Abstract
Buildings in Southern China widely use a double-skin roof to reduce heat entry through the roof to the building interior during summertime. Concrete roof tiles are preferably installed as the outmost layer of the double-skin roof due to their resistance to hail and wind damages and their attractive price. However, after construction, the tile’s top tends to be darkened by dust deposit and algae growth, increasing the heat entry through the roof to the building. Here, we show that this heat entry can be curtailed by lowering the emissivity at the tile’s underside. Temperatures and heat fluxes at different elevations of a double-skin roof with concrete tiles as the outmost layer of the roof are monitored. The underside of each concrete tile is coated with a specific paint to get a unique emissivity. Observations reveal that lowering the emissivity of concrete roof tiles could cut down the summer heat gain of buildings in tropical regions.
Highlights
A double-skin roof is composed of a pair of parallel sheets intermediate by an air layer [1]. e outmost sheet of the roof shields the sunlight from the roof deck and reduces heat entry through the roof to the building due to the heat loss in the heat transfer caused by the air layer [2, 3]
In Southern China, concrete tiles are typically constructed as the outmost sheet of a double-skin roof due to their resistance to wind and hail damages, their attractive price, and the easy installation
Assuming that the emissivity and absorptance of both sheets do not vary with the temperature, net long-wave radiation absorbed by the roof deck, And (W/m2), ([13], pp. 495-496), is
Summary
A double-skin roof is composed of a pair of parallel sheets intermediate by an air layer [1]. e outmost sheet of the roof shields the sunlight from the roof deck and reduces heat entry through the roof to the building due to the heat loss in the heat transfer caused by the air layer [2, 3]. E outmost sheet of the roof shields the sunlight from the roof deck and reduces heat entry through the roof to the building due to the heat loss in the heat transfer caused by the air layer [2, 3]. In Southern China, concrete tiles are typically constructed as the outmost sheet of a double-skin roof due to their resistance to wind and hail damages, their attractive price, and the easy installation. As the heat transfer in the air layer is radiationdominated, heat entry through the roof to the building interior would be cut down by modulating the emissivity of the deck and the tile’s underside. Temperatures and heat fluxes at different heights are observed to confirm the influence of the emissivity of the tile’s underside on the heat entry through the roof to the building interior
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
