Wood stove "puffing"

[goof008]

Hey guys, just a simple question:
We've had some very windy days the last month, and twice the wind pushed the smoke back down the chimney and into the house. It also reduced the size of the fire in the box, so the next bit of wind could get down easier. I ended up putting a small fan in front of the stove to provide fresh air, so when it happened, the fire could restart.
Is there a way to stop this from happening? My chimney is installed per stove makers guidelines, but doesn't go over my roofs peak. Could that be it?
Any advice would be great.

 

[leon]

wood stove puffing

Hey guys, just a simple question:
We've had some very windy days the last month, and twice the wind pushed the smoke back down the chimney and into the house. It also reduced the size of the fire in the box, so the next bit of wind could get down easier. I ended up putting a small fan in front of the stove to provide fresh air, so when it happened, the fire could restart.
Is there a way to stop this from happening? My chimney is installed per stove makers guidelines, but doesn't go over my roofs peak. Could that be it?
Any advice would be great.

your chimney need to be above the roof line for sure and a cap is a good idea simply to reduce the effect of downdrafts- I have had times when the fire is so starved for combustion air the flame follows the intake air outside the lower ash pit automatic damper door and one would think there is smurf with a flame thrower behind the ash pit door.opcorn:

 

[wildbio]

your chimney need to be above the roof line for sure and a cap is a good idea simply to reduce the effect of downdrafts-

+1
also look at this thread:
http://www.arboristsite.com/showthread.php?t=58621&highlight=wind+cap

 

[smokechase II]

Cap

A good cap is probably the solution.

 

[goof008]

It's a metalbestos chimney, with a cap on it. I don't know if that's a good one, but that's the one that fit. I'll try adding a section of chimney and see if it helps any. It was never an issue last year (my first with the stove/chimney) so this is new. Does it make a difference if the chimney is on the windward or leeward side of the house? In both cases, the wind would hit the chimney before hitting the roof.

 

[wildbio]

It's a metalbestos chimney, with a cap on it. I don't know if that's a good one, but that's the one that fit. I'll try adding a section of chimney and see if it helps any. It was never an issue last year (my first with the stove/chimney) so this is new. Does it make a difference if the chimney is on the windward or leeward side of the house? In both cases, the wind would hit the chimney before hitting the roof.

if the top of the chimney is not 2 feet above the peak you will have drafting problems.
if wind is adding to the problem you need a wind cap
take a look at this site for additional info:
http://www.chimneysweeponline.com/hodraft.htm

 

[goof008]

if the top of the chimney is not 2 feet above the peak you will have drafting problems.
if wind is adding to the problem you need a wind cap
take a look at this site for additional info:
http://www.chimneysweeponline.com/hodraft.htm

Thanks for the link...I think that wind cap will help. I'll probably throw another 2' section to the top of the chimney also, but it goes from my basement up 2 1/2 stories, so I think I get good draft, but anything to keep me from getting up at 2:30 a.m. to deal with a smoky basement is a good thing. Thanks for you help.

 

[Ken05]

It's a metalbestos chimney, with a cap on it. I don't know if that's a good one, but that's the one that fit. I'll try adding a section of chimney and see if it helps any. It was never an issue last year (my first with the stove/chimney) so this is new. Does it make a difference if the chimney is on the windward or leeward side of the house? In both cases, the wind would hit the chimney before hitting the roof.

Think of your roof like an airplane wing - the windward side will have high pressure and the leeward low. Getting the pipe two feet above the peak negates these effects.

 

[scalo]

Thanks for the link...I think that wind cap will help. I'll probably throw another 2' section to the top of the chimney also, but it goes from my basement up 2 1/2 stories, so I think I get good draft, but anything to keep me from getting up at 2:30 a.m. to deal with a smoky basement is a good thing. Thanks for you help.

I have the same setup as you..chimney from the basement and up 2 stories. My chimney is about 2.5' above the roofline and I have a very rare puff back issue. Mine seems to be mostly from not giving the stove enough air through the intake. Once I up the amount of air everything is good.

Good luck
Scott

 

[aandabooks]

I've got mine through two stories and above the peak of the house by a couple of feet. Don't keep the cap on when I'm burning. Had 45 mph wind last night and the fire was dancing with the backdraft but no smoke backing up into the house. That is the first time I've heard the chimney whistle.

Matt

 

[logbutcher]

The roof is like a wing, eddying winds on low pressure days down any flue.
Keep the flue pipe at least 3 feet above the roof AND be sure that it is at least 10 feet from any roof surface from the 3 feet top. Roofs are like whitewater running making currents go where you don't expect them.

Surrounding trees can "push" wind around-trim.

But then on those low barometric pressure days, with warmer temps above freezing-- for us in the northern climes-- sometimes any flue will back puff at times. Low fires keeping the flue cool will make it easier for those puffs.

 

[mayor]

I've fixed a bunch of those problems in our area.....here's what I do.

1. Make sure the chimney is above the roof sufficiently.
2. Make sure it has a good cap.
3. Take a piece of old stainless stovepipe and cut a square piece out and rivet or sheetmetal screw it too the wind side of the cap.....it doesnt have too be big.....and usually about 6" tall will work fine.....wrap it around the back side of a round cap or across the back side of a square cap.......problem cured!.

All ya need is a pair of tin snips and a battery drill with a 1/8" bit.....screw or rivets (use stainless steel or copper rivets so they dont rust or melt).

Best thing too do is call your roof guy or local chimney sweep......especially on steep roofs.

 

[bama]

How tight is your house sealed up? I had some trouble and I put in a fresh air intake that leads right up to the draft on my furnace. No more smoke at all. I have a 4" intake and it works great. Only time I might have trouble is if the dryer, bathroom fan, and furnace are all running at the same time. I knew I wouldn't have many air leaks after siding the house, new windows, sealing leaks this summer, so I am really glad I did this.