തണുത്ത അന്തരീക്ഷം പ്രധാനം ചെയ്യുന്നതിൽ ശീതീകരണ സാമഗ്രികളെ സഹായിക്കുന്ന പ്രധാന ഘടകം

                                REFRIGERANTS

A refrigerant is a substance used in a heat cycle to transfer heat from one area, and remove it to another. Usually a gas at room temperature. Found in pretty much everything that cools, and sometimes in things that heat, most commonly air conditioners, fridges, freezers, and vehicle air conditioners. Traditionally, fluorocarbons, especially chlorofluorocarbons (CFC’s), were used as refrigerants, but they are being phased out because of their ozone depleting effects. Other common refrigerants used in various applications are ammonia, sulphur dioxide, and non-halogenated hydrocarbons such as propane. Most refrigerants found in end of life devices are ozone depleting and global warming inducing compounds.

Refrigerants use thermodynamic phenomena of phase changes, which help the gas to convert into liquid or the liquid to gas. Because of this remarkable ability, it can be used in many devices like ACs, refrigerators, freezers, cooling machines, etc.

Despite such usefulness, many of the refrigerants are responsible contributing to global warming. It is said and has been studied that refrigerants affect our environment adversely and slowly diminishing the layer of ozone. However, we will discuss regarding this issue some other time as today we are focusing on some common refrigerants available and refrigerant types.

TYPES OF REFRIGERANTS

The chemical arrangement of the refrigerants decides in which group it should be considered. As per the various manufacturers’ guidelines, there are four main refrigerant types:

1.    CFCs – Chlorofluorocarbons

2.    HCFCs – Hydro chlorofluorocarbons

3.    HFCs – Hydro fluorocarbons

4.    Natural Refrigerants

Gases like HC and CO2 are natural, but CFC, HCFC, HFC, etc. are considered under the synthetic class. Let us give you some details explaining each type of refrigerant.

1) CFCS – CHLOROFLUOROCARBONS

These are the refrigerants which contain chlorine, fluorine, and carbon. R11, R12, R115, etc. are included in CFC refrigerants. This type of coolant can be used for commercial as well as daily purposes. It was developed in the past – in the 30s – and at that time it was non-toxic, non-flammable, and non-reactive.

But in the early 70s, it was proved that it is hazardous for the layer of ozone and unfriendly for the environment. The chlorine atom splits the extra oxygen atoms in the composition of ozone, and so it is liable for ozone depletion. So, CFCs were banned in the late 80's because of adverse environmental effects. Nowadays, it is estimated that half of the total CFCs have been improved.

R11, R12, R13, R113, R114, R500, R502, R503 are the top refrigerants covered under the group of CFCs. Some of them are also known for the greenhouse gas effects.

2) HCFCS – HYDRO CHLOROFLUOROCARBONS

HCFCs were referred to as the substitute of CFCs. It contains hydrogen, chlorine, fluorine, and carbon. Of course, it is not like this group’s refrigerants are not at all affecting the layer of ozone, but they affect only around 10%, which is extremely less than the CFCs.

HCFCs are non-toxic, cheap, and competent. But yes, even if they do not harm the environment much, they are known as greenhouse gases! They can also deplete the ozone slowly, but continuously.

R22, R123, R124, R401A, R401B, R402A, R403B, R408A, R409A, R414B, R416A are the refrigerants which are covered under the group of HCFCs.

3) HFCS – HYDRO FLUOROCARBONS

These refrigerants do not include any particles of chlorine. So, they are not at all harmful to the environment and do not deplete the ozone layer. But just like any other refrigerant, they have some powerful impact on global warming as compared to natural refrigerants.

When there was the ban of HCFCs, this group comes in. It includes hydrogen, fluorine, and carbon. So, if compared to other refrigerants, it has the lower potential of global warming.

R23, R134a, R404A, R407C, R410A, R417A, R422A, R422B, R422D, R507, R508B are included in the HFC group. This group of refrigerants is always in demand by refrigerant manufacturers because of its environment suitability.

4) NATURAL REFRIGERANTS

As the name suggests, natural refrigerants are completely natural. They are not created by any men like the other ones. They do not harm the nature, environment, or the ozone layer.

Moreover, they are quite inexpensive as compared to other refrigerants. Air, HC, ammonia, CO2, H2O, etc. are the examples of natural refrigerants. They have zero ozone depletion potential and negligible effects on global warming.

What are the most common refrigerants nowadays?

·         R134a (HFC)

·         R-12 (CFC)

·         R-410A (HFC)

·         R-22 (CFC)

·         R-404A (HFC)

This is the top common list of refrigerants. These refrigerants can also be used in HVAC equipment.