Heavy puffer sauna stove needs help please

[bandoo]

5 yards high with the negative impact of a horizontal run (even at 30 degrees) is less than ideal for even the best drafting stove. Add in the fact that you are using an 8" pipe on a mid sized stove and I can see issues rising up. Issues that you obviously are dealing with.

Can you add height?

Yes I can.
Do you think I should have stayed at 6"?

 

[begreen]

How is the 8" pipe joined to the 6"? Is it very well sealed at this joint?

 

[Jags]

Yes I can.
Do you think I should have stayed at 6"?

Yes, I do. You may be able to compensate (to some degree) by adding some height to the stack. If you want to test that theory a few bucks at the local home store and a couple of sections of the tin duct used for forced air furnace will add some height. If it works, you know which direction to go. If it doesn't you threw $6 down the drain.

 

[bandoo]

Yes, I do. You may be able to compensate (to some degree) by adding some height to the stack. If you want to test that theory a few bucks at the local home store and a couple of sections of the tin duct used for forced air furnace will add some height. If it works, you know which direction to go. If it doesn't you threw $6 down the drain.

They don't sell that stuff at the home stores around here. I go to a guy who works with galvanized and stainless steel and he makes it.

I am getting ready to light it in a few hours. I wonder if there are any tests I can try?
Was it you that suggested that I block off some of the top of the stack when it starts puffing?
What do you mean "compensate to some degree".
What would be a permanent solution? Cut the stack off at the stove and replace the whole thing with 6"?

 

[Jags]

Welp - covering part of the stack when the back puffing starts was an idea that popped into my head in hopes that it would reduce the capability of pulling air down the stack (thus causing a back puff). Simply a testing idea.

Compensate to some degree is "trickery". An oversized stack = less draft. Taller pipe = better draft (until a certain point).

Permanent solution would be to go 6" all the way - but that is assuming 6" will stop the back puffing.

If you are going to start this thing in the near future - you might want to try one of two things.
1.) Hair dryer (or heat gun) - set to it hottest and pointing up the stack for 5 min before lighting fire (creates a draft and preheats the stack).

2.) Using the top down fire starting method. Use the search feature, there is mucho info on how to make this happen. And do this at the far back of the stove right below the exhaust outlet.

I would really like to know what the stove and stack temps are at when you are running full throttle. A few bucks at a hardware or home store will buy a magnetic one.

 

[bandoo]

Welp - covering part of the stack when the back puffing starts was an idea that popped into my head in hopes that it would reduce the capability of pulling air down the stack (thus causing a back puff). Simply a testing idea.

Compensate to some degree is "trickery". An oversized stack = less draft. Taller pipe = better draft (until a certain point).

Permanent solution would be to go 6" all the way - but that is assuming 6" will stop the back puffing.

If you are going to start this thing in the near future - you might want to try one of two things.
1.) Hair dryer (or heat gun) - set to it hottest and pointing up the stack for 5 min before lighting fire (creates a draft and preheats the stack).

2.) Using the top down fire starting method. Use the search feature, there is mucho info on how to make this happen. And do this at the far back of the stove right below the exhaust outlet.

I would really like to know what the stove and stack temps are at when you are running full throttle. A
few bucks at a hardware or home store will buy a magnetic one.

I used the to down fire method this time. It really heatd up the stack.
My thermometer wouldn't stick because is made of stainless steel, but it was very hot.

About what you asked before.
I was wrong, there are little explosions with fire coming out the air inlet.

What would be the difference between smoke coming out and the little explosions, implication wise?

We are thinking of changing the shape of the inlet to a rectangle from the circle in case there is some harmonic thing happening with the round stove body.

Also thinking about putting a small restricter piece of metal inside the pipe stove where it's welded to the stove because I noticed that my VC and Hartland have 8" pipes bet at the stove they are pinched oval reducing the draft??

Any ideas?
Thanks again....

 

[Jags]

The little explosions are technically a "back draft" (like the movie). You are getting more combustible gasses in the firebox than the oxygen entering the box can support and it is causing it to drag air in from someplace else (most likely your stack). The will have a negative impact on your draft as it is fighting the whole hot air rises vs "I need oxygen".

Gonna have to figure out how to make the draft work.

Did the top down startup help with the initial drafting? Stove start up faster?

Edit: are you by chance using very small splits?

 

[bandoo]

The little explosions are technically a "back draft" (like the movie). You are getting more combustible gasses in the firebox than the oxygen entering the box can support and it is causing it to drag air in from someplace else (most likely your stack). The will have a negative impact on your draft as it is fighting the whole hot air rises vs "I need oxygen".

Gonna have to figure out how to make the draft work. We usually crack the stove door open when we start it and that seems to run fine then without the puffing...

Did the top down startup help with the initial drafting? Stove start up faster? Yes that's a great method although we left the door open a little till it was going good, then closed it and the draft till a quarter inch then it ran ok the rest of the night.

Edit: are you by chance using very small splits?

To start there is some kindling but then we throw some big stuff in.

What do you think of changing the shape of the inlet? I guess making it smaller isn't such a great idea.
When the door is cracked open during starting it goes great. Then shutting the door and just a tiny inlet it's fine..
The fire chamber is pretty big...

 

[Jags]

What happens when you open the air inlet ALL THE WAY open??

 

[bandoo]

It will start to puff.

 

[Jags]

It will start to puff.

Yeppers - you gots a draft issue. Maybe add another air inlet??

 

[bandoo]

How about making the one I have bigger,or is 2 in different positions more effective?
So I probably don't need more pipe? Is the 8" pipe hurting me?
Thanks again...

 

[Jags]

I am taking a SWAG here so you may want other opinions: Yes, I think the 8" is hurting draft. I think you need additional height (or get rid of the horizontal run) and I am questionable on the primary air inlet. I just don't know what to think about the air inlet. If you clamp it down, no puffs, if you open it up, puffs, open the door, no puffs. Makes me think that you may need more air than the primary is allowing for, but again, its confusing.

I would start with one and then move forward if the problem is not resolved, leaving the air adjustment as the last mod. Simply one dudes opinion.

 

[bandoo]

By 'air adjustment last', do you mean an additional air inlet?
I can't get rid of the horizontal.
Also the 8" is doing what, like lowering the velocity of the updraft?
At this point I can only add height and make a additional air inlet in the door.
How would more height help?
well yo the only dude answering....thanks

 

[Jags]

Also the 8" is doing what, like lowering the velocity of the updraft?

Zactly!
I would either increase stack height (if staying with the 8") or go to 6". See how it goes. If it doesn't fix it, increase primary air.

 

[bandoo]

I just put the new pipe in for about $400+ (stainless steel) so I can't really do that one..

The guy who built the stove welded that big piece of 8" steel water pipe to the top of the stove. It connected to my old horizontal about halfway along the horizontal to the stack and from there 6" pipe to a T an then to the top. It puffed the same. So I figured it was big into small was the prob so I bit the bullet and replaced the rest of the 6 with 8 so it was one size..
The 6 was getting pretty deteriorated anyway. When it continued to puff I started the thread....

If I increase the height then do I overcome the disability of the 8"? Or is that a fundamental prob now even if it alleviates the puff? Am I losing heat from it?

Since opening the door a crack stops the puff how does the additional height help? When it's burning and I open the door it really starts to roar..
just asking..............

 

[Jags]

Extending the flue will help increase the draft (hot air rises thingy). Opening the door a crack introduces MORE air and allows the smoke to exit more easily.

 

[bandoo]

OK,
I will keep you posted..............
thanks again