air leakage

The durability of air barrier systems is a topic that is rarely discussed during the design phase of most projects. An unfortunate amount of effort is spent on drawing details and specifying products with the sole intention of meeting energy code requirements, with much less thought being given to how those systems actually will be constructed and possibly worse – how those systems will fare over time.   

Air leakage in a rotary heat recovery device in air handling unit (AHU) was studied by a laboratory experiment. The experiment tested a commercial AHU with rotary heat recovery and equipped with various leakage control techniques, e.g. Automatic Leakage Control (ALCTM), rotor speed control (RSC) and purge sector, etc. In the test, exhaust air transfer ratio (EATR ) of the AHU was measured by tracer gas method at two levels of airflow rates in both constant airflow and constant pressure operation modes of the test AHU.

Unintended airflow through building envelopes leads to an increased demand in heating and cooling energy. The most common way to measure air leakage of buildings is the blower door test, which quantifies the overall leakage rate of one room or a building. To reduce air leakage and associated energy loss in new and existing buildings, it is necessary to identify leak locations and prioritize sealing of more substantial leaks.

The fan pressurization method is a common practice in many countries for measuring the air leakage of houses. The test results are sensitive to uncertainties in the measured pressures and airflows. In particular, changing wind conditions during a test result in some pressure stations having more or less uncertainty than others. Usually, it is necessary to fit the measured data to the power-law equation.

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.

In October 2016, a research project was completed on the "Evaluation of faults in airtight layers recommended action for construction practitioners." Written by the Fachverband Luftdichtheit im Bauwesen e. V. (Association for Airtightness in the Building Industry), the Aachener Institut für Bauschadensforschung und angewandte Bauphysik gGmbH...

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. One of the FLiB working groups has taken on the task of testing...

Airtightness/air permeability are inseparable from leakages and their detection, categorization, or evaluation. The diverse contexts due to the main construction methods, structures, materials used, individual conditions on site for each building, and the perspectives of the different disciplines regarding airtightness, make it hard to take quick...

To describe the effectiveness of the thermal anemometer device in assisting airtightness testers to evaluate leakage zones, and specific leakages. There are two main aspects: While the building is pressurised to 50Pa use is made of internal doorways to close off each room to make a 'zone', and an airspeed reading is taken...

Leakages in the building envelope may cause severe damage to a building and thus inevitably become an issue not only for building physics, but also for the law. In the case of such legal disputes, the different perspectives of scientists and lawyers frequently turn out to be a problem. This is further acerbated by the different levels of...