The 4 to 5 Ton 18 SEER MrCool Universal Central Heat Pump Condenser is a top-quality choice to solve tough home heating and cooling problems. It has an 80 percent heating output when outside temperatures are below zero, and largely eliminates the need for a gas furnace or auxiliary electric heat. It will continue to heat, even with outdoor ambient temperatures as low as -22°F. This 4 to 5 Ton MrCool Universal Central Heat Pump uses 24V non-communication control technology between the condenser and evaporator. That means you can use this unit with other third-party air handlers and thermostats, such as the Nest or other WiFi enabled thermostats.