Inclusion of methyl stearate/diatomite composite in gypsum board ceiling for building energy conservation

Gypsum board with the advantages of low cost and ease of placement is widely used in buildings as ceiling and interior wall coverings. The interest in phase change material integrated gypsum board has been growing significantly over the last few years. In the present work, a composite form-stable phase change material (FSPCM) for use in gypsum board was developed based on methyl stearate and diatomite by a direct impregnation method. The material properties and thermal behaviour of the methyl stearate/diatomite composite were examined through different characterisation techniques to check its suitability for use in building materials, and particularly in gypsum board. Thermal cycling tests and thermogravimetric results confirmed that the FSPCM exhibited excellent thermal reliability and stability for long-term thermal management applications. The FSPCM was then integrated into gypsum board for potential use as building false ceiling for energy conservation. A small-scale test chamber with FSPCM-integrated gypsum board ceiling was prepared and modelled. The thermal/energy performance is evaluated and an economic analysis is performed against the conventional gypsum board without FSPCM in real environmental conditions. The results show that the use of FSPCM in gypsum board ceiling is economically feasible with cooling load savings of 16.2%.