Aircraft engineer here. I'd like to point out a counterexample. The "air cycle machines" that create cool air in aircraft air conditioning systems run on compressed air bled off from the engines. They don't involve phase changes, the air stays gaseouos the whole time.
LMF5000 t1_j18sxl0 wrote
Reply to Why do we use phase change refrigerants? by samskiter
Aircraft engineer here. I'd like to point out a counterexample. The "air cycle machines" that create cool air in aircraft air conditioning systems run on compressed air bled off from the engines. They don't involve phase changes, the air stays gaseouos the whole time.