Really need some input and help here sizing/stove considerations

[TDog78]

So I have been a member here for some time but to give you a short history here it goes. My family and I have made a drastic change in our lives over the past few years including 1. Moving from the rat race of the big city (Denver) 2. Closing down my commercial construction company 3. Our place is in the middle of nowhere (cannot even see a neighbor without a spotting scope!! (LOVE IT) 4. In short we have downsized our commitments, house, really everything to get more back to the basics and to spend more time together as a family especially while my three kids are still young, and so far we are loving it.

If you look at my older posts I was designing a home to be in the neighborhood of 1500 square feet or so....to make a long story short the final evolution of our design and downsizing has our house at the following and it is what we will start building here this late winter.

It will be about 600 square feet upstairs with 8 foot ceilings and a basement of 400 square feet. The upstairs will consist of one small bedroom an open passageway to a utility room with one bathroom and a open kitchen/family room where the stove will be placed

It will be well insulated with a r-60 ceiling, 2x6 walls with r-23 roxul in the stud cavities and either 1.5 inch or 2 inch poly iso insulation on the outside of that with a great deal of care going into all of the air sealing etc, (I will not bore you with the details) and the basement will have insulated walls as well (r-20)

We mostly burn elm in this neck of the woods

My elevation is 4400 feet

With the air tightness of the home I will be utilizing an outside air combustion kit with the stove.

We are having real trouble with the sizing on the stove. With our past house plan and stove research we had decided on a alderlea T5 but obviously that is too large. We love the T4 but are concerned that it would be too large as well. We heated our former house with a stove that was way too big for the house and freaking loved it even when we sat around in our undies with the front door open letting the below zero air in from out side but we would like a more intelligent pairing on this one. Is a 1.5 cubic foot box like in the t4 too big for this design? Any other suggestions on a good small stove. We researched to death the previous picking with the t5 and with me doing 95 percent of the work myself including all the design etc I cannot turn this into a super long project and am hoping that you all can help as much as you did last time. Thanks for your time, Travis.

 

[begreen]

A 1000 sq ft home that is super-insulated is going to need very little heat until it gets very cold outside. Normally body heat, lights, refrig, dryer etc. will heat the house. If it has solar gains, you may be opening some windows during the daytime. I suspect this home will require minimal if any wood heat on many days. If the goal is longish burntimes in the Alderlea series the T4 would be a good choice, but I'd also consider the Blaze King Ashford 20 and Woodstock Keystone. These cat stoves will burn steadily at a low output. Actually, almost any small stove would probably do. Mostly I suspect you will be starting short hot fires and letting them go out. If so, the Jotul 602, Morso 2B might also be worth considering. Run the heat loss calcs on the house a zero degrees and that should tell you the btus needed.

 

[TDog78]

Can I even call it 1000 square feet with 400 of it being a basement and insulated to boot. I have always been leery of the cat stoves as my buddy has one and he has to replace it fairly often and I love the KISS principle but because of your suggestions and the logic behind them I will look at them further. I appreciate the input and additional options.

 

[begreen]

I was assuming the stove would be installed in the basement. Is that incorrect? If so, and only 600 sq ft. I would get a tiny stove and would run it on a high quality compressed fuel, like HomeFires or Northern Idaho Energy Logs, one log at a time. Do your heat loss calcs soon, before buying the stove.

 

[TDog78]

No, it will be on the main floor.

 

[begreen]

Go small, very small. (see above comments for fuel)

 

[TDog78]

I have acres of standing dead elm and could never justify buying my fuel. Do you know of a good heat loss calculator as the wood stove is such a centerpiece of our home and we love burning wood and the heat it provides soo much I would rather insulate my house less then do without or have to buy pre made fuel.

 

[begreen]

As noted, the house is largely going to heat itself. 600 sq ft is not much to heat when it is well insulated. That's why I thought about heating from the basement. You can burn wood in a small stove. I suggested the compressed wood product because they release heat steadily so that you could get closer to say 8,000 btus per hour. But if you prefer to burn elm, that's ok. There may be more swing in the temperature cycle, but you can moderate that by opening a window a bit.

http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm

 

[TDog78]

Gotcha, thanks for the link. I will be checking out all of the aforementioned stoves. Right off the bat I notice the Jotul 602 has a box size of about .82 cubic feet (how cute) and the F100 nordic qt is just slightly larger but has the viewing glass which the wife is in love with and I enjoy too but I ran across some pretty negative reviews on the F100.....functionality wise etc how different is the 602?

