Furnace fan power consumption?
Most forced hot air furnaces run on 115, heat pumps and A/C compressors run on 240, but the fan that delivers the air run on 115. Motors vary depending on the age of the unit, older units are not as energy efficient. Many modern muti-speed heaters run on DC voltage. There should be a plate on the heater somewhere that tells the power draw in amps. Power consumption in watts(P)= voltage(E) x current(I). That is a rough answer because AC voltage works differently than DC. But roughly, a motor that draws 5Amps consumes 575Watts.