Abstract
The basic principle of passive solar heating systems is to make a proper combination of the building components, especially the thermal mass with the element of solar heat collection such as windows, in addition thermal insulation of building envelope under the given climate. In spite of the heat storage element is more important among them, the behaviors of the thermal mass have not yet been known thoroughly. In order to enable one to design more comfortable indoor climate and the energy conservation in a building, to clarify the behaviors of the thermal mass and to know the ways to decide the good size of the thermal mass for a building are required. In this paper, by the results of the experiment using test cells, the energy consumption of auxiliary heating and the behaviors of the thermal mass in direct gain systems are discussed. The principal results were as follows ; 1. There is a tendency that the maximum houly energy consumption dicrease with increasing heat capacity of test cell. 2. The daily energy consumption of the test cell with the thermal mass are influenced by not only the solar gain of the day but also those of several days before. 3. The swing of temparature in the thermal mass vary with the thickness of the thermal mass, and therefore the effect of thermal mass on the energy consumption of auxiliary heating depends on the thickness of thermal mass.
