Double Wall vs Triple Wall Pipe

[Don H]

A friend has a recently purchased Papa Bear. He installed it using triple wall pipe and now seems to have trouble creating a good draft. He complains of smoke coming into the room through the draft caps, especially during windy days or with a small fire in the box.

Chimney configuration is straight up from a T at the back of the rear vent stove. Stove is in a converted porch room attached to a 2 story house. The pipe is about 12' from the main house and about 3' above the 2nd story roof line.
There's plenty of fresh air in the room thanks to drafty windows. No modifications have been made to the stove.

Any ideas on what the problem is?

 

[bholler]

How tall is the chimney from the stove to the top of the chimney? And yes doeble wall is far better than triple

 

[coaly]

Assuming the chimney is 6 inch...... and the home is in an area cold enough to cause a good draft this early in the season........
That house configuration can be a problem.
You get so much heat moving away from the stove and rising into the rest of the house, the stack effect requires more draft. Would have been a good place to use the double wall that stays hotter easier than the triple wall. Anything to increase draft will make it better. Including avoiding small fires.

If the house is drafty upstairs, or has an air leak on the second floor, that allows more warm air to rise out of the house competing with the chimney as well. Can the converted porch be closed off until stove is up to temperature? That would isolate the problem if the house is competing with the chimney.

If the wind direction is toward the side of the house with stove, it will get positive pressure on that side of the house, pushing down the chimney, further aggravating the issue. If the wind is from the other side, it can go over the house, putting the top of the chimney in a low pressure area which helps. Depending on other factors, the wind can go over the top of the house and be turbulent hitting the chimney top just right pushing down the flue. Sometimes raising the flue gets you into a worse air flow than lower....... I go to directional wind caps and vacu-stack with mixed results. (I had one on a lake that it was the only solution that cured it)

I've had a case where the stove worked fine when I was there. Days later I would get a call back with the same problem....... I found someone in the house wanted their bedroom cooler than the rest of the house and would open an upstairs window after I was gone. The house became a better chimney than the chimney.......... Make sure there are no power venters running on water heaters, or furnaces overpowering the chimney draft as well.

 

[Don H]

The pipe is 6" and is about about 16' long, I'm guessing. He wanted it above the 2nd floor roofline even though he's far enough away that that would not be required.
It was still rather warm outside when they were running the stove, maybe in the 50s.
I'd have to ask about wind direction.

I did recommend double wall pipe before he installed but the triple wall was on sale at Home Depot so he went with that.
I hadn't thought about any windows in the rest one the house being open.

Thanks for the info! I'll pass this on,