INDOOR CLIMATE OF A LARGE ENCLOSURE WITH UNDER FLOOR RETURN SYSTEM IN HEATING CONDITION

摘要

In large enclosures such as gymnasiums, it is difficult to control the air temperature and create a comfortable climate for people with respect to the heating conditions. There are two main reasons that the air temperature in an occupied area is not increased efficiently in large enclosures. 1) Hot supplied air goes up and stays in the upper area due to buoyancy and it takes long time to reach the lower occupied area. 2) The heat capacity of the building structure affects the air temperature and cold air stays in the lower area. In this paper, field measurements are presented, which verify that the under floor return system in a gymnasium improves these problems. A supply air temperature control simulation and CFD coupled simulation are also presented, and the details of the temperature distributions and time dependence are discussed.