HVAC Checker - Version 1.0.0 The BTU Analysis family of programs are premiere heat load calculation programs. The HVAC CHECKER program is similar to the PLUS and REG programs, but is scaled down for the homeowner's use. It is not intended to be used for commercial purposes! The BTU Analysis programs have been commercially distributed and are marketed through professional organizations, trade advertisements, and word of mouth. They are currently used in six (6) foriegn countries and the U.S. Used in temperate, tropic, artic, and arid climates. They have proved themselves accurate and useful again and again. The PLUS program is designed for general heating, air-conditioning, heat pump and commerical studies. The CHECKER program is designed for general heating and air-conditioning studies.