Should I install a damper?

[Fractal20]

I moved into a house a little over a year ago with a quadra-fire 4300 ACC stove. This past winter I was never able to get a satisfying burn time. I'd say 4 hours until there weren't enough coals to restart the fire. There are a few things that might be issues and it seems like many of them have been discussed on other threads on this forum. Perhaps the best summary would be post #17 by richg here https://www.hearth.com/talk/threads/quadra-fire-why-the-bad-rep.121562/. Here are some things I have addressed. Just to get the obvious possible issue out of the way, I replaced the gasket on the door twice last year and I replaced the gasket on the glass in the door. I'm pretty sure those aren't the issue. I also think my wood is adequately dry. I am currently burning pine leftover from last season, and I had thought it seemed dry last year. But I also would have thought wetter wood would smolder and not burn as fast... so I guess I don't know much.


(1) There is a burn rate assembly in the top left. Oddly, when I first took off the paneling to investigate possible issues, it had looked like somebody had taken a hammer to the burn rate assembly and it was completely deformed. So I ordered a new one and replaced it. But as noted in the picture, this wedge-shaped slider does not completely close the gap. In fact, there is a screw that prevents it from covering the last quarter inch, and the slider doesn't fit snug along the box so there is also an air gap along the whole. See richg's pictures with helpful annotation below.

(2) There are NO controls to the secondary air intake tubes. e.g. the stove is not designed so that air can be turned off for these. See richg's pictures with helpful annotation below.

(3) I believe the flue is too tall. I haven't measured the exact distance, but it goes up through two stories.

(4) When I swept the chimney before this burning season, I realized that the flue has a larger diameter than I am used to. Additionally, the diameter increases right above the chimney. My understanding is that an increase in diameter can increase pressure and contribute to an over draft (and I assume a wider diameter is creates a larger draft anyway).

So together it seems like there is a combination of overdrafting and that the design of the stove is such that you can't cut off very much of the air intake. The main thing I am considering and would love advice on is if I should put in a damper. Also I'm wondering if it might be worth rigging up magnetic tape to make a better seal on the burn rate assembly and or rigging up something that can slide across the secondary air intake in order to close that off as well.

Do those things seem reasonable? Would you suggest starting with just the damper and seeing how that goes? I feel a little uncertain messing with modifying the other intakes, since I'd hope the designers of the quadra-fire know what they were doing. Any suggestions would be welcome.

 

[armanidog]

Is your house fairly air tight? Does the stove use an outside air intake? Does your stove have an ash door?
One other thing, is the baffle and/or ceramic blanket in the correct position?

 

[old greybeard]

I couldn’t imagine running my stove without a flue and stovepipe thermometer, and a damper. I balance my burn with the damper and air intake. Running a big Osburn with 20ft vertical run straight up.
And neither of the 2 epa stoves Ive owned had any secondary air control.

 

[kennyp2339]

Have you tested your draft with a meter?

 

[Fractal20]

Is your house fairly air tight? Does the stove use an outside air intake? Does your stove have an ash door?
One other thing, is the baffle and/or ceramic blanket in the correct position?

The house is old and not very air tight. There is no outside air intake, but that is something I'm definitely interested in! The stove does have an ash door, the manual does discuss that an overdraft issue could be caused by issues with the ash door seal. I've tried to be sure to clean the seal well when I remove ash to try and be sure the seal is okay. Admittedly, I haven't tested the ash door seal beyond that. I suppose I could make some smoke down there and see if it looks like it is getting sucked through. I will do that.

I replaced the ceramic blanket. The baffle is a little beat up but not too bad. I think both are in the correct placement e.g. snug on the back of the stove without have the blanket scrunched up. But this is my first experience with an EPA stove and these type of features.

Have you tested your draft with a meter?

I have not tested my draft with a meter. I could look into buying one if you think that would be an essential test to help remedy the problem.

 

[begreen]

#1 - That is correct and true for most EPA stoves. It is to prevent smoldering.
#2 - Also correct. Only a few stoves regulate the secondary air.
#3 - Is there an attic also? That will add height. If the flue system is >25' then yes, add a key damper
#4 - The stove is designed for a 6" flue. Consider replacing the stovepipe from the stove to the ceiling support box with 6" stovepipe and the increaser at the ceiling support box.
#5 - ACC - This stove has a startup air system (ACC) that has 2 functions. It opens up full air a the front in the beginning and feeds air to the base of the fire in the rear of the stove. Make sure that this is functioning correctly and not stuck in the start mode or leaking. The ACC is on a timer that is supposed to shut down and close these supplemental air feeds after 25 minutes.

 

[Fractal20]

#1 - That is correct and true for most EPA stoves. It is to prevent smoldering.
#2 - Also correct. Only a few stoves regulate the secondary air.
#3 - Is there an attic also? That will add height. If the flue system is >25' then yes, add a key damper
#4 - The stove is designed for a 6" flue. Consider replacing the stovepipe from the stove to the ceiling support box with 6" stovepipe and the increaser at the ceiling support box.
#5 - ACC - This stove has a startup air system (ACC) that has 2 functions. It opens up full air a the front in the beginning and feeds air to the base of the fire in the rear of the stove. Make sure that this is functioning correctly and not stuck in the start mode or leaking. The ACC is on a timer that is supposed to shut down and close these supplemental air feeds after 25 minutes.

Thanks for the info begreen. I am confident the ACC shuts properly. I have been running the stove with the side paneling off in order to be able to be certain that the air intakes are closing properly. I need to properly measure the flue system height. I actually think the flue is in the 20-25' range.

A couple of questions

0) If the flue is actually under 25' do you think the issue is just the increase in the diameter of the flue? Or that it suggests there is some other issue somewhere, like the ash box door?

1) Just to be sure, are you saying running 6'' all the way until the ceiling support box would decrease the draft? e.g. the overdraft is exacerbated by having the increase in diameter so close to the stove top?

2) Is there an optimum height to put key damper? Out of laziness, I was speculating that if I put it right near the stove I might get away with not having to take it out when I sweep the chimney.

 

[begreen]

A couple things not discussed yet. How fully packed is the firebox? How thick are the average splits? Pictures help.

 

[Fractal20]

A couple things not discussed yet. How fully packed is the firebox? How thick are the average splits? Pictures help.

Thanks again begreen for your time. I tried to do a pretty full pack and took some pictures last night after I saw your response. Attached is:

(1) An example of the size of some of the splits (more than what is shown was put in the firebox)

(2) 5 minutes into loading the firebox pretty fully, at this point I shut down the air intakes just to try and get the longest burn time possible to hopefully illustrate the issue. One thing I should maybe point out is that visually, there isn't an apparent affect on the flames when the burn rate assembly and ACC are closed.

(3) About one hour after adding wood

(4) About 2 hours and twenty minutes after adding the wood

I wen't to sleep at that point. I'd estimate that the coals were spent by 3 and a half to 4 hours after adding the wood. If it is helpful the 5th photo is of the air intakes. You can see the burn rate assembly in the top left is as closed as it goes and the ACC is fully closed on the bottom on the left and right

 

[begreen]

The split thickness looks good but I see a lot of air in the #2 shot. The stove can be packed tighter.

 

[Fractal20]

The split thickness looks good but I see a lot of air in the #2 shot. The stove can be packed tighter.

So from the pictures you don't necessarily think anything is wrong in terms of an overdraft?

 

[begreen]

This doesn’t look too bad. It looks like with a fuller fire box and turning down the air sooner the burn can be extended.

 

[begreen]

@Fractal20 have things improved with the addition of a key damper?