The project was prompted by a dispute over whether ventilation systems with heat recovery perform equally efficiently irrespective of variations in degree of envelope air tightness and climate. Three out of six already existing test buildings that had different degrees of air tightness were chosen for the tests.
The conclusion was, that controlled air change rates of buildings could be achieved only by constructing building envelopes that are as airtight as possible, and are incorporated with balanced mechanical supply and extract ventilation systems with heat recovery. To avoid ‘sick building syndrome’ it is important to make sure that the ventilation systems operate continuously.
The research was financed by National Technology Agency of Finland TEKES. A Doctoral thesis was written on the subject (Binamu 2002).