Looking for freestanding wood stove advice for top to bottom ICF new construction.

[C&C]

Hi everyone,

I was referred here from an unrelated forum for some quality advice on my situation!

We just started construction on a total ICF walkout basement home. The basement walls, cap over the basement/ground floor, upper story walls, and roof will all be ICF. Foam and concrete everywhere, which presents a few challenges. We will have 2000sq ft in the basement and 2200sq ft on top of that of conditioned space.

I want a wood stove for backup/supplemental heat to our forced air HVAC system. If I don't mind the work of wood processing I may use it more full time.

Originally we planned to have a wood stove or fireplace upstairs in a living room, but as the house design changed we ended up with a clerestory roof design, and the chimney would exit in the middle of the low side roof, and on the front of the house. It would be hard to make it look good there.

I then started thinking with an unisulated slab on the basement it may actually be the coldest part of the house, and we could have the stove on the walkout wall side, this also puts the chimney in a position to run straight up and end up on the high side of the roof and the back of the house. Only downside is a long chimney run up and out through 2 layers of concrete and foam. Also worried about getting too hot in the basement and getting air exchange with the upstairs. This stove location is drawn in on the attached floor plans below.

I hope this all made sense, I'm typing quickly from my phone before I head out to start the first day of wheat harvest on the farm. I will check back in later and update as needed!

Thanks

 

[KDubU]

Are you planning to have any floor ducts to get the heat from the basement to the main floor? It should be easy to heat an ICF house if the stove is placed right.

 

[C&C]

Are you planning to have any floor ducts to get the heat from the basement to the main floor? It should be easy to heat an ICF house if the stove is placed right.

Well I never thought of it until it was suggested recently, so now I'm trying to figure out the best way to do something like that.

When I was a kid growing up in an old farm house with no HVAC in my room upstairs we had floor fans bringing up air from downstairs that helped quite a bit, but I'm not sure where I would put something like that in this house

 

[begreen]

It might work ok. The basement floor should definitely be insulated as well. Consider making the left side wall for the basement stairwell open instead of a solid wall and size it for a 3' wide door at the top.

Do you have a heat loss analysis for the HVAC? What size furnace is going in?

 

[C&C]

It might work ok. The basement floor should definitely be insulated as well. Consider making the left side wall for the basement stairwell open instead of a solid wall and size it for a 3' wide door at the top.

Do you have a heat loss analysis for the HVAC? What size furnace is going in?

That wall is a load bearing ICF wall to support the concrete roof ridge beam so it can't be changed, originally we had planned on an open stairway before the roof design we settled on. There won't be a door though and it's about a 4ft wide stairway

My HVAC guy is putting in a 5 ton AC unit for the whole house, I was going to ask what kind of heat loss and BTU's he was planning on and discuss this stove issue but he hadn't called me back yet, need to try him again.

Edit to add:

On your basement slab insulation comment, I've seen it done a lot but I was apprehensive about potential long term issues of having my slab supported by styrofoam, my builder who is a huge ICF fan and pretty efficiency minded said he never does it. I am young and hope to live in this house until I die and let the kids have it, so I want to avoid anything that might lead to more cracks over time.

My thinking was it should actually help me in the summer time, but I know it will be a drain in the winter, but I am definitely not an expert on this stuff, I didn't even know insulation under slab was an option before researching for this house

 

[begreen]

That wall is a load bearing ICF wall to support the concrete roof ridge beam so it can't be changed, originally we had planned on an open stairway before the roof design we settled on. There won't be a door though and it's about a 4ft wide stairway

It can still be an open wall stairwell with either openings between the stud or better yet, with a proper support column at the base of the stairwell.

5 ton is large, but it's understood that OK gets hot in the summer. Be sure the system is zoned. The basement heating/cooling needs will be different from the first floor. The heat loss calcs for the furnace will be helpful in determining the stove size, but I would err on the large side of things. OK can also get pretty cold in the winter with nothing between it and Canada but prairie.

PS: Get some big shade trees growing as soon as possible. They will help reduce the AC load.

 

[C&C]

It can still be an open wall stairwell with either openings between the stud or better yet, with a proper support column at the base of the stairwell.

5 ton is large, but it's understood that OK gets hot in the summer. Be sure the system is zoned. The basement heating/cooling needs will be different from the first floor. The heat loss calcs for the furnace will be helpful in determining the stove size, but I would err on the large side of things. OK can also get pretty cold in the winter with nothing between it and Canada but prairie.

