A heat pump is an energy-saving device that allows heat to flow from a low-level heat source to a high-level heat source. As the low-level heat source of the heat pump, air is inexhaustible, available everywhere, and can be obtained free of charge. Moreover, the installation and use of air source heat pumps are relatively convenient. The research, production and application of air source heat pump (also known as air-cooled heat pump) developed rapidly in the late 1980s in China. The current products include household heat pump air conditioners, commercial unit heat pump air conditioners and heat pump cold and hot water units, etc.
Air source heat pumps have the following characteristics:
(1) The air source heat pump system integrates the cold and heat sources, and does not need to set up a special refrigeration room or boiler room. The unit can be placed on the roof or the ground at will, without occupying the effective use area of the building, and the construction and installation are very simple.
(2) The air source heat pump system has no cooling water system, no cooling water consumption, and no cooling water system power consumption. In addition, many cases of Legionella infection caused by cooling water pollution have been reported. From the perspective of safety and hygiene, the air source heat pump also has obvious advantages.
(3) Since the air source heat pump system does not need a boiler, a corresponding boiler fuel supply system, a dust removal system and a flue gas discharge system, the system is safe and reliable, and does not pollute the environment.
(4) The air source heat pump cooling (hot) water unit adopts a modular design, and there is no need to set up a standby unit. During the operation, the computer automatically controls the operation state of the unit to adjust the output power and the working environment.
(5) The performance of the air source heat pump will change with the outdoor climate.
(6) In places with low outdoor temperature like the north of China, auxiliary heaters are required due to insufficient heat supply of heat pumps in winter.