Thermal performance and optimized thickness of active shape-stabilized PCM boards for side-wall cooling and under-floor heating system

Abstract

Phase change materials (PCMs) have the potential to maintain thermal comfort of occupants while reducing the energy consumption due to their high energy storage capacity. In this paper, thermal performance of active heat conduction–enhanced shape-stabilized phase change material (HCE-SSPCM) encapsulated boards, fitted with active hot/chilled water pipes were investigated for side-wall cooling and for incorporation in an under-floor heating system. Numerical model based on finite difference method was developed to study the effect of HCE-SSPCM on annual heating/cooling energy consumption saving and indoor air relative temperature fluctuation rate reduction. Our study shows that there exists an optimal location for HCE-SSPCM according to thermal resistance value of each layer and ambient conditions. The recommended thickness and thermal conductivity of HCE-SSPCM wallboard were 30–60 mm and 1–1.5 W·m−1·K−1. Compared to the room without HCE-SSPCM boards, the maximum annual heating energy consumption saving would be 16.2%. Indoor air relative temperature fluctuation rate for heating would be reduced by 41.3%. The maximum annual cooling energy consumption saving would be 4.53%. Indoor air relative temperature fluctuation rate for cooling would be reduced by 56.2%. Our research provided scientific evidences for application of PCMs to reduce energy consumption in residential buildings without sacrificing indoor thermal comfort.