R-600a vs. R-134a: Which Is The Better Refrigerant?

If the compressor is the heart of the refrigerator, then its refrigerant gas (AKA Freon) is its blood. These gases facilitate the heat transfer process that fridges use to create a cold environment for our food.

In the Philippine refrigerator market, there are two kinds of refrigerants in use: R-600a and R-134a. While these two gases have the same function, they have different characteristics that make one better than the other in some aspects.

To briefly put it: R-600a (Isobutane) has less impact on the environment and is generally more efficient vs. the R-134a (Norflurane) gas. However, one of the drawbacks of the R-600a gas is that it is flammable and it can cause minor health concerns when it escapes from the refrigerator.

In this article, I will give you a brief overview of these refrigerants, and I will also give you a rationale on the R-600a vs R-134a debate.

How a refrigerator works

Refrigerators work by harnessing the power of the evaporation process to cool down their compartments. It does this by continuously evaporating and condensing a refrigerant gas that runs through copper tubes inside the refrigerator.

As the liquid form of the refrigerant evaporates, it absorbs the heat from its surroundings, and thus producing a cool environment. Now that the refrigerant has turned to a gas, it needs to be condensed back into its liquid form to start the process again.

The catch-all term for these refrigerant gases is “Freon”. Freon is actually a brand name of the chemical Dichlorodifluoromethane R-12, which was the most commonly used refrigerant gas back in the day.

Since Freon is a CFC (chlorofluorocarbons), it has been phased out in lieu of more environment-friendly refrigerants because of its capability to damage the ozone layer.

Thus, the refrigerants R-600a and R-134a were born.

R-600a vs. R-134a

This section will be the comparative analysis between the two refrigerant gases. I will divide this into 4 sections: Eco-friendliness, cooling performance, health concerns, and flammability.

Eco-friendliness

As stated earlier, the main reason why the R-12 gas was replaced is due to its impact on the environment. Hence why we should expect that both the R-600a and the R-134a gases to be more environmentally-friendly compared to the R-12 gas.

The eco-friendliness of Refrigerant gases are measure by two metrics: its Global Warming Potential (GWP) and its Ozone Depletion Potential (ODP).

As the United Nations Environment Programme (UNEP) explains it, the GWP is:

“…a measure of the relative global warming effects of different gases. It assigns a value to the amount of heat trapped by a certain mass of a gas relative to the amount of heat trapped by a similar mass of carbon dioxide over a specific period of time.”

United Nations Environment Programme (UNEP)

Meanwhile, the UNEP also defined the Ozone Depletion Potential as:

“a relative index of the ability of a substance to cause ozone depletion. The reference level of 1 is assigned as an index to CFC-11 and CFC-12.”

United Nations Environment Programme (UNEP)

Here are the comparisons the GWP and the ODP of the three refrigerants:

RefrigerantGlobal Warming PotentialOzone Depletion Potential
R-1210,9001.0
R-134a1,4300.0
R-600a30.0

As you can see, both R-600a and R-134a refrigerants are a vast improvement compared to the R-12 gas. Both do not have any potential to damage the ozone layer. However, the R-600a has a lower global warming potential compared to the R-134a, hence it wins this round.

Winner: R-600a. It has a lower global warming potential compared to the R-134a refrigerant.

Cooling Performance and Efficiency

The cooling performance of these refrigerants are measured by their coefficient of performance (COP). The COP is the ratio of the heat removed from the refrigerator to power input needed to do this task. A higher COP means higher efficiency and thus lower operating costs.

Here is a comparison of the COPs of these refrigerants:

RefrigerantCoefficient of Performance
R-125.35
R-134a4.62
R-600a5.12
International Journal of Research and Analytical Reviews (IJRAR)

As you can see, the R-12 gas has the highest COP compared to the other two gases. However, since it is already phased out, the best alternative to this is the R-600a gas which has almost the same COP as the R-12. Meanwhile, the R-134a gas has a COP of 4.62, which is lower than the other two gases. Thus, R-600a is more efficient than R-134a.

Also worth noting is that the R-600a requires a shorter time to reach -21°C (60 minutes) compared to the R-134a (135 minutes)[1].

Winner: R-600a. It has a higher COP and can reach a lower temperature in a shorter period of time compared to the R-134a.

Health Concerns

Refrigerant gases can leak given the right circumstances. And these gases can cause adverse health effects when a person is exposed to it.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) designated refrigerant gases into two classes of toxicity: lower toxicity (Class A) and higher toxicity (Class B). These two classes are further subdivided into designations of 1 – 3 where gases with a designation of A1 has a lower toxicity compared to gases with a designation of A3.

Here is a comparison between the R-134a vs. R-600a gases:

RefrigerantASHRAE Toxicity Safety GroupClassification
R-12A1Low toxicity
R-134aA1Low toxicity
R-600aA3Low toxicity
American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

As you can see, while both gases are considered as having low-toxicity, the R-134a beats out the R-600a with its designation of A1 compared to the A3 of the latter.

Winner: R-134a. While both of these gases are considered as non-toxic, the R-134a refrigerant will have less adverse effects on your health compared to the R-600a gas, hence making it safer overall.

Flammability

The ASHRAE also designated these refrigerant gas based on their flammability. Here is their designation scheme:

CategoryDesignation
No Flame PropagationA1
Lower FlammabilityA2L
FlammableA2
Higher FlammabilityA3

Now, here is their designation of these refrigerants:

RefrigerantASHRAE Toxicity Safety GroupClassification
R-134aA1No Flame Propagation
R-600aA3Highly Flammable
American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

As you can see, the R-600a is considered as highly flammable which makes it more of a safety concern versus the R-134a.

With that said though, refrigerators use only small amounts of R-600a gas. Fridges need ~50g of this gas to function – 66% lower than when using R-134a [2]. This amount won’t pose that much danger of your refrigerator blowing up or being engulfed in flames – it’s still flammable though.

Winner: R-134a. Unlike the R-600a gas, R-134a will not catch on fire even if it is exposed to flames.

Conclusion

As we’ve discussed, the R-600a is more efficient and has less environmental impact compared to the R-134a. However, it’s drawback is that it is flammable and its adverse health effects when it does leak from your refrigerator.

With all of this said, I personally recommend buying an R-600a refrigerant nonetheless. It’s cooling efficiency will save you more in the long run. Also, while it is flammable, most refrigerators do not have enough of this gas to precipitate a catastrophic explosion.

In fact, I’ve seen that a lot of companies have already shifted from R-134a to R-600a. Usually, R-600a has been used for no-frost models, while R-134a has been used for direct cooling models. But now, I’ve seen more and more direct cool models use R-600a, and it looks like it is the current trend.

If you have more questions about what kind of refrigerator to buy, we’ve published a comprehensive fridge buying guide to help you in your buying journey.

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