Hybrid demand controlled ventilation system

The purpose of this system is to provide one improved ventilation system allowing significant good indoor air quality, heating (and cooling) energy savings and acceptable thermal comfort on summer, by using especially renewable energy.This concept is based on sensors measuring relative humidity in bathroom and kitchen, occupancy in bedrooms and toilet, and agitation (i.e. the number of people) in the living room.Driving forces are as much as possible natural ones (thermal stack effect, and wind induction), assisted with a photovoltaic supplied roof cowl fan whose speed is adapted to only compensate natural stack effect deficiency in the hotter times.According to total ventilation forces evaluation, motorised inlets and extract grilles are driven in order to ensure suitable air renewal in each room, in correlation with need measurements.In case of very hot times, a night cooling mode consist in an over-ventilation (maximum fan assistance) and in the opening of motorised windows, during summer nights, when outdoor temperature is colder than indoor.