Flat-plate collectors heat the circulating fluid to a temperature considerably less than that of the boiling point of water and are best suited to applications where the demand temperature is 30-70°C (86-158°F) and/or for applications that require heat during the winter months.
Air-based collectors are typically used for heating buildings and drying crops. Liquid-based may be glazed or unglazed. Glazed liquid collectors are the commonest type of solar collector for providing domestic and commercial water and for heating indoor swimmingpools. Unglazed collectors are most often used for heating outdoor pools. A special type of unglazed collector called a perforated plate collector is used to preheat ventilation air for commercial buildings or, in some cases, 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.

