Experimental Study for Re – Covering Building Roofs and it's Effect on Space Inside Temperature

Abstract

The Heat Gain through concrete roof which is used in Iraqi building is reduced by increasing the value of thermal resistance of that roof this is done by addition of several materials to the external surface (roofing brick 30 mm thick, plastic tile 1.5 mm thick, light glass fiber, 1.5 mm thick with air gap 75 mm, Aluminum metal sheet ordinary & reflective with air gap or insulation 25 mm). The researcher was build (4.5 x 4.5 x 3) m sample room in 3rd floor in building at Baghdad city (33.2°N) with 200 mm thermal insulation for other room surfaces and A.U Air – conditioner of 1.0 ton refrigeration capacity is used to maintain the standard thermal comfort, the roof surfaces temperature were measured from 5:00 a.m to 11:00Pm (19 hr/ Day) during May to September. Finally, it was found that the Aluminum reflective metal sheet with insulation saved about 42V. from electrical energy which consumed in ordinary ceiling for cooling purpose, and followed that , used plastic tile with saved 39%, and flooring brick at 31% , and the difference saving between reflective and ordinary metal sheet is (14 – 15) % and also between used insulation or air gap is (19 – 20) %