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Reports of the ASIEPI project on building and ductwork airtightness

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These reports are key results of the work performed on building and ductwork airtightness within the ASIEPI project. They present the work done and the acknowledgments addressed through the different deliverables and productions, from October 2008 until March 2010.


The summary report provides a synthesis of the work while the full report gives more details about the issues addressed. Both include information for policy makers regarding the way better envelope and ductwork airtightness is stimulated in the member states, including indications on the impact of the measures taken to transform the market.


Building and ductwork leakage are detrimental to energy conservation, comfort, and hygiene. They can cause building damage and can prevent proper control of the ventilation airflow rates. Through the ASIEPI project, we have identified that while some key elements for a market transformation on envelope airtightness are under development in many countries, status quo seems to prevail for the duct market. With the objective of all new constructions being “nearly zero energy buildings” in 2020, policy makers need to know how better airtightness can be stimulated. Within ASIEPI, we have come to the following recommendations :


To the question “How to promote a market transformation of envelope airtightness?” the following 3 main recommendations can be formulated:


  • to include airtightness with fair reward in the EP calculation methods of the member states, combined with compulsory measurements and/or quality management approaches for claiming such reward in the EP-calculation, in labels and in subsidies;
  • to promote cooperation with building professionals through development of practical tools and through pilot and research projects;
  • to promote a global dissemination strategy depending on the target which is potentially wide as it includes owners, builders, designers, craftsmen, measurement technicians.

To the question “How to support a market transformation of ductwork airtightness?” Based on the Scandinavian success stories, the following 3 main recommendations can be formulated:


  • to develop dissemination on the benefits connected to good ductwork airtightness aimed at the building professional community and at industries to convince them that airtight round duct systems have many additional benefits (low costs, space efficiency) over both rectangular duct systems and round ducts without pre-fitted seals;
  • to support industrial development of efficient products because a technology push was clearly observed in Scandinavia where 90-95% of ductwork installed are spiral- seam steel circular ducts with factory-fitted sealing gaskets;
  • to include requirements in national regulation, with penalties for non-compliance, and to develop technical guidelines and/or standards.

Major contributions of ASIEPI on the “building and ductwork airtightness” issue are described in the summary report. They include:


  • A review of regulations requirements, partly based on a questionnaire submitted to experts within the 13 countries represented in the consortium, and summarised in one conference paper;
  • A focus on 5 countries where a market transformation is underway, with 2- to 4-page reports that analyse the market transformation mechanisms;
  • A focus on technical issues, with a series of information and conference papers on very low-energy buildings, calculation and measurement methods;
  • Awareness raising, namely through several national and international workshops, internet sessions, and presentations in conferences.