PS: Get some big shade trees growing as soon as possible. They will help reduce the AC load.

I think you may have misunderstood, that wall to the left of the stairway will be solid concrete, no studs, and I don't have the time or budget to pursue a steel beam at this point. The ICF blocks are already here and footings are poured.

The weight of the concrete roof will rest on exterior walls and the 2 interior ICF walls you can see on the floor plan. One between bedrooms and living area, and one between the garage and living area upstairs. They go all the way down to footings. The only wood in the house will be for interior dividing walls, nothing load bearing.

HVAC guy is planning on a separate zone for the basement, but all pulling from the same unit with a flow diverter and separate thermostats. That seemed to be the simplest and most cost effective route.

Despite the large size this house is actually a relatively low budget project for us. We're aiming to come in at $100/sq ft or less all said and done. Which is a little less than a lot of traditional wood homes built in the area

 

[begreen]

The stove will primarily heat the Family room area. Some heat will make it up the stairs, but it could use some assistance in the form of floor vents (with fusible-link dampers) to create better convection.

 

[C&C]

Got to talk to my HVAC guy a little this afternoon, if we move the stove back upstairs, I asked him about using the HVAC fan to circulate air to the basement, since the return air will pull from the living room area upstairs and we could direct it to the downstairs zone. He thought that would work fairly well, maybe a few degrees difference between the floors, but tolerable probably.

There's pro's and con's to either location. With the basement having a walkout door on the back of the house it's perfect location to bring wood in and out, I could have some stacked right outside, but getting the heat and chimney where they need to go is harder. We have plenty of room down there too and plan to have the TV down there.

With the stove upstairs it will be harder or not as neat to bring wood in and out, but the chimney and heat issues should be better, but I'm not sure what kind of heat I can realistically push to the basement with this setup. We have less floor space to work with upstairs too, might get a little crowded but we can definitely make it work.

He is planning on a 5 ton AC and I think he said a 115,000 BTU furnace but both of them variable rate as they are probably too much for the house the majority of the year but he hasn't done a final load calculation yet. He is in an ICF home himself so he seems to know what I need. He wanted bigger units to help with very long duct run we have.

 

[EbS-P]

Put the wood stove where you will spend the most time, unless it’s truly for emergency use.

Don’t cheap out on the HVAC design. Insist on a full manual J and ask to see the room by room loads. The only way I would put a 5 ton unit in that size of new construction was if it was a variable speed compressor. Humidity control in the basement needs to be planned for. Ideally basement would be separate HVAC system. Adds cost. At least insist on a two stage compressor and go for a heatpump with gas furnace.

As far as wood stoves welcome learn lots. I like the Pacific Energy models.

Edit. You don’t oversize equipment for long duct runs you over size the ducts. Manual D (and J) is all software driven now. Anyone not using is suspicious in my mind.

 

[C&C]

Put the wood stove where you will spend the most time, unless it’s truly for emergency use.

Don’t cheap out on the HVAC design. Insist on a full manual J and ask to see the room by room loads. The only way I would put a 5 ton unit in that size of new construction was if it was a variable speed compressor. Humidity control in the basement needs to be planned for. Ideally basement would be separate HVAC system. Adds cost. At least insist on a two stage compressor and go for a heatpump with gas furnace.

As far as wood stoves welcome learn lots. I like the Pacific Energy models.

Edit. You don’t oversize equipment for long duct runs you over size the ducts. Manual D (and J) is all software driven now. Anyone not using is suspicious in my mind.

You lost me with the D and J I'll have to look that up.

Put the wood stove where you will spend the most time, unless it’s truly for emergency use.

Don’t cheap out on the HVAC design. Insist on a full manual J and ask to see the room by room loads. The only way I would put a 5 ton unit in that size of new construction was if it was a variable speed compressor. Humidity control in the basement needs to be planned for. Ideally basement would be separate HVAC system. Adds cost. At least insist on a two stage compressor and go for a heatpump with gas furnace.

As far as wood stoves welcome learn lots. I like the Pacific Energy models.

Edit. You don’t oversize equipment for long duct runs you over size the ducts. Manual D (and J) is all software driven now. Anyone not using is suspicious in my mind.

Thanks for the advice! I'm not familiar with the Manual J and D terms, but will look into that. I know this guy said he has not done the load calculations yet, sounded like he had a program for that, he's just been getting a rough plan together, routing the ducts is a unique situation in this house with no attic space across the majority of it.

