Abstract
“Air to air” heat pumps (HP) are intended for residential, industrial and other premises direct heating. The advantages of air heat pumps in comparison with other types of heat pump heating plants are examined. Power indices of an “air to air” heat pump at 1Gigacal/g heat capacity for heating residential premises to provide temperatures from 18 to 26 оС inside the premises when the temperatures of the lowpotential heat source (outdoor air) were from +8 to -40 оС were investigated. During a heating season the use of equivalent fuel was significantly saved as compared with heating using a gas boiler room (365-435 t e.f against 846,2-973,2 t e.f). But at low temperatures of outdoor air (lower -15… -25 оС) heating efficiency of the air heat pump decreased. For cold climate regions of Russia it is rational to use a bivalent heat pump technology (“air to air” HP + gas boiler installation). The economic efficiency of the bivalent heat pump technology using the “air to air” HP at outdoor air temperatures of -15...-40 оС and -25...-40 оС was defined. Power consumption reduced about 2 times in comparison with the gas boiler installation. The term of payback of the bivalent heat pump technology was 4,4 years according to the economic estimation (using capital investments and energy resources values during period when the estimation was carried out). A technical feasibility as well as energy rationality and economic efficiency of using outdoor temperatures for premises heating were proved. Keywords: “air to air” heat pump, air heating, bivalent heat pump technology, boiler installation, economic efficiency