Streamlined wall-mounted evaporators extend as little as 7" from the wall to accommodate most room configurations. The Indoor unit (evaporator) is mounted inside the room, enclosed in a neat and handsome space saving cabinet. It is connected to the outdoor unit (condenser) via refrigerant lines & inter-unit wiring through a 3 1/2" opening in the wall. Since no ductwork is required, installation is simple. fast & efficient. There is no need to use up window space or cut large openings in existing walls, which could undermine the integrity of your structure, and even pose security risks Whisper Quiet operation while delivering comfort throughout the room.Compressor is located in the outdoor unit, operating noise is virtually eliminated from the indoor. Hi-Efficiency, Balance, Noiseless and Space-Saving Rotary Compressor.