 

[begreen]

The F100 is ok. BrotherBart has one. He can fill you in on more details about it. You'll need to cut the wood a bit shorter for it. The Morso 1410 is another one, but only 12" splits for it.

 

[TDog78]

Have you had any direct experience with the Morso 2b. I like the longer splits it takes plus I think it has enough glass the keep the boss happy. Seems to be compared a lot to the Jotul 602.

 

[begreen]

No, I have more experience with the 602. The 2b has a good track record.

 

[TDog78]

Ok, so my heat load calculations are saying 18,348 BTU/Hour providing the best information that I currently have on the house design. My issue now is how can you apply that to the stoves since the manufacturers numbers are typically inflated so much.

 

[Grisu]

Ok, so my heat load calculations are saying 18,348 BTU/Hour providing the best information that I currently have on the house design. My issue now is how can you apply that to the stoves since the manufacturers numbers are typically inflated so much.

One cu ft of average hardwood in a non-cat stove will give you roughly 100,000 BTU. Burn that over 5.5 hours and you are at your heating load. Thus, a 1 cu ft stove loaded 4 times a day will do it. Or get a slightly larger catalytic stove and load it only twice a day. The Woodstock Keystone/Palladian with the additional soapstone to moderate the heat output would be my favorite. If you want less heat just don't load it full and let the retained heat in the soapstone do its thing after the wood is burned up.

 

[begreen]

Ok, so my heat load calculations are saying 18,348 BTU/Hour providing the best information that I currently have on the house design. My issue now is how can you apply that to the stoves since the manufacturers numbers are typically inflated so much.

I ran some rough numbers on just the main floor 600 sq ft and came up around 12K BTUs. Does that sound correct. I am assuming the stove will not be heating the basement.

 

[TDog78]

The stove will be heating the basement as well. A mini split system will provide the heat when we are away and cooling in the summer and thus the only air moment I will have will be a HRV. Hopefully enough of the heat will make it down there. In my last house the furnace never ran and the basement got cool but not cold with the underwear weather upstairs. Part of the 600 square feet upstairs in our new place does include about 175 square feet of utility room that is slab on grade that I entered into the heat load calculations. It was a pretty detailed calculator that I used to come up with the 18000 BTU an hour or so but I would like to check it against others.

By the way I really really like that Woodstock Keystone. It accommodates the split size I like, has nice viewing and good burn times. After reading some more I think I can get over the cat issue but I am leery if I can run the thing low enough for such a small space after doing the calculations. My wife just got home and is not to fond of the longer and narrow morse/jotul stoves but alas looks are not everything.

 

[rijim]

If you want longer burn times with a house that small, a cat is the way I would go. Woodstock would be my first choice.

 

[Oldman47]

begreen, a lot depends on the temperature difference between inside and outside. I live in a house built in the late 70s that has a gas furnace rated at 80,000 BTU and 90% efficiency. My insulation is not up to modern standards so I only have R13 walls and an R30 top floor ceiling. At 1800 square feet I never see my furnace on more than half of the time so that means the 80k is gross overkill. My coldest weather condition around here is close to 0ºF and I heat to around 68ºF so a difference of around 70º. If I was willing to have no reserve I could use nothing more than a 40k furnace and meet all of my heating needs but it would need to run continuously on those coldest days. In fact when I had to replace the furnace about 15 years ago I detuned the new one so it will only run at about 60k. If you drop the basement and the OP is willing to only heat about 70º above outside air temperature I would expect to need something in the 13k range for absolutely minimal heating needs. I always like to keep something in reserve so would probably use a 20k or so heat source for that place, ignoring the basement. Who knows if he has the same heat loss sources that I do like windows, doors, air leak rates, etc. That kind of thing could throw off the calculation by at least a factor of 2, meaning he could need closer to 25k BTU/hr. In that case a stove rated at 30k BTU continuous would be the least I would consider.

 

[TDog78]

So, with me having no research at all concerning cat stoves since they were never an option in the beginning then I guess my biggest question is if a cat stove is able to achieve a low and slow burn with lower heat output better then a non cat stove. In the case of the keystone I know it shows up to 45000 BTU max but would it be able to efficiently hold closer to half that with little negative effect. I am also sure their 45000 number is at sea level using the best wood possible in a lab and I am almost a mile high, don't burn oak. Also is the claim of a more spike free and even heat with the soapstone a sales gimmick or a legitimate and noticeable feature.

 

[Grisu]

So, with me having no research at all concerning cat stoves since they were never an option in the beginning then I guess my biggest question is if a cat stove is able to achieve a low and slow burn with lower heat output better then a non cat stove.

