A wood stove for our earth sheltered home?

The building inspector, mortgage company and common sense will probably dictate that I  should have a “proper” automated heating system in the home.  I would call that my “backup” since I am hoping that I have designed the system well enough to call passive solar my primary heating system.  However, I also assumed I would have a back up to the back up in the form of an efficient wood burning stove.  We have a lot of “free” wood on the property (4 acres of Oak and Cherry) and you never know when power will go out rendering the other “backup” useless.  There is also this idea that it may take some time to “charge” the thermal storage soil around my home (some earth sheltered homes report a 3 year period before the home stabilized), and a wood stove would be a “free” way to do that.   Of course, there is also just something nice about sitting around a wood fire…

Modern Woodstove

So here is my first choice, picked out several years ago… I liked that it was a full 360 degree stove.  I had mentally situated it between the entry, dining and living rooms so that we could sit around it like at a camp fire.  It looks simple, but has many of the advanced features you would expect from a more traditional stove (blower, outside air intake, re-burner, etc.)  Its manufacturer, Focus Creation, has a lot of cool wood stove designs.  I expected they would cost more than a more traditional wood stove, but this one turned out to be nearly $15k and the one on the next page of the catalog (similar, but telescoping) was $44k…  It is an advanced stove, but you could get a 2012 Mercedes Benz SLK for a lower list price than that.  “Ooo, but it telescopes!!!”  Anyway, maybe if I already had that car, I wouldn’t mind shelling out for the unique stove…

We continued to shop around for more standard domestic wood stoves and found that they are generally inexplicably expensive…  They are about the same weight as a motorcycle, but much much simpler mechanically and yet, more expensive.  They are nothing compared to the technology or entertainment potential of a high end 3D TV, and yet cost much more…  I wonder why that is?

Jotul F100 wood stove.

Anyway, market mysteries of supply and demand aside; I eventually ended up going with something smaller and relatively simple… The Jotul F100.  I liked the arches on the door which would be similar to the vaults of the room.  It is only supposed to keep 1200 feet warm, but that should be good enough for us.   It does have decent efficiency, but not some of the advanced features that more pricey wood stoves had.

The main problem was the back of it…  Actually, the back of pretty much all the domestic wood stoves I looked at…  They all looked like junky old CRT televisions, many even had the big energy efficiency sticker like you would find on your clothes dryer.  An that was before you added the even uglier blower assembly…  The only solution is to put it up against a wall.

I spoke to the sales guy who was quick to correct my pronunciation…  “oh, do you mean the ‘yot’l’ wood stove?”  “Yes, sorry, I am not up on all the in-crowd Northern European wood stove name pronunciation”…  Anyway, it “starts” at $1,168.  But, at that price, you just get a paperweight.  If you want the fan, that is 250$.  If you want the “outside air kit” (to prevent it from sucking all the warm air out of your home), that is another $100.  I don’t think the legs were even included in that base price.  Then I asked about stove pipe…  They sales guy said, “$800 to $2,600”.  I asked him to break it down for me and he said that he could get me a deal on the first 8ft out of the stove for only $899.  Well we were already past the low end of his estimate and I hadn’t even reached my ceiling yet.  He said it was about 100$ a foot after that…   I have since found double wall stainless steel pipe online for about 50$ a foot, so I will keep shopping around.

I also looked into the cost of a professional install…  I love how they like to ask all sorts of questions and keep asking to come out and measure, but then really don’t have a very complicated formula for the price…  “Well, I have never done anything like that [earth sheltered roof], but its usually either $500 or $1000.”   Assuming that I look after getting the pipe thru the cement ceiling and out the outside of the dirt roof, he figured the rest of the work was on the low end, ~$500.

I don’t know if you have been adding that up, but I have to figure that my little Jotul wood stove will come in at close to $4,000 and that is before I put any gas in my chain saw…  Hmpf, free wood heat indeed!

But Mr. Pronunciation did fill me in on some other rules that I was not very familiar with.  The pipe must extend at least 3 feet out of the roof, but must be at least 2 ft taller than anything within 10 feet.   Hmm…  I have a 22ft radius house with a 10 ft radius “storm room” on the second floor.  Since much of the other layout is already in place, this means I have three options for where to place the stove…

1) I keep it where it was, about 2/3rds of the way out in the living room…  But then I have an ugly backed wood stove with a very tall (18 ft?) shiny metal pipe sticking out of my earth covered roof, probably with guy wires to keep it steady…

2) Move it to where the piano is currently and let the chimney climb right up the side of the storm room…  I kind of liked this idea and imagined a traditional stone chimney as well as tapping into the pipe with a second stove in the storm room (some day when I find a cheaper one on craigs list).  But the cost would definitely be higher and the stove would then be in a major transit path next to the kitchen.  My wife was concerned about the logistics of sitting around a hot stove in the middle of a traffic pattern.

3) We move it out and put it agains the outside wall, pretty much 11ft from the tower and hope that any rising smoke doesn’t just impinge on the storm room…  This is a serious problem because the prevailing winds will most likely drive it that way.  On the bright side, the little pipe could appear to be coming out of the entry cottage (if we do it right).  This also knocks out a window on that internal wall, or maybe reduces it to a high transom.

We didn’t really have much option for where to place the wood stove…

Anyway, this third option is what I sent the architect…

At this point, it is in the budget, and I am expecting to put in the pipe to make a hole when we shotcrete the ceiling, but I also plan to save purchasing the stove for last… If we have any budget left.

Costing this out has really undone my theory of using the fire place for “free” supplemental heating while we charge the earth that first year.  I could buy a lot of convenient conventional heat with my geothermal furnace for the cost of a wood stove.  However, I would still like to get one eventually for its ambiance and grid independence.

We will see how it goes.