Heat pump technology: A heat pump is a kind of high-grade heat energy equipment that can obtain low-grade heat from the air, water or soil in the nature, work through electric power, and output the available energy, and can change the power consumption into three times or even more than three times of the heat, Is an efficient energy supply technology. Heat pump technology in the field of air conditioning can be divided into air source heat pump, water source heat pump and ground source heat pump three categories. As the heat pump is to extract the energy in nature, high efficiency, without any pollutant emissions, is the cleanest and most economical way of energy. As resources become increasingly scarce today, as the most advanced way for mankind to utilize low-temperature thermal energy, heat pump technology has gained worldwide attention and attention. Heat pump technology used in air conditioning field of domestic enterprises, with a mature technology research and development capabilities in this area, has developed air source heat pump, water source heat pump, ground source heat pump, heat pump water heaters and other four series of heat pump products, and for different regional climatic conditions And resource conditions to deepen the product technology and types of access to more than 100 patents. Xishu advocate and regional air source heat pump units for the user to save operating costs for the country to save energy. Central air-conditioning air source heat pump Air source heat pump is the use of the air in the influx of energy tends to the summer heat the indoor heat to the outdoor temperature, the room cool; the winter can use outdoor air heat to make the room warm. Because this kind of central air-conditioning real cooling, the heating calories from the outdoor air cooling system in the summer does not require cooling, so the operating cost is very economical, but also save a lot of water resources, while the system does not produce any pollutants, Very consistent with China's energy-saving environmental trends and policies. However, for a long time, ordinary air source heat pump central air conditioning can only be applied in the middle and lower reaches of the Yangtze River in the southwest and south China, but not in the winter in the north. In 1996, the air source heat pump to improve the technology, Xisu unit unique technology to effectively solve the problem of incomplete defrosting, making it the lowest temperature in winter in the Yangtze River and the Yellow River Basin -8 ℃ region successfully used.