Investigation of Temperature Reducing Performances of Passive Daytime Cooling Materials under Outdoor Conditions

Abstract

Due to the rapid depletion of conventional energy sources and rising fuel and energy costs, efforts to reduce energy consumption have increased rapidly in recent years. Research shows that a significant portion of the total energy used in buildings (20% - 40%) is spent on cooling. The high production and operating costs of existing cooling systems, as well as their long-term harmful effects on the environment and human health, have led to alternative solutions that can reduce their use. One such solution is the development of materials that can reduce the heat generated by solar energy in buildings. These materials are called Passive Daytime Radiative Cooling (PDRC) materials, which, in principle, dissipate heat caused by solar energy into the environment as thermal radiation (specifically through the atmospheric infrared window between 8 µm and 13 µm), and therefore can significantly reduce the use of existing cooling systems. In this work, the cooling performances of three different PDRC materials in the field were investigated. The measurements were carried out in Kocaeli/Türkiye, where it has a Mediterranean and oceanic climate, between June and September under the influence of solar irradiance, ambient temperature, and wind speed. It was observed that PDCR materials reduced temperatures by within 4˚C - 8˚C with an uncertainty of approximately 10%.