Ventless Gas Heaters - Ventless gas heaters are furnaces that heat rooms and do not vent air to the exterior. Instead, the fuel needed for the combustion process for heat is taken from the air inside of the room, and the resulting heat is vented back out directly from the unit. Because there is no outside air exchange -- which is the reason most traditional heaters lose the majority of their heat -- ventless heaters are much more efficient than traditional heating systems, however, there are some drawbacks and limitations to be aware of.
Because all combustion heaters require oxygen for fuel, traditional heaters draw on the unlimited supply of outside oxygen to complete combustion. In addition, there are many types of combustion heaters such as pellet stoves and wood-burning stoves that do not completely burn away the fuel. The result is the smoke is released into the air as the burning process takes place; this must be vented back into the outside air where it can dissipate, but the drawback is that much of the heat is vented as well. Lastly, burning any substance nearly always results in the emission of carbon monoxide, which is known to be poisonous to humans and animals, and can result in death if it is released into an unventilated room.
Although gas heaters burn much more efficiently than wood- or pellet-burning units, the resulting carbon monoxide has always called for an outside air vent to be installed to safely operate the unit. Ventless gas heaters, however, do not use such a vent; instead, they simply vent the heated combustion exhaust directly into the room in which they are placed, and provide a much more effective heat source as a result.
Ventless Gas Heaters