Ceramics-Silikáty 68, (3) 366 - 377 (2024)

Energy conservation and emission reductions are becoming increasingly important in the construction industry due to the economy's rapid growth and the acute energy scarcity situation. Phase change composite foamed cement materials were researched and manufactured to address the performance of thermal insulation materials in the integrated construction of building photovoltaic systems. The results show that the phase change material mainly exists in the free form between the pores of the foamed cement, and a small part of it is adsorbed on the surface of the foamed cement. As the mass fraction of phase change materials increases, the thermal conductivity of foamed cement materials gradually decreases, from 0.0708 W/(m-K) to 0.0534 W/(m-K). The higher the density and quantity of the phase change material added to the foamed cement, the higher the foamed cement's thermal conductivity. The interior surface temperature of the roof increased by 1.6 °C at night and decreased by 2 °C during the day thanks to the phase-change composite foamed cement roofing. The direction of the heat flow on the inner surface of the ordinary roof and phase-change composite foamed cement roof is basically the opposite. The phase-change composite foamed cement roof absorbs heat during the day and emits heat at night, and it reduces the heat gain better, with an average heat gain reduction of 48.5% and 59.9%, respectively.