A gas furnace burns natural gas to generate heat, delivering air at 100–140°F and excelling in Utah’s very cold winters at any outdoor temperature. A heat pump moves heat from outdoor air into the home using electricity — typically delivering 2–4 BTUs of heat per BTU of electricity consumed. Modern cold-climate heat pumps remain effective down to −13°F, making them viable for most Utah valley locations. Below that temperature or in mountain communities with more extreme winters, a hybrid system (heat pump + gas furnace backup) is the best configuration — using the heat pump efficiently during moderate cold and the furnace on the coldest nights. Both systems require Manual J sizing to perform correctly.