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I live in the traditionally temperate Pacific Northwest, but after the heat waves of summer 2021 I'm thinking about giving up and finally buying an air conditioner. But I've heard that air conditioners use refrigerants like Freon that damage the ozone layer and contribute to global warming. (In theory it should be possible to recover and recycle refrigerants... but in reality it sounds like a lot of refrigerant does end up in the atmosphere.)

In 2021, is it possible to buy an air conditioner with a refrigerant that doesn't damage the ozone layer or have a massive global warming potential?

I'm living in Canada, if that matters.

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When I bought a portable air conditioner unit, I was happy to see some genuine progress made in the refrigerants.

Long time ago, I bought my older portable air conditioner unit and it used R410a as the refrigerant. It consists of artificial hydrocarbons that have some hydrogen atoms substituted with fluorine. Apparently it doesn't cause ozone depletion which was why it was allowed as a refrigerant, but its global warning potential is horrible. Its global warming potential is over 2000, meaning that about half kilogram charge would cause as much damage as a ton of carbon dioxide if released to the atmosphere. To put that into context, in its lifetime the unit will probably consume around 5000 kWh of electricity, and at 100 g / kWh emissions from generating electricity in the relatively clean Finnish grid, the emissions caused by the electricity consumption would be 500 kg, half of the damage that would be caused if the unit releases all its refrigerant charge. Also the emissions from electricity generation are rapidly decreasing whereas the damage caused by R410a leak stays the same.

However, good refrigerants have been available for long. We have however been too scared of using them because they are flammable (but there's so little of these refrigerants in one AC unit so something like a barbecue grill would be a far greater flammability hazard). My new portable air conditioner unit uses R-290, or in other words propane. It has a global warming potential of 3. Only 0.24 kg of it is used, so this means if all of it are released, it corresponds to only 0.72 kg of CO2 emissions.

I wonder why the government doesn't get rid of special permits needed for installing split air conditioner units. With propane as refrigerant, it could be perfectly well vented to atmosphere with no damage.

So, look for propane (R-290) as the refrigerant.

I wonder why cars use today R-1234yf. Probably some chemical company was worried that their revenue stream from specialty AC chemicals would go away if propane was allowed and lobbied for everyone to switch to a more expensive patented chemical.

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  • Great answer, thanks!
    – Nic
    Aug 15 at 13:44
  • The challenge with alternative refrigerants such as ammonia or propane/butane is that they introduce a safety issue where none existed before. Even if the fire risk is small, there was no fire risk before. Since new technology is generally proven in large-scale commercial systems where the propane charge would be significant enough to cause damage, it takes a while to make it's way to smaller systems where there's less risk.
    – LShaver
    Aug 16 at 3:27
  • The original refrigerant was ammonia. CFC refrigerants were seen as a major breakthrough because, unlike ammonia, they don't kill you when they leak.
    – Mark
    Aug 17 at 0:30
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It seems the later models of refrigerative air conditioners (heat pumps) use refrigerant R-32. Freon, also known as R-22, is not being used by the major manufacturers for new air conditioners.

R-32 doesn't affect the ozone layer. The following picture is from a manufacturers website. It's just a convenient visual of the similar data in tabular format.

Some more info about R-32.

enter image description here

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    Based on the global warming potential, R-32 should not be used. About its only benefit that as an old chemical, its patents have expired. Propane is far better and causes less global warming damage if vented to the atmosphere.
    – juhist
    Aug 15 at 12:53
  • I notice that the circle for CO2 (Global Warming Potential = 1) is clearly not 675 times bigger than the circle for R-32 (GWP = 675). Very "convenient" visual from the manufacturer!
    – aucuparia
    Aug 17 at 21:47

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