Practices

QUALICHeCK FACT SHEET #54: Ductwork airtightness in France

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QUALICHeCK FACT SHEET #54: Ductwork airtightness in France: Regulatory context, control procedures, results

 

Ductwork airtightness is an input parameter in the French energy performance (EP) calculation method for new buildings (RT 2012) which influences the energy performance rating. If the ductwork airtightness class used in the calculation is better than the default value (2.5*class A), the ductwork airtightness has to be justified in accordance with a third-party testing scheme operational since 2014. Furthermore, there is a minimum ductwork airtightness requirement set to leakage class A if the building applies for the Effinergie+ or BEPOS labels. Field data collected through the testing scheme suggest that awareness is slowly growing as the leakage class distribution has shifted towards tighter systems compared to previous data.

 

This QUALICHeCK fact sheet focuses on the French regulation requirements since 2014, the control procedures and the field results in the field.

 

The ductwork airtightness scheme in the French EP regulation has just started in 2014 to put more emphasis on the significant impact of duct leaks on the energy performance and indoor climate, and thereby avoid negative effects of building airtightness improvements without appropriate ventilation provision.

 

The approach developed firmly builds on the success of the regulatory and voluntary approach to building airtightness requirements reported in previous fact sheets, yet with significant differences. The approach to ductwork airtightness is based on:

 

  • a voluntary option to value ductwork airtightness in the EP rating, with a default value in the calculation software which can be changed to a better-than-default value;
  • the requirement to justify for a better-than-default ductwork airtightness value either with systematic testing or with the implementation of a certified quality management approach;
  • the development of a competent tester scheme, to secure appropriate testing and reporting;
  • the development of scheme for quality management approaches as alternate ways to justify for a given ductwork airtightness level. Unlike for envelope airtightness, this scheme was never used in practice for duct systems and is under revision.

Preliminary feedback for the application of this approach shows a positive trend, with a clear shift of ductwork systems towards tighter classes. This trend needs to be confirmed and amplified.

 

To download the fact sheet, please visit the relevant QUALICHeCK webpage.