 5 collective systems
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Fig. 4.9: compact solar collector and boiler combination
4.5.3b Central heating and solar heating combination In this system the storage tank is heated by a central heating boiler and solar heating. And supplies heat for tap water. The storage tank usually contains 120200 liters. In the top of the tank is constantly kept at 60oC. This system is suitable for placement
of collectors in the faรงade since the height of the collectors in relation to that of the tank is not fixed. Collector, tank and boiler should be placed close together to prevent heat loss through piping. A disadvantage of this system is that is takes up a large amount of room which also should be accessible for maintenance.
fig. 4.11: solar boiler heating assistance
Fig. 4.10: central combination
and
solar
heating
4.5.3c solar boiler with electric heating assistance This system strictly is used when there is no connection to a gas network. Electric assistance consumes much more energy than gas-based systems. It only supplies enough heat for water.
with
electric
4.5.3d solar boiler with integrated gas heating assistance This system can handle the heating of water and air. A gas burner is integrated into the storage tank and the circuits for water and air heating are separated. This system can improve the energyconsumption considerably. Since this system makes use of a reversion tank, the collector should be placed at least 3 m above the storage tank. Although the tank is larger than with other systems the whole combination for appliances for this system takes less room since there is only one tank and no boiler.
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4.5.4 Supporting techniques Next to these four systems certain techniques are applied to support the systems. These techniques are concerned with the covering of days with less sun, freezing problems, types of collectors and pumps.
Fig. 4.11: solar boiler with gas heating assisitance
4.5.4e Collective systems -fully collective: this is only applied for water heating with a long circulation channel. The long channel causes a lot of heat loss, making this system inefficient. This of course has a negative effect on the energy performance. -semi-collective: Collectors on a rooftop can supply heat for apartments underneath. It can supply for a maximum of 4 stories. With more stories the system is inefficient because the heating fluid/water needs to be pumped over a too great height.
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4.5.4a Reversion tank If there is not enough solar heat then this system is applied often. It also helps defrosting the collector. During days in which no heat can be extracted form the sun or surroundings fluid in the collector flows back into a reversion tank. This prevents the freezing of the collector fluid. For this it is important that the collector is placed higher than the boiler and heat exchanging boiler. The pump circulates the fluid through the collector and boiler. It can be connected to PV-cells. The advantage of this system is that it is more or less self regulating. If there is not enough sun to use for heating the PVcells produce less electricity thus automatically turning of the pump so that the fluid can be stored in the reversion tank.
Fig. 4.8: compact solar collector and boiler combination
Fig. 4.8: reversion tank
4.5.4b Anti-freeze fluid It is also possible to use antifreeze fluid in the system. The advantage of this is that it does not matter whether the collector is placed higher or lower than the boilers. 4.5.4c â&#x20AC;&#x2DC;Thermo-siphonâ&#x20AC;&#x2122; This system is based on the principle that warm fluid rises. This means there is a automatic circulation of collector fluid. And thus, there is no energy needed to pump around the fluid. For this it is important that the storage tank should be placed higher than the collector.
Fig. 4.8: compact solar collector and boiler combination
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4.5.4d Vacuum heat pipe collector The heat pipe collector consists out of a number of glass vacuumed pipes place closely next to each other. Above the pipes a water pipe is connected. This water flows to the heat exchanger in the storage tank. The closed heat pipe is halffilled with a special fluid that vaporizes easily with solar heat. In the upper parts of the glass pipes this fluid condenses because of the lower temperature caused by the flowing water. With condensation heat is released into the flowing water which is directly transported to the heat exchanger. Heat pipes are more effective per square meter than conventional collectors.
