Integration of solar powered fans and moving-aircavity for attic temperature reduction

• Main Author: Ho, Mun Ling
• Format: Final Year Project / Dissertation / Thesis
• Published: 2020
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utar.edu.my/5308/1/1606413_fyp_report_%2D_MUN_LING_HO.pdf; http://eprints.utar.edu.my/5308/

With an increasing demand of building’s cooling load, the cool roofing technology system is important in modern roof design to reduce the building’s electricity consumption by keeping buildings cool. Cool roof system is the substantial building approach. The focus of this study is to design a cool roof system that promotes both the passive and active cooling methods. The cool roof system in this research project integrated solar powered fans as the active cooling element and radiative surface on moving air cavity as the passive cooling element. In addition, the cool roof was fabricated with lightweight foam concrete tile of density 1250 kg/m3 and water cement ratio of 0.6. The main purpose of this project is to reduce the attic temperature by rejecting the heat from entering the structure. Six small scale roof prototypes were built to evaluate the performance of each cool roof designs in reducing attic temperature. The performance of cool roof was compared with the conventional metal deck roof. The roof prototypes experienced 30 minutes of heat exposure from two spotlight halogen lamps of power 500 W each. The experiment was carried out indoor. The temperature variation was measured by the temperature sensor, K-type thermocouple. Four thermocouples were used and assigned at roof surface, ambient, moving air channel and attic. In this cool roof system, the moving air cavity, solar powered fans and rockwool were implemented in stages to determine the efficiency of each element in enhancing the cooling performance. The maximum attic temperature decreased from 38.7 ℃ (Roof Design I) to 32.5 ℃ (Roof Design VI) after the integration of cool roofing technology. This eco-friendly cool roof system which was built by the combination of lightweight foam concrete roof, moving air cavity, solar powered fans and rockwool successfully reduce the attic temperature by 6.2 ℃ as compared to the normal roof design.