A refrigerant is an element in the form of liquid or gas. A specific area in the refrigeration succession cools down using the refrigerant. The process seizes heat from space and then releases it into another space. This is the act of a refrigerant.
Refrigerants in refrigerating systems (air conditioners) absorb fluid and release heat. Apart from this, Thermodynamic phenomena of phase change are the process also used by refrigerants. This helps the liquid to convert to gas and gas into a liquid.
The process of refrigerant starts in the evaporator component of the system. The refrigerant liquid will absorb heat and also change to vapour under low pressure. The vapour travels to the compressor component of the system.
The compressor pressure and temperature increases. The release of heat from the vapour happens at this stage. The release of heat happens in the condenser component.
The refrigerant then changes back to liquid form. It travels back to the evaporator. Repetition of the process happens again and again with the same liquid. There are different types of refrigerants.
Modern equipment that uses refrigerants includes ACs, cooling systems, freezers, and refrigerators. In spite of their usefulness, refrigerants also contribute to global warming.
Different Types of Refrigerants In HVAC:
The classification of refrigerants into different groups is due to their chemical composition. The most common refrigerants include Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons (HCFCs), Hydrofluorocarbons (HFCs), and Natural Refrigerants.
Freons or halocarbons are synthetically produced. The classification also depends on their chemical elements chlorine (Cl), hydrogen (H), carbon (C), and Florine (F).
- Chlorofluorocarbons (CFCs) – R11, R12, R113, R114, R115
- Hydrochlorofluorocarbons (HCFCs) – R22, R123
- Hydrofluorocarbons (HFCs) – R134a, R404a, R407C, R410a
The two numbers that characterize all refrigerants are:
- Ozone Depletion Potential (ODP)
- Global Warming Potential (GWP)
The value range of ODP is 0 – 1. ODP that is closest to 1 is harmful to the ozone layer. CFCs have big ODP values. This is because they contain chlorine. Nowadays, CFCs are not used due to their harmful impact on the environment.
GWP value ranges from 0 to several thousand. If the GWP value is big, the refrigerant is more harmful and can cause global warming.
Inorganic refrigerants like carbon dioxide and ammonia have small GWP values. HCFCs are been phased out. The only HCFCs allowed nowadays is one without chlorine.
The refrigerant types that make the most common list include:
This is also a halo alkaline refrigerant. It has thermodynamic properties. Norflurane is often referred to as R-134A.
A single component makes R-134A. It is not blended like R-22 and also as an R-12. This means the refrigerant doesn’t need the use of many recovery machines.
The Environmental Protection Agency regulations specify that any product that recycles or uses a blend will need a separate machine for each component.
R-134A is also the only refrigerant as an alternative to retrofit R-12 air conditioning systems in all types of vehicles. The retrofitting process should follow proper procedures to avoid safety hazards and other problems.
Retrofitting is not an easy process. The process also involves changing the vehicle’s dryer/receiver or accumulator. Remove the old compressor oil.
Replace the high-pressure switch of the vehicle’s air conditioner after this process is complete. Do the entire process in a thorough and careful manner to avoid contamination. Cross-contamination can happen if any R-22 is still left in the system.
Cross-contamination of E-134A and R-22 will affect the cooling system of the vehicle. It will make it less reliable. The compressor’s head pressure goes up to dangerous levels. The system will fail completely when the pressure goes beyond the permissible levels.
R-134A uses a special oil blend of polyol ester or polyethene. R-134A refrigerant is a better choice for the environment.
This refrigerant has thermodynamic properties. It is a common replacement refrigerant to retrofit R-22 equipment. The mix of hydrofluorocarbons includes a blend of difluoromethane, pentafluoroethane, and also 1,1,1,2-tetrafluoro-ethane.
Ductless split systems, packaged air conditioners, and also water chillers use the refrigerant. Apart from this, it is also present in direct expansion systems and light air conditioning found in commercial, residential, and industrial properties.
R-407C also works in refrigeration systems with medium temperature. Many new appliances use R-407C. New appliances that use nitrogen as a holding charge will work best with R-407C. This is because it uses polyol ester oil.
R-407C is quite common in new refrigeration systems and appliances. R-407C is also present on some R-22 systems. The procedure involves an oil change when retrofitting. R-407C is an alternative to freon. It is safe for the environment.
R-404A is a safe alternative to R-22. The use of the refrigerant is in refrigeration systems that also require a temperature between -45° C and 15° C. This translates to -49° F and 59° F. The wide temperature range makes it useful in industrial and commercial transport industries.
The properties of this refrigerant are similar to R-22. This also offers better performance.
R-404A does not react rapidly with air or water. This makes it safe for many uses. It is also colourless, non-inflammable and odourless.
Users should take adequate safety precautions when using refrigerant. Direct contact with R-404A can cause frostbite. Exposure to high heat or fire can rupture the refrigerant tank. R-404A is available in stores that sell cooling as well as heating products.
This refrigerant is a blend of difluoromethane, two hydrofluorocarbon refrigerants, as well as pentafluoroethane. R-410A is a non-ozone depleting refrigerant. It provides energy efficiency than R-407C and R-22. Chlorine is not even there.
The high refrigeration capacity and pressure make it more suitable than R-22. This helps in providing better performance.
The process of buying an R-410A is easy. Companies that manufacture refrigeration systems and air conditioning make units that use R-410A. R-410A is a popular choice for air conditioning, commercial refrigeration, and chilling units.
The alternative to Freon will not be effective in R-22 a/c units. This is because of the higher pressure in R-410A. The need is for a different pressure gauge than what is usually there in R-22. The charge of the refrigerant is in its liquid form. The charge is only in short bursts.