Features

High-efficiency and energy saving:
The power consumption of air-source heat pump is as low as 1/4 of electric heating. A considerable cost could be cut off with for user.

Safety and reliability:
The water is heated by through the refrigerating medium, which completely aviods hazards of explosion, gas poisoning, electroshock, etc. With high-tech and intelligent controller, the unit can work smoothly from 10C-40C

Enviornment-friendly:
The refrigerator is R417 that match the international standard on enviornment protection. In the process of heating, there is no wast substance released. The unit provides users a clean and comfortable living enviornment.

Air-source heat pumps

Working principle:
Air source heat pumps are relatively easy (and inexpensive) to install and have therefore historicall been the most widely used heat pump type. However, they suffer limitations due to their use of the outside air as a heat source or sink. The higher temperature differential during periods of extreme cold or heat leads to declining efficiency, as explained above. In mild weather, COP may be around 4.0, while at temperatures below around − 8 ° C (17 ° F) an air-source heat pump can achieve a COP of 2.5 or better, which is considerably more than the COP that may be achieved by conventional heating systems. The average COP over seasonal variation is typically 2.5-2.8, [9] with exceptional models able to exceed 6.0 (2.8 kW).

The working fluid, in its gaseous state, is pressurized and circulated through the system by a compressor. On the discharge side of the compressor, the now hot and highly pressurized gas is cooled in a heat exchanger, called a condenser, until it condenses into a high pressure, moderate temperature liquid. The condensed refrigerant then passes through a pressure-lowering device like an expansion valve, capillary tube, or possibly a work-extracting device such as a turbine. This device then passes the low pressure, (almost) liquid refrigerant to another heat exchanger, the evaporator where the refrigerant evaporates into a gas via heat absorption. The refrigerant then returns to the compressor and the cycle is repeated.

In such a system it is essential that the refrigerant reach a sufficiently high temperature when compressed, since the second law of thermodynamics prevents heat from flowing from a cold fluid to a hot heat sink. Practically, this means the refrigerant must reach a temperature greater than the ambient around the high temperature heat exchanger. Similarly, the fluid must reach a sufficiently low temperature when allowed to expand, or heat cannot flow from the cold region into the fluid, i. e. The fluid must be colder than the ambient around the cold temperatureheat exchanger. In particular, the pressure difference must be great enough for the fluid to condens at the hot side and still evaporate in the lower pressure region at the cold side. The greater the temperature difference, the greater the required pressure difference, and consequently the more energy needed to compress the fluid. Thus as with all heat pumps, the energy efficiency (amount of heat moved per unit of input work required) decreases with increasing temperature