[kelnos]

Air conditioners (the things that can make a room colder, but not hotter), are indeed heat pumps, but in the US when we refer to a "heat pump" we mean the same technology, but with a reversing valve so that it can make rooms both colder and hotter.

[Gigachad]

Interesting. I’ve never seen one that couldn’t heat and cool before. Even crusty 30 year old window units can do both. Seems almost absurd to not utilise it both ways.