Experiments on solar absorption using a greenhouse-effect gas in a thermal solar collector

This paper investigates an augmentation to the thermal solar absorption of solar collectors by introducing a greenhouse gas between the glazing and the absorber part of the solar collector. Experiments are designed and conducted to compare the effect of adding the gas on the efficiency of the collector without that addition. The maximum temperature rise of the absorber, the time of heat retention before reaching room temperature, and the energy conversion efficiency in heating up water for domestic use were all studied.