A Theory on Increasing the Heat Transfer Performance of Building Wall

Abstract

The target of traditional thermal conductivity of wall research is the spatial distribution form. In these studies, the change of thermal conductivity with temperature is neglected. Meanwhile, case studies are always used. This method needs large computation and it is hard to obtain the optimal result. In order to overcome the problems, a new approach has been put forward in this paper. Different from the traditional approach, the new approach solves an inverse problem under the concept of passive ideal energy-saving buildings to obtain the optimal distribution of heat ability with temperature on an external wall. The result for a typical summer day shows the heat ability distribution of a wall in summer is a staircase. It is similar to the heat pipe. It is also found that the optimal heat transfer property of the external wall is closer to the heat pipe when its heat capacity per square meter (ρcpL) is of extreme value. This study can provide guidance to researchers in building materials.