Simpson Dura-Vent's Type B Gas Vent system is for use with natural gas or liquid propane category I and draft hood equipped appliances, and appliances tested and listed to use Type B Gas Vent for a wide range of applications, including: natural gas fireplaces, gas-fired furnaces, boilers, water heaters, and wall or space heating applications.
Simpson Dura-Vent's Type B Gas Vent systems are UL Listed to UL 441 and UL 1777 (MH6357). ULC Listed to ULC S605 (CMH1276 & CMH1407).
How Size and Height Affect Stove Performance
The amount of heat the vent gases lose as they flow determines how much condensation will occur and how strong the draft will be. To control the heat loses, proper selection of venting materials is of vital importance.
Vent Termination Chart
Using listed Type B Gas Vent caps may terminate in accordance with this table.
Gas Vent Specification Chart
1. Clearance to combustibles is the air space between vent and combustibles.
2. Maximum height varies with equipment over 50", for taller applications refer to SDV sizing handbook 2. (L202). 14"-16" Require screws.
3. When oval is used on wall furnaces, minimum height required from bottom of furnce to cap is 12", minimum 16" stud space.
4. Limited by sizing tables.
5. 18" pipe OD is one inch larger than ID and 20" - 30" OD is 2" greater than ID.