There are various kind of airtightness tester organizations. Some organizations are led by the qualification scheme in the country for example the British ATTMA and iATS and the Belgian BCCA. In France Qualibat is in charge of the qualification process with about 1000 qualified testers and Syneole is the trade union for airtightness testers. Among other things, Syneole represents airtightness testers in standardization and regulation working groups and is part of the commission for tester qualification.

In Germany the association FLIB, more than 300 members, helps to improve both the implementation of airtightness and the measurement protocol by editing guidelines and contributing in standardization committee (such as for ISO 9972’s national annex). 

There are also smaller associations of testers, such as the Association Blower Door CZ (A.BD_CZ) in the Czech Republic, gathering 21 members in 2022, which represents about half of the testers operating in the country. Its objective is also to improve measurement practice by performing round-robin tests with its members.

Since September 2012, TightVent hosts an airtightness associations committee (TAAC) with representatives of national/local associations or groups including, Syneole, A.BD_CZ, FLiB, iATS and ATTMA.

Requirements depend on the country and the context of the measurement. Most EU countries include in their regulations either required or recommended minimum airtightness levels with or without mandatory testing. There are several countries (e.g.United Kingdom, France, Belgium, Ireland) where, by regulation, airtightness testing is mandatory for certain building types or in the case of specific programmes [1].

References

[1] Leprince V., Kapsalaki M., & Carrié F., R., “VIP 37: Impact of Energy Policies on Building and Ductwork Airtightness”. AIVC, 2017.

In most European countries the building preparation is based on ISO 9972 requirements. However, the interpretation of these requirements may differ from one country to another, and based on different building preparation rules.

Building preparation errors are probably the dominant source of uncertainty in an airtightness test. The reference testing protocol in Europe is described in ISO 9972, in the USA in ASTM 779-19, and in Canada in CGSB 149.10-2019. Nevertheless, ISO 9972 proposes 3 different methods (with different preparation requirements):

• Method 1: Test of the building in use
• Method 2: Test of the building envelope
• Method 3: Test of the building for a specific purpose according to a standard or policy in each country

Many countries have developed specific guidelines to detail or adapt to the ISO 9972 requirements.

A study has been performed to compare building preparation rules for airtightness testing in 11 European countries [1]. Information has been collected through a questionnaire sent to TAAC (TightVent Airtightness Associations Committee) members [2]. It has been found that building preparation differs significantly from one country to another and that methods 1 and 2 described in the standard are either too detailed or insufficiently described to fit the specificities of each country. This has supported the creation of “method 3” in ISO 9972:2015 (which is one of the major changes compared to former EN 13829:2000). "Method 3" needs to be defined at the national level which allows to adapt the measured extent and the building preparation to the purpose and context of the test. More specifically, it allows each country:

• to describe more precisely the basic principles of the preparation to avoid ambiguities; and
• to have some flexibility to specify rules consistent with their energy performance calculation method.

The main obstacles to harmonize pressurization test methods between countries are:

• In each country the test method shall be consistent with the energy performance calculation method. But there are significant differences in calculation methods between countries in the way airflow rates are taken into account.
• There are specific devices and construction traditions in each country that may require tailored rules.

Therefore, it is clear that building airtightness should not be compared between countries unless precaution is taken in the sample analyzed and in the interpretation of the results.

The figure below shows how 6 openings categorized as "other" in the standard are prepared in the countries asked in the above-mentioned study. It shows, for example, that in some countries the air exhaust of a clothes dryer will be left open while in others it will be sealed.

References

[1] Leprince V. & Carrié F.R, "Comparison of building preparation rules for airtightness testing in 11 European countries", 35th AIVC Conference "Ventilation and airtightness in transforming the building stock to high performance", Poznań, Poland, 2014

[2] TightVent Airtightness Associations Committee (TAAC), "TAAC Deliverables", Retrieved on April 6, 2022

Eurovent Certita Certification have a certification programme for rigid and semi-rigid ventilation ductwork systems divided into the following sub-programmes:

• Rigid metallic ductwork systems with circular cross-section (DUCT-MC);
• Rigid metallic ductwork systems with rectangular cross-section (DUCT-MR);
• Semi-rigid non-metallic ductwork systems predominantly made of plastics (DUCT-P);

Each sub-programme applies to ductwork systems fitted with integrated sealing solution as described in the Technical Certification Rules ECP-19.

This programme contains amongst other, airtightness and static gauge pressure limit criteria and is based on European standards.

The certification process is to periodically check the resilience of the company quality system by auditing manufacturing sites and the certified performances of a ventilation system by a third-party laboratory measurement.

The certification brings the supplier products, its technical documentation and quality resilience to a reliable level.

The DUCT program does not cover other types of ventilation ductwork elements like flexible ducts, double-wall ductwork or ductwork made of insulation ductboards.

The Swedish type approval for metallic ducts has been a very important driver for the ventilation business. The requirement based vision has driven the ventilation business since the beginning of the 1970’s  to sustainable solutions with demands on airtightness and strength without a demand for sheet steel thickness. This has led to airtight energy efficient  duct work solutions with as little material as possible.

The Swedish Type approval issued by governmental Boverket is only valid in Sweden but has been widely used in other countries as well. There are two Swedish bodies accredited by SWEDAC to issue type approvals, RISE and Kiwa.

Finland has developed their own approval based on the Swedish type approval and is handled by the Finnish Ministry of Environment, and Eurofins Expert Service Oy is authorized by the Finnish Ministry of Environment to issue type Approvals for building products.

TAAC  is the TightVent Airtightness Associations Committee, launched in September 2012 by the TightVent Europe platform, with the primary goal to bring together national associations and experts in order to promote reliable testing/inspection and reporting procedures.

The scope of TAAC includes various aspects such as: building & ductwork airtightness requirements in the countries involved; competent tester schemes in the countries involved; applicable standards and guidelines for testing; inspection of ventilation systems; collection of relevant guidance and training documents; share of knowledge and experience; and information on ongoing research work in the field of building and ductwork airtightness.

At present the participants are from Belgium, Czech Republic, Estonia, France, Germany, Hungary, Ireland, Latvia, Netherlands, Poland, Portugal, Spain, Sweden, Switzerland, UK and the US.

In case you are interested to join this initiative, please write an email to: info@tightvent.eu.

Links:

For more information please see:

• About TAAC: https://tightvent.eu/taac
• TAAC participants: https://tightvent.eu/taac/taac-participants
• TAAC deliverables (publications, webinars etc.): https://tightvent.eu/taac/deliverables
• Becoming a Tightvent partner (for companies): https://tightvent.eu/contact
• Becoming a TAAC member: https://tightvent.eu/taac/contact-join