Abstract: Disclosed is a heating unit consisting of a boiler chamber in which a two-phase liquid system is placed under a slight vacuum and supplied with a source of thermal energy. The activation of the source of thermal energy causes the lower phase liquid to vaporize and percolate through the upper phase liquid and circulate into a radiator section made up of finned tubes with an air flow being directed thereacross. The air flow absorbs the heat of the vapor which then is directed to the areas to be heated. The vapor continues to circulate into a header where the vapor is condensed back to the liquid state by a plurality of finned condensation tubes inside the header. The finned tubes of the radiator section have 90.degree. elbows extending upwardly into the header to prevent any condensed liquid from returning into the radiator of the system, and directing the vapor toward the coldest side of the header so as to enhance the condensation process.

Abstract: Disclosed is a heating unit consisting of a boiler chamber in which a two-phase liquid system is placed under a slight vacuum and supplied with a source of thermal energy. The activation of the source of thermal energy causes the lower phase liquid to vaporize and percolate through the upper phase liquid and circulate into a radiator section made up of finned tubes with an air flow being directed thereacross. The air flow absorbs the heat of the vapor which then is directed to the areas to be heated. The vapor continues to circulate into a header where the vapor is condensed back to the liquid state by a plurality of finned condensation tubes inside the header. The finned tubes of the radiator section have 90.degree. elbows extending upwardly into the header to prevent any condensed liquid from returning into the radiator of the system, and directing the vapor toward the coldest side of the header so as to enhance the condenation process.