They have a compressor heat pump on the outside, and wall units either on the wall or ceilings of each room. They can be tailored as single units or double or compressors that can handle as many as four individual rooms with separate fan thermostatic controlled units. They cut our usage from 4000 KWHs to about a thousand, then we put in a 10.5K solar system. We also put a separate meter on the apartment which made a huge difference because we aren't paying for a tenant's power anymore.

The Mitsubishi and Fujitsu mini splits are incredibly efficient compared to other heating and air