[jabl]

I think butane or propane is the standard refrigerant for household refrigerators all over the world nowadays; the US is the odd man out.

R134a is still unfortunately widely used in cars. Newer cars are moving to R1234yf, which is expensive, maybe CO2 in the future.

[semi-extrinsic]

Mercedes is already doing CO2, and the next-gen EV platforms are going that route as well, from what I hear. The high pressure of CO2 systems mean that they're very compact, and thus much easier to integrate with battery pack temperature regulation, AFAICT.

[jabl]

That's good to hear.

I think the interest for EVs might be due to CO2 systems being capable of working as heat pumps as well, producing hot air. Otherwise you'd waste a lot of electricity in cold climates.

[semi-extrinsic]

Exactly this, both that they're able to heat the interior of the car, but also that they can play the role of battery cooling system (just heat a small radiator instead of inside of car).

[mohaine]

Part of this is the regulation in the US around refrigerant reclamation. Once a gas is used as a refrigerant, it has be reclaimed/recycled or large fines can be assessed, even though the rules do not apply when the same gas is used in any other context.

This makes switching to a new gas much harder as the infrastructure for reclaim/recycle does not exist for the new gas, no mater how safe or better it is.

[z2]

I wonder if the use of these same gases for canned air is at all significant compared to its use as a refrigerant. Regulators seem not to care if people squirt off KGs of the gas to dust off keyboards!