Wall furnaces, space heaters & hydro-furnaces

About Wall furnaces, space heaters & hydro-furnaces

Direct-vent wall furnaces draw combustion air from outside and exhaust back through the same wall, which makes them a clean way to heat a room or zone with no ductwork. Vent-free fan convectors need only a gas line but are restricted in some states and rooms, so check local rules first. Hydro-furnaces combine a condensing water heater with an air handler for homes that want forced-air heat and hot water from one appliance.