R410a and R22 refrigerant comparison application and installation specifications 1. Introduction to the properties of R410a refrigerant 1. R410a is a HFCs refrigerant mixed with two working fluids of R32 and R125 at a mass fraction of 50% and 50%. It is a near-azeotropic mixture (pseudo-azeotrope), and its thermal performance is close to a single working fluid. Compared with R22, the condensing pressure of R410a is increased by nearly 50%. It is a high-pressure refrigerant and needs to improve the pressure strength of the system. Since the thread and bell mouth shape of the R410a high-pressure connecting pipe, the shape of the refrigerant filling nozzle and the vacuum pump connecting pipe all need to be changed or replaced, the measuring instruments for maintenance and quantitative refrigerant charging equipment are also dedicated. The power performance of R410a is the closest to HCFC-22 (R22), and it is used more in small and medium-sized room air conditioners.
2. High chemical and thermal stability. Compared with the R22 system, the R410a system has a significant advantage: the heat transfer of the evaporator is 35% higher, and the heat transfer of the condenser is 5% higher.
3. R22 uses mineral oil, and R410a uses POE synthetic oil.
4. R410a is called an environmentally friendly refrigerant because it does little damage to the ozone layer.
2. Comparison of R22 and R410A refrigerant characteristics
Three, R410a refrigerant special tool equipment requirements
Copper pipe wall thickness value
Four, R410a refrigerant air conditioner special accessories
Compressor: If the system needs to replace the compressor, R410a inverter compressor must be used, and R22 compressor must not be used for installation. For R22 system, the compressor of R410a must not be replaced. Use the original compressor when replacing, and the compressor with frequency conversion must use the original model, and the replacement opening time should be less than 30min.
Heat exchanger: the diameter of the copper pipe is reduced (φ7 threaded pipe), the strength is increased, and the performance is improved.
High and low pressure shut-off valve: R410a system can only use dedicated shut-off valve, absolutely can not install R22 system into R410a system. The stop valve of R410a can be installed in the R22 system, but the price is more expensive and it is not recommended to install this way.
The difference between R410a high and low pressure valves and R22 high and low pressure valves: There is no special mark on the valve body of R22, and there is a special mark on the valve body of R410a: R410a, and the refrigerant charge port of R410a low pressure stop valve is larger than that of R22. The nozzle is large.
Four-way valve: For the same reason, the R410a system can only use a dedicated four-way valve. The difference between the R410a four-way valve and the R22 four-way valve also depends on the label identification: most R410a will be directly marked with "R410A".
Five, R410a refrigerant air conditioner installation and maintenance points
1. System maintenance tools must be dedicated, not mixed with R22;
2. The pressure gauge and connecting hose must be high-pressure resistant, and the pressure-resistant value must be greater than 33kgf/c㎡ to avoid bursting during maintenance;
3. When adding refrigerant to the system, it is necessary to ensure that the weight of the refrigerant in the tank is greater than 10%, and keep the tank inverted (when there is no siphon) to avoid the imbalance of the added refrigerant ratio;
4. During the maintenance process, if the system needs to be replaced with parts and welding operations, the system must be vacuumed, and a check valve must be installed on the vacuum pump to prevent air backflow;
5. After the live welding operation of the system is completed, in order to ensure the dryness of the system, it is best to replace the filter drier, and after the system pipeline is disassembled, the nozzle must be bandaged and isolated to prevent moisture in the air from entering the pipeline;
6. During the maintenance process, try to avoid exploding the refrigerant tank at high temperature for a long time, so as not to change the composition and affect the cooling effect;
7. Before installation and maintenance operations, confirm the name of the air conditioner refrigerant, and then perform different operations on different refrigerants. In an air conditioner that uses R410A refrigerant, you must never use refrigerants other than R410A or mix with other refrigerants.
8. When installing and emptying, please use a vacuum pump to exhaust the air in the connecting pipe and prevent the lubricating oil in the pump from flowing back into the refrigeration system.