He did say if I'm OK with the price he would strongly recommend a variable AC unit and furnace. The heat pump is a good suggestion I had forgotten to ask about too, so many things to keep track of, and of course it hits during my busy season too.

As far as the wood stove location, I do expect we will spend most evenings in the basement, with the TV and Office being down there, and potentially any other fun things we may end up with like a ping pong table or whatever.

 

[EbS-P]

You lost me with the D and J I'll have to look that up.


Thanks for the advice! I'm not familiar with the Manual J and D terms, but will look into that. I know this guy said he has not done the load calculations yet, sounded like he had a program for that, he's just been getting a rough plan together, routing the ducts is a unique situation in this house with no attic space across the majority of it.

He did say if I'm OK with the price he would strongly recommend a variable AC unit and furnace. The heat pump is a good suggestion I had forgotten to ask about too, so many things to keep track of, and of course it hits during my busy season too.

As far as the wood stove location, I do expect we will spend most evenings in the basement, with the TV and Office being down there, and potentially any other fun things we may end up with like a ping pong table or whatever.

With no attic all the main ducts will be hanging down into the basement. Which is better than the attic from a performance perspective but makes design more of a challenge as you will have space with only 7’ of head room.

I didn’t see a mechanical room. It’s nice to have a bit of dedicated space for air handlers water heaters ect. One idea I got off of YouTube was to plan for a chase from the mechanical space that goes from basement to up to second floor. It can house supply and return ducts meaning you could have some wall registers on main floor. Ventilation and humidity control in the safe room need to be well planned.

If doing a 4-5 ton system you need a lot of return air. We just had 4 ton ductwork installed and we have 2 14x20 and one 20-30 returns. The supply and return take up a lot of space.

As wood stove placement I really don’t see any other options comer install in the dining room would be my only other suggestion.

Great job on design btw. What part of OK? Ex Kansas farm boy here. We had 5k acres to harvest at the peak. 1/2 was custom farmed. I miss it for about 2 days one year we burned and entire tanker of diesel in 3 weeks.

 

[C&C]

With no attic all the main ducts will be hanging down into the basement. Which is better than the attic from a performance perspective but makes design more of a challenge as you will have space with only 7’ of head room.

I didn’t see a mechanical room. It’s nice to have a bit of dedicated space for air handlers water heaters ect. One idea I got off of YouTube was to plan for a chase from the mechanical space that goes from basement to up to second floor. It can house supply and return ducts meaning you could have some wall registers on main floor. Ventilation and humidity control in the safe room need to be well planned.

If doing a 4-5 ton system you need a lot of return air. We just had 4 ton ductwork installed and we have 2 14x20 and one 20-30 returns. The supply and return take up a lot of space.

As wood stove placement I really don’t see any other options comer install in the dining room would be my only other suggestion.

Great job on design btw. What part of OK? Ex Kansas farm boy here. We had 5k acres to harvest at the peak. 1/2 was custom farmed. I miss it for about 2 days one year we burned and entire tanker of diesel in 3 weeks.

The upstairs ducts will be run along the vaulted upstairs ceiling in the living area, most likely framed around to hide them right under the ridge beam of the roof. The bedroom hallway and bathroom, etc will have an attic space, but the master bed and bath will be vaulted again.

Basement will be capped at 9ft and have mechanicals run then I'll come back with either suspended ceiling tiles or framed out sheetrock at 8ft.

I think we have a plan to contain all mechanical/utility stuff in the garage. I'll make a steel platform to hang off the garage sidewall for HVAC (vaulted ceileings in garage too) and water heater, etc will go in that unlabeled closet looking area in the garage, most likely not framed out as shown just what architect drew in. Our builder is great at ICF work but doesn't use computers so we had it drawn up elsewhere and now we're winging some changes.

We farm NE of the Enid area, covering about 5k acres with probably 3500 in wheat right now to harvest ourselves with 3 combines if nothing major breaks down!

 

[EbS-P]

The upstairs ducts will be run along the vaulted upstairs ceiling in the living area, most likely framed around to hide them right under the ridge beam of the roof. The bedroom hallway and bathroom, etc will have an attic space, but the master bed and bath will be vaulted again.

Basement will be capped at 9ft and have mechanicals run then I'll come back with either suspended ceiling tiles or framed out sheetrock at 8ft.

I think we have a plan to contain all mechanical/utility stuff in the garage. I'll make a steel platform to hang off the garage sidewall for HVAC (vaulted ceileings in garage too) and water heater, etc will go in that unlabeled closet looking area in the garage, most likely not framed out as shown just what architect drew in. Our builder is great at ICF work but doesn't use computers so we had it drawn up elsewhere and now we're winging some changes.

We farm NE of the Enid area, covering about 5k acres with probably 3500 in wheat right now to harvest ourselves with 3 combines if nothing major breaks down!

Sounds like you have a handle on it. Hope the weather hold out for the next couple weeks! I just spent $15k on ductwork and whole house dehumidifier and it was a challenge for my decent well respected HVAC contractor. Had I not been living on site I’m quite certain that it would have not been done correctly. (They started without a load calc so they just guessed what size of ducts and they were way off.) Plumbing and electric there just aren’t as many ways to do it wrong. HVAC is a whole other story. The industry is experiencing some quite rapid changes coupled with new much tighter homes means they have less room for errors.

Why ICF has not caught on down here in hurricane country is beyond me

 

[C&C]

So my current thinking is I have two options.

We either we carry on with the stove in the basement, which is what I'd really like to have, and hope we can push enough heat upstairs to be happy. I'm thinking the dual zone HVAC system may help here, with the open stairway if I can push more air to the basement with the damper surely we can push some heat upstairs to where the return is located.

2nd option is I just discovered wood fired furnaces are actually cheaper than free standing stoves I've been looking at. I could add that in the garage and tie ducts into the main HVAC system I'm sure. But I lose all of the appeal of sitting around a fire, it requires power, and we lose any ability to cook or heat water with the stove during an outage.

 

[EbS-P]

So my current thinking is I have two options.

We either we carry on with the stove in the basement, which is what I'd really like to have, and hope we can push enough heat upstairs to be happy. I'm thinking the dual zone HVAC system may help here, with the open stairway if I can push more air to the basement with the damper surely we can push some heat upstairs to where the return is located.

2nd option is I just discovered wood fired furnaces are actually cheaper than free standing stoves I've been looking at. I could add that in the garage and tie ducts into the main HVAC system I'm sure. But I lose all of the appeal of sitting around a fire, it requires power, and we lose any ability to cook or heat water with the stove during an outage.

If you want to heat all the time with wood furnace makes sense. But it’s going to complicate hvac installation. Again if this is supplemental heat put it where you spend the most time. The cost of the chimney pipe will be about what the stove costs for a two story run.

If you want the stove to heat the whole house the room it’s in will be 90+ degrees and the bedrooms won’t feel warm. Wood furnace will make the temps more uniform and could probably heat the whole house.

Power outages I’d just plan on a generator if you are really concerned. Cooking on camp stove or grill works good enough.

I’m gonna throw this out there from left field. Would you consider a wood cookstove???? There are trade offs it’s not the best heater but heats. https://www.drolet.ca/us/en/cookstoves/db04815/

Looking at your layout again. What think you could get a stove upstairs in the living room on the garage wall. with the pipe exiting and n the back pitch of the roof. It would just need and angled off set inside to get back behind the peak It might look weird. It might not. Basement stove is the most logical. Do you like modern or more classic style.

 

[C&C]

If you want to heat all the time with wood furnace makes sense. But it’s going to complicate hvac installation. Again if this is supplemental heat put it where you spend the most time. The cost of the chimney pipe will be about what the stove costs for a two story run.

If you want the stove to heat the whole house the room it’s in will be 90+ degrees and the bedrooms won’t feel warm. Wood furnace will make the temps more uniform and could probably heat the whole house.

Power outages I’d just plan on a generator if you are really concerned. Cooking on camp stove or grill works good enough.

I’m gonna throw this out there from left field. Would you consider a wood cookstove???? There are trade offs it’s not the best heater but heats. https://www.drolet.ca/us/en/cookstoves/db04815/

Looking at your layout again. What think you could get a stove upstairs in the living room on the garage wall. with the pipe exiting and n the back pitch of the roof. It would just need and angled off set inside to get back behind the peak It might look weird. It might not. Basement stove is the most logical. Do you like modern or more classic style.

I don't see my wife really wanting to cook on the wood stove if not necessary, but I thought it does make a nice bonus capability to a free standing stove VS a fireplace or furnace. We will have a backup generator, but that is reliant on propane delivery again same as our main furnace will be.

I have always wanted a wood burning fireplace or stove inside, I just enjoy them anytime we go somewhere with one, but besides that the wood stove seemed like a good backup heat in case we either can't get or run out of propane, as well as putting all the wood from trees I plan to thin out to good use. The land we are building on has so many unwanted or overcrowded trees I don't think I would ever need to go anywhere else for firewood.

If I see that I can handle processing whatever amount of firewood we need on top of my normal work, I'm definitely not against using it more full time for heat, but I won't know that until I've done it. I should have child helpers around for at least another 18 years too. 🤣

 

[EbS-P]

I don't see my wife really wanting to cook on the wood stove if not necessary, but I thought it does make a nice bonus capability to a free standing stove VS a fireplace or furnace. We will have a backup generator, but that is reliant on propane delivery again same as our main furnace will be.

I have always wanted a wood burning fireplace or stove inside, I just enjoy them anytime we go somewhere with one, but besides that the wood stove seemed like a good backup heat in case we either can't get or run out of propane, as well as putting all the wood from trees I plan to thin out to good use. The land we are building on has so many unwanted or overcrowded trees I don't think I would ever need to go anywhere else for firewood.

If I see that I can handle processing whatever amount of firewood we need on top of my normal work, I'm definitely not against using it more full time for heat, but I won't know that until I've done it. I should have child helpers around for at least another 18 years too. 🤣

I put stoves in both our fireplaces. I Like them some much more than an open fireplace. If I were to pick a new free standing stove today it would be a Pacific Energy T5 or T6.

 

[C&C]

After some thought and discussion my wife and I decided to just keep moving forward with the stove in the basement, hopefully it works out ok!

Haven't fully settled on a specific model yet, sleeving that exposed wall for 3" outside air inlet and sounds like I'll need about 12" sleeve for chimney routing up through the floor and roof, but I've got some time to nail that down while basement floor and walls get poured and cure.

 

[EbS-P]

After some thought and discussion my wife and I decided to just keep moving forward with the stove in the basement, hopefully it works out ok!

Haven't fully settled on a specific model yet, sleeving that exposed wall for 3" outside air inlet and sounds like I'll need about 12" sleeve for chimney routing up through the floor and roof, but I've got some time to nail that down while basement floor and walls get poured and cure.

Basement fresh air intakes are hard as they are not allowed to have any vertical rise above the stove. The reason is they could function like a chimney. The best solution is planned mechanical ventilation for the basement that you can control. ERV or ventilating dehumidifier

 

[begreen]

Basement fresh air intakes are hard as they are not allowed to have any vertical rise above the stove.

There is an exception. They are allowed as long as they don't directly connect to the stove. Some stove models have an air gap built-in to prevent reverse venting out the OAK. In lieu of that, terminating the outside air with a gap short of the stove connection will provide the necessary break.

 

[C&C]

Basement fresh air intakes are hard as they are not allowed to have any vertical rise above the stove. The reason is they could function like a chimney. The best solution is planned mechanical ventilation for the basement that you can control. ERV or ventilating dehumidifier

This is a Walkout basement, so not a problem here. It will exit the house just above the floor. The walkout is the only reason I'm even wanting the stove in the basement, if I didn't have an outside door right beside I wouldn't even consider it. Hauling wood and ash through the house and up and down stairs doesn't sound fun!

 

[begreen]

It may work out fine. The house is already ahead of the curve with good insulation and sealing. It may take a little fine-tuning for heat distribution. If you can leave the basement ceiling unfinished for a season in case there is a need to install some fire-dampered floor vents, that would make it easier. Keep us posted on progress.

 

[EbS-P]

This is a Walkout basement, so not a problem here. It will exit the house just above the floor. The walkout is the only reason I'm even wanting the stove in the basement, if I didn't have an outside door right beside I wouldn't even consider it. Hauling wood and ash through the house and up and down stairs doesn't sound fun!

Sounds like it’s time to pick a stove!

 

[C&C]

It may work out fine. The house is already ahead of the curve with good insulation and sealing. It may take a little fine-tuning for heat distribution. If you can leave the basement ceiling unfinished for a season in case there is a need to install some fire-dampered floor vents, that would make it easier. Keep us posted on progress.

The underside of the basement ceiling is the easy part, the concrete floor over the top of that won't be much fun to cut holes in later on!