Benedikt Kölsch, Adeline Mélois, Valérie Leprince
Bibliographic info:
13th International BUILDAIR Symposium, 2-3 June 2023, Hannover, Germany

Purpose of the work 
ISO 9972 describes the measurement procedure and calculation methods for determining the air permeability of buildings using the fan pressurization method. However, recent works have strongly underlined the need to improve the method's reliability to measure a building's air leakage rate described in this standard. Indeed, environmental conditions during the test, more specifically wind and temperature differences, may cause a significant error and thus increase the resulting uncertainty. The goal of this study is to lay a foundation to propose a review of the current ISO 9972 standard. 

Method of approach 
The here presented project will point out issues with the current standard. Additionally, a list of incorrect or irrelevant contents will be provided, inducing difficulties in performing the test, inconsistencies with other standards (national standards or ASTM), or points that should be added for clarification or to cover new aspects. CEREMA sets up a working group of experts in the field of building airtightness testing to cover these things, defines the list of issues in detail, and discusses how each problem may be solved. If there is a general agreement, the process of rewriting starts on this issue. If not, it means that research is needed, and studies will be performed to identify the most relevant solution to additions or changes in the current standard. 

Content of the contribution 
The contribution to this symposium will consist in presenting the list of issues that the group of experts identified to improve the current version of ISO 9972 and the first decisions. Furthermore, it will outline a roadmap to further necessary steps to improve the standard.  
Results and assessment of their significance  
The project will start in January 2023 and lead to a review proposal for ISO 9972. Therefore, the first further defined results will be obtained in 2023. 

A revision and improvement of ISO 9972 is important due to more experience and new scientific findings in a more reliable operation and implementation of the fan pressurization method. This work shows the essential findings and most relevant issues that should be addressed in a revision of this standard. 

For further information please contact Benedikt Koelsch at: