Wood or propane for heating small space?

[mike82934]

As some know, I'm making plans for a very small (approx. 120 square-feet) wood-framed cabin that will be built on top of a flatbed trailer.
The ones I've seen built have all had a small propane heater, usually the type that you might find in the cabin of a boat. I assume that it's for convenience and to save space. My thought was to put an extremely small woodstove in, like one of the Sheepherder's stoves from Cabela's ( http://www.cabelas.com/cabelas/en/templates/pod/horizontal-pod.jsp?_DARGS=/cabelas/en/common/catalog/pod-link.jsp_A&_DAV=MainCatcat20075-cat550002&rid=&indexId=cat550002&navAction=push&ma sterpathid=&navCount=1&parentType=index&parentId=c at550002&id=0005876 ). They're intended for use in a canvas outfitter tent, so I assume they'd be safe for a small cabin.
My main concern is that it may be too much for the space. If you have a propane heater with a thermostat, you can easily regulate the amount of heat, but it's a little more tricky with a woodstove. Then again, I like the idea of being able to go gather and stock up firewood instead of having to drive to town to refill a propane tank.
I'm leaning slightly toward the propane heater, but I was wondering what you folks think, from a practical (and self-sufficient) viewpoint?

[ozarksnick]

We lived aboard a boat for a while one summer a ways back.

I had intended to install one of these deals in the boat if we stayed aboard during the winter:
Cozy Cabin Solid Fuel Heater (http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/268728/377%20710/0/wood%20heat/Secondary%20Search/mode%20matchallpartial/0/0?N=377%20710&Ne=0&Ntt=wood%20heat&Ntk=Secondary%2 0Search&Ntx=mode%20matchallpartial&Nao=0&Ns=0&keyw ord=wood%20heat&isLTokenURL=true&storeNum=5002&sub deptNum=12&classNum=543)

Says it will burn charcoal, logs, pellets.

I've always thought it would also work well in one of those Tumbleweed Houses on trailers. The Tumbleweeds sound a lot like what you're talking about.

[cinok]

We live in a small scbin that we are still building its 420 sqft with my wife 2 boys and myself. I wood love to have awood stove but space is the issue we us a vent free glowwarm propane heater due to space. Once we add on we will be putting a cozy wood stove in. Your space is smaller but just you.

[mike82934]

Yeah, the Tumbleweed houses are where I got my inspiration, I've wanted one ever since I first saw them five or six years ago. But they want an awful lot of money for even the smallest one, so we decided to build one ourselves. I think it has a lot of advantages over a camper, not just aesthetically, but as far as insulation and quality of construction.
That stove sounds nice, but the cost spooked me a little bit. Maybe I could offset the cost by selling the big woodstove I have now, seeing as how I won't have a use for it anymore.
Another thing my wife brought up was that we'll probably need propane for cooking anyway, so maybe I'll just go that route with the heating, too. It is a very small space, so it may be more efficient than I think. I guess we'll see.

[cinok]

Mike we live in eastern OK not hard winters but it does get chilly, we work off of 100lb cylnders from nov to april last year we went used 3 cylinder it's about $69 to fill them the 3rd cylinder lasted up to last week for our stove

[Mr.B]

THere was an artical in Backwoodsmen magazine about making a wood stove out of an old propane tank for under about $20. Im not sure which issue Id have to dig through my pile.

[ozarksnick]

$500 is not a lot of money for a wood stove. Especially not one made to be used in such small spaces.

And the propane versions may be cheaper initially, but you'll really pay for it when you're purchasing gas in the future. Especially if fuel gets more expensive.

My own opinion, but I'd sure rather not be dependent upon anyone for my heat.

[mike82934]

cinok: Thanks for the figures, that gives me a starting point to estimate cost...how big is your place and what all are you running (if you don't mind me asking)?

Mr. B: I'll try to do an internet search for that, sounds worth a look.

nick: I hear that loud and clear. I'm just trying to figure which would be preferable for me- bigger upfront cost with lower cost later, or vice-versa.

I appreciate all the help, guys. :)

[cinok]

420 14x28 catherdral ceiling with 2 lofts for sleeping we run the heater and regular 4 burner stove with an oven also used the same tank for propane BBQ

[JAK]

mike82934,

I like your thinking. Here are my thoughts. I would first figure out what the maximum rate of heat loss might be for such a space, on your coldest night. It probably isn't much. Something that small doesn't need to be superinsulated, but it should be reasonably insulated and you should try and make it reasonably air tight, no major cracks or drafts, but not super airtight. Once that's all said and done it doesn't need much heat, but it needs some. I would guess that whatever you are doing for hot water might be enough for space heat, and on the coldest nights you might just fill up some jerry cans with close to boiling hot water and set those around and that will provide you with the extra heat you need on those nights.

How much? Probably 5000 BTU would be more than enough, and thats only about 1 pound of wood per hour. If you could make a small wood fired boiler that gives most heat to the hot water and as little as possible to the living space then you might only need to fire it up once a day, and then get your heat out as you need it rather than going from sauna to icebox every 8 hours or so. Let's figure it out more detailed. but still fairly rough.

