NO-94-16-1 -- Stratified Flow in Rooms with a Cold Vertical Wall PDF

Natural convective flows from cold vertical surfaces are often the cause of thermal comfort problems in winter. The objective of this research is to improve the design methods for convective flow along cold surfaces and to develop expressions for the airflow beyond the floor area that influences the thermal comfort in the occupied zone. The velocity and temperature distribution are measured in the flow beyond the floor area in both a two- and a three-dimensional air distribution case. The results in the near-floor region show that the flow close to the cold surface has the same characteristics as those in isothermal wall jet flow. Furthermore, the flow far downstream has the same characteristics as those in gravity currents. Expressions for the maximum velocity and the temperature difference in the vicinity of the floor have been developed in both test cases. These expressions show a decrement of both parameters and, therefore, an improvement in thermal comfort with increasing distance to the vertical surface.

KEYWORDS: cold, walls, vertical, thermal comfort, winter, research, air flow, temperature distribution, speed, measuring, floors, properties, isothermal, testing.