9. Pay attention to the compressive strength of weak points such as bent parts, welded parts, and stress concentration parts, and avoid situations that seriously affect the thickness of the wall such as pipeline collapse.
10. If refrigerant leaks during operation, please ventilate in time.
11. Full attention should be paid during construction operation, and clean piping should be used to prevent mixing of moisture. Also, be careful not to use piping that has already been used. It is necessary to ensure the use of new piping during installation and construction.
12. The air conditioner using R410A refrigerant has a much higher pressure than that of R22 refrigerant. Therefore, in terms of material selection, it must be compatible with R410A. Copper pipes and copper-aluminum pipes with a wall thickness of 0.7mm are available in the market and must not be used. The wall thickness of the copper pipe of the extended pipeline shall be above 0.8mm.
13. When the amount of refrigerant is insufficient, be sure to check for leaks before adding refrigerant. The flushing amount cannot exceed 2% of the prescribed amount of refrigerant. See the introduction of refrigerant addition for the adding steps.
14. Since R410A is an almost azeotropic mixed refrigerant, when adding the refrigerant, use a liquid method. (When adding by gas, the composition of the refrigerant will change, resulting in changes in the characteristics of the air conditioner.)
15. It is forbidden to use air or refrigerant for pressure leak detection.
16. After the refrigerant leaks, it cannot be added directly, because the refrigerant will change the composition due to the leakage, which may cause abnormal high pressure, causing the circulation pipeline to rupture and crack.
17. When installing, please follow the installation steps below. Otherwise, poor installation will cause abnormal operation of the refrigerant circulation pipeline, water leakage, electric shock, and fire.
18. After the installation work is over, please carefully confirm that there is no leakage of refrigerant. If the refrigerant leaks indoors, it will form toxic gas once it comes into contact with electric sparks from electric fans, heaters, and electric stoves.
6. Installation steps of new refrigerant air conditioner
1. R410a characteristics and precautions
2. Installation process and precautions
Seven, take the time to introduce the steps
Pipe connection for vacuum
8. Introduction of refrigerant injection
Determine the type of refrigerant (refrigerant) charged
The color of the refrigerant tank of R410A is pink, which is used to distinguish other refrigerants.
Precautions for charging refrigerant
Refrigerant tank equipped with siphon:
In order to ensure the effective charging of the refrigerant, the siphon tube does not touch the bottom of the refrigerant tank; that is to say, when the refrigerant in the tank is lower than the siphon tube mouth, the liquid filling of the refrigerant cannot be guaranteed.
Pipe connection for filling refrigerant
1) Put the refrigerant tank on the electronic scale, connect the pipeline as shown in the figure, record the reading of the electronic scale, and determine the weight of the refrigerant to be charged.
2) Slightly turn on the switch of the refrigerant tank and turn it off immediately;
3) Press the thimble valve lightly to let the gas spray out from the thimble, and release it immediately (press the thimble valve for too long, just press it to release)
4) Repeat 2), 3) operate 2 to 3 times;
5) Open the low pressure valve of the pressure gauge, and then turn on the switch of the refrigerant tank to charge;
6) Observe the reading of the electronic scale according to the weight of the refrigerant that needs to be increased; turn off the switch of the refrigerant tank or the low pressure valve of the pressure gauge when enough refrigerant is filled;
*Do not charge a large amount of refrigerant at a time. Because the repair port (low pressure on the gas side) is filled with excessive liquid refrigerant, it will damage the system.
7) Quickly unscrew the pressure gauge hose connected to the service port; if the action is too slow, it will cause a large amount of refrigerant leakage and even frostbite the skin.
8) Install the screw cap of the repair port. It is recommended to use soapy water to check if the refrigerant leaks. (Ensure that the system has no leaks)
9) When a leak is found in the system, all the original refrigerant in the system should be discharged, and the vacuum should be re-filled.
