FEM thermal performance analysis of multi-layer external walls during typical summer conditions considering high intensity passive cooling

Abstract

Quality of indoor environment as well as energy consumption in buildings are a growing concern in the context of overheating of buildings, as the EU legislation is primarily focused on heating season. The statistical data of EU have shown that there is already a large amount of buildings not comfortably cool during summer and the trend is increasing. Therefore, the main goal of this paper is to evaluate the influence of high intensity passive cooling as one of the passive solutions for overheating of buildings on the overall thermal response of building envelope systems. Specifically, a variety of multi-layer external walls during realistic summer time conditions of Central European climate were considered. For this purpose, a finite element method was used to simulate the non-stationary thermal response of several heavy weight and light weight external wall constructions. The results have shown that indoor air change intensity as well as internal heat gains have a significant impact on heat flow through the building envelope. Clear difference in thermal behaviour was detected between light weight and heavy weight envelope systems, as a consequence of different thermal mass and thermal insulation position. While the results of the conducted study represent guidelines to architects, designers, investors and other stakeholders in building industry, the growing popularity of light weight constructions, especially in residential buildings, dictates further research of building envelope configurations and passive cooling system impact on the thermal response of constructions.