Assume a 10'x8'x12' box, for roughly 600 square feet of surface area.
Let's say it is insulated to R10, including insulated shutters on the coldest nights.
Let's say the inside/outside temperature difference is 80 degF on coldest nights.
Let's also say that the infiltration losses are equal to the conduction losses.
This would work out to a heat loss of 600 x 80 x 2 / 10 = 960 BTU/hr, or say 1000 BTU/hr.

So a small 5000 BTU/hr stove would ony need to run 5 hours a day on such days/nights. Problem is, such a small space might fluctuate in temperature quite a bit. That's why it might be better to design your small wood stove to be most effecient at heating up hot water rather than your space. This is tough, so some heat will still escape to your space, which is OK, but your hot water tank will give off the rest of the heat fairly more slowly the rest of the day and night. Most fall/spring days you might just need a little hot water and that should be enough, and you might even want to keep a window open at times. On the very coldest days/nights in winter you might have a morning fire and use that hot water and then fire it up again for supper and perhaps again in the evening. Maybe as little as 2 pounds of wood and kindling for each burn cycle. That seems like very little. In practice it might be hard to make a wood boiler that small and that efficient, so you might end up having to open windows and doors when its fired up, and closing windows and doors and shutters at night and still waking up cold on the coldest mornings. So don't get too carried away I guess.

Here is a design for an evvicient cook stove that might get adapted to a small wood fired hot water heater. I think the last publication on the bottom is a good start...

http://www.aprovecho.org/web-content/publications/pub1.htm
Design Principles for Wood Burning Cook Stoves,
Aprovecho Research Center, Partnership for Clean Indoor Air, Shell Foundation, June 2005 (1MB pdf)

Another thought might be to run a small stove pipe to a bigger one of these, just to heat up hot water and use that for heat as you need it. They are very effcient. Depending on how well insulated your cabin is it might be enough, but you might want something a little more conventional also. Maybe build your own volcano kettle out of steel, and add a tap, and a stovepipe of course. Also a way to add fuel, and maybe some removable insulation so you don't overheat your space and to hold the heat longer through the night.
http://www.kellykettle.com/how-it-works

If you scaled a Volcano Kettle up to hold 5000 BTU of heat that would be 40 pounds of water x 125 degF. (200F down to 75F). That's about 5 U.S. gallons. Fun project if you are into welding. Be sure and include a safety release valve. ;)

Maybe invest in a carbon-monoxide detector also. ;)

[mike82934]

Thanks for the figures, JAK. :)
I've pretty much decided to go the propane route, mainly for ease of heating large quantities (more than 2-3 gallons) of water whenever I need to, regardless of season. It will probably change to wood whenever I find a permanent location, but in the meantime, I think propane would be the most convenient.
Does anyone have any experience with this sort of gadget? http://www.cabelas.com/cabelas/en/templates/pod/horizontal-pod.jsp?_DARGS=/cabelas/en/common/catalog/pod-link.jsp_A&_DAV=MainCatcat20075-cat20097&rid=&indexId=cat20097&navAction=push&mast erpathid=&navCount=1&parentType=index&parentId=cat 20097&id=0006339 I ask because, if I don't always have access to a pressurized water source, with something along those lines we could still have a shower every once in awhile. A gravity-fed system would be a possibility too, but it's something I don't really want to get into with the space constraints.

[flatwater]

I have the hotman pressure tank one. All it is is a stainless steel weed pressure spray tank with a cheap burner with it. It works great but I just use the tea pot set to boil I pore that into the tank with to gallons of cold water and I have a nice hot shower (100 DEGS) and usually have a gallon left over.
Flatwater

[DavidOH]

I am deciding myself.
Here are some options for wood heating:
$310.99 *http://www.go2marine.com/category.do?no=11510
http://i37.tinypic.com/jts9le.jpg
or
$699 to $1200 http://www.marinestove.com/index.htm
http://i33.tinypic.com/1zz5np4.jpg

I have seen the Sheephearder's stoves. They scare me because they are not air tight.
Anything under $500 most likely would not be.
Someone could die from lack of oxygen in an enclosed cabin with those.
The ones for boats are made for small enclosed areas.

Propane options are available with auto shut of for low oxygen.

I'm torn between buying and setting up both, because of the times I would be out.
Propane I could leave running, a wood stove I couldn't leave unattended.

[ozarksnick]

Don't be scared of the non-airtight stoves.

