Draught Risk from Cold Vertical Surfaces

Glazed facades and atria have had a boom in the 1980's as an architectural feature in building design. Natural convective flows from these cold surfaces are in winter time, however, often the cause of thermal discomfort and there is a need for research to improve the design methods.The objective of the research is to develop expressions for the airflow beyond the floor area, which influences the thermal comfort in the occupied zone. Measurements of velocities and temperatures are carried out in a two-dimensional test case.They show that the characteristics of the flow in the near floor region are very similar to the characteristics of stratified flows. Expressions have been developed for the rate of decrement of the maximum velocity with distance from the surface and for the maximum temperature difference between the cold airflow along the floor and the rest of the occupied zone