- AC unit pumps out cold air only.

- The heat that comes out of the "heater" which is basically engine heat.

Are both statement correct?

If so, then when we turn on the AC and set the temp to warm (for example) or warmer. Does the AC pump out cold air, then the engine warms it up?

Isn't it a very inefficient process?

Please educate me.

 

AC doesnt make air cold. AC removes moisture. The lack of moisture in unheated
air makes the moisture on your skin go away which makes you cold because
moisture helps retain heat.

Using heat and AC to defrost a window say, is like a double punch, the heat helps
the defrosting action while the AC sucks away the condensation.

 

AC doesnt "pump out" anything. it uses a typ of heat exchanger type system where the refrigerant is compressed (by the ac compressor) which elevates the temperature (pressure ^, temp ^), then cooled by air flowing over the pipes (making it a liquid). then it goes though a valve where the pressure is dropped, therefore the temp goes down and the same air that passed by the pipes before is cooled by taking the water out of it (thats why you see ac units "leaking" water - it's just condensation dripping) and convection heat transfer. then it goes through your vents at the nice, cool temperature and dry too.