Except it is not 100% efficient.
It will have losses, which will add extra heat to the surrounding area over what was removed from the target area.
Thus contributing to the increase of entropy in the universe. And bringing us one step closer to the heat death.
The real trick is to reverse-cycle your AC, and pump the heat into your home. Because of math and algorithms, this one trick will decrease entropy and take us further away from the heat death.
ACs also generate heat as a waste product (they’re not 100% efficient), but I’m not sure that actually heats up the surrounding area to a noticeable degree.
They're more than 100% efficient (they move more watts of heat than they produce), but they're less than ∞% efficient (they use Watts of energy still, so they still produce Watts of heat)
A heat pump can heat a home by more than the energy in the electricity it uses. It's more than 100% efficient at "converting electricity into heat in your home". It does that by not actually covering electricity but by moving heat, and it is less than 100% efficient at converting electricity into motion, and introduces some waste heat
The efficiency of a machine isn’t measured at how effective its job is, but how efficiently it does that job. If it moved heat without producing any waste heat, it would be 100% efficient. If it produces any waste heat at all it’s not 100% efficient. No machine can ever be more than 100% efficient. That would violate the laws of thermodynamics.
Yes your right should have been more clear. If AC moves hot air from a house. This hot air goes out then imagine hundreds of AC doing that. Would that in turn heat up the area around it.
As long as the temperature inside remains constant, as much cold leaks out as is transported inside. So the only residual heating outside would be from inefficiensies in the system, not the moving process itself.
To be extra clear: An AC transports the heat, not the hot air. It removes heat from the air and transfers that heat to the outside air.
There's also heat pumps that work with water instead of air. So they remove heat from the air and push it into water. This water can be a closed loop, or be open where the water is lost.
It can also work the other way around where the heat pump takes heat from outside and pumps it into water, heating up the water to then be used for heating a home or taking a shower. There are also water-water pumps that work on water on both ends.
Because heat pumps pump the actual thermal energy, the medium doesn't really matter much.