A parametric study on the thermal response of a building wall with a phase change material (PCM) layer for passive space cooling

This paper presents a parametric study on the thermal response of a building wall outfitted with a phase change material (PCM) layer for passive space cooling. The effect of six factors was studied via heat flux reductions. The factors were (1) outdoor air temperature, (2) indoor air temperature, (3) insulation level, (4) PCM layer thickness, (5) PCM layer location within the wall cavity, and (6) PCM phase transition temperature. A numerical model, which was verified against experimental data, was developed for this purpose. It was found that an optimal PCM layer location range, which results in heat flux reductions higher than 50%, existed within the wall cavity for each outdoor-indoor air temperature difference. It was determined that PCM layer location within the wall cavity was a first order parameter. As the thermal resistance of the wall insulation increased, the optimal location of the PCM layer shifted slightly toward the outside of the wall. As the PCM layer thickness increased, peak heat flux reductions increased up to a point after which the performance decreased. For the studied cases, the optimal PCM layer thickness was 7 mm. For better results during space cooling, it was observed that the PCM phase transition temperature should be in the range of 27 degrees C - 31 degrees C when the indoor air temperature was set at 24 degrees C.

Automated summary

This paper presents a parametric study on the thermal response of a building wall with a phase change material (PCM) layer. The results show that using PCM layer in an optimal location and under suitable conditions can effectively improve the energy efficiency and space cooling effect of the wall.