The purpose of this study is to analyze indoor thermal environment of a highly insulated airtight house in seasonal hot-humid area. In this paper, shelter performance, indoor thermal environment, and energy consumption of a highly insulated airtight house installed with central ventilation system and ordinary houses were investigated in Kitakyushu. The major conclusions of this measurement are as follows. l)This house is excellent in heat insulating and airtightness compared with the ordinary houses. The heat loss coefficient per floor area of the house is 2.53 W/(m^2・K) and equivalent leakage area per floor area of the house is 0.94 cm^2/m^2 measured by the pressrization method. (0.56 cm^2/m^2 by the depressurization method) 2)There is a room for improvement in the indoor thermal environment on air-conditioning during the summer, because this house had no consideration for solar shading and there are some problems about the position of thermosensor for air-conditioning and the balance of the air-flow below the floor level. 3)It is efficient to use the ventilation system installed with a sensible and latent heat exchanger at a highly insulated airtight house diring both summer and winter.
