Why is the stove pipe on your website so much more expensive than what I saw at the big box store? Because they are two different products!
All pellet stove piping is definitely not the same. There are a few different brands on the market and without a doubt, Simpson DuraVent is the biggest name in pellet venting. It’s available in the big box stores, home improvement stores and online retailers in both stand-alone sections and commonly sold together in a box known simply as a horizontal installation kit. There is also another pipe that is manufactured by the same company with a very similar name, Dura-Vent Pellet Vent Pro (Which is by far the better of the two).
The difference between Simpson Dura-Vent and Dura-Vent PelletVent Pro
DuraVent is an “L” type vent which means it is “all fuel” and it is only sold in 3” and 4” diameters, which are the designated diameters for pellet stove installations. The venting is comprised of a stainless steel core that meets the required diameter covered by a ¼” air space between a galvalume (galvanized steel and aluminium) outer skin. The top of the vent is riveted together the airspace is plugged at the bottom by a lytherm rope gasket that is meant to seal the pipe sections as each component in twist-locked together. The venting is tested to UL641, ULC S609, and ULC/ORD C441. Simpson DuraVent is often installed wrong because it requires that all sections be sealed with RTV silicone and screwed together (through the outer skin ONLY) with 3 screws equidistant from each other around the circumference and the vent itself requires a 3” clearance to combustibles.
Why should I pay more for PelletVent Pro?
The problems with the venting being installed wrong stems from a problem that Simpson has in its marketing of the product…for they have another DuraVent pellet venting system called, DuraVent PelletVent Pro. It looks similar but is much different. The PelletVent Pro venting is twice as expensive as its cheaper DuraVent cousin. It uses a laser weld on the lengthwise seam as opposed to the DuraVent which is a fold over the seam. Because of this, all sections of PelletVent Pro fit together seamlessly. Pellet Vent Pro has a silicone seal built in and requires no additional silicone or screw fasteners. In addition, the PelletVent Pro venting uses a slip collar on all elbows and T fittings so aligning components just requires a slight corrective turn of the vent, whereas the older style DuraVent requires precision planning…components cannot be taken apart without unlocking the seal.
Lastly, and probably the biggest misconception is that all DuraVent has a 1” clearance to combustibles. Only the Pellet Vent Pro is designed for 1” to clearance to combustibles. DuraVent is 3”. Routinely Duravent components sold in home stores are affixed with the wrong UL sticker and the product actually says that it is 1” clearance…but with reading NFPA211 Standards for Solid Fuel Heaters and Venting, pellet venting that requires silicone and screws must have a 3” distance to combustibles. Another factor when considering the pipe is how hot it will get. The version sold at the box stores can feel twice as hot to the touch which is worrisome and also causes the product to break down a lot faster. Pellet Vent Pro will last twice as long as its counterpart. Please also note that these pipes are not interchangeable as they will not connect to each other.