Abstract
In winter of Japan, solar radiation is considered to be effective for thermal comfort. Therefore, the plan type of house mainly facing to the south has been traditionally adopted. However, high density residence in urban area has required the plan facing to the west or east not to the south. It is needed to investigate the thermal environment in residences facing to the east or west from the view point of thermal comfort. In this paper, thermal comfort indoors is discussed mainly for radiation effect based on field observations for both of the south-north rooms residence and the east-west rooms residence. The effect of indoor solar radiation in winter expressed as the effective radiant temperature is the most intensive in the south room, two times larger than the east and west room. Thermal environment in the room is predominantly formed by solar radiation transmitted through the window, even in case there is no direct solar radiation. Awnings, devices added above the windows to intercept solar radiation, make thermal environment worse in the case of no incidence of direct solar radiation. The thermal comfort indices such as the P4SR and the index of thermal stress were used to evaluate the indoor thermal environment of residence in summer, but they were not able to show the difference in thermal comfort between residences facing to the south and the east or the west.
