What type of vent must be used when the vent of a wall furnace will be concealed in a partition wall?

When a vent for a wall furnace is concealed within a partition wall, a BW vent is the appropriate choice. BW vents are specifically designed for Category I appliances, which include wall furnaces. They are built to function safely in a concealed space, providing the necessary clearance and insulation from combustible materials.

The BW vent system is typically made of a double-wall design, which helps to contain the heat of the flue gases and reduces the risk of heat transfer to surrounding materials. This is essential in a concealed installation where there may be combustible framing or materials nearby. The construction of BW vents allows for safe discharge of combustion gases while maintaining the integrity and safety of the surrounding structure.

Understanding the requirements for venting in concealed spaces is crucial, as improper venting can lead to dangerous situations such as carbon monoxide buildup or fires due to overheating of nearby materials. This context highlights the importance of selecting the right type of vent for specific installations to ensure both efficiency and safety in heating systems.