What type of vent is listed and labeled for use with wall furnaces?

The correct answer is that a BW vent is specifically designed and labeled for use with wall furnaces. BW vents, or combustion venting systems, are constructed to safely vent the products of combustion from wall-mounted appliances, ensuring that harmful gases do not enter living spaces. They are typically categorized as a system that helps maintain safety by directing flue gases outdoors, complying with code requirements for proper venting.

Type B vents are generally used for gas appliances that are not wall mounted, whereas Type L vents are suitable for appliances burning oil or gas that produce low-temperature flue gases. Type M vents are typically used for positive pressure systems, which do not apply to wall-mounted furnaces that require careful handling of the venting. Each of these other types has specific applications that do not align with the requirements for wall furnaces, underscoring the importance of using the correct vent type to maintain safety and efficiency in heating systems.