Special Gas Vents
For Category II, III, or IV Appliances and/or Condensing and High Efficiency Appliances requiring a listed UL-1738 Special Gas Vent. Double wall typically used when routing through a building or shaft, as single wall requires further clearances and might not be able to be fully enclosed at all. Single wall typically used on unit heater or tankless heater applications. See Appliance Installation & Operating Instructions for clarification.
Sample Specifications
Double Wall Option
Prefabricated system listed to UL-1738 Standard for Venting Systems for Gas-Burning Appliances, Categories II, III, and IV made with AL29-4C stainless steel inner liner, 1” insulating air space, and 400 series stainless steel outer jacket. Vent shall be designed for maximum 550°F and positive pressure of 15” W.C.
Single Wall Option
Prefabricated system listed to UL-1738, Standard for Venting Systems for Gas-Burning Appliances, Categories II, III, and IV made with AL29-4C stainless steel. Vent shall be designed for maximum 550°F and positive pressure of 15” W.C.
Complete with: factory appliance flue connector, boot tees, drain caps or inline drains, stack supports, roof flashings, and termination.
All items specifically required by Appliance and Gas Vent manufacturers installation instructions. Submit AutoCAD Drawings with Draft Calculations showing that the vent system is in complete compliance with both the Appliance and Vent manufacturers’ installation instructions.
