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.

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