CAN4-S605-77

These requirements cover the design and construction of Type B (round or oval) and Type BW Gas Vents. Type B Gas Vents are intended for the venting of flue gases, having temperatures not exceeding 470 degrees F, from certified gas-fired appliances with draft hoods or diverters. Type BW Gas Vents are intended for the venting of flue gases from gas-fired recessed heaters and the maximum input to a Type BW Gas Vent is determined by the maximum input of the recessed heater to which the Type BW Vent is intended to be connected.