How to modify the existing fireplace for wood insert compatible?

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ZKlongisland

New Member
Feb 15, 2022
21
Roslyn, NY
Hi everyone,

First time posting and seeking advice on how to best modify existing fireplace to accommodate wood insert. The fireplace has an external river stone domed opening. (photo w dimension provided) And as it exist, the domed opening will allow for 24" h x 28" w rectangular spacing for wood insert.

The internal opening of the fireplace (behind the river stone) is 32" h x 48" w x 24" d and I think I can chip away the river stone to enlarge the river stone covered opening to make room for larger wood burning insert.

Any advice on what to use to chip away the river stone which is ~ 5" thick?

I'm considering following wood burning inserts:
Osburn inspire 2000
Expedition II wood insert (Quadra-Fire)
Vermont Casting Montpelier II

Thanks in advance
[Hearth.com] How to modify the existing fireplace for wood insert compatible?
 
Maybe a rotary drill, make a ton of holes in a line and chip them off off. I would think you could go up to the metal lintel of the chimney opening. Anything that would cut would make a HUGE mess. If you get a surround plate then you wouldn’t ever see it.
 
I think you meant to type 38" wide, not 28". Will none of the inserts of interest to you fit the opening, without increasing its height or width?
 
The Expedition and the Montpelier are the same inserts under the hood. They lack user control of the air supply to the fire other than the ACC startup. My preference of the 3 would be the Osburn.
 
Maybe a rotary drill, make a ton of holes in a line and chip them off off. I would think you could go up to the metal lintel of the chimney opening. Anything that would cut would make a HUGE mess. If you get a surround plate then you wouldn’t ever see it.
That’s better than my idea of just using chisel and hammer
 
I think you meant to type 38" wide, not 28". Will none of the inserts of interest to you fit the opening, without increasing its height or width?
There are three width measurements. 48” across the internal firebox, 39 1/2” across the bottom opening of the river stone facade, and 28” across the top opening at 24” height.

I just saw the mf fire nova 2 and love the large viewing window. But the minimal required dimension is 28” h x 33” w x 16”d. I’m going to start chipping away to enlarge the opening.
 
The Expedition and the Montpelier are the same inserts under the hood. They lack user control of the air supply to the fire other than the ACC startup. My preference of the 3 would be the Osburn.
Thanks. I’m down to deciding between Osborn inspire and a new insert I just saw in the showroom, mf nova 2. Osburn may fit without enlargement (listed dimension is 24”h x 28 1/2” we 20”d) but nova 2 will some chipping away.
 
I think the first choice you need to make is whether you need a controlled burn rate of if single burn rate is fine. Controlled burn rate is important if you're depending upon your fireplace for heat vs just using it for ambiance.

As best I can tell the Stuv would fit without modifying your stone - https://stuvamerica.com/en/products/stuv-16/ - however, its a single burn rate.
 
How often do you think you'll be pulling it out once it's in? I'd consider getting a mason or just removing a few stones. Get the insert in and running, then put them back on.
 
I think the first choice you need to make is whether you need a controlled burn rate of if single burn rate is fine. Controlled burn rate is important if you're depending upon your fireplace for heat vs just using it for ambiance.
Good point. But we can sharpen it even more by saying it's possible to heat your space with a ZC fireplace. Heck, you could heat your first floor with an open fireplace, I did it one winter 25 years ago in my parent's home, and it was a lot of fun... at first. The down-sides to doing this are:

1. You need to be nearby, as you'll be loading a few splits every few hours, to control the burn rate and keep the heat coming. With a stove, you can load up a half day's worth, or more, set it, and forget it.

2. Your wood usage is inversely proportional to the appliance efficiency, if not worse, as I'll explain in point 3. But, keeping up with the wood supply chores on anything with low efficiency can get old very quickly.

3. The higher inlet air requirements, in the absence of an OAK, will cause all rooms not exposed to the direct heat of the stove to get very cold. This is because you'll be drawing all of the make-up air required to feed the appliance thru every gap in every window and door frame, from every far-off room of the house.

Point 3 should not be taken lightly, as the drop in temperature in those rooms out of the line of sight of the fireplace will cause you to want to produce even more heat than you would need otherwise, making the efficiency problem somewhat exponential in nature. In fact I am still dealing with it today on my BK's, but to a much lesser degree (they don't draw nearly as much air when turned down). We had four fireplaces in the house where I grew up, some of which had outside air inlets in their floor, others which did not. There was an enormous difference in how cold far-off rooms of the house got, depending on which of those fireplaces we ran.
 
I think the first choice you need to make is whether you need a controlled burn rate of if single burn rate is fine. Controlled burn rate is important if you're depending upon your fireplace for heat vs just using it for ambiance.

As best I can tell the Stuv would fit without modifying your stone - https://stuvamerica.com/en/products/stuv-16/ - however, its a single burn rate.
I’m now leaning towards getting the Stuv 16–68. The listed dimension for it is 27 1/8 w x 24 3/8 h. I re-remeasured the opening of my fireplace and I was able to get a rectangular clearance of 28w x 24 1/2 h. So I have a good chance of being able to fit the Stuv (with minimal trim) without needing to do any chipping.
 
How often do you think you'll be pulling it out once it's in? I'd consider getting a mason or just removing a few stones. Get the insert in and running, then put them back on.
This is news to me. How often would one need to pull out the wood burning insert after it’s been installed. I hope never to pull out the insert once it’s installed.
 
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7 1/4" diamond tipped saw blade on a corded Circular Saw will get you through enough that you could make a clean break.

Amazon product ASIN B01FOQJGVS
Thank you for the advice. I think I found an insert (stuv 16-68) I could install without needing to cut out the existing opening.

Just as a thought, what would you use to smooth out the stone after making the clean break with the circular saw. Would it require a metal file or standard sandpaper?
 
This is news to me. How often would one need to pull out the wood burning insert after it’s been installed. I hope never to pull out the insert once it’s installed.
Some installs or stoves don't allow for bottom up cleaning and there are times the chimney is situated where getting on top is not an option for the normal home owner. Although uncommon, there are situations where sliding the insert out is necessary.
 
Thank you for the advice. I think I found an insert (stuv 16-68) I could install without needing to cut out the existing opening.

Just as a thought, what would you use to smooth out the stone after making the clean break with the circular saw. Would it require a metal file or standard sandpaper?

You left us all hanging here.. No final results, no impression of insert performance.. c'mon! Spill those beans!
I'm actually interested about performance. I am on the fence between stuv 16-78 vs stuv-6 76x60
 
You left us all hanging here.. No final results, no impression of insert performance.. c'mon! Spill those beans!
I'm actually interested about performance. I am on the fence between stuv 16-78 vs stuv-6 76x60
I ended up getting BK Sirocco...mostly because Stuv did not allow me to control the air intake.
 
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