Reduce overall heating costs while getting reliable heat and air conditioning regardless of outdoor temperatures. These packaged terminal heat pumps (PTHP) transfer heat rather than generating it to reach set temperatures more quickly and operate more efficiently than conventional systems in small, enclosed spaces. They also have an auxiliary electric heater that kicks in when outside temperatures fall below freezing, so they are more effective at colder temperatures than packaged terminal air conditioners (PTAC). Like a PTAC, the PTHP is a self-contained, through-the-wall unit with a built-in compressor, so there's no need for external wiring, refrigerant lines, or landscape barriers. Install them in a cutout of an exterior wall and control them with a remote, wall-mounted thermostat. Good for hotels, multi-unit buildings, and room additions.