What type of vents are suitable only for draft hood-equipped gas-fired appliances?

Type B vents are specifically designed for use with draft hood-equipped gas-fired appliances. These vents are constructed to handle the high temperatures and corrosive gases produced by these appliances while maintaining proper ventilation. The primary function of a Type B vent is to safely convey flue gases from the appliance to the outside atmosphere while allowing for a suitable draft that promotes efficient combustion.

Draft hood-equipped appliances regulate the draft and help to prevent backdrafts or spillage of combustion gases into the living area. Type B vents are required in these situations because they are designed for use with appliances that utilize a draft hood, helping to ensure that the gases can escape properly and minimizing safety hazards.

Using other types of vents with draft hood-equipped appliances could lead to inadequate venting, potentially causing hazardous conditions such as carbon monoxide buildup. Therefore, it is crucial to use Type B vents specifically for these appliances to ensure compliance with safety standards and regulation.