Once considered a luxury, an air conditioner has now become an integral part of most households. Explained in simple language, it is a machine that takes in the warm air of your room and converts it to cool air so that your room temperature becomes livable and comfortable. But how does an air conditioner manage that?
The magic is created by a chemical called refrigerant that is present inside every air conditioner. Back in the 1990s, refrigerants were touted as culprits for depleting the ozone layer of the environment and causing pollution. But over the years, we have seen a more environment-friendly version of refrigerants being used in cooling appliances.
Here, we discuss what exactly is a refrigerant, how it works and its various types down the history line to the present usage.
What is a Refrigerant?
A refrigerant is a compound used in air conditioners and refrigerators and is present in a fluid or gaseous state. It can easily absorb heat from the environment and cause refrigeration or air cooling after combining with other components like the evaporators and the compressors.
How Does a Refrigerant Work?
No refrigeration, air conditioning, and freezing technology are possible without a refrigerant. The refrigerant absorbs heat and releases it by transmuting from the liquid phase to the gas phase and back to bring about the cooling of the room.
Typically, the refrigerant is present inside the condenser copper coils of the AC. The compressor of an air conditioner changes the liquid refrigerant into a high-temperature and high-pressure gas that moves to the outside coil of the AC where it releases the heat through condensation. As it reaches the indoor coil, it cools downs to the point where it can cause evaporation upon meeting the warmer indoor air. It siphons heat from the air cooling it down. The refrigerant converts back to the liquid as it returns to the compressor to restart the cycle.
The level of a refrigerant remains the same throughout the life of an air conditioner unless leaks occur. A low refrigerant level not only hampers the cooling ability of an air conditioner but also causes severe damage to the compressor. Hence, any issue with the refrigerant must be repaired at the earliest.
Types of Refrigerants
As already stated, refrigerants have also undergone development and change with time. They are basically characterized by two numbers i.e. the Ozone Depletion Potential (ODP) and the Global Warming Potential (GWP).
The range of ODP values is 0 to 1 with a higher value signifying the refrigerant being more harmful to the ozone layer. Likewise, the GWP value ranges from 0 to several thousand with a bigger value symbolizing the refrigerant to be more harmful to the global warming effect.
Now, let us throw light on the various kinds of refrigerants used over the years.
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Chlorofluorocarbons (CFCs)
These are refrigerants that contain chlorine. Its typical examples are R11, R12, R113, R114, and R115. These refrigerants had both high ODP and GWP values and were touted as being highly detrimental to the environment by causing ozone layer depletion as well as contributing significantly to the greenhouse gas effect. Consequently, its use has been banned since 1994. It is no longer used in any AC.
Hydrochlorofluorocarbons (HCFCs)
These include refrigerants like R22, R123, and R124. These refrigerants are popularly referred to as freons. These refrigerants are slightly better than the previous refrigerant. While they cause less damage to ozone depletion; they have a far deeper impact on global warming.
In India, about 50 to 60 per cent of air conditioners (those manufactured till 2016) still use the R22 refrigerant. But a mandate has been passed by the EPA under the Clean Air Act of 2010 to phase them out by 2020 globally. In India, it is to be phased out by 2030.
Hydrofluorocarbons (HFCs)
The earlier two refrigerants were considered harmful because of the presence of chlorine in them. These are the latest refrigerants on which most ACs run. Without any chlorine, these are eco-friendlier versions of refrigerants. They offer better air quality with improved reliability and better comfort. The most common examples of this are R-32 and R-410A.
R-410A
This refrigerant is a mixture of two refrigerants i.e. R-125 and R-32. It is used quite widely. While it offers zero ozone depletion, it does have an impact on global warming with its GWP score being 2088. The refrigerant exhibits better performance due to its higher pressure and refrigeration capacity. According to the latest news, this refrigerant is under consideration to be phased out but its timeline is still to be decided.
R-32
It is the refrigerant that is fast replacing R-410A and is becoming the ultimate choice for most air-conditioners. The refrigerant causes no harm to the ozone layer and has about one-third impact on global warming than R-410A. Its GWP score is just 675. The performance is also optimum because of its higher pressure and refrigeration capacity. Today, it is one of the most commonly used refrigerants in air conditioners.
Hydrocarbons (HCs)
These are the latest and most eco-friendly refrigerants available in the Indian market and worldwide. These are completely halogen-free, offer zero ozone, depletion potential and are lowest in the GWP score as well. While they have high-energy efficiency; they are highly flammable in nature as they are hydrocarbons. Its most common examples are R-290, popularly called as ‘Propane’ and R-600A, popularly called ‘Iso-Butane.’
The ODP scores of both these refrigerants are zero while the GWP score of both propane and iso-butane is 3. These refrigerants and especially the R-600A are being used in refrigerators with no report of any accident so far.
There is a growing demand for these refrigerants to be used in ACs, especially in inverter air conditioners. Currently, only the Godrej NXZ series of air conditioners use the R-290 aka Propane refrigerant. But it is the future of refrigerants that will be widely used in the future.
Wrapping up
Refrigerants are an essential component of two of our everyday appliances-refrigerators and air-conditioners. It’s time that we rise to our responsibility to secure the future of coming generations and start using only those appliances with eco-friendly refrigerants.