INVESTIGATIONS OF FLAT PLATE COLLECTORS USING TRANSPARENT INSULATION MATERIALS

Abstract

Theoretical and experimental investigations have been carried out on a flat-plat collector using covers employing Transparent Insulation Material (TIM). It has been found that for a minimum front heat loss coefficient an air gap of 20 mm between the plate and the TIM and 15 mm between the TIM and the outer cover should be used. The collector performance indicates that there is no advantage in using a TIM for domestic hot water heating, but that it could usefully be employed for medium temperature applications, i. e. aboye 80°C. A value of U/rη0=3.53 W/m2K has been achieved for the flat-plate collector with 100 mm TIM encapsulated between two Teflon films and an outer Tedlar cover.