Fig. 4.13: Vacuum heat pipe colletor
4.6 VENTILATION AND AIR QUALITY Although the energy label is focused on diminishing energy consumption ventilation also plays an important role. Because of more and better insulation and houses are sealed more and more making natural ventilation difficult. For this reason ventilation has become an important subject since this affects the indoor climate which influences health. The so called MAC-value (maximum acceptable concentration) for CO2 can be reached within 2,5 hours in a baldy ventilated room. Also the indoor air becomes humid in a badly ventilated environment which heightens the chance of unhealthy bacteria and moulds. Humid air costs more heating energy as well. The ideal humidity is between 60 and 70%. Due to these reasons it is important to actively ventilate when insulating a house. Although mechanical ventilation costs energy, there are different ways to ventilate and insulate simultaneously in an energy efficient manner. 4.6.1 Saving energy There are a few basic ventilate:
was
to
Ventilation: Informatiecentrum duurzame energie technieken: http://idet.nl/frameset _ woningbouw.htm Milieu Centraal: http://www.milieucentraal.nl/pagina?onderwerp=Vocht%20en%20ventilatie
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4.6.1a Totally natural ventilation opening of windows, doors or grates to let air in or out. This way of ventilating does not lower energy use, but it also does not worsen energy performance drastically. This was visible in the results of the EI-software research in chapter 3. 4.6.1b Natural ventilation with mechanical suction of exhaust air This system has been mentioned in the section on heat pumps. In combination with heat pump boilers it can improve energy efficiency, but in itself it does not automatically reduce energy use. 4.6.1c Balanced ventilation This is a fully mechanical ventilation system in which incoming and exhaust air is mechanically controlled. With this system it is possible to save energy by using a heat recovery system. Warm exhaust air is then used to preheat the fresh incoming air. 4.6.1d Ventilation on demand This ventilation is based on CO2 and moisture measurements. Ventilation only takes place if the air quality is not up to
standards. Because of this, it is and energy saving ventilation system. 4.6.2 Balance ventilation with heat recovery As explained in this chapter in the section on heat pump (boilers), balanced ventilation with heat recovery is a fully mechanical system. This system mostly is used for new buildings or large renovations. So it is less relevant as a solution for normal existing houses. This system has a high efficiency of 95%. The indoor climate is of good quality throughout the year since the system works continuously. Through heat recovery energy is saved as well. 4.6.2a Advantages -Energy Saving Dirty and humid exhaust air form the kitchen, toilets and bathrooms is in fact just replaced by fresh, cleaner air that enters the living room and bedrooms. With heat recovery 95% of the heat is preserved. The ventilators used for these system are automatically regulated low-energy ventilators which are twice as efficient as conventional ventilators. Because of these reasons a lot of energy is saved: about 300 to 400
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m3 of gas per year. When looking at appliances it is gives the greatest improvement of the EI for the lowest price. -Health and comfort Since there is a constant flow of fresh air into the house the quality of the indoor climate is constantly appropriate. Ventilation also keeps the humidity low, preventing mould, bacteria and mites to thrive. With the balanced ventilation system it is very easy to combine an so called bypass cassette. In the summer this can help with saving energy and imp[roving the comfort of the indoors. The bypass cassette is used for night ventilation. AS the air cools at night air is let in and this makes a more comfortable indoor climate possible. To improve the air quality a pollen filter can be added as well. 4.6.3 Ventilation on demand The second possibility to ventilate efficiently is through ventilation on demand. Although this system doe not warm up incoming air, this option is more easy to apply to existing buildings. It is an effective way to ventilate without
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using a system of air ducts as is done with balanced ventilation. Fresh outside air is sucked into the living spaces by means of decentralized units with low sound and air-cleansing features. The exhaust air is sucked out ventilating from the kitchen, bathroom and toilets through a centralized system. The amount of exhaust air that is sucked out, is adjusted to the amount of air coming in. This can be done with a wireless network. 4.6.3a Advantages -Energy Saving This system only ventilates rooms where needed at specified times. Next to this also the amount of ventilation can be regulated. Because of this overuse and draft is kept to a minimum level. -Health and comfort This system makes use of regulators that can be installed by the user to ventilate at certain times with a specified amount. Sensors can be added to this system that switch on ventilation when the CO2 percentage of the air is too high or when the humidity reaches a certain limit.
-Air filters There are different types of filter that can be connected to the ventilation units. The so called G2 filter system can be utilized under standard dust conditions. It blocks 50% to 70% of particles that are larger than 10Âľm as pollens, hairs, sand textile threads mite droppings. An F6 filter can block up to 99% of dust particles larger than 10Âľm.
