Heat Transfer in External Walls Made from Autoclaved Aerated Concrete

Abstract

The paper is devoted to the analysis of heat transfer and humidity migration processes in walls made from autoclaved aerated concrete blocks. The paper gives theoretical calculation of heat transfer and humidity migration processes in autoclaved aerated concrete walls as well as based on practical measurements. Analyzing experimental data, the model for heat transfer and humidity migration processes in walls made from autoclaved aerated concrete blocks was created and tested. The influence of drying process in autoclaved aerated concrete wall on the heat transfer process of the wall was also studied in this paper. The offered model of calculations takes into account the property of autoclaved aerated concrete as a porous material to enable the most accurate description of heat transfer and humidity migration processes in the external walls of enclosures in various exploitation conditions. Humidity migration in autoclaved aerated concrete takes place from closed micro pores to smaller semi opened ones, and then to bigger connected pores. In contrast to already known calculation models of the heat engineering qualities of external walls this model takes into account material internal structural changes, which consider the irregular structure of autoclaved aerated concrete, allowing for each separate diffusion process in layers