What are hydrocarbons (HCs)

Hydrocarbons (HCs) are substances composed of hydrogen atoms bonded to carbon atoms. Examples are methane (CH4), propane (C3H8), propene (C3H6, also known as propylene) and butane (C4H10).

These are all flammable and non-toxic according to the ASHRAE 34 safety classification: their safety class is A3, with the “A” meaning “low toxicity” and the “3” meaning “high flammability”.

 

 

Advantages of HCs as refrigerants

There are three main advantages:

Lower global warming potential

HCs have very low global warming potential, So it helps in reduction of CO₂ emissions if we use hydrocarbons as refrigerant. 

Conveniently originated from nature

HCs are extracted from the soil, also together with oil. Their reserves on Earth are immense. And it’s convenient to tap them, as well, their price is lower than that of other synthetic refrigerants.

Better refrigerant performance

 HCs work more efficiently cooling/heating as a refrigerant than the others. In fact, their latent heat of vaporization is even twice as high as other synthetic refrigerants, which means a higher cooling/heating effect with the same refrigerant mass flow

 Improvement in energy efficiency

Case studies show that the migration from the HFC R404A to the natural refrigerant R290, on average, can allow up to a 10 per cent improvement in energy saving.

Better thermal regime in favor of compressor

In parallel to natural refrigerants, there are the new synthetic blends available in the market with low GWP, also known as A2Ls. The table (pictured) shows the main criteria that should be taken into consideration when reaching a decision. One of these criteria is the thermal regime, which is better in natural refrigerants, meaning it doesn't heat up the compressor as much as the A2Ls. This aspect contributes to the energy efficiency and the reliability of the compressor.