Is an open fireplace stove install an “alcove”?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

the4machin3

New Member
Oct 2, 2020
12
Binghamyton, NY
I’m reviewing options for a new stove install (and I don’t want an insert). I have narrowed it down to a Morso 7110 which would vent from the rear of the stove and then up through an existing chimney. As I looked at it, I realized I could possibly pull out the rock facade and the metal fireplace firebox and put a smallish stove (I had my eyes on the Drolet Columbia II) basically in the fireplace and vent it directly up. I have a couple questions, the first being: is this considered an alcove? Do I need to have the 7” to rear and 10” to the sides clearance listed for alcove install (assuming double walled pipe)? Or since it’s sitting in the midst of all non-combustible fireplace box, does it not matter? Second question: would it be much less efficient being set back in the chimney than my Morso idea sitting in front? Thanks!

43FF822B-84D1-4729-8096-84F00126056B.jpg
 
Last edited by a moderator:

gthomas785

Minister of Fire
Feb 8, 2020
501
Central MA
No, the clearance requirements are to the nearest combustible material, so fireplace brick doesn't count.

There may or may not be a section in the stove's manual about fireplace installs. Usually the sticking points are mantel and trim clearances. Also floor protection.
 
  • Like
Reactions: the4machin3

EbS-P

Minister of Fire
Jan 19, 2019
1,226
SE North Carolina
A fireplace is not an alcove. Do you know what fireplace you have?
I like my stove set in the fireplace. Two reasons the floor plan is uninterrupted. I was able to set it back far enough to get 16” of original hearth in front. Second it looks better than an insert in my fireplace.

I do think heat output is compromised some, but I get really clean lower heat burns. To really pump out the heat you need a blower. I have a cheap pellet stove convection blower on the floor behind the stove pointing up. Insulated Block-off plate is a must.
If it’s an exterior chimney that is going to reduce heating efficiency more. The further out of the firebox you place the stove the more heat you will get.
Just some thoughts.
Evan
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,620
South Puget Sound, WA
I’m reviewing options for a new stove install (and I don’t want an insert). I have narrowed it down to a Morso 7110 which would vent from the rear of the stove and then up through an existing chimney. As I looked at it, I realized I could possibly pull out the rock facade and the metal fireplace firebox and put a smallish stove (I had my eyes on the Drolet Columbia II) basically in the fireplace and vent it directly up. I have a couple questions, the first being: is this considered an alcove? Do I need to have the 7” to rear and 10” to the sides clearance listed for alcove install (assuming double walled pipe)? Or since it’s sitting in the midst of all non-combustible fireplace box, does it not matter? Second question: would it be much less efficient being set back in the chimney than my Morso idea sitting in front? Thanks!
Is this a full masonry fireplace with a masonry chimney? If so no problem. Or is this a Zero Clearance fireplace with a metal chimney running up a chase? If the latter, it can not just be torn out and a wood stove put in its place. Behind and above the ZC fireplace is all combustible. If this is a gas fireplace, it could be even more complicated.

That said, with careful measuring and preparation, the area may be turned into an alcove - for some stoves. The Morso 7110 not only has side and back clearance requirements for an alcove, it also has ceiling clearance requirements, in this case 48" with double-wall stove pipe.

Screen Shot 2021-02-27 at 7.34.07 AM.png

If you can post an outdoor shot of the backside of this fireplace up to the chimney, that would help.
 
Last edited:

the4machin3

New Member
Oct 2, 2020
12
Binghamyton, NY
Is this a full masonry fireplace with a masonry chimney? If so no problem. Or is this a Zero Clearance fireplace with a metal chimney running up a chase? If the latter, it can not just be torn out and a wood stove put in its place. Behind and above the ZC fireplace is all combustible. If this is a gas fireplace, it could be more complicated.

That said, with careful measuring and preparation, the area may be turned into an alcove - for some stoves. The Morso 7110 not only has side and back clearance requirements for an alcove, it also has ceiling clearance requirements, in this case 48" with double-wall stove pipe.

View attachment 275462
Yes, this is a full masonry chimney. It’s block with clay liner. The Drolet would be the one I would modify the chimney and set it “inside” the “alcove” type place, if research shows that’s possible.
 

the4machin3

New Member
Oct 2, 2020
12
Binghamyton, NY
A fireplace is not an alcove. Do you know what fireplace you have?
I like my stove set in the fireplace. Two reasons the floor plan is uninterrupted. I was able to set it back far enough to get 16” of original hearth in front. Second it looks better than an insert in my fireplace.

I do think heat output is compromised some, but I get really clean lower heat burns. To really pump out the heat you need a blower. I have a cheap pellet stove convection blower on the floor behind the stove pointing up. Insulated Block-off plate is a must.
If it’s an exterior chimney that is going to reduce heating efficiency more. The further out of the firebox you place the stove the more heat you will get.
Just some thoughts.
Evan
Thanks for your thoughts. I am not sure I’m 100% sure what you mean on “What fireplace I have” but it’s a metal firebox - did they call them HeatForm, or something? Behind that it’s all cinder block and up the chimney are clay tiles. I was assuming either way I would do a SS liner up through the clay. I was also planning on an insulated block-off plate like you mentioned. How far out of the box would depend on the position of the chimney and the stove pipe coming out of the stove, I suppose.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,620
South Puget Sound, WA
The clearance requirements are to combustibles. If there are no combustibles surrounding the stove in any direction then this could be possible. The Columbia is 29" tall. Would there be room? A clean-looking stove that would fit easily would be the MF Nova.
 

the4machin3

New Member
Oct 2, 2020
12
Binghamyton, NY
The clearance requirements are to combustibles. If there are no combustibles surrounding the stove in any direction then this could be possible. The Columbia is 29" tall. Would there be room? A clean-looking stove that would fit easily would be the MF Nova.
I am not sure yet if room can be made. As the lintel stands now, no. But I was going to tear out the hearth to get a few inches down, and then pull off the stone facade, which I believe will enable a higher lintel on the block. Then I’d re-facade with brick, and put down a new hearth of something that looks nice. A lot of work, but the stove option for top flue are plentiful. The Morso 7110 was the only rear flue stove I found that worked. I’ll check out the MF Nova. Thanks!
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,620
South Puget Sound, WA
Yes, we are waiting for choices that were available before 2020. The Hampton 200 and 300 models were available with short legs and rear vent. They were good stoves that worked well with existing fireplace lintels.