air leakage

While the importance of air barrier systems in buildings has been understood for decades, it is only in the past decade or so that they have been given appropriate attention in the energy codes of most countries. While at least one country has had air barrier requirements in their codes since the mid-1980s, the “model energy codes” of others have largely ignored the issue until recently.

Purpose of the work

Purpose of the work

Based on the results of the FLiB e.V. research project „Evaluation of leakages in airtight layers – Recommendations for action for construction professionals”, testing methods in building practice for the detection, analysis, and evaluation of leakages are put up for discussion.

Method of approach

Purpose of the work

Purpose of the work

To describe the effectiveness of the thermal anemometer device in assisting airtightness testers to evaluate leakage zones, and specific leakages.

Method of approach

There are two main aspects:

Purpose of the work

Purpose of the work

Condensation risks in wooden building components are mainly caused by water vapor penetrating the cross section of the component through airflow. Even small pressure differentials result in a lot more vapor flowing through a joint of only a few millimeters than that which would migrate by diffusion through many more undisturbed square meters of area.

Heating energy in buildings represents a significant proportion of the total global energy consumption. Uncontrolled airflow through the building envelope contributes significantly to its energy losses.  

Addressing the airtightness of the building envelope is key to achieve thermal comfort, good performance of ventilation systems and to avoid excessive energy consumption. Previous studies have estimated an energy impact on infiltration on the heating demand between 2 and 20 kWh/(m2·y) in regions with temperate climates. In Spain, this issue has not yet been addressed in depth. This study aims to assess the energy impact of uncontrolled air flows through the building envelope in residential buildings in Spain.

Between 2017 and 2018, the Centre for Studies and Expertise on Risks, the Environment, Mobility and Planning (Cerema) organized an airtightness measurement campaign in 117 multi-family collective and single-family French dwellings. These dwellings were built before 2005, that is, before the release in 2005 of the fifth French thermal regulation for new dwellings, that was the first to introduce specific requirements for airtightness.