Solar Thermal Flat Plate Collectors

Glazed flat-plate collectors are insulated, weatherproofed boxes that contain a dark absorber plate under one or more glass or plastic (polymer) covers.

The main common component of solar collectors is the absorber plate. A coated metal plate absorbs the sun’s radiation and causes its temperature to rise above the ambient. The plate then releases energy through radiation and convection to its immediate surroundings. Heat is thus transferred to the heat-transfer fluid which in turn feeds the hot water system.

A flat-plate collector consists of an absorber, a transparent cover, a frame, and insulation. Usually an iron-poor solar safety glass is used as a transparent cover, as it transmits a great amount of the short-wave light spectrum. Only very little of the heat emitted by the absorber escapes the cover (greenhouse effect).

In addition, the transparent cover prevents wind and breezes from carrying the collected heat away (convection). Together with the frame, the cover protects the absorber from adverse weather conditions. Typical frame materials include aluminium and galvanized steel; sometimes fibreglass-reinforced plastic is used.

The insulation on the back of the absorber and on the side-walls lessens the heat loss through conduction. Insulation is usually of polyurethane foam or mineral wool.

Flat plate collectors can more easily be integrated with roofs, and offer a more aesthetically attractive option, especially if combining with solar PV. If you have any questions or queries regarding flat plate collectors please do not hesitate to contact us