Draught measurements in ventilated and non-ventilated buildings.

Measurements of the air temperature and air velocity were carried out in four buildings without air-conditioning using a newly developed anemometer whose sensitivity allows the examination of the dynamic behaviour of air movements. Recent results describing the physical reasons of draft problems were employed in order to re-examine the correlation between air movements and draft problems in a building. From the resulting evaluation criteria follows that besides, the environmental temperature and the mean air velocity, the magnitude of the turbulent fluctuations is important . Measured with these criteria the air movements of all buildings without air-conditioning lie within the range of thermal comfort. The air movements in most of the buildings with air-conditioning lie also in the range of thermal comfort, however, almost half of the values lie within the range of thermal discomfort or in the transitional range. This result coincides almost entirely with the results from questionaires about the thermal comfort in the tested buildings. The number of complaints about draft problems is significantly higher in air-conditioned rooms than in rooms without air-conditioning.