Wood stove in an ICF house

[onesojourner]

We are currently in the process of building a new home and all the exterior walls are insulated concrete forms (ICF). Do any of you have any examples of wood stoves being used in this kind of construction? I am worried about putting in a stove that will roast us out with even a small fire. The house is about 3200 sq ft. It is a walk out basement with only one basement wall exposed. There is 2.5 inches of foam on the outside, 8 inches of concrete and 2.5 inches of foam on the inside. The windows are u-.24 and including doors there is about 285 sq ft. Roof will be spray foamed with about 5 inches of open cell. The climate zone is 6b in this area. My initial though was to go with the f400 but now I am wondering if the F3 would keep the space more comfortable. I have designed the hvac system to have return airs up a cathedral ceiling right in front of the stove to help circulate the warmth through the house.

If any one has put a wood stove in an ICF, SIP or even spray foamed house, I would love to hear the results.

 

[Jags]

Two things come to mind. First you will want a stove that has an option for an OAK (Outside Air Kit), because of your very tight envelope. Second, you will want something that can go slow and low. Consider the small cat stoves from BK or the new hybrid from Woodstock (and there are others). I am thinking that you will want to stay away from the tube steel/cast stoves. These stoves are typically cyclical in their burn pattern and may roast you out at their peak burn. Soap stone on some of the tube stoves can also tame the cyclical beast.

 

[charly]

I agree with Jags,,, look into a cat stove that you can really turn down.... A friend built a 2 bedroom apartment off the back off a his garage using ICF's for the whole place, with a crawl space ,, 4 foot high for the mechanicals. Here's what they found out,,, they had radiant heated floors that they never wound up using,,, he said they heated the place with just two tiny space heaters and they ran so little their electric bill was nothing...... basically he said you could heat the place with a match! So I guess that's good news,,, you certainly won't burn much wood.

I see your using open cell foam on your roof... I believe someone posted on here that open cell foam on a roof could take on moisture causing major mold issues, due to sudden temperature extremes? Closed cell is better dealing with any moisture. We use to have a log home with 8 inch thick sip panels on the roof.. I will tell you what I did read,,,,, ants love the foam. A building inspector noticed the 2 in rigid foam panels against our outside foundation walls and also pointed out that the ants love to eat that stuff. Just a heads up for soil contact,,, maybe they love to just nest in the panels. I guess if you don't have ant's in your area your fine.

 

[Jags]

I agree with Jags,,,

Most people do.

 

[charly]

Most people do.

 

[onesojourner]

Thanks guys. I have always shied away from cat stoves. In my mind they just make things more complicated and there are more things to wear out. The wife is not a big fan of the look of the soapstone stoves, and I am not sure I can make any headway on that front. Are there any other cast iron stoves out there other than Jotul, VC and Pacific energy?

 

[Jags]

Quadrafire Isle Royale, but being the owner of one, I don't think I would recommend it for your application. It likes to run at about 550-600F and it will do it for several hours. I think it might blast you out the front door.

Just a side note: The cat stoves of today are a little more refined than the cat stoves of yesteryear.

 

[begreen]

I think you will be ok with the Castine. This is a big space and the Castine will run well with a partial load of fuel. If it starts getting warm, let the stove go out. However, if you wish to heat 24/7 with wood then I would look into the Woodstock Keystone. Regardless of stove, definitely plan on connecting it to an OAK as Jags suggested.

Other cast iron stoves to consider: Hearthstone Shelburne, Hampton H300, PE Alderlea T4, Quadrafire Yosemite, Napoleon 1600c.

 

[Jags]

This is a big space...

Ya know, you are right. At 3200 sqft if he can get good air movement he might actually want the firepower. For some reason I minimized the size of the home in my head. That is a lot of area to heat, although VERY efficient to heat.

 

[onesojourner]

Thanks Guys. I am pretty partial to Jotul, but we will see what happens.

 

[jeff_t]

Keep an eye out for new Blaze King cast iron-clad stoves. Supposed to be 2 and 3 cu ft models.

Don't be afraid of the cat. My stove is stupid simple to run. I would imagine the new ones will be, too.

 

[begreen]

Something to think about is why you are putting in the stove. What will be it's primary role? Is it for 24/7 heating or a beautiful fire at night to enjoy or power outage security? Or possibly all the above? The reason I bring this up is a small stove may be better if the primary function is the fire view. Conversely, if 24/7 some cat stoves are great burning at a low setting, but the fire is not so exciting to look at, if visible at all .

 

[jeff_t]

Something to think about is why you are putting in the stove. What will be it's primary role? Is it for 24/7 heating or a beautiful fire at night to enjoy or power outage security? Or possibly all the above? The reason I bring this up is a small stove may be better if the primary function is the fire view. Conversely, if 24/7 some cat stoves are great burning at a low setting, but the fire is not so exciting to look at, if visible at all .

That is a good point. ICF house in MO isn't gonna take much. An evening fire would probably do it most of the time.

 

[Space Cowgirl]

Hello, I know this is an old thread, but I was hoping the OP could come back and tell me what he decided and how it's working out for him.

