So what is the difference between an air source heat pu […]
So what is the difference between an air source heat pump and a heating and cooling air conditioner?
Differences in heating methods
Air source heat pump
The air energy heat pump itself is just a device to provide hot water. It supplies heat, and then cooperates with other heating terminals to achieve heating, such as radiators, fan coils, air-energy floor heaters, floor heating pipes, etc., can be used as the heating terminals, and different heating methods can be selected according to different houses.
air conditioning
Whether it is a cabinet-type air conditioner or a wall-mounted air conditioner, heating can only be achieved by means of active hot air outlet. To
Differences in parts
Air source heat pump
Heat pump special compressor, antifreeze high-efficiency tank condenser, system high pressure protection and control. To
air conditioning
Compressor, fin condenser or plate condenser.
Among these components, the biggest difference between air source heat pumps and air conditioners is the compressor.
Different compressors determine the use effect and use area of the product.
Take R22 as an example.
The air conditioner adopts air conditioner compressor, the maximum operating pressure does not exceed 2MPa, the compressor ratio is less than 7, and the maximum exhaust temperature does not exceed 90°C.
However, the air source heat pump must use a heat pump compressor with a maximum operating pressure of 3MPa, a compressor ratio of 12 or even higher to 20, and a maximum exhaust temperature of 110°C.
The difference in these parameters requires that the processing accuracy of the heat pump compressor, bearing strength, and motor temperature resistance performance are orders of magnitude higher than that of air conditioning compressors.
Difference in heat transfer mechanism
Air source heat pump
Although the heat transfer is achieved through refrigerant, in the final heat exchange stage, the heat pump uses water to exchange heat, and the air conditioner uses refrigerant as the medium from beginning to end.
In the water cycle, even if the heat pump is shut down, the water flow will always stay in the indoor pipe and continue to emit temperature. This is equivalent to adding a buffer process of heat. Moreover, if a fan coil or an air-energy floor heating machine is used as the end, the hot air is obtained from the hot water at the end, so the overall humidity is more in line with human physiological habits and will not cause "air conditioning diseases" such as dry mouth and tongue.
air conditioning
The air conditioner adopts "fluorine cycle" to realize heat conduction. The air outlet of the air conditioner discharges a large amount of hot air, and the purpose of heating up is indeed achieved, but this kind of aggressive active thermal convection scheme will greatly increase the evaporation of water on the human skin surface, resulting in dry air, dry mouth and poor comfort.
Difference in operating mode
Difference in power consumption
Although the air source heat pump is energized all day. But when the heating is completed, the unit will stop working and automatically keep warm.
Therefore, the air source heat pump saves electricity than the air conditioner, and can better protect the compressor and extend its service life.
Difference in operating temperature
Air conditioners are used frequently in summer, especially in northern regions.
However, the air source heat pump integrates hot water, heating, and cooling, and has a longer running time in winter. Especially in winter, the demand for hot water is large, so the air source heat pump needs longer operation to raise the water temperature, and the compressor needs more time to operate, so the compressor basically runs in the area with higher refrigerant. .
Operating temperature is one of the main factors affecting the life of the compressor. Under the same operating time, the overall load of the compressor in the air source heat pump is higher than that of the compressor in the air conditioner.
Difference in use environment
Part specification selection requirements
Air conditioners and air source heat pumps can be used at different ambient temperatures.
When the air conditioner is heating, the maximum ambient temperature is 21°C. According to the national standard, the best use environment is 21℃ to -7℃.
But the air source heat pump is different. For the hot water machine, it is also used in spring and autumn. According to the national standard of the air source heat pump, its use range is 43°C to -20°C.
Because the ambient temperature range of the air source heat pump is wider, the specifications and selection of the parts it uses are more demanding than the air conditioner.
Temperature and pressure requirements
Due to different use environments and purposes, air source heat pumps have higher requirements in terms of temperature and pressure.
The maximum air outlet temperature of the air conditioner is also 50°C, and the condensing pressure is 1.8-2MPa at this time.
The air source heat pump requires 60°C or even 65°C, at which time the condensing pressure reaches 2.5-2.8MPa. The pressure difference of 30-40%, coupled with the low temperature environment, especially -20℃, the evaporation pressure is also very low, 0.2～0.15MPa, the water temperature still has to be heated to more than 50℃, or 60℃ or even 65℃, At this time, the condensing pressure is still 2.7 ~ 2.8 MPa, and the compression ratio is much greater than 15, which is greater than the use range of the air conditioning compressor.
Differences in system defrost
Generally speaking, the greater the difference between the temperature of the refrigerant and the outdoor temperature, the more severe the frosting.
The air source heat pump itself transfers heat by a small temperature difference, while the air conditioner uses a large temperature difference. To
Air source heat pumps focus on heating in winter. They absorb heat in a low temperature environment. In winter, the temperature is minus ten or twenty degrees, and the temperature of the refrigerant is also minus twenty or thirty degrees, and the temperature difference is only ten degrees;
Air conditioners focus on refrigeration, and the highest temperature in summer is 45°C, while the compressor discharge temperature reaches 80 to 90°C, or even 100°C, with a temperature difference of 40 to 50°C. HVAC Encyclopedia
Therefore, in the same situation, the heat exchange area of the air source heat pump is much larger than that of the air conditioner, which is why the air source heat pump is larger than the air conditioner.
According to the conventional control logic, the defrosting time of an air conditioner is generally about 10 minutes, while the defrosting time of an air source heat pump heating unit is usually a control logic for one place. For example, Qingdao in Shandong and Qinhuangdao in Hebei have more defrosting than Shanxi. Frequently. Professional air source heat pump manufacturers generally have one control logic for each latitude, and they are adjusted according to local climate conditions.
Whether it is from the control logic and the area of the evaporator, or from the difference between the refrigerant and the outdoor temperature, the defrosting performance of the air source heat pump is far better than that of the air conditioner, and the possibility of frosting is less, so the whole can provide The effective heat is greater than that of an air conditioner.
Differences in implementation of national standards
Air source heat pump
Mainly include domestic hot water, commercial hot water, domestic heating, commercial heating and other standards. With heating capacity and coefficient of performance as measurement indicators, cooling and heating machines must also assess cooling capacity and energy efficiency ratio. To
air conditioning
It mainly includes domestic air-conditioning, multi-line, air-cooled chillers and other standards, which use cooling capacity and energy efficiency ratio as the measurement index.