Natural vent (B-vent) Gas Fireplaces and Stoves

Natural vent (or B-vent) fireplaces and stoves are systems based on a b-vent vertical pipe that exhausts the fumes by drawing them out of home through the chimney and roof. These systems are fueled by natural gas or propane and use the room air for combustion.

B-vent appliances do not have a sealed glass front, and are based on natural air convection. Their efficiency is limited and they can be a cause of poor indoor air quality.

How Natural-Vent fireplaces and stoves work

Natural-Vent fireplaces and stoves use natural air movements. They take the air necessary for burn from indoors. Since the combustion gases are hot, they naturally rise up through the chimney. And since the walls of the chimney become hotter whenever the fireplace or stove is used, this fact also favors the flue gases to retain their buoyancy and their temperature, and to exit through the chimney.

Disadvantages

The B-Vent design make stoves and fireplaces less efficient than direct vent gas solutions. Part of the heat will escape through the chimney, and the system can also cause back-drafting: instead of exhausting gases outdoors, the indoor air may pull those gases back into the house.

Advantages

B-vent systems are relatively easy to install, and cheaper than direct-vent systems. They may have some advantages relatively to gas vent-free systems, but they are also less flexible and more expensive than these last appliances.

Alternatives to B-vent gas systems

The more direct alternative to Natural B-Vent gas systems are Direct-Vent gas systems. Direct-Vent gas systems are clearly more safe and efficient. But pellet stoves and inserts, and other efficient fireplace inserts and stoves, are also major direct alternatives.

Other more environmental alternatives include solar based systems, ground heat-pump systems or some radiant heating solutions.