Air change rates in dwellings. Luftwechsel in Wohnungen.

Points out that increased levels of thermal insulation in dwellings make ventilation heat loss an increasingly significant proportion of total dwelling heat loss and of great significance for sizing heating installations and selecting their control equipment. Treats attempts to reduce ventilation loss by specifying greater tightness of building structures, especially windows. Investigates whether adventitious air infiltration of a dwelling is still sufficient under these circumstances to ensure minimum required fresh air supply or whether fresh air supply must be supplied by other means.