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Many CEN-standards are ISO-standards, e.g. EN ISO 13790, 6946, 10077 and 14683. How can these standards make reference to the se

If an ISO (International Organization for Standardization) standard is also an EN ISO standard, then it is a European standard just like any other EN (European) standard. As illustrated in several CENSE Information Papers, e.g. P92 or P94...
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why was the term “heat transfer” introduced instead of “heat loss” in the CEN standards to support the EPBD?

Heat is lost from a building or building part by transmission or ventilation, as a result of a positive temperature difference between the indoor and outdoor (or other) environment. However, if the indoor temperature of the considered...
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Does the airtightness depend on construction type?

Measurements usually show that light (e.g., timber-frame or steel) constructions are leakier than massive construction, but this is not bound to be. In fact, PassivHaus houses are often light constructions and are very airtight. The...
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What is the effect (extent) of the aging process in the airtightness performance?

There is little information on the subject at the moment. A study referenced in a paper written by Erhorn et al. and presented at the 2008 AIVC conference shows airtightness values of 31 “Passivhaus” houses at commissioning and 2 years...
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How is a pressurisation test performed on single apartments?

The airtightness measurement of single apartments is usually performed the same way as in individual houses. Therefore, there is no specific protocol to balance the pressure between the apartment under test and other apartments. Different...
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How do you measure the airtightness of multi-family buildings?

Measuring or evaluating the airtightness of multi-family buildings is challenging as there may be technical and practical difficulties that prevent from pressurizing the whole building. These difficulties include for instance building...
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Why are there different indicators (n50, q50, w50, etc.)?

Now in Europe, many countries have adopted the n50 value (i.e., the leakage flow divided by the volume) for their EP regulation while others (e.g., Belgium, France, UK) use the envelope area normalisation. The rationale behind this latter...
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Is it possible to compare airtightness measurements between the Member States?

To some extent yes. A collection and analysis of some data collected through the ASIEPI partners has been presented at the 2008 BlowerDoor conference (Papaglastra et al., 2008). However, caution should be exercised when comparing...
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How do you deal with envelope airtightness value in energy losses calculation?

There are three major ways to estimate this impact: - the simplest is to evaluate the infiltration losses based on a rule of thumb established by Drubul in 1988 (*) and suggested by Kronvall (**) in 1978. The rule says that the...
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What is the energy impact of envelope leakage?

Energy wastage due to envelope leakage has been estimated in various countries through numerical simulations: - in Belgium and in Germany, the energy impact has been calculated to be about 10% of the energy performance level for individual...
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Is ductwork airtightness good in the Member States?

The SAVE-DUCT project has shown that there are large discrepancies between countries on this subject (the project report is available through AIVC at www.aivc.org). Analyses performed on measurements results have shown that Belgian and...
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What are the minimum requirements regarding airtightness for low-energy buildings?

To our knowledge, only two low-energy labels include a minimum requirement for low-energy buildings: - the PassivHaus standard (www.passivhaus.de) that requires an airtightness better than 0.6 air changes per hour at 50 Pa (n50 <= 0.6...
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Is there a database to see which levels of airtightness are compulsory in EU MS, or guidelines?

There is no up-to-date document at this time. Anwered by: Rémi Carrié and Gaëlle Guyot (CETE de Lyon) Date: 2008/12/12
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Is there a certification process for the pressurisation test technicians?

There exists a certification scheme in Germany which is not compulsory to perform tests. There exists a compulsory authorisation process in France for technicians who perform test on BBC-Effinergie buildings. To our knowledge, there is no...
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Are there countries where airtightness testing is compulsory?

To our knowledge, the UK is the only country that has made testing mandatory. This has been in force since 2002 for large buildings and extended to most buildings in 2006. Anwered by: Rémi Carrié and Gaëlle Guyot (CETE de Lyon) Date: 2008...
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Are the methods validated, which are offered for the calculation of energy needs in EN ISO 13790?

The monthly method and the simple hourly method were indeed validated by comparison to detailed calculations and to the actual energy use of several buildings (monthly values). The monthly method for heating has been in use since 1990. (...
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Regarding the methods offered for the calculation of energy needs in EN ISO 13790. What is the difference between the monthly me

This is explained in detail in annex I.5 of the standard EN ISO 13790. The main difference is that the degree day method contains an implicit assumption about the effect of internal and solar gains on the heat balance (independent of the...
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Where can I find background information and more technical information, concerning the content of EN ISO 13790?

Background information on the origin and rationale of the monthly method can be found in Annex I of the standard EN ISO 13790. It also contains more technical information concerning the content of EN ISO 13790, as well as Annex H of the...
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Why are different methods offered for the calculation of energy needs in EN ISO 13790?

Each method has its own applications: the seasonal method is the simplest, but it is applicable only in climates where seasons are clearly defined, the monthly method is easy to use in buildings without or with small intermittence effects...
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How can I make the energy performance of systems visible on the Energy performance certificate (the energy label)?

This is possible if not only the overall energy performance (in MJ or kWh), but also the system energy performance is reported separately. The same goes for the local production of renewable energy. EN 15603 describes how this could be...