Solar Thermal Flat Plate collectors are some of the oldest proven technology available on the market today. A flat-plate collector consists of an absorber, a transparent cover, a frame, and insulation. Usually, a low iron safety glass is used as a transparent cover as it lets through a great amount of the radiation from the sun. Simultaneously, only very little of the heat emitted by the absorber escapes the cover (greenhouse effect). In addition, the transparent cover prevents wind from cooling the absorber. Together with the frame, the cover protects the absorber from adverse weather conditions. The insulation on the back of the absorber and on the side walls lessens the heat loss through conduction. Insulation on better quality panels is usually mineral fibre insulating materials like glass
wool or rock wool.