Ground source heat pump (Ground.Source.Heat-Pumps) (also known as water central air conditioning, water pump) is the use of solar energy resources of the earth are stored as a heat source, heating and cooling air conditioning system can be set to convert. It uses the underground soil or groundwater temperature relatively stable temperature characteristics: Winter: When the unit during the heating mode, it absorbs heat from the soil / water through electrically driven compressor and a heat exchanger to heat the earth concentrate, and a more high temperature is released into the room. Summer: When the unit in the cooling mode, it is extracted from the soil / water cooling, by operation of the unit will focus on cold, into the interior, while the indoor heat emissions to soil / water to achieve the purpose of air conditioning. Only one set of equipment to meet the heating and cooling requirements, and can also provide domestic hot water, reducing the initial investment of equipment, is the most economical energy saving central air conditioning system.