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Author’s notes Notes Author’s Ending this manual it is fitting to say some things about the process and the motivation behind this manual. Actually my interest in the Energy Label for houses was sparked by the fact that there was a lot of discussion around the subject. The energy label is very new and there seemed to be some problems introducing it. Just before the introduction januari 1st of 2008 a television programme called ‘Radar’ (from the TROS broadcasting company) showed how different inspectors handed out different labels for the same house. I wanted to figure out if any measures were taken to prevent this. Furthermore I was actually curious about the criteria the certification is based on. Naiefly I as a student thought that probably many factors hadden’t been taken into account such as house types, house age and measures to improve energy performance. During my research, though, I found out that this is abslutely not the case. Everything is regulated quite securely through legislation from Europe. It is hard to criticize concrete aspects of the energy certification since actually they are quite complete and clearly outlined. The problem actually lies more in
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the informing of the public. The Ministry of Housing, Spacial Planning and Environment does have a website an shows campaigns on the television, but these media only give very general information on the criteria upon which certification takes place. I think the public has the right to know precisely what these criteria are. Certainly if people have to pay an amount of money to get an Energy Certificate. For this reason I also think it is bad that ISSO-publications are costly. If everybody understands the theme of sustainable building and systems we can meet our goals to a energy efficient and sustainable world more quickly. Finally, I can say I learned a lot by looking for the information I needed to make this reference manual. Going back to the television programme named earlier, I now also no that measures have been taken to maintain the quality of inspections through examination of certifying companies and there inspectors. To stay up to date on developments around energy-consumption and energy saving check: www.new-energy.tv Albert Richters
references Internet legislation
The EPBD Buildings Platform (EU-initiative): http://www.buildingsplatform.eu The EPBD directive: http://www.buildingsplatform.eu/cms/index.php?id=13 http://www.buildingsplatform.eu/cms/index.php?id=118&publication _ id=2904 Papers on standardization by CEN: http://www.buildingsplatform.eu/cms/index.php?id=181#c733 European Commitee for Standardization: http://www.cen.eu
Energy Label
VROM website on Energy Label: http://www.vrom.nl/pagina.html?id=31994 SenterNovem site on the Energy Label: http://www.senternovem.nl/energielabelgebouwen/index.asp
Certification abroad
Energy Performance Certificate U.K.: http://en.wikipedia. org/wiki/Energy _ Performance _ Certificate LiderA (in english): http://www.lidera.info/Lidera _ ingles.html Information on French sustainable building:http://www. twanetwerk.nl/default.ashx?DocumentID=10010 Code for Sustainable Homes: http://en.wikipedia.org/wiki/Code _ for _ Sustainable _ Homes
Improvements
Insulation: http://www.milieucentraal.nl/pagina?onderwerp=Gevelisolatie Glazing: http://www.milieucentraal.nl/pagina?onderwerp=Dubbele%20beglazing#Voor- _ en _ nadelen Central heating: http://www.milieucentraal.nl/pagina?onderwerp=Centrale%20verwarming#Leeg Heatpumps: http://www.sbr.nl/warmtepompen/default.aspx?ctid=3750 Solar heating: -SBR: http://www.sbr.nl/zonneboilers/ -Milieu Centraal: http://www.milieucentraal.nl/pagina?onderwerp=Zonneboiler Ventilation: -Informatiecentrum duurzame energie technieken: http://idet.nl/frameset _ woningbouw.htm -Milieu Centraal: http://www.milieucentraal.nl/pagina?onderwerp=Vocht%20en%20ventilatie
Publications Isso publication 82.1 Isso publication 82.2
Software Software is courtesy of DGMR consultants for industry, traffic, environment and software. Name and version: ECW V2.00
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The Energy Certificate, also known as the â&#x20AC;&#x2DC;Energy Labelâ&#x20AC;&#x2122; has recently been introduced in the Netherlands. There are many questions about what the Energy Label actually is, and what the criteria are for certifying a house on its energy performance. This manual intends to be an overview of the main themes surrounding the Energy Certificate. From legislation to ways to improve the energy performance of your house. Use this manual as reference and as a source of references. Only together we can really save energy.