ELI5: Why a refrigerator doen't need a coolant change but my car does explainlikeimfive

Laying in bed last night, this popped into my head:

How can it be, that my fridge, which operates 24/7 for years never needs a change of coolant, yet my car, which operates fewer hours, does?

Thanks!

Submitted January 29, 2016 at 11:39AM by cdnexpat_ch http://ift.tt/1PmlQIu explainlikeimfive