Do ventilation systems accomplish the necessary indoor air quality in low energy houses?

Abstract

The aim of the EU EPBD is to realize lower energy consumption in buildings, without neglecting the indoor air quality. A suggested measure is to improve the air tightness of the building, combined with a well-designed ventilation system to guarantee a good indoor air quality. The research presented here analyzed the indoor climate of 71 recently built dwellings in Flanders, Belgium, ranging from standard execution over low energy up to even energy positive houses. These houses represent a wide range of air tightness levels and different types of ventilation systems. In each house, temperature, humidity and CO2 concentration were monitored in living room, master bedroom and bathroom during 2 weeks in winter. These measurements were complemented with air tightness measurements. Results showed good to reasonably good indoor air quality in all houses, independently of the type of ventilation system. Also the internal humidity was very acceptable in almost all houses. Only in some dwellings with a natural ventilation system, the average indoor climate class in the living room reached a level ICC3 or ICC4. Furthermore, no correlation was found between air tightness and indoor air quality. Even in very air tight dwellings, good indoor air quality was achieved, also with natural or mechanical exhaust ventilation.