Experimental study for the effect of air gap in building walls on heat gain reduction

Abstract

The thermal performance of the building depends on the design and construction characteristics of the walls that interact with the external climate factors and that play a role in creating the thermal environment. Therefore, the current study aims to improve the thermal performance of the building walls by building hollow (double) walls and finding the optimal thickness of the air gap between the walls used as thermal insulation to improve or reduce heat gain, and thus reduce cooling loads. Experiments were carried out on different days in the summer on a model room of sandwich panel with dimensions of 2 m length, 2 m width, 2.4 m height (32.5 latitude) kut city, Iraq. In the southwest wall, two holes were made, the dimensions of these two holes (1 m length, 0.3 m width). Six models of hollow (double) walls were built in these two openings with air gap of 1,2,3,4,5,6 cm thickness . Each model of these walls contains three air gap separated from each other by a layer of cork. The experimental results showed that the greater the thick of the air gap gave the smaller amount of heat gain, therefore, the optimum thickness of the air gap was 6 cm, which gave 19.45 % heat gain reduction more than that of 1 cm thickness.