Abstract—Soil has been proven as a promising cooling source in arid region, yet it has underperformed in hot-humid tropical countries. This paper aims to investigate the cooling performance (soil temperature) in hot and humid regions under the enhancement of different porous materials such as gravel woodchips and rice husk. Two experiments were conducted to evaluate the materials. In the first experiment, the performance of the surface covered by these materials was compared with other surface conditions such as the empty surface and the surface covered by a building model. The soil temperature at the depth of 0.25 m and 1.00 m below the surface covered by wood chips is the lowest, 0.8°C and 0.4°C lower compared to the soil temperature of the empty soil surface. In the second experiment, the porous materials were examined under the desired radiation intensity (1000 Wm-2) from a halogen lamp. The soil surface covered 2cm-thick and 5cm-thick wood chips is 3°C and 4°C lower than the soil surface covered by gravel. The soil under the 2-cm-thick rice husk has the lowest temperature. Its soil surface is 1°C lower than the soil surface covered by 5 cm of wood chips.
Index Terms—Hot and humid regions, passive cooling, porous materials, soil cooling, tropical countries.
The authors are with School of Mechanical Engineering, Universiti Sains Malaysia (USM), 14300, Nibong Tebal, Penang, Malaysia (e-mail: email@example.com; firstname.lastname@example.org).