Applicability of CFD simulation to designing passive architectures was investigated using a passive solar room with a Trombe wall system inside it. In the investigation non-steady numerical simulation was performed to predict thermal environment in the test room. Two weather models assuming a typical fine winter day were compared, one was the model based upon the data in Osaka and the other was that in Sapporo. The test room has glazing in the south side wall and in the north side one. Each glazing was covered with an insulating door during night.

Thick insulation in buildings offers great potential not only for decreasing cooling load but also for changing its calculation method, and for changing system design, operation or control of the system and the thermal environment of the room. The research results of room air temperature changes in well-insulated buildings, show the effects of the daily swing of outdoor temperature and solar radiation are quite small. A simple calculation method for cooling load based on steady state theories is available for such buildings.

In order to design an environment-conscious house, it is desirable for summer indoor environment, to re-examine thermal conditions warmer than thermal comfort. The role of air movement is important, as it reduces the magnitude of discomfort. This paper discusses the comfort produced by air movement considering two main sensations; coolness and strength of movement, based on results obtained by a series of experiments carried out with five male and five female subjects.

As the sensible heat gain or cooling load are decreased by using thick thermal insulation in a building, the need for dehumidification increases. Especially in Kushiro, it is rather cool and humid in summer because of its foggy weather. In this study, two types of dehumidification systems were developed and their performances were examined. The first is a heat-recovery type, which uses a cooling coil and a sensible heat exchanger. The second is a moisture-absorbent type, which uses heating and cooling coils and an absorbent.

Although most new houses in the Hokuriku region are equipped with air conditioners, some people living in farmhouses still feel that cross ventilation is more desirable. Comparative measurements were made between a new house and a farmhouse. Simplified simulations were also carried out to clarify the effects of thermal insulation and earth floors on cross ventilation in summer. The role of thermal insulation in hot and humid regions is different from that in cold regions, where there is a large difference between outside and inside air temperatures.

In the design of natural ventilation systems, there is a wide range of possibilities with regard to the selection of window type and the positioning of windows in the facade. Each window type has unique characteristics, which affect air flow and thermal comfort conditions in the occupied zone. A combination of various window types and faade locations in a room should be capable of improving thermal comfort and minimising draught risk.

The influence of wind is an important part of the bioclimatic town planning criteria. Ventilating and mechanical action of the wind towards reduction of air pollution in urban areas is becoming increasingly important and must be analyzed along with other factors such as · thermal losses, comfort etc.