Another source of electric heat, the Portable Furnace uses Infrared Light instead of Resistive Elements to produce heat. These lights shine on a specially designed heat exchanger. A fan blows air across the heat exchanger, delivering treated air into the room. Most portable electric furnaces also filter the entering air. These components, exchanger, fan, and filter contribute to the furnace connotation and raise it one step above the standard portable electric heater.

The most common portable furnaces are rated at 1500 watts, like most portable heaters. The infrared heat source is supposedly some 30 percent more efficient than resistive heat, which is probably true because resistive heat has always been a waste of electric energy. Because of its design, the portable furnace is safer than resistive heaters with their exposed elements, but the portable furnace is considerably more expensive.
The 1500 watt output limits the portable furnace’s use and payback period. 30 percent savings is good, but the scale is fairly small, BTU wise. The Portable Furnace is NOT to be confused with the standard Electric Furnace used for central heating and air conditioning systems. The portable furnace is a floor model, a room heater, it is not installed in an attic or cellar and not connected to ductwork.