Just don't build yourself a hermetically sealed house to live in! ;D

The only woodstove I've used for the past two years is a $150 Vogelzang that is most definitely not airtight. But my house is also most definitely not airtight! ;D

[flatwater]

In a small space things can become real hot really quick. You also have to be careful not to burn up your oxygen supply in a small area. They used to make these miniture potbellied stoves that burned charcole. As much as we would like to be independent of the big oil companys we also need to be smart and safe. For that small of a space , I would stick with a propane heater you can adjust.
flatwater

[machinemaker]

Just a DIY idea. buy a cheap barrel stove kit and put it just outside your cabin. build a small shed around it that has 16" of clearance around the stove, but leaves access to the door of the stove. in the space between the barrel stove and the wall of the shed or small container put 2 u shaped vent pipes that go through the wall of the cabin, so that the u is on its side, one end of the u lower near the floor. Then back fill the space between the stove and the shed with sand. the stove outside of the cabin will not take any of your living space, but will heat the sand which will act as thermal mass and stay warm for hours, the u shaped ducts will warm up in the sand and there will be natural convection that draws cool air off the floor and warn air out the top vents. you can also put a loop of copper tube in the sand next to the stove to pre heat water for your water heater.
kent

[otterbob]

I use a 10,000 BTU Non-vented Propane wall heater in my 8'x8' office with 8'x8' loft { shed }
Here in Colorado at 6100' altitude with no problems !

Got it from Northern tool on sale for $49.00 USD {Actually bought 3 of them for different places }

It has a thermostat that needs no electricity and works as well on a 20lb bottle as it does on a 100lb bottle.

I have to keep the thermostat set low or it will run you out of such a small building !

I do recommend you install a ceiling fan if you have electricity to maximize your heating { put it on reverse during the winter }

Otter Bob

http://www.coloradojingjing.com/bob/office/bobspictures/10000btu-office-heater.jpg

[fnfredux]

propane, its easy and fuel is readily available. I have several of the ventless, three different styles. They keep you cosy and if you get the kind with the ceramic burn surface (forget what they call it) you get a better radiant heat than the flame ones. I jus looked at a site yesterday that had rally small pellet stove with practically no clearance, of cousre no pricew listed so $$$$ I suspect.
http://www.inglenookenergy.com/Stoves/Pellet_Freestanding/littlegnomepellet/littlegnomepellet.htm

[Backwoods_Bob]

I would absolutely recommend a small wood stove.
For self sufficiency, if for no other reason.

Design every shelter you built to be fully functional without electricity and store bought propane, especially if it's a small cabin in the backwoods.
This means enough windows so you don't need lights during the day. It means a wood stove. I could go on, but you get the idea.

No reason not to have a small propane heater as well, especially since you are probably gonna have a propane fired stove for cooking?

The best low cost stove I can recommend for a cabin is the old M1941 army stove.

http://image.sportsmansguide.com/dimage/145523_ts.JPG?cell=200,200&cvt=jpeg

http://www.sportsmansguide.com/net/cb/cb.aspx?a=490240

These are fantastic little stoves, will burn wood or coal, and run 90 bucks from Sportsman's Guide.

We lived in a small travel trailer while building our straw bale cottage and used one of these to heat the trailer.

I used patio blocks behind and under the stove to absorb some of the heat.
My brother used one of these stoves for many years to heat a small cabin in Colorado. He burned many a ton of coal through his, while I burned nothing but wood.
His stove was set ontop of and welded to a steel automotive rim to raise it up a bit.

It may overheat a small cabin if you get it blazing, but so what?
One of the great luxuries of a wood stove is being able to sit comfortably in your cabin with the door wide open when it's 3 below zero outside.

You get the best of both worlds, lots of delicious fresh air and the intense radiant warmth that only a wood stove can provide.

Nothing can heat up a cabin faster than a wood stove if you've been away and it's cold out!

Visit your cabin in the middle of the winter and it will take all day for a propane heater to make the place comfortable.

Not to mention nothing is cheaper than firewood. You can likely cut it youself from around the cabin.

- And it gives you someplace to burn the trash!

Now, our little travel trailer did have a built in propane furnace. It was an old trailer and the furnace had a pilot light and did not use electricity to operate.

The little wood stove would not hold an overnight fire with the junk we were feeding it and when we started waking up to frozen water in the tea kettle we started running the propane furnace at it's lowest setting when we went to bed.

So, use propane if you wish, but by all means include a wood stove!

[fnfredux]

I would absolutely recommend a small wood stove.
For self sufficiency, if for no other reason.

Design every shelter you built to be fully functional without electricity and store bought propane, especially if it's a small cabin in the backwoods.
This means enough windows so you don't need lights during the day. It means a wood stove. I could go on, but you get the idea.



The best low cost stove I can recommend for a cabin is the old M1941 army stove.

http://image.sportsmansguide.com/dimage/145523_ts.JPG?cell=200,200&cvt=jpeg

http://www.sportsmansguide.com/net/cb/cb.aspx?a=490240

These are fantastic little stoves, will burn wood or coal, and run 90 bucks from Sportsman's Guide. *

*

WOW, I LOVE IT! Thanks for the info.

[Backwoods_Bob]

Your welcome!
My wife and I lived in an 18' travel trailer for a year and a half while building our straw bale cottage.

That little stove is the only thing that got us through a winter of sub zero temps and 15 feet of snow.
They really really work. Kinda like a small pot bellied stove.
You do have to cut your wood quite short, something like 8."
Despite the fact