Advice sizing a wood stove stand alone.

[1870farmhouse]

Greetings good people, just signed up and have some questions.
I purchased an 1870 German clapboard farmhouse in August.
The original fireplace is great looking with some quite valuable 6” tiles surrounding the firebox facing.
Dimensions of the fire box are 31” H, 35”W, 19” D.
Remember there’s 6” tile on sides and top so the combustible minimum should be 37” H and 47” wide. The floor fire tiles extend out 20” and is 61” wide which is and extra 13” on both left and right sides.
The chimney was swept in May 2024 in preparation for market listing.

I am planning on running 6” insulated pipe through the chimney to a full close rain cap.

I will include floor plans of my house for any extra advice for moving heated air throughout my home.

My house is 1170sf so just under 600sf per floor, with that what size wood stove can I fit in my fireplace to best heat my home?

In the future I am thinking of installing electric duct returns to pull warm air from the 2nd floor and possibly the finished walk up attic down to the first floor to promote circulation.
My home is wood construction. 1.25” thick exterior boards on top of 1.5” thick diagonal structural boards that affix to standard framing 2x6” studs 16” on center.
So I have 2.75” of solid wood on stud framing. There is no insulation so between the 1.5” diagonal boards and the lathe that holds my plaster walls is a void of about 4.5 inches, these voids are how I would place return ducts/registers from 2nd floor down to first and 3rd floor down to first.
In the future I may do blown in rock wool insulation as it’s the best for this type of construction as the voids were purposely made to move air to not allow water to create mold inside the wall voids and create draft. Rick wool sheds water and is good at still allowing air movement in its blown in form. But that’s down the road. I have a feeling if the wood stove dies 1/2 of what I expect it to do I will be very happy.
The current fireplace just puts out little heat and burns wood fast.
I see videos of wood stoves burning for 5-9 hours on one loading of 5-7 16” pieces of wood where my current fireplace would burn that in 1-1.5 hours and out out little in comparison heat to a wood stove.

As you can see in the floor plan the living room the fireplace is located is actually 11’4” x 17’2” and close to the front door and stairs to second floor.

I am thinking of buying a lightly used 1977 Vermont Castings Vigilant which looks to be
30” wide, 22” deep, 29” tall

My house is 1170sf not including my walk up finished attic.
Should I overcompensate estimated heating square footage by a certain percentage?

If you are still reading and viewing the included photos thank you for taking your time and any advice you may have.

 

[Gearhead660]

So, you are planning to put a stove in the fireplace or in front of it? The Vigilant will be lucky to get 5 hours out of a load. Being an old farmhouse, I would do any insulating you can now. Will pay back greatly and allow whatever stove you get to heat your home easier.

 

[stoveliker]

Some remarks:
1. putting ducts where you indicate is not a good idea. There is now no (and there will be no) insulation between the duct and the outside (other than the 3" of wood). Ducts generally loose a lot of heat when running through cold spaces such as wall cavities without insulation on the oustide, or attics and crawlspaces that are not conditioned. Moreover, moving cold air towards the stove generally works better.
If upstairs gets too warm, better to close a door or so, or add a curtain at some place.
To move heat downstairs better, use a fan running low (!) on the ground pushing cold air towards the stove. It'll be replaced by warmer air flowing a bit higher. Run the fan too hard and things will mix (turbulence) and heat transport won't be as efficient.

2. If you buy a 1977 VC, you'll likely have to rebuild it. Unless it's just been refurbished.

3. Buying a stove that can heat the current house will likely heat you out of the home when it gets insulated better, unless you buy a large stove now that you can also run at much lower heat output later.

 

[begreen]

Nice fireplace. The living room is isolated by doorways from the rest of the house. That means that the kitchen and dining room will get a lot less heat from the stove. The small hall and stairwell jog doesn't help. A greater volume of the hot air will go upstairs. This greatly reduces the actual area heated by the stove.

Is there any insulation in the walls or attic? Is there a basement?

The Vigilant was a good stove in its day, 45 years ago. I agree that unless it has been recently and properly rebuilt, it might perform poorly. Parts are getting scarce for them.

 

[1870farmhouse]

So, you are planning to put a stove in the fireplace or in front of it? The Vigilant will be lucky to get 5 hours out of a load. Being an old farmhouse, I would do any insulating you can now. Will pay back greatly and allow whatever stove you get to heat your home easier.

