These are typically called mini-splits. The cooling coil is mounted inside the building / room and the evaporator coil is installed outside the building. Refrigerant lines penetrate the building wall and carry the acquired heat outside. In addition, I want to say about the existence of btu calculation formula for air conditioner that will help you with Air-conditioning units.
Mini-split heat pumps are not only great solutions for whole home or new constructions but make good retrofit add-ons to houses with “non-ducted” heating. There is no duct work and they are very efficient.