Due to its advantages such as dual-purpose (cooling and heating), environmental friendliness, energy efficiency, and safety, coupled with the boost from the "coal-to-electricity" policy, air source heat pump (ASHP)/Heat Pump for Heating And Cooling can solve both cooling and heating needs simultaneously. Thus, it has been rapidly promoted and gained wide attention and favor from users. Then, how efficient is ASHP in energy saving?
Principle of Air Source Heat Pump/Heat Pump for Heating And Cooling
ASHP absorbs heat energy from the air, compresses it via the compressor, and then transfers the absorbed heat to water through a plate heat exchanger (PHE), thereby realizing cooling in summer and heating in winter. In summer, it produces low-temperature chilled water that is delivered to fan coils for cooling; in winter, it generates high-temperature hot water supplied to floor heating systems, radiators for heating, ultimately achieving the dual-purpose function.
The cooling principle of ASHP /air source heat pump system unit is the same as that of ordinary air conditioners, both achieving cooling by transferring heat between indoor and outdoor. The unit releases heat through the condenser and absorbs heat (releases cold air) through the evaporator at the indoor unit. However, ASHP system adopts water system as the main heat transfer medium, so the temperature difference between the chilled water produced by the unit and the indoor air is smaller than that of Freon. Thus, the outlet air temperature of fan coils is only about 12-15℃, compared with 7-10℃ of Freon, the temperature difference with indoor air is smaller, reducing air dryness and having less impact on indoor humidity, resulting in higher comfort. Due to the inertia of water, the heat storage stability is better, and cooling can continue even after the unit is turned off, which indirectly improves energy efficiency.
Different from air conditioner heating, ASHP heating offers multiple indoor heating methods, including floor heating, radiators and fan coils. Floor heating is the first choice in terms of comfort, and the unit can continuously provide the water temperature required for floor heating. With air injection enthalpy increase technology, ASHP unit can absorb more low-temperature heat in low-temperature environments and convert it into high-temperature heat needed indoors via the compressor, consuming only low electricity during the whole heating process. ASHP /air source heat pump system is divided into normal temperature type, low temperature type and ultra-low temperature type. When the average temperature is minus 5℃, it can generate more than 3 kWh of heat by consuming 1 kWh of electricity, thanks to the energy efficiency ratio (EER) higher than 3.0. Its energy efficiency is much higher than that of air conditioner with electric auxiliary heating, and only about 30% of the energy consumption of gas-fired boiler for heating.
Ultra-Low Temperature ASHP/Heat Pump for Heating And Cooling
ASHP technology is an upgrade of water system, adopting DC inverter compressor and fan, combined with air injection enthalpy increase technology to absorb more heat from low temperature. It can generate heat required for floor heating even at minus 35℃. For ordinary air conditioners, frequent defrosting consumes all energy in defrosting, while ASHP can keep the bottom of the unit at a certain temperature all the time, enabling advance defrosting and frost prevention. Of course, the heating capacity will decrease at minus 30℃, but it can still generate more than 2 kWh of heat by consuming 1 kWh of electricity.
Other Characteristics of ASHP System
① Wide application range: It can work at above minus 30℃, suitable for heating in more than 95% of areas in China. Cooling, as its basic function, has a wider application range, and it can be used normally throughout the year without being affected by severe weather such as wind, frost, rain and snow.
② Strong continuous heating capacity: Compared with solar water storage heating or hot water supply, it is not affected by natural environment. ASHP /Heat Pump for Heating And Cooling can heat continuously and provide hot water needed for heating or daily life.
③ Easy installation: The ASHP unit is similar to the outdoor unit of ordinary central air conditioners, occupying small area. The connected buffer water tank can be replaced with a hybrid core to reduce space occupation. With dual-purpose feature, it is not necessary to consider the installation position of gas-fired boiler, saving equipment installation space. It is connected by water pipes, which is fast and convenient.
④ Low use cost: Compared with solar energy, its energy consumption is slightly higher when the sunlight is good, but lower in bad weather such as cloudy, rainy, snowy days and at night; compared with electric floor heating, the cost is only about 50% of it; compared with gas-fired boiler, the cost is only about 30% of it.
Summary
ASHP /Heat Pump for Heating And Cooling has extremely high energy efficiency, which is most reflected in the floor heating method in winter. For a 100-square-meter house, gas heating costs 1200-1500 RMB per month, while ASHP only needs 400-500 RMB per month, showing its high energy efficiency. If used in areas with higher temperature in winter, its energy efficiency will be even higher.
Key Term Abbreviations
- ASHP: Air Source Heat Pump
- PHE: Plate Heat Exchanger
- EER: Energy Efficiency Ratio
- DC Inverter Compressor: DC Variable Frequency Compressor
- Air Injection Enthalpy Increase Technology: Jet Enthalpy Increase Technology