Planning on putting stove in the firebox area hence the included dimensions

 

[1870farmhouse]

Nice fireplace. The living room is isolated by doorways from the rest of the house. That means that the kitchen and dining room will get a lot less heat from the stove. The small hall and stairwell jog doesn't help. A greater volume of the hot air will go upstairs. This greatly reduces the actual area heated by the stove.

Is there any insulation in the walls or attic? Is there a basement?

The Vigilant was a good stove in its day, 45 years ago. I agree that unless it has been recently and properly rebuilt, it might perform poorly. Parts are getting scarce for them.

Doorways yes but no doors between living room and the kitchen/dining room.

I’m planning on using 2-3 registers with electric fans to draw hot air that rising up the stairs down to the kitchen and dining room this spring/summer.

No insulation. As mentioned in the post the exterior wall is 2.75” of solid wood on standard 16” framing comprised of mostly 4x6 studs and then interior is pasted on lathe. So where modern insulation exists there is a void and that’s done o purpose to allow air circulation to avoid water damage/rot/mold.

I can always blow rockwool into these voids as rockwool sheds water and is the best suggested material for this type/age construction but I rather install the stove and see how that works. Then install the return registers and see how that works and blowing rockwool would be phase/step 3.

We had a cold snap for 7-10 days last week where highs were in the high teens and nights in single digits and I was surprised honestly how I’d held considering lack of insulation. During that time I set the heat to 65 when I got home from work and set it to 57 when I went to bed.

The attic has no insulation. That’s on my list to do as it’s a walk up and mostly finished and I want to make it a 4th bedroom and office.
But I am probably putting on a new roof this summer so I’m waiting until that’s done.
I started installing R-30’fiberglass batts in the basement ceiling and have done about 1/3 of it last 2 weeks when I have free time.

 

[1870farmhouse]

Some remarks:
1. putting ducts where you indicate is not a good idea. There is now no (and there will be no) insulation between the duct and the outside (other than the 3" of wood). Ducts generally loose a lot of heat when running through cold spaces such as wall cavities without insulation on the oustide, or attics and crawlspaces that are not conditioned. Moreover, moving cold air towards the stove generally works better.
If upstairs gets too warm, better to close a door or so, or add a curtain at some place.
To move heat downstairs better, use a fan running low (!) on the ground pushing cold air towards the stove. It'll be replaced by warmer air flowing a bit higher. Run the fan too hard and things will mix (turbulence) and heat transport won't be as efficient.

2. If you buy a 1977 VC, you'll likely have to rebuild it. Unless it's just been refurbished.

3. Buying a stove that can heat the current house will likely heat you out of the home when it gets insulated better, unless you buy a large stove now that you can also run at much lower heat output later.

The reason I’m buying the stove first is to avoid over insulating and not get heated out of the house.
Insulating this type of aged construction can cause many issues and I prefer to do this in steps. I highly prefer burning more wood than $1000’s on insulation.
I have a wood splitter and already have 4 cords stacked ready for next winter 25/26.
I live in an area where the minimum acreage is 3 acres but most have over 8 and 2 neighbors have horse farms over 300 acres each much of it wooded that I am allowed to collect wood from and have access with my truck or my atv.

Yes registers lose heat but you can get insulated ducts and I feel installing a couple will create healthy circulation.
Hot air rises, if I return that air from the upper floors to the first floor that creates circulation. I really prefer not having free standing fans.
A high school friend is a HVAC engineer and he came up with that and he does a lot of colonial/old home installations.

I’m pretty much stuck with blown in rock wool which isn’t cheap but is on my list.
If I had the money and time I would remove the wood exterior and tack on tyvek water barrier and put back the exterior layer and then repaint but imagine what that costs. Probably 7000-10k. I figure I can do the blown in rock wool myself for under 4000.

My house also has the original 1870 window panes which are beautiful but single pane and a loss for sure.
So that’s why I’m starting with the stove then return registers and then rockwool blown in insulation in the walls.
R-30 insulation is bought and sitting in the basement with 1/3 installed mostly under the living room.
And when the roof is redone I’m sold on fiberglass batts covered by ship lap in the attic.
Currently there is no attic insulation and bare rafters where I can see the plywood the shingles are nailed to and some shingle nails poking through that plywood.
So yeah once that’s insulated I’m sure it will have a heavy difference in energy loss. Wish I had a FLIR/IR camera to have something to compare to once the new roof and insulation is completed.

