Study of variants to classical mechanical exhaust ventilation systems by using mechanical exhaust in habitable rooms

Nowadays, due to the higher energy performance of dwellings, ventilation plays an increasing role in maintaining a good indoor comfort. Therefore new ventilation strategies in combination with demand controlled ventilation are needed to accomplish high energy-efficient ventilation (limiting ventilation losses and auxiliary energy consumption) while providing good indoor air quality, thermal and acoustic comfort.
The classic ventilation approach of mechanical extract is based on air supply in the living rooms which is transferred towards the wet or functional rooms where the air is extracted. In this paper a modification on this principle is presented with natural air supply in the living rooms and mechanical extraction in bedrooms (night zone) or each room.
By means of different simulation studies the performance of these ventilation strategies combined with demand controlled is compared in terms of indoor air quality and average air flow rates according to different national methodologies (Belgium and France). The evaluation of the indoor air quality is based on the exposure to CO2 and relative humidity in the rooms.
Besides simulations, results of an in-situ measurement campaign of a ventilation system according to the modification are presented.
It is found that by applying the modified ventilation strategies a remarkable better indoor air quality and even a more energy efficient ventilation -compared to the classic ventilation approach- can be achieved.