Heat Losses of Highly Efficient Flat Plate Collectors with a Selectively Coated Double Glazing
Abstract
The heat losses of a flat plate collector with a selectively coated double glazing depend among other parameters on the height of the two gas-filled gaps. Within the hermetically sealed glazing cavity inert gases instead of air can be used to decrease the convective heat transfer. To identify the impact of the mentioned parameters, heat loss measurements at a prototype collector were carried out. Therefore the gap sizes were varied and as filling gases of the glazing cavities air, argon and krypton were applied. For each filling gas optimum gap sizes are experimentally identified. These results are in accordance to the Nusselt-equation developed by Hollands . Further the impact of different inclination angles on the heat losses of the collector was determined experimentally.