What type of vent must be used if the vent of a Wall Furnace is concealed in a partition wall?

When a wall furnace's vent is concealed within a partition wall, a BW vent must be used. BW venting systems are specifically designed to handle the requirements and conditions associated with venting gas appliances. They feature additional insulation and are designed to operate with higher temperatures while minimizing the risk of heat loss or damage to building materials surrounding the vent.

BW vents are constructed to be used in concealed spaces, ensuring that the vent can safely carry combustion gases away from the appliance while maintaining the integrity of the surrounding structure. This is crucial in preventing issues such as condensation, which may occur if the proper type of vent is not utilized.

In contrast, other types of vents, like single wall or double wall vents, may not provide the same level of safety or efficiency required for a concealed application. Type B venting is also not suitable for this scenario, as it is designed for specific configurations and uses outside of concealed wall applications. Therefore, selecting the BW vent ensures compliance with safety standards and optimal functioning of the gas appliance in a concealed setting.