In recent years, monoblock air source heat pumps (ASHPs), including air to water heat pumps and air to air heat pumps, have been widely used. In addition to their residential application in hot water and house heating, more and more schools, factories, hotels, office buildings and other places begin to use ASHPs. As the representative of new technology and new energy, air source heat pump hot water heaters are naturally supported by many people and businesses. Multiple functions in one unit is a feature of these new energy products. In addition to hot water, they can also provide underfloor heating in winter and air conditioning in summer.