Absorptance of Different Local Coated Surfaces to Global Solar Radiation in Egypt

Abstract

The absorptance of different oil painted surfaces to total solar radiation depends mainly on their color. The surface coating color of buildings, greenhouses, mulchs and absorbers (solar collectors) affect the amount of absorbed total solar radiation. The surface is heated much when its absorptance has a higher value and vice versa. To test the absorptance of 11 coated surfaces and one sheet without color, an experimental setup to measure the surface temperature is designed and installed at Mansoura University, Egypt. The absorptance of these locally coated surfaces is calculated. Results have shown that, (G.I) sheets coated with black bored (Bb), polish black (Pb), brown (Br), red (R), violet (V), green (G), blue (Blu), G.I. sheet without color, dark yellow (Yd), yellow (Y), silver (S) and white (W), are 0.92, 0.886, 0.881, 0.852, 0.844, 0.824, 0.823, 0.794, 0.782, 0.777, 0.716 and 0.661 respectively.