Using tables from the National Fuel Gas Code or our Sizing & Application Guide, determine the diameter of venting required. The Sizing & Application Guide also offers tips on good design including multi-appliance system sizing and design. The System Design and Installation Guide is an additional resource.
Size: 4" only
Type BW plate spacers are required at the first ceiling level above a wall furnace to center and space vent properly and to provide the required opening between floors. Firestop spacers must be used at subsequent levels.