Woodstove in fireplace help, 13" square flu, limited space

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hopkid

Member
Aug 14, 2012
6
NH
Hello All,

Thank you in advance for any expertise and sharing. I have gained so much from this site over the past decade, I can typically answer any questions by searching. I can't seem to get any conclusive answers on this latest project, I'd appreciate any help/feedback. I have burn't wood throughout my life, boilers, fireplaces and my last house was just a small F3.

This newer house has a pretty big fireplace, 38" wide, 33" tall in the center, slightly smaller width in the rear, and then goes up a 13" square, lined, masonry chimney, about 32' tall (7 yrs old, good condition). This has a chimney top mounted damper, and so much draft that the fireplace actually cools the house in the winter. My wife and a I finally decided to go back to a stove. I have settled on a used VC resolute aclaim, 2490 since if fits nearly perfectly to meet clearences. I plan to heat with this on weekends only, maybe a cord a year.

My questions are with the install, I do plan to buy the short feet so I can actually use the top feed, but I want to keep this set back into the fireplace. I can come right out of the top of the stove and up the chimney... but then what? I have looked at making a block off plate, and then just terminating a stove pipe into it. I know there are concerns with gas expansion, cooling, creasote, etc. So what is the next cheapest option; 6" single wall stainless? Is that really better for the amount I'm going to use this? I could terminate that right below the top damper, or just remove the damper and install a cap. What do you think? This is a larger central chimney with all the appropriate clearences.

I'm also concerned with cleaning the flu/liner. For those that have a similar setup, do you just pull your stove out to clean and then push it back in? I have a 12 pitch metal roof, so I have to clean from below.

Thanks!

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gthomas785

Minister of Fire
Feb 8, 2020
501
Central MA
You need a liner. Dumping into the smoke chamber is not a safe or legal option. Go with an insulated liner and you will thank yourself.
For cleaning, You may be able to fit a brush through the bypass damper of the stove. If that's not possible, it may make more sense to bring the liner down to a T and then horizontally into the back of the stove, and clean through the bottom of the T. That would put the stove out a little further into the room, not sure if that would be a problem or an advantage in your situation.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,584
South Puget Sound, WA
Must have a full, 6" liner with an insulated block-off plate in the damper area. I am sorry to note that the Resolute Acclaim, is not at all like the original Resolute. This stove was a maintenance nightmare and gave VC a black eye.
 

hopkid

Member
Aug 14, 2012
6
NH
Thanks for the feedback. If I insulate the blockoff plate, at the top of the chimney were the damper is, do I really need a fully insulated liner? This is a central chimney, it's quite tall. Thanks. I've heard about the issues with the combustion chamber in these stoves, I'm not looking for top efficiency, just an improvement over the fireplace which shouldn't be hard to do.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,515
central pa
Thanks for the feedback. If I insulate the blockoff plate, at the top of the chimney were the damper is, do I really need a fully insulated liner? This is a central chimney, it's quite tall. Thanks. I've heard about the issues with the combustion chamber in these stoves, I'm not looking for top efficiency, just an improvement over the fireplace which should be hard to do.
Yes you will still need a full insulated liner.
 

MongoMongoson

Member
Feb 6, 2021
162
Wisconsin
I know there are concerns with gas expansion, cooling, creasote, etc.

The gas expansion you mention is the reason you need a 6" liner. You need to keep the flue gases moving and you need the proper draft. Matching the flue diameter to the output diameter of the stove gives you the proper draft. Although, with 32' feet you are going to have a LOT of draft.

Even if you have enough draft because of the height of your chimney, if you dump your smoke into a 13" square flue the velocity that the smoke is moving is going to drop, and a lot of the worst of it will end up deposited on the inside of your chimney. It will have too much time to cool on its way up the stack.

Sometimes people require an insulated liner to help ensure they have enough draft. Keeping the gases hot helps ensure your draft keeps drawing. That won't be an issue for you... but you still need to insulate the liner.

The cooling and creosote you mention is the reason you need an INSULATED liner. With 32' feet, that gives your flue gases an awful lot of travel time to cool and condense on the inside of your chimney. You need the insulation to keep them hot until they exit your chimney. Believe me, you don't want to have a chimney fire. You really don't want to have one when you have a lot of fuel (creosote) lining the inside of your chimney.

I don't know about your stove, but I've been able to clean mine using a Soot Eater from below. It goes in the stove, turns 90 degrees to vertical, then through 2 45s and a cleanout T before it gets to the Class A chimney. No problems with the bends. As long as you can get through your stove you should be able to clean from the bottom.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,584
South Puget Sound, WA
Have you considered extending the hearth a bit so that the stove can move forward outside of the fireplace cavity? It would get hooked up to a tee on the end of the liner. This would make top loading easier, facilitate cleaning and the stove would heat the area much better.
 

CanFireman

Member
Mar 23, 2018
15
Canada
Is the stove approved to be installed within an alcove? If yes, what are minimum dimensions? Even if you can, should you? Could create a maintenance nightmare. These stoves are heavy. Sliding them in and out once or twice a year to sweep vent will get old in a real hurry.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,515
central pa
Is the stove approved to be installed within an alcove? If yes, what are minimum dimensions? Even if you can, should you? Could create a maintenance nightmare. These stoves are heavy. Sliding them in and out once or twice a year to sweep vent will get old in a real hurry.
That isn't an alcove it's a fireplace
 

EbS-P

Minister of Fire
Jan 19, 2019
1,215
SE North Carolina
Forward/back Stove placement in a fireplace is a compromise. I chose as far back as I could so I didn’t need a hearth extension.

I can remove baffle and clean the top vent stove very easily without moving it. Making cleaning easy means you are more likely to do it.

I don’t need a ton of heat so losing some of the radiant heat was ok. On the coldest 4 nights a year I wish it was out further. April- October I’m glad is sitting that far back. make sure you can easily get to the bypass damper handle.

Evan
 

hopkid

Member
Aug 14, 2012
6
NH
Thank you for all the replies. I prefer the stove set in the fireplace for space, and so I can keep a screen around it, I have many kids. I was able to borrow a lift and get to the top of my chimney. To my surprise, I actually have 11x11.5" clay liners for the fireplace. Sounds like I'll still want/need an insulated liner for it. I will look into the soot eater, that may work great in my application, thank you! I'll need a few extensions, I measured 35' 6" to my stove from the top of the chimney.

Anyone know how to remove on of these top mounted dampers? I read the installation instructions, it looks like an adhesive was used.

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PaulBunyun

New Member
Oct 15, 2019
40
Michigan
I have a similar set up as you. I have a new Lopi Liberty in my existing brick fireplace. It is full masonry. I elected to have it out as far as possible to benefit from the heat output. As others have stated it is crucial that you vent the stove correctly using a liner (preferably insulated). It may even be code in you area. The only question the inspector had for me when I had mine permitted was if there was a liner running all the way up. I also put in a block off plate to retain the heat and not lose it up the chimney. As for cleaning, I can either pull the baffles down to access the liner or the Lopi has a sliding door above the baffles to allow smoke to go straight up when loading wood or opening the door. This gives me easy access to the liner and I can sweep from the bottom. I use a drill powered soot eater that I got off Amazon which works great. Having the ability to clean from the bottom was a necessity for me as my roof is very steep. Good luck!