Abstract: The specification and drawings disclose an apparatus for collecting incident solar radiation and using it to heat a fluid such as air. The disclosed apparatus comprises a housing having a generally triangular cross-section which defines an upwardly facing chamber having its open upper end closed by a sheet of solar transmissive plastic material. Positioned within the chamber, generally at the juncture of the bottom and end wall, is a mass of heat-absorbing material. A plurality of focusing lens are positioned within the chamber and arranged to focus solar radiation upon the mass. Heat absorbed and collected by the mass is extracted by air which is passed over the mass by a duct system including a blower. The blower and duct system is arranged to cause air to pass over and about the heat-absorbing mass to an outlet duct from which it is conveyed to a point of use or storage.