 

[stoveliker]

All I'm saying is that if you can use the fans you want to transport cold(er) air, it'll be more efficient.
Cold air is heavier, and the losses will be less.

If I were you I'd consider adding a through-the-wall fan from the kitchen (floor!) under the stairs to the stove room.

The kitchen will be cold, sucking cold air out of there and depositing it in the stove room will create a circulation from stove room to dining room to kitchen. It'll help both (and the dining room more, which is good as the kitchen also produces heat).
That will do more to keep the lower floor warm than pumping air from upstairs down.

You can still do the latter, but creating a circulation as I suggest is going to be far more effective in heating the lower floor.

Upstairs the bedroom in the lower left corner is going to be coldest...

 

[1870farmhouse]

All I'm saying is that if you can use the fans you want to transport cold(er) air, it'll be more efficient.
Cold air is heavier, and the losses will be less.

If I were you I'd consider adding a through-the-wall fan from the kitchen (floor!) under the stairs to the stove room.

The kitchen will be cold, sucking cold air out of there and depositing it in the stove room will create a circulation from stove room to dining room to kitchen. It'll help both (and the dining room more, which is good as the kitchen also produces heat).
That will do more to keep the lower floor warm than pumping air from upstairs down.

You can still do the latter, but creating a circulation as I suggest is going to be far more effective in heating the lower floor.

Upstairs the bedroom in the lower left corner is going to be coldest...

I don’t want fans running around my house.

I am making a new door way(marked in blue) to create a better natural walkway between the kitchen and living room and create better air flow.
The lower left bedroom is getting a return register to the 1st floor bath and the other register will go from bedroom to the dining room below.
I’ll look into transferring air from kitchen to living room, good point.

Ever heard of anyone diverting stove heated air into the existing heat ducting to be delivered around the home???

 

[1870farmhouse]

So, you are planning to put a stove in the fireplace or in front of it? The Vigilant will be lucky to get 5 hours out of a load. Being an old farmhouse, I would do any insulating you can now. Will pay back greatly and allow whatever stove you get to heat your home easier.

Is there a general rule of thumb you guys go by to size a stove?
If my house is 1200sf should I get nothing less tha. A 1600sf or 2000sf rated stove to make up for possibly industry overrated numbers or to account for the age of my home and the lack of modern insulation.

It seems the prices of a quality cast iron stove does change much to bump up to the next level.

You say the vigilant needs to be reloaded every 5 hours, that much better than that amount of wood 5-7 pieces only lasting me 1.25-1.5 hours currently putting little heat in the traditional fireplace.

And to be honest I’m getting the vigilant for $300 so I was thinking when I run the 6’ insulated chimney liner I can install it knowing to leave the liner a bit long so if I replace the stove next winter that stove may be a few inches shorter and I’ll have so liner to work with to attach to a new stove.
I know the liner isn’t like an accordion but I should be able to safely get an extra 6-10” of liner for later use?
Or is there a professional solution that connected 2 liners safely?

So, you are planning to put a stove in the fireplace or in front of it? The Vigilant will be lucky to get 5 hours out of a load. Being an old farmhouse, I would do any insulating you can now. Will pay back greatly and allow whatever stove you get to heat your home easier.

 

[stoveliker]

I don’t want fans running around my house.

I am making a new door way(marked in blue) to create a better natural walkway between the kitchen and living room and create better air flow.
The lower left bedroom is getting a return register to the 1st floor bath and the other register will go from bedroom to the dining room below.
I’ll look into transferring air from kitchen to living room, good point.

Ever heard of anyone diverting stove heated air into the existing heat ducting to be delivered around the home???

Okay. I thought your ducts in walls would have a local fan too.

The return from that bedroom will be returning colder air so that's good (in my view).

It is illegal to have a return (sucking in air) within 10 ft of a stove. You'd facilitate the quick spread of smoke and carbon monoxide throughout the home if something goes wrong.