Better than a non-cat stove? Surely. Low enough to be convenient for you all the time from fall to spring? Questionable. Stoves don't have thermostats; there are trade-offs that need to be made. A small cat stove will still be the best option if you want to heat with a wood stove. Worst-case-scenario: You will need to open a window.

In the case of the keystone I know it shows up to 45000 BTU max but would it be able to efficiently hold closer to half that with little negative effect.

That's something to ask the Woodstock customer service.

Also is the claim of a more spike free and even heat with the soapstone a sales gimmick or a legitimate and noticeable feature.

The soapstone will give you a more gentle, radiant heat but don't expect a masonry heater. There are plenty of threads about this stove. I suggest trying a forum search.

 

[rideau]

First, Woodstock's claims are conservative. They give both a lowest and highest output with hardwood. I'm sure the Keystone can run all day producing 12,000 BTU's or less per hour, but check the figures with Woodstock. They are very accommodating and will gladly answer any questions if you call them, without putting any sales pressure on you.

Cat stoves are very easy to run. The Woodstocks are very high quality. Cats last a long time and more than pay for themselves in wood saved, to say nothing of processing time and storage area. Woodstock's price on cats is very reasonable too. They also send parts to you the day you call them.

I'm guessing your basement is mostly below ground? If so, it will likely stay around 50 degrees without heat, so you may be able to send enough heat down there to make the area comfortable. However: your upstairs is really small, and you are going to lose a fair % of that to a wood stove, hearth and wood storage. I'd seriously consider putting the stove downstairs. Will the design allow air to flow upstairs?

Also: hope you have designed an airlock entry . With the small size of the home, I'd consider an airlock entry with seating on one side and coat/boot/ski/snowshoe storage on the other side. Maybe even room for a few days wood storage, so you don't have to go out in severe weather. The small footprint concerns me: have you planned enough storage area? Room for the kids for studying etc as they grow older? Food storage/freezers if you are going to grow your own food? If you want to stay really small, hope you are designing this to be easy to add onto, in the event you need to do so. Are there bedrooms for the children downstairs? Bathroom down there, or just the one bathroom? If only one bathroom, reconsider. An injury can make climbing stairs problematic.

I'm sure you have thought all that through, but I wish someone had made a few suggestions to me before I built my home. I love it, and thought long and hard, and designed just what I wanted within the parameters I could afford at the time. However, having lived in it for over 35 years, there are a few things I would do differently if I were building today. Foremost, I'd have an airlock entry as described above. Saves a lot of space, a lot of heat, and keeps a lot of mess out of the house, but items handy. With my country/outdoor lifestyle, it would have made a ton of sense for me...and kept my house a lot cleaner and less cluttered.

 

[begreen]

Woodstock lists the range of output for the Keystone on their site. 35K BTUs is the maximum continuous output, but 8,500 is the lowest. That's why I suggested this stove as an option. It's range of output falls within the calculated need. Soapstone stoves also buffer the heat swings well. They are much more effective at this than a radiant stove. Heating only 600 sq ft, your needs are going to be on the lower end of this stove's output. There will be some windows opened at times when you want a fire, but it's not cold enough outside to warrant one due to the house's well insulated envelop. But when it's 10F outside and the winds are blowing at 40mph, you folks will be snug and warm. And it will have the reserves for those -20F nights.

 

[skysong]

What plans do you have for your basement space? I'd like to share a little of my experience... I have a multi-level house around a stairwell...all very open between the floors. The stove was installed on the middle level. What we found out was that heat spread around that floor and went up, with very little going down to the bottom floor. We tried fans but it just was too cold in that bottom room to be comfortable. The next year we put a stove in the bottom level and it works, with a very nice even temperature through out the whole house. The middle level stove is only used if we need an extra punch of heat on very cold days or if we want ambiance in that room, we use 4 eco bricks for a nice slow even heat. We don't regret our first stove placement, but that year of insanely hot stove room (90's), trying to get heat to the lower level, was not pleasant. Our floor plan between levels was open and the temp. variances were still too much for comfort. I hope my experience can help with your plans.

 

[ailanthus]

Good for you for prioritizing your family over the rat race. You're getting good advice from others on sizing the stove. It's good a smaller stove should easily be adequate so it doesn't take up too much sq footage. Definitely share some pics of the house & stove as things progress.

 

[skysong]

I just re-read the thread....you mentioned that with the stove in your last house, you had "underwear weather" upstairs in order to heat the basement. Will the stove size do this if it's required here?