[natermer]

Propane makes a good substitute for R12 with very little modifications. I wouldn't use it inside a home or anything like that, but I have used it to make older vehicles blow cold.

It's extremely good refrigerant. The biggest problem people have is that it ends up too cold and icing up the system.

It sounds dangerous, but it's really not. Propane is only flammable with the correct mixture of air. Otherwise you couldn't light it with a blow torch. Even if you have a leaky system it isn't going to leak fast enough to cause a issue. Also propane is significantly heavier then air so anything that leaks out is going to go to ground. And the amount of propane you use is not very significant.

Cars that end up having issues with propane are typically home built propane fuel conversions with no ventilation under the tanks or connections. The propane can then pool in the low places and build up enough to cause a explosion.

[userbinator]

R152A, also known as "canned air", is actually very usable in an R12 system without any modification: https://www.youtube.com/watch?v=3wkBnhcyO3Y

(That guy restores old refrigerators, so he probably knows a thing or two about refrigerant substitution...)

[glenneroo]

Would a propane tank pose any danger to occupants during/after an accident?

[Johnny555]

Proponents of propane as refrigerant claim that it's not more dangerous than the 10 gallons of gasoline in the gas tank. I'm not sure I agree. Since propane is heavier than air, it doesn't dissipate as quickly as, say, natural gas would.

And while its true that you need the right mixture of propane and air for it to ignite, with the right-mixture, you've got a fuel-air explosive formed right next to an ignition source (the car's engine and battery).

[bigiain]

Like propane, gasoline fumes are also heavier than air. This becomes a problem in boats, where propane and/or gasoline fumes "collect" down in the hull with no natural ventilation path. Boats with propane stoves or gasoline motors need gas detectors and ventilation to ensure dangerous (suffocating or exploding) levels don't build up below decks...

[Spooky23]

Safe until it leaks.

[freedomben]

This might be the most amazing and interesting comment I've ever seen. Thank you :-)

What you say makes good sense too since many RVs have propane refrigerators. I've long wondered how it works exactly. Probably time for a DuckDuckGo search.

[Vendan]

Propane fridges actually burn the propane for heat, so it's not using it as a "refrigerant", just as a heat source.

[userbinator]

Those commonly use ammonia and hydrogen as the actual refrigerant: https://en.wikipedia.org/wiki/Absorption_refrigerator