Heat pump is high in the energy of the drag, the heat flow from low to high heat source technology. It can convert low-grade heat energy (such as air, soil, water, solar energy, industrial waste heat, etc.) that can not be directly used into the available high energy so as to save some high energy (coal, oil, natural gas, electricity, etc.) . The use of low-energy heat pump technology can save fuel, rational use of energy, reduce environmental pollution, as an energy saving and environmental protection both ways. Some studies show that compared with the energy consumption of the regional boiler house, the energy consumption of the heat pump station of the same capacity is as follows: when using river water (5 ~ 6.6 ℃) as the low-level heat source, the annual coal-saving rate is 12.68-14.08% 13.6 ℃) as low-level heat source, annual coal-saving rate was 21.59-39.98%. When using industrial wastewater (18-20 ℃) ​​as low-level heat source, the annual coal-saving rate was 39-39.98%. The efficiency of the heat pump is related to the temperature difference between the indoor and outdoor environment of the building. The smaller the temperature difference, the higher the heat pump efficiency. Some researches show that the use of air source heat pump is not only related to the outdoor temperature, but also closely related to the relative humidity of the outdoor air, which greatly limits the scope of its use from the perspective of defrosting the heat pump unit during winter operation. With ground-source heat pump systems, ground-source heat pumps are more efficient and dependable than air-source heat pumps because they are reasonably well-designed because the temperature of the soil is closer to the indoor temperature than outdoor air. In addition, because the same volume flow rate of water heat capacity is 3500 times the air, water and refrigerant heat transfer effect is much better than the air and refrigerant convection heat transfer, so the ground source heat pump heat exchanger coil than the air source heat pump Much smaller and less ground-source heat pump system components to reduce operating costs.