One system. Heating, cooling, and lower bills.

An outdoor unit pulls heat out of the air, even when it's cold outside, and moves it through refrigerant lines to an indoor air handler. The same ductwork that used to carry warm air from a furnace now carries it from the heat pump. In summer, the cycle reverses, and the same system cools the house. Two pieces of equipment become one, with one bill and one set of filters to change.

One outdoor condenser, refrigerant lines run through small holes in the wall, and up to eight indoor heads, one per zone, each set to its own temperature. Every head is controlled separately, so the bedroom stays cool while the kitchen warms up. Best fit for additions, finished basements, sunrooms, and older homes where ducts never existed (or aren't worth keeping). No reworking the bones of the house to get year-round comfort.