No abstract

This research focuses on the application of phase change material (PCM) combined with the fiber cement roofing sheet to reduce heat transfer through the building. The experimental study was divided into 4 conditions including the single-layer fiber cement roof (SF), the single-layer fiber cement roof installed with the PCM layer (SF-PCM), the double-layer fiber cement roof (DF), and the double-layer fiber cement roof installed with the PCM layer (DF-PCM). For each condition, the fiber cement sheet was set at an incline angle of 40°with the horizontal plane. The thermal source was controlled at temperature of 60°C, 70°C and 80°C for 360 min to investigate the thermal behavior and compare the heat gain through the roof. The results showed that the DF-PCM could reduce the room temperature by up to 3.1%, 3.8% and 3.7% when compared with the SF, and up to 5.6%, 5.2% and 4.8% when compared with the DF at the controlled heat source temperature of approximately 60°C, 70°C and 80°C, respectively. It indicated that the use of PCM integrated into the fiber cement roofing sheet could reduce the heat transfer and interior room temperature, leading to energy saving.

This research aimed to study the possibility of producing the electricity from mechanical energy in the condensing unit of air conditioner. The electrical generator with the capacity of around 28 W was operated with the rotor motor of the condensing unit of air conditioner. Then, the electricity generator was tested with the room dimension of 6.60 m x 5.15 m x 2.60 m. The quantity of electric voltage, current, power, ambient and room temperature, ambient and room humidity was recorded for 3 days during a working period from 8 am to 5 pm. The results show that the electrical generator with the capacity of 28 W is suitable because it was not a load of motor in the condensing unit which was checked by the rotation frequency. Approximately 0.065 A of current, 85 V of voltage and 5.5 W of electrical power were constantly produced from the generator during the period of 8 am to 5 pm. The potential of electricity generation was around 14.1 W/day.

This study is concentrated on improving the thermal efficiency of autoclaved aerated concrete (AAC) by incorporation of black powder as an additional component. Black powder is a waste product of the automotive refinishing industry in Thailand. The dynamics of heat transfer and the cooling load of air conditionings in four simulated houses with different wall materials (brick, cement block, AAC, and black powder AAC) were investigated. The results from the comparison of heat fluxes of the interior surfaces demonstrated that incorporated black powder significantly increased the thermal effectiveness of construction materials, as observed from the black powder AAC. In addition, it was demonstrated that the cooling load and the power consumption of air conditioning in the house with black powder AAC walls was reduced, and the power consumption was saved approximately 25.5%, 37.9%, and 48.1% compared with the commercial AAC, the brick, and the cement block houses, respectively. The black powder AAC provided the highest power consumption reduction.