B-Vent, also known as Type B vent or natural draft vent, is commonly used for venting gas appliances that are designed to use indoor air for combustion. These appliances typically have a draft hood to facilitate the flow of air and exhaust gases.

Type B-vents are double-walled metal chimneys/flues and can be used only with listed, draft-hood equipped gas appliances. Type B gas vents such as the Ameri-Vent™ are permitted for venting gas-fired appliances and have their own set of combustible clearance and installation specifications.

It operates on natural air convection and is also known as the Type B vent. Type B vents are a standard design that most modern gas furnaces use. It draws air from within the house for combustion. Gases produced during combustion are very hot and as such, easily rise through the flue.

Type B-vents are double-walled metal chimneys/flues and can be used only with listed, draft-hood equipped gas appliances. A Type B vent is intended for relatively low-heat applications. B-vents are not permitted for use with incinerators and are not intended for use with appliances burning anything other than LP or natural gas.

Many people refer to b vents as the most natural vent. These vents work by drawing air from the room so it can supply oxygen to the fire. That air will travel through the vent’s chamber and be released through the chimney. These vents allow people to keep their fire going while using minimal air.