For a double-wall single-appliance, fan-assisted vent, if the chart number didn’t work, which vent should be installed?

For a double-wall single-appliance, fan-assisted vent, if the chart number didn’t work, which vent should be installed?

• A. Direct vent
• B. B vent
• C. PVC vent
• D. Chimney chase

Answer: (B)

When a chart number doesn’t match a listed option, choose the vent type that fits the common venting needs of a standard gas-fired appliance with a chimney-like exhaust. The B vent is designed for gas appliances that exhaust through a chimney or vent chase and may be aided by a fan. It handles the typical exhaust temperatures and draft requirements for this setup. Direct vent is for sealed combustion units that bring in outside air and vent through separate pipes (often through a wall); PVC venting is for high-efficiency direct-vent appliances using plastic piping; a chimney chase is just the housing for a vent, not a vent type itself. Therefore, the appropriate choice for this scenario is the B vent.

When a chart number doesn’t match a listed option, choose the vent type that fits the common venting needs of a standard gas-fired appliance with a chimney-like exhaust. The B vent is designed for gas appliances that exhaust through a chimney or vent chase and may be aided by a fan. It handles the typical exhaust temperatures and draft requirements for this setup.

Direct vent is for sealed combustion units that bring in outside air and vent through separate pipes (often through a wall); PVC venting is for high-efficiency direct-vent appliances using plastic piping; a chimney chase is just the housing for a vent, not a vent type itself. Therefore, the appropriate choice for this scenario is the B vent.