Effect of short-wave radiometer position on solar absorptance of clothing materials in outdoor measurements

Abstract

Solar absorptance of the clothed human body is an important factor in thermal comfort assessment of outdoor. The objective of this research is to provide information for measuring the solar absorptance of clothing material adequate for outdoor. Combined short and long wave radiometer and pyranometers were used in the measurement. Three plane objects of square, rectangle and person-shaped fabrics having same 0.51 m² in area were adopted in the measurements. The following findings were obtained through the experiments. In order to obtain the appropriate solar absorptance of the target fabric, the measuring instruments should be placed so that the shortwave radiation reflected from the surroundings of the measuring field does not impinge on the sensors. Otherwise the reflected shortwave radiation from the surroundings should be taken into account properly in the calculation. Solar absorptance of the measuring fabrics is independent of the object shape. The solar absorptances of 100% cotton black and white were 0.67 and 0.21, respectively.