What are the most common refrigerant gases in refrigeration?

Refrigerant gases are elements used to cool a specific area within refrigeration systems, such as freezers or air conditioning units. This is possible thanks to the thermodynamic phenomena they utilize, which allow them to change the gas into a liquid phase and vice versa. In this post by Inditer, you will find everything you need to know about the most common refrigerants in refrigeration.

How many types of refrigerants are there?

Generally speaking, the most common refrigerants in refrigeration are divided into inorganic (water and ammonia, for example) and organic (halocarbons or hydrocarbons). Within the halogenated hydrocarbon family, three types currently exist:

• CFC: a fully halogenated halocarbon containing chlorine, fluorine, and carbon; it is hydrogen-free, and its stability causes it to remain in the atmosphere for a long time, making it harmful to the ozone layer.
• HCFC: a partially halogenated halocarbon containing chlorine, fluorine, and carbon which, unlike the former, does contain hydrogen.
• HFC: a partially halogenated halocarbon containing hydrogen, fluorine, and carbon, but no chlorine.

What are the most widely used refrigerants?

The 3 most common refrigerants in refrigeration today are all chlorine-free fluorocarbons with hydrogen atoms (HFCs):

R-410A Refrigerant

This refrigerant is the result of a mixture of hydrofluorocarbon and pentafluoroethane, called difluoromethane. It is a gas that is not harmful to the ozone layer and is typically used in commercial and residential air conditioning equipment and in water chillers.

R-134A Refrigerant

This is a haloalkane refrigerant with thermodynamic properties and is a better option for the environment than R-410A thanks to its combination of special polyester or polyethylene oil. It is used in commercial and domestic refrigeration systems, automotive air conditioning equipment, and water chillers.

R-404A Refrigerant

This gas is another safe alternative, especially for refrigeration systems requiring a temperature between -45°C and 15°C. This wide temperature range makes it useful in the industrial and commercial transport sector. One of its greatest strengths is that it does not cause ozone depletion.

At Inditer, we offer refrigeration evaporators suitable for industrial refrigeration equipment, such as cold rooms for freezing and preservation or workroom climate control units. We have standard designs available, but we also adapt to our clients’ needs to offer customized devices. Do not hesitate to contact us with your questions.

Classification of refrigerants

As indicated by the Refrigeration Installation Regulations of Royal Decree 552/2019, the most common refrigerants in refrigeration are classified according to their effects on health and safety, dividing them by flammability and toxicity.

Classification by flammability

• Category 1: This group includes refrigerants that show no flame propagation when tested at +60°C and 101.3 kPa.
• Category 2: These are refrigerants that do show flame propagation when tested at +60°C and 101.3 kPa; have a lower flammability limit equal to or greater than 3.5% by volume (V/V); and have a heat of combustion less than 19,000 kJ/kg.
• Category 3: These refrigerants possess characteristics such as showing flame propagation when tested at +60°C and 101.3 kPa; having a lower flammability limit of less than 3.5% by volume (V/V); and having a heat of combustion greater than or equal to 19,000 kJ/kg.

Classification by toxicity

• Category A: These are refrigerants whose average concentration does not generate negative effects for workers exposed to them during an 8-hour workday. Furthermore, their value is equal to or greater than an average concentration of 400 ml/m3 [400 ppm (V/V)].
• Category B: Conversely, these are refrigerants that do not generate such effects, but whose value is lower than an average concentration of 400 ml/m3 [400 ppm (V/V)].

In this way, a combination of up to 8 different classes of the most common refrigerants in refrigeration is established based on the mentioned criteria. There is also an additional categorization, independent of these two factors:

Classification by function

• Primary refrigerant or refrigerant fluid: A refrigerant belongs to this category when it is the transmitting agent in the refrigeration system, meaning it performs a thermal exchange primarily in the form of latent heat.
• Secondary refrigerant or cooling fluid: These are intermediate substances used to transport heat between the primary circuit and the medium to be cooled or heated. Examples of this division include water, brine, or air.

Which refrigerants were most used in the past?

The refrigerant used par excellence in recent decades in commercial and light industrial refrigeration is R-404A, thanks to the characteristics that made it ideal for low, medium, and even high temperatures.

However, EU Regulation 517/2014 on fluorinated gases established that as of January 1, 2020, its commercialization would be prohibited. This has led various gas manufacturers and distributors to work in advance on direct substitutes.

Furthermore, in the 1990s, the use of HFC gases stood out as a replacement for others like CFC or HCFC to reduce damage to the ozone layer. Although they are still used today, better alternatives are also being sought to curb the greenhouse effect they generate and, consequently, their impact on global warming.

We hope this post on the most common refrigerant gases in refrigeration has been useful to you. Remember that at Inditer, we have the refrigeration evaporators you need, manufactured with state-of-the-art systems, guaranteeing high quality and durability in any installation. Contact us to get yours.

And do not forget that for any questions or advice you may need, you can take a look at the other posts on our blog, featuring all kinds of specialized notices and recommendations for the heat exchanger industry.