 

[1870farmhouse]

Okay. I thought your ducts in walls would have a local fan too.

The return from that bedroom will be returning colder air so that's good (in my view).

It is illegal to have a return (sucking in air) within 10 ft of a stove. You'd facilitate the quick spread of smoke and carbon monoxide throughout the home if something goes wrong.

My house has a propane powered forced hot air system for heat via ductwork. I guess I could turn on the furnace under (fan only) but the furnace is in the basement under the living room so I don’t know how efficient it would be to draw the stove heat down to Deliver it to the entire house via its ductwork.

I am interested in installing a copper coil around the stove pipe to act as a heat exchanger for supplementing the electric hot water heater and radiant heating I’m planning on installing in the kitchen and both bathrooms once I rehab them. Looks like I have about 28” of solid stovepipe I can place on top of the stove before switching to the insulated chimney liner and I was planning on wrapping that 28” pipe with the soft copper pipe.
I have read some on stove water jackets and how some people use copper pipe in back and forth design contacting the back of the stove units as well. I also have read where an extreme amount of heat exchanging can be bad as it changes the engineered heat amount through the chimney liner thus changing how the stove was designed to work under but that’s only some extreme heat exchanging nothing anywhere close to what I want to do. I was thinking of creating a 4 zone manifold for the water heater/1st bath/kitchen/master bath.
I’m also interested in possibly taking that heat exchanged energy and transferring it to a earth battery, a 55 gallon drum filled with coiled copper pipe then filled with sand where that hot heat exchanged water can transfer heat energy to the sand and can stay hot for over a day. It’s a great way people store extra energy from solar panels.

I would have no returns within 10’ of the stove. Any Returns would be upstairs sending warm air that has risen back down to the first floor.

Currently there are (2) open air registers in the floors of that bedroom in the lower left to the kitchen ceiling and from the bedroom in upper left to the dining room below so I’m looking for an option to send air down using those existing holes so I don’t have to tear out plaster.
But considering hot air rises those floor registers wouldn’t be as efficient gathering warmer air as a register I install in those rooms close to the ceiling

This is a labor of love and scientific curiosity. That’s why I’m doing the wood stove first, then taking in the improved results to see if circulating the air via register is worthwhile then lastly introduce the blown-in insulation.

Currently burning 5-7 pieces of 16” hardwood per hour in the original fireplace with really no heat and 90% for the romantic view of the fireplace fire.
Even with a $300 1977 vigilant if I can get 4-5 hours of burn time and actual heat I’ll be very happy and I can always sell that vigilant for $300 very easily and either find another used stove or buy a new one because the chimney liner should be able to be used with any stove I do upgrade to.

You saw the firebox size I listed and the extended floor fire tiles and fire tiles framing the firebox so what do you think about sizing?

For a 1170sf house with no insulation should I look for a 1600,1800,2000sf rated stove? Do you guys always wish you went one step larger and just step it down if it’s too much ?

That living room is 11x17 so will a larger rated stove than 1200sf make the living room unbearable?

I’d like to primarily rely on the wood stove for heating the house as I can get/split all the wood I want minus my personal time and gas for my splitter and that seems much cheaper than propane and I like the feeling of not being reliant on an outside fuel source(propane)

 

[stoveliker]

I don't know if the heat distribution will work out.
You always can make smaller fires in a larger stove, or intermittent fires.

If you're willing to do some trial and error, rather than expect a working solution from the start, then try it.

 

[1870farmhouse]

I don't know if the heat distribution will work out.
You always can make smaller fires in a larger stove, or intermittent fires.

If you're willing to do some trial and error, rather than expect a working solution from the start, then try it.

Have any advice on sizing? Any rule of thumb like if I have a 1200sf house I should add a certain percentage or ratio because the manufactures fudge their numbers or adding for loss due to a second floor?
At 1200sf should I look for a stove that does 1400,1600,1800,2000+ sf?

What are your thoughts on having a blower? Worth it or not?

 

[stoveliker]

I really can't say

Square footage ratings are useless because it's not square footage that is the issue but BTU needs and heat distribution. Stoves are space heaters. So it depends on how much you need and that depends on what percentage of the home it actually spreads to.

Your spreading proposals contain a lot of thoughts that often don't work well.

So it's hard to tell "this is what you need" .