Today's question comes from Chris. "Hey Dan, What is the lowest outside temperatures in which the Mitsubishi GL Series Ductless Heat Pump will heat?" This specific model has heating capabilities down to -13F. But you're not going to get 100% performance from that low.  Heat pumps lose efficiency the colder it gets outside. With this one you will at full capacity  at about 5F. If it never gets below 10F where you live, then a heat pump like this would be good for you. But if you live somewhere that gets much colder, like -20F then this wouldn't work well for you.