jaue2023004: Assessing the Heat-shielding Effect of Double Roofing with Air Passage

Abstract

This paper describes the results of CFD analysis to assess the heat-shielding performance, specifically regarding heat storage, of double roofing with ventilation. A double-roofing structure has solar shielding material at a certain distance from the roof’s surface. This is expected to dissipate most of the received solar radiation to the outside through ventilation between the roof surface and the shielding material. The unsteady CFD analysis shows that the amount of heat transferred from the ceiling to a room at night on a concrete roof accounts for about 30% of the total throughout the day. When solar-shielding material is applied to the concrete roof, the heat transfer from the ceiling to the room at night can be reduced by about 90%. Additionally, we confirmed that the heat-shielding performance as an alternative to the specifications for standard external heat insulation.