About vertical piping in pellet stove Exhaust

[indoorairpro]

I read multiple threads about having vertical piping in pellet stove exhaust pipe. Originally I had a 45 off the back of the stove that went through the outside wall directly next to stove (stove is caddy cornered) and vented through a sidewall down ward type vent. After reading the threads I elbowed up outside and added 5 ft of vertical piping and a cap. nothing fancy, cap looks like a pointed hat with three legs to create a space underneath for exhaust to escape. I did this so if power went out less smoke would get in house. Well i had stove on lowest setting and power went out. I waited to see if I started smelling smoke, before turning on generator, to see if vertical pipe worked. It did not, within a few seconds started smelling smoke in house. A month into season i went outside and about a ten by ten foot section of siding around cap is all sooted over, hopefully it will just hose off in summer. I also notice that i can smell the stove outside now when with the old piping i could not.
So what good did adding the vertical pipe do. I see no difference. and I did not tee to the vertical i elbowed up to it so it would flow better.

 

[TimfromMA]

The only real benefit to adding vertical rise to the pipe is so that natural draft will pull the smoke out in a power failure. It may also be required in some cases depending on the vents location.

 

[alternativeheat]

I read multiple threads about having vertical piping in pellet stove exhaust pipe. Originally I had a 45 off the back of the stove that went through the outside wall directly next to stove (stove is caddy cornered) and vented through a sidewall down ward type vent. After reading the threads I elbowed up outside and added 5 ft of vertical piping and a cap. nothing fancy, cap looks like a pointed hat with three legs to create a space underneath for exhaust to escape. I did this so if power went out less smoke would get in house. Well i had stove on lowest setting and power went out. I waited to see if I started smelling smoke, before turning on generator, to see if vertical pipe worked. It did not, within a few seconds started smelling smoke in house. A month into season i went outside and about a ten by ten foot section of siding around cap is all sooted over, hopefully it will just hose off in summer. I also notice that i can smell the stove outside now when with the old piping i could not.
So what good did adding the vertical pipe do. I see no difference. and I did not tee to the vertical i elbowed up to it so it would flow better.

Apparently not much. I can tell you that my 26ft of 4" works perfectly. In fact I think if I fed it pellets it would continue to burn a lazy slow flame in a power outage and more if I supplied a little secondary air. No smell of smoke at all in a power outage.. And great natural draft. I'm not sure 5 ft of 3" will create much draft. It should but maybe not enough to offset your stoves requirements. As soon as someone mentions going vertical I automatically think 4" venting though.

 

[LuvMyPellets]

I added 7Ft vertical last year after 5 yrs of straight out with 3inch. No smoke in the house now when it goes off due to a power failure.

 

[SidecarFlip]

A short vertical section isn't enough to create even a minimum amount of natural draft, it has to be appreciably longer and a bigger bore. Like alternative heat, I have a substantial vertical run, in 4" as specified by my stove manufacturer (most all manufacturers will specify a 4" vent past 'X' number of feet of pipe run, no matter if it's vertical or horizontal) and I too have good natural draft, in fact, so much, that I keep my combustion fan turned down manually and not running on automatic (I can custom tailor the burn parameters on my stove btw).

If I lost power (don't happen with a standby gen set) the vent would literally suck the smoke out, I know, I've tried it before.

Far as sooting your siding, good luck with that. One thing about termination of a vent near any siding, especially light colored siding, it will eventually soot and discolor it. Seen that happen many times in the past, one reason my termination is vertical, above the eavestroughs, I have light green vinyl siding......

On termination caps, it's always advisable to use a pellet/corn vent specific termination cap, you have a 'B' vent cap (natural gas / propane) tent style.

That cap will allow a back draft on a cooler running pipe such as your pellet stove, Solid fuel specific termination caps are designed to prevent a backdrafting situation and twist lock on the pipe end as well.

 

[Bob E]

I don't get any smoke smell in the house when I pull the power plug with 4.5' of 4" vertical vent pipe, a corn/pellet style termination cap, and an OAK.