LAUSR

Abstract Long-term monitoring was performed between December 2017 and November 2018 on cool roof–applied building (CR) and non-cool roof–applied building (NCR). The study was conducted in Changown city South Korea, which has a humid subtropical climate, to identify the temperature reduction effect on different building layers (rooftop surface, ceiling surface and air, and room air). With respect to the temperature reduction effect by layer according to the application of a cool roof (NCR−CR), the rooftop surface temperature showed an increasing temperature reduction effect with increase in air temperature. Ceiling surface and air temperatures showed similar temperature reduction effects in summer and winter, whereas room air temperature showed greater temperature reduction in the winter than in summer. This finding was contrary to the results for room air temperature in the winter reported in previous studies. In conclusion, the present study confirmed that applying cool roofs on buildings located in humid subtropical climates has more pronounced effects in terms of reduced indoor temperature (ceiling surface, ceiling air, and room air) in winter than in summer. The long-term measurement results produced in this study may be used as basic data for establishing criteria for cool roof performance and product selection in South Korea.