The thermal pumps "water / water" use warmly podpochvenny (soil) waters, open reservoirs or technological cooling water. Ground waters are characterized by rather stable temperature 6. 15°C during the whole year. In comparison with other sources of low-potential heat, use of water provides the highest efficiency of the thermal pump.
The water thermal pump of skvazhinny type For realization of such systems artificially created wells and soil wells are applied to the thermal pump: water intaking and water reception. The water taken from a well (well) moves in the thermal pump where, being cooled, comes back through water reception wells and wells again under the earth. A big lack of the thermal pumps working with ground waters, high cost of works on arrangement of wells and wells, and as operational costs of a supply and water drainage is. Besides, thermal pumps of this kind are periodically necessary for clearing of deposits in the heat exchanger of oxides of iron and silt. At design of systems using thermal pumps with wells and wells it is necessary to consider requirements, sometimes very rigid, local administrations in questions of the organization of sewage. Use of water of the rivers and lakes as heat source for heatpump systems has one essential shortcoming – extremely low temperature during the winter period (it can fall to level 0°C). Sea water can be used as heat source mainly in averages and large systems. On depth 25. 50 m sea water has constant temperature in a range 5. 8°C, and, as a rule, problems with formation of ice do not arise. But cost of such systems very big because of use of expensive equipment on a fence of water and its filtration. For such system special thermal pumps, which not коррозирует from sea water are used. It is possible as to consider as examples of possible sources of low-potential heat the sewer cleared and crude sewage, industrial drains, waters of turnaround systems of cooling of the industrial enterprises, the condensers of water vapor applied by electricity generation. These sources of heat are interesting thanks to high temperature of the environment, but distribution of systems such is limited to need design of individual heatexchange surfaces. Not the unimportant factor, braking application of heatpump systems of these types is excessive impurity of a source, it leads to fast pollution of heat exchangers and as a result reduction of their efficiency. Frequent planned actions for their cleaning become the solution of these problems.