Performance Characteristics of Various Refrigerants In Heat Pumps

To choose the heat pump industry, you need to understand some common knowledge of refrigerants.

1.R22

R22 refrigerant also belongs to the Freon refrigerant category. The chemical name is difluorochloromethane, and the chemical formula is CHF2Cl. R22 refrigerant is also a medium pressure and medium temperature refrigerant, with a boiling point of -40.8 ℃, a freezing point of -160 ℃, a critical temperature of 96 ℃, and a critical pressure of 4.974 MPa. R22 does not burn or explode, has low toxicity, but has strong permeability and is difficult to detect leaks.

The unit volume of R22 is similar to the unit volume of ammonia refrigerant. Although the minimum temperature can reach -80 ℃, it is not economical.

At present, R22 refrigerant still accounts for the largest proportion in the use of air conditioning, mainly used in some old-fashioned air conditioning refrigeration systems. R22 refrigerant contains the element "Cl", which poses a great threat to the ozone layer. It has already been eliminated.

2.R410A

R410a is a HFCs refrigerant composed of R32 and R125 mixed in a mass ratio of 50% and 50%. The phase change temperature slip of R410A is less than 0.2 ° C, so refrigerant leakage does not require refilling.

The capacity and pressure of R410a refrigerant are higher than R22, and the working pressure is 50% -60% higher. The operating noise of R410a is significantly 2-4 decibels lower than that of R22 compressor.

Due to the high pressure and density of R401A, the refrigerant pipe diameter can be greatly reduced, and the compressor size and displacement can also be greatly reduced. Meanwhile, R410A liquid phase has high thermal conductivity and low viscosity, making its transmission characteristics significantly better than R22.

R410A is internationally recognized as the most suitable refrigerant to replace R22 and has been promoted in countries such as Europe, America, and Japan. When using R410A, the total heat transfer characteristics of the system are greater than R22, which can improve system efficiency and reduce the heat transfer area of the heat exchanger.

3.R32

R32 is the abbreviation for difluoromethane (CH2F2). R32 is colorless and odorless, slightly flammable (A2 grade). Its combustion limit in the air is 14%~31%, and it will burn and explode when exposed to an open flame.

R32 refrigerant is soluble in oil, but not in water. The ODP of ozone depletion potential is 0, and the global warming coefficient GWP is 670. The pressure is about 60% higher than R22. The product should be resistant to high voltage, and the tools and equipment used for maintenance should also be resistant to high voltage.

The pressure is equivalent to R410A, and the thermal properties of R32 and R410A are very similar. R32 has low viscosity coefficient and high thermal conductivity.

Although R32 has many advantages, it is a flammable and explosive refrigerant. Air conditioning installation and maintenance are inherently dangerous tasks. Now, coupled with the uncertainty of R32, we have to consider safety issues. Need to pay attention! R32 refrigerant needs to be vacuumed, no open flames allowed!

4.R290

R290 (propane), also known as cold coal, is a new type of environmentally friendly refrigerant mainly used in small refrigeration equipment such as central air conditioning, heat pump air conditioning, and household air conditioning.

R290, as a hydrocarbon refrigerant, has an ODP value of 0 and a GWP value of less than 20. Compared with R600a, R134a, and R404A, R290 has outstanding advantages in refrigeration performance. Due to its flammable and explosive properties, the filling capacity is limited, and the safety level is A3. When filling R290, vacuum should be applied to prevent the formation of explosive mixtures. There is a risk of combustion and explosion when encountering heat sources and open flames. During storage and use, it is strictly prohibited to work with heat sources and open flames!

5.R600a

R600a isobutane (C4H10) is a novel hydrocarbon refrigerant with excellent performance. Derived from natural ingredients, does not damage the ozone layer, has no greenhouse effect, and is environmentally friendly.

Its characteristics are high latent heat of evaporation and strong cooling capacity; Good flow performance, low delivery pressure, low power consumption, and slow load temperature recovery. Compatible with various compressor lubricants.

It is a colorless gas at room temperature and a colorless transparent liquid under its own pressure. R600a is mainly used to replace R12 refrigerant and is now mostly used in household refrigerator equipment.

R600a is also a combustible gas that forms an explosive mixture when mixed with air. There is a risk of combustion and explosion when encountering heat sources and open flames. Contact with oxidants and undergo violent reactions. Its vapor is heavier than air and can diffuse from lower places to distant places. It will catch fire and backfire when encountering a fire source.

During use, insufficient R600a in the refrigeration system can cause excessive pressure, abnormal machine noise, and shortened compressor life.

6. R717 (ammonia)

R717 (ammonia) refrigerant (NH3), ammonia is a medium temperature refrigerant. Pure ammonia has no adverse effect on lubricating oil, but the presence of moisture can reduce the lubrication effect of refrigeration oil.

Copper and copper alloys are not used for pipelines and valves in ammonia refrigeration systems. The synthesis technology of R717 (ammonia) is mature, easy to prepare, inexpensive, does not damage the ozone layer, and has no greenhouse effect.

The refrigeration capacity per unit volume is greater than R22, with a high latent heat of vaporization and a high coefficient of refrigeration heat release. Ammonia refrigerants are widely used in large cold storage and supermarket food display cabinets.

Tetraammonium vapor is colorless and has a strong pungent odor. Ammonia is toxic to the human body, and splashing ammonia onto the skin can cause frostbite. When the volume of ammonia vapor in the air reaches 0.5-0.6%, it can cause an explosion.

Therefore, the ammonia concentration in the air of the computer room should not exceed 0.02 milligrams per liter. Ammonia is not easily combustible at room temperature, but when heated to 350 ℃, it decomposes into nitrogen and hydrogen, which can explode when mixed with oxygen in the air.

About LAILEY&COATES

LAILEY&COATES is British own OEM heat pump manufacturer based in China. We have strict quality control system in production facilities, Offering OEM production with competitive factory price. Our heat pump products range covering, R32 EVI air source heat pump with monoblock type, R32 inverter air to water heat pump for home heating, swimming pool heat pump, heat pump water heater etc, applications for inverter heat pump for home heating and cooling,  swimming pool heating and cooling, Hot Spring, Hot tob, Koi pond, pond heating, Aquaculture industry, Please visit our website to know more detail: https://www.laileyheatpump.com/Air-Source-Heat-Pump-pl3623279.html，also you can contact us directly: contact@laileyandcoates.com.cn , you will get the professional answer fast.