The problem of heat supply is one of the most urgent in power engineering. The current analysis of the production and consumption of energy in the world shows that despite the observed decrease in the proportion of organic fuel consumed in the overall balance due to the use of renewable sources of energy (wind, geothermal, solar, bioenergy, etc.), at least in the first half of the 21st century, organic fuel -gas, oil, and coal -remains the basic source of energy as before. This means that when traditional methods of heat supply are used, the intensity of emissions of harmful products of combustion of organic fuel also persists.Discussion of the efficiency of the centralized heat supply based on combined production of heat and electrical power at heat and electrical power plants (EPP) for large and middle-sized cities in Russia (and previously in the USSR) has continued in scientific and technical periodicals over the last two decades. It has become increasingly evident that the advantages of the combined method of production of heat and electricity (fuel savings, low price, etc.) are depreciated by significant losses of heat in extensive heating systems, and the enormous outlays for building, operating, and maintaining them [1]. The heat supply of middle-sized cities and villages is basically from small EPP and boilers located within the boundaries of a population center whose harmful emissions cause great injury to the population. Heat pump installations (HPI) [2] which transform low-potential environmental thermal energy (water, soil, air) and "thermal wastes" from industrial enterprises and municipal services into thermal energy of the required potential can be an alternative to this traditional heat supply system. Heat is transferred from a low-potential source (LPS) to a higher temperature level by delivering mechanical energy in a compressor (vapor-compression HPI) or by additional delivery of heat (in absorption HPI).The use of HPI basically improves the heat supply conditions: the consumption of primary energy (organic fuel) can be reduced by two times; the heat supply system becomes decentralized, not requiring extensive heating systems; production of electrical power and the related emission of products of combustion of organic fuel can be relocated beyond the boundaries of population centers.The efficiency of using HPI is to a great degree related to the existence (selection) of a low-potential heat source. The LPS can be selected for wide use of HPI of the same type in the region: heat from soil, ground waters, natural waters (including salt water), etc. However, in many cases, the use of HPI is determined by the local conditions of the real consumer: the existence of a local LPS, the features of utilization of the heat produced, the features of the local power supply, etc. In this case, heat supply with HPI can be fully integrated in the existing centralized system of a city or village.HPIs of the vapor-compression type are now the most common ones in the heating systems of foreign countries (USA, Ca...