An electric fan heater uses a fan to exhaust gas while a direct vent water heater has a draft natural extraction. A direct vent heater draws combustion air from outside, while a power vent draws air from inside house. They can extract combustion air, either inside or outside house.
A direct vent water heater air extracted outside combustion through a ventilation tube horizontal and returns exhaust gas back out through another tube. A heater vent draws combustion air energy from inside house in space around heater. A fan forces exhaust gases through a flue, which may be vertical or horizontal.
Both ventilation and electric heaters to avoid direct vent gas streams toxic combustion in house. Heater has a direct vent intake system and exhaust sealing and electrical ventilation uses a fan to force exhaust gases of house. Because a direct vent water heater uses natural air flow, which may be located a maximum of only four feet away from an adjacent outer wall. An electric fan heater may have a length of up to 40 feet combustion, and having an exhaust driven electric air. To find the model number of devices can take a few minutes late, but it ensures that the order or purchase is correct for the device.