換気および壁面相互ふく射を考慮した多数室室温・熱負荷計算法

抄録

Recently, residential houses tend to be well insulated. As the heat loss through building envelops by heat conduction is considerably reduced with well insulation, the portion of heat loads caused by the natural ventilation is increased in such houses. On the other hand, room surface temperatures are important when considering the thermal comfort of building. Therefore, the natural ventilation and radiant heat exchange are essential factors for the computer simulation to predict the thermal comfort and the heat loads. A method for the calculation of room temperature variation combined with natural ventilation and radiant heat exchange among room surfaces is described in this paper. Since the temperature of room surfaces are related each other with radiant heat exchange among the surfaces, the dimension of the simultaneous equation composed of heat balance of the room air and the building components usually exceeds 100 for a ordinary sized house. In addition to this the air flow balance equations for the calculation of natural ventilation1 are non-linear. Therefore long processing time is needed if solving the simultaneous equations directly solved, in order to save the processing time the method reducing dimension of heat balance equations to the number of the total rooms by algebraic operations is used in this study. The Newton-Raphson method with the accelerate coefficient was used for speedily convergence of non-linear simultaneous equations. As the proper initial room pressures are needed for solving the equations, the method finding the initial pressures is also described. Example calculations were carried out for a well insulated house using the average weather data of Tokyo in order to examine the effects of the air flows in a residential house on the heat loads and the room temperature variations.