air handling unit (AHU)

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.

The airtightness test of the building is one of a few building envelope measurements used in practice, which is quantitative, not just qualitative as e.g. infrared thermography. The so-called blower-door test result may be a measure of the building design and construction quality and could also be used for the energy demand for heating and cooling analyses.