Using lightweight cement composite and photocatalytic coating to reduce cooling energy consumption of buildings

The LCC has a thermal conductivity of 0.39 W/m.K, 80% lower than that of the concrete (1.98 W/m.K). The photocatalytic coating increases the solar reflectance of the LCC specimen from 0.41 to 0.78 without significant effect on the thermal conductivity. The LCC and photocatalytic coating reduce the heat gain in 9 h exposure to simulated sunlight by 33% and 54%, respectively, while their combination reduces the heat gain by 69%. The inner surface temperature of the specimens is reduced by 3.7 °C, 4.3 °C, and 8.0 °C after 9 h exposure to simulated sunlight due to the use of LCC, photocatalytic coating, and their combination. The results indicate that the energy consumption for cooling building interior can be reduced significantly by the use of the LCC, photocatalytic coating, or a combination of these.