Flat Plate Solar Collector

A flat-plate solar collector is one of three main types of solar collectors, the other main types being evacuated tube collectors and batch solar heaters.

Flat-plate collectors are commonly used in solar water-heating systems in homes and in solar space heating. A flat-plate collector consists basically of an insulated metal box with a glazed glass cover and a dark-colored absorber plate. Heat from the sun strikes the absorber plate and is transferred to a fluid that circulates through the collector in tubes.

Solar swimming pool heaters use a version of flat plate collectors that are much cheaper to produce. These panels have no insulated metal box or glazed glass cover. The absorber plate and tubes are usually manufactured from a plastic material rather than metal. As these panels are trying to raise a large volume of water by a few degrees, they depend on moving larger quantities of water. The high temperatures required for washing and other household chores, is not required.

A special type of unglazed collector called a perforated plate collector is used to preheat ventilation air for commercial buildings or for drying crops.

Flat collectors can be mounted in a variety of ways, depending on the type of building, application, and size of collector. Options include mounting on a roof, in the roof itself, or free-standing. The type of thermal system, drain-back or closed loop, can also have a big impact on how the panels are mounted. A drain-back system must ensure that all water is removed from the panels and tubing, if these systems are used in climates where freezing can occurr.