Reduction the Effect of Heat Transmission for the Heat Capacity of Building Wall in Summer

Abstract

For the wall model of a building affected by solar radiation, a one-dimensional transient thermal conduction analysis was conducted. The purpose of the analysis was to examine the effect of wall thickness and heat capacity on heat transfer. On the westward wall in summer, the temperature distribution indoor the wall became parabolic. Even after the evening, the heat flux direction was outdoor from the wall and indoor from the wall, even in the conditions where the sol-air temperature was higher than the indoor temperature. The re-emit of the outside surface continued from evening till the morning of the next day. In the daytime, the heat quantity that entered from the outdoor air into the wall body did not all flow through the room, but a part was re-emitted to the outdoor. Particularly in the case of materials with low thermal conductivity and high volumetric specific heat, the effect of re-emit was remarkable. Regarding the amount of re-emit, the woody material with a large volumetric specific heat and the glass wool with a small volumetric specific heat were compared. It was suggested that the heat capacity could reduce the heat flux.