Well visually some people prefer b vent units because their open they have access to a lot of oxygen and you can generally get a nice big visual flame but you can also get a nice flame on a direct vent.
B vent fireplace vs direct vent.
Direct vent is much more efficient you re pulling fresh air from outside of the house.
This makes b vents an optimum choice for small rooms since the energy output of a direct vent fireplace can overwhelm a small space.
Gas vent fireplaces exhaust their fumes through the roof via a pipe.
A direct vent has a sealed glass front and pulls all of its fresh air from outside the home.
Because the design of a b vent system is simple it is typically less expensive to install than a direct vent fireplace system.
In general b vents do produce less heat than direct vent models.
The position and look of the logs in the fireplace cannot be altered or incomplete combustion will occur.
Natural vent models resemble conventional wood burning fireplaces.
Direct vents can be vented vertically or horizontally through an exterior wall.
Direct fireplaces have a sealed glass front and typically a smaller flame than a b vent fireplace or a vent free fireplace.
Direct vent appliances are typically higher in efficiency than b vent appliances and put out a lot of heat even with a low flame setting.
They take air to burn from the inside of the home.
Direct vent appliances are typically higher in efficiency than b vent appliances and put out a lot of heat even with a low flame setting but still do not produce as much heat as their vent free counterparts.
Vented fireplaces are further divided into two subcategories natural vent and direct vent.
Direct vent systems use indoor air for combustion.
The b vent pipes used in natural vent fireplaces are however smaller than the a class chimneys used in traditional wood stoves.
If you desire a realistic looking flame a b vent may be a good choice for you.
Natural vent or b vent gas fireplaces and stoves use the air that is already contained inside of a room for combustion.