Air quality and energy conservation by different ventilation strategies.

The increasing awareness that indoor air quality aspects may restrict energy conservation by infiltration and ventilation measures has led to extensive investigations of different ventilation strategies. Aiming at a reduction o f energy consumption air infiltration and ventilation rates have t o be minimized. But in order to maintain healthy, safe and comfortable conditions for the inhabitants and to avoid damages to the building fabric the outdoor a i r supply should not remain under minimum ventilation rates. To find out advantages and disadvantages of various ventilation systems, to assess the role these systems will play in different ventilation strategies and for defining ventilation standards in the Federal Republic of Germany in 1980 the main activities of a r&d programme " Air Infiltration and Ventilation in Residential Buildings" had been started, supported by the Federal Ministry for Research and Technology. First results show that the conflicting requirements energy conservation and adequate indoor air quality in many cases best are met by mechanical ventilation and heat recovery. In unoccupied test houses as well as in occupied buildings the total energy consumption coul be reduced by 10 t o 20 %. Inhabitant's behaviour and functional deficiences o f the systems can decrease these effects in practice.