We just built a 2000 sf (3000 sf with basement) ICF house in MO,and I had planned on heating with a wood stove, but I'm having second thoughts. This summer, which was hot, it only cost about $30 a month to keep it air conditioned. It's been getting down into the 30s at night the past couple of weeks, and the house has stayed above 65 without heat. I'm concerned that any wood stove we put in is going to roast us. I also don't want to spend several thousand dollars on one if our heating costs are only going to be less than $200 a year with the heat pump. But I love fire! A gas fireplace insert is just not the same. I'm so conflicted.

Any thoughts? Or should I start a new thread?

 

[begreen]

It sounds like you may not need a wood stove. You could check this out this year by tracking the amount of heat needed to keep the place warm during a particular cold snap in the teens. What is the current primary heating system size in BTUs? That may provide a hint of what might work.

If having a small fire is important then there are smaller stoves and fireplaces on the market. They may require opening a window or two if having a fire on the holidays is important and it's 40F outside. But I would not expect the stove to be much of a cost savings. Even a small stove like the Englander 17VL is going to cost somewhere around $2500-3000 by the time it's installed. The chimney system would be the major portion of the cost.

If you have natural gas already in the house it might be good to look at some of the newest gas fireplaces. Some have a pretty good, natural looking flame.

 

[kennyp2339]

Hey BG - wasn't there a couple from Virginia that installed a BK stove on here last year with one of those supper insulated houses?

 

[begreen]

A small BK stove could be a logical choice depending on the heat loss requirements and location. It helps to do the math in advance. If 10K btus is going to be too much for the stove area at say 35F then even a BK would be too large a heater. That would be an expensive installation for just a few days or a week of cold temps in a mild climate. It's also possible that the stove would have to run on its lowest setting, thus providing minimum fire view and more likely a blackened window. Super-insulated houses can be heated well enough in milder winter temperatures by just lighting, appliances and human body heat.

 

[Space Cowgirl]

The current heat system is a 2 ton heat pump with a 15,000 btu auxillary heat strip. That worked well for the AC this summer, so supposedly it will also be able to handle heating. We shall see. I cook a lot, and that tends to raise the temp in the house a few degrees.

We also have the basement set up for radiant heating (the pipes are installed, but nothing is connected to them yet.) We may or may not complete that system, depending on how things go this winter.

I don't think we actually need a wood stove, but I do just like a fire. When we lived in Maine, we heated almost exclusively with wood, and enjoyed it. I like the smell of it, the sound of it, everything. I even like stacking wood. But I hate being hot. I guess we could just open windows, but...that seems slightly nuts.


I went and looked at gas logs yesterday, and the flame looks good, but you don't get the whole fire experience. No good smells, no crackle. The logs stay the same. Significantly less mess, though.

We actually got a little electric fireplace for our bedroom and built it into an old mantel just for quick, cheap ambiance, and I think it's just about as good as gas logs. Maybe I should just get a crackle box and a smoke smell candle and pretend.

The problem is the living room has a big 2 story wall that was designed for an awesome stone fireplace. Something fireplace-y has to go there.

(The bedroom electric thing. This isn't quite done yet, but you get the gist.)

 

[begreen]

A wood stove is not going to provide much crackle and smell unless you get a small one that has a fireplace screen option. For sure if you get a stove it should have an outside air supply. Air quality is important in a tight house. You don't want smoke in there. Is there a good HRV system for air exchange?

 

[brad wilton]

Seeing how it's a super effiecent house might not a nice fireplace work you said you built a two story open wall for one?

 

[Space Cowgirl]

I'm aware I sound like a pain in the butt here. "Wah, my house is too efficient to have a fireplace. Boo hoo." Sorry. I'm kind of working through this, and coming to terms with the fact that my wood-burning dreams may not be the best thing to do. Thanks for indulging me.

Yeah, I'm thinking about a regular fireplace, too. I've been reading some ICF forums, and those guys think that putting a regular FP in an ICF is basically negating all the awesomeness of the ICF. Plus, you have issues with the chimney drawing correctly because the house is so tight. And I think they have a point. They're pretty awful with efficiency, right? I do think it's cool that the temp here is practically self-regulating. Basically, I want to have my cake and eat it, too.

Thanks for the replies so far.

I'd really love to hear from anyone who has an ICF and heats with wood. It seems to be a rarity.

 

[begreen]

The solution for you is the probably similar to the OP. Retrofitting a fireplace is going to be expensive. Instead maybe put in a nice hearth in front of the stone wall and run a chimney straight up and out. Install a stove that compliments the decor and has a screen door option. Enjoy the occasional night fire for a few hours when the mood strikes. You may need to open a nearby window but enjoy. In the case of the OP the stove choice was the Jotul Castine.

Or build a nice faux fireplace and put an LED TV screen in there hooked to DVD player with a nice fire DVD playing.

 

[rsw49]

I just did a search on the OP's recent activity and it looks like he went with the Jotul F100. Sounds like he is happy with its performance in his 3000 sf home.

 

[kennyp2339]

I don't think we actually need a wood stove, but I do just like a fire. When we lived in Maine, we heated almost exclusively with wood, and enjoyed it.

What do you have for heat when the power goes out? The beautiful state of Maine is susceptible to ice storms, and very cold air; if I lived there I would want a back up.

 

[begreen]

I think she lives in Missouri - MO