Abstract
This paper investigates the indoor thermal environment, and determines existing problems in energy efficiency and comfort with an emphasis on the importance of the position of small openings, taking into account the resident's lifestyle. Measurements were performed in a well-insulated and airtight house in Japan. The distribution of velocity and temperature at the center-plane of the living room, wall surface temperature and the temperature across the five undercut doors were measured under the condition that all interior doors and exterior doors were closed. The measured results agreed well with the predicted results by CFD analysis. Further, by these CFD simulations, it can be seen that there has been significant improvement in the indoor thermal environment after adjusting the small openings to the optimal position. Next, the open and closed status of interior doors in winter and summer was estimated based on the measured room temperatures over a long period. The results show that interior doors are usually closed in winter and during the summer period when the air-conditioning system is in operation, while they are open when the air conditioning system is not in use. Generally speaking, it is more effective for installing uppercut doors to improve the indoor thermal conditions both in summer and winter than undercut doors, and thus the effect is strongly influenced by the resident's lifestyle.
