Too strong draft on very tall chimney

[showrguy]

I'll be following this thread for advice from the pros..
I recently added a key damper to my 35' stack because I had too much draft..
Well, guess what...... I still have too much draft..even closed as tight as possible....grrrrrrrr..

 

[begreen]

How tall is the chimney system from stove to the chimney cap? Can you post a picture of the setup so that we can see where a damper might be added and if it's necessary. It may not be. Usually if the draft is too strong then fires start very easily with the door closed. That has me wondering about how well seasoned the wood supply is.

 

[begreen]

I'll be following this thread for advice from the pros..
I recently added a key damper to my 35' stack because I had too much draft..
Well, guess what...... I still have too much draft..even closed as tight as possible....grrrrrrrr..

In some cases of extreme draft two key dampers may be required during very cold weather. Not sure if this is the best option for you. Do you already have a separate thread on this topic?

 

[showrguy]

In some cases of extreme draft two key dampers may be required during very cold weather. Not sure if this is the best option for you. Do you already have a separate thread on this topic?

No sir,
I mentioned it in the BK thread but it got buried quick ..

 

[begreen]

No sir,
I mentioned it in the BK thread but it got buried quick ..

Is the flue system straight up, or are there turns in the flue path?

EDIT: Moved to new thread. It was confusing the OP's other thread.

 

[showrguy]

Is the flue system straight up, or are there turns in the flue path?

Yessir, 15'of double wall black to ceiling box, then another 15' of class A stainless, then another class A painted black through the roof, so about 35' total..
Recently removed the 1st 4' section from the stove, installed a 3' section, then 6" key damper section. Drilled a probe hole 32" from stovetop for manometer, just looke at it -.13-.15 w/c, with damper shut as tight as possible....22 deg. F, calm conditions..
My chimney is all Ventis piping that I was really happy with the quality.... The 6" key damper section is a real POS, it's made in CHINA, is nowhere close to fitting correctly, is outa balance, lop sided, ect...

Edit;;; all straight..

 

[Allagash350]

I don’t see how it is a draft issue (implying it is too strong and burning up the fire too fast) when you also state you can’t get a fire going and need to open the ash pan door (not a good idea btw).
I have a strong draft and my stove burns great. Can get a fire going easily because of it.

I have learned to cut the air back a lot sooner than I normally would to account for the draft and get good burn times.

How full are you loading it, with what sized wood, and what temps are you seeing?

I think before installing a damper or anything I would reasses what you may be doing to add to the situation. Not criticizing or questioning you just mentioning it as you said you were newbies and there are a lot of factors for burn times etc.

 

[electrathon]

In some cases of extreme draft two key dampers may be required during very cold weather. Not sure if this is the best option for you. Do you already have a separate thread on this topic?

Is there any reason that you should install two dampers instead of welding a few of the holes shut in one damper? It seems like you would have a cleaner install that way.

 

[showrguy]

Yes, with the tall stack it probably drafts like a Hoover, but has it been measured? what is the metric for determining draft is still strong? As noted in another thread, if the blower is on, burn times are not going to be all that great. The stove is heating a lot of sq ftg..

I have a manometer installed, 32" off of stove top, before the damper, somewhat permanent..
Before the damper I was seeing -.23. To -.26
And yes, it's been measured, I put those #'s in the last post you quoted..
I hardly ever use the fans..
My highest t-stat setting is at the 5oclock position, hardly ever have it above that.
And I agree, the stove is heating a lot of space, almost 2x what it's advertised to do..... Kinda neat, huh ??

 

[electrathon]

What are you guys looking for as an ideal reading on the manometer? How much difference are you seeing depending on outside temperature and other variables?

 

[showrguy]

What are you guys looking for as an ideal reading on the manometer? How much difference are you seeing depending on outside temperature and other variables?

For my stove the mfg. recommends -.03 to -.05.
I'm sure when temps are warmer the draft would be less.. But I have'nt checked it in those conditions yet..
We're super cold and windy here, heard yesterday on the radio, it's been 32 years since it's been this cold, this long..
And we got 3 days to go !!

 

[begreen]

Is there any reason that you should install two dampers instead of welding a few of the holes shut in one damper? It seems like you would have a cleaner install that way.

It's a touchy area. Both situations risk closing off draft too much and causing smoke or CO to back up into the house if draft fails or is insufficient late in the burn cycle.

 

[begreen]

As a test maybe try changing out the current cap for a 8" to 6" (or 5") reducer and see what the manometer reads. If that makes a marked improvement then add a cap for the smaller diameter.

 

[showrguy]

I don’t see how it is a draft issue (implying it is too strong and burning up the fire too fast) when you also state you can’t get a fire going and need to open the ash pan door (not a good idea btw).
I have a strong draft and my stove burns great. Can get a fire going easily because of it.

I have learned to cut the air back a lot sooner than I normally would to account for the draft and get good burn times.

How full are you loading it, with what sized wood, and what temps are you seeing?

I think before installing a damper or anything I would reasses what you may be doing to add to the situation. Not criticizing or questioning you just mentioning it as you said you were newbies and there are a lot of factors for burn times etc.

This post describes the OP's situation..From the original thread... Does not pertain to my draft situation..

 

[maple1]

I think I would try to find a better key damper. I never had any problems shutting down draft to near nothing with mine. Not that I wanted to, just that in fiddling with it, it happened. I have a similar chimney size, but with a boiler on the bottom, with manometer hooked to it. It can spike to over 0.3 with winds happening outside. Can't imagine still pulling that much draft with the key damper closed - it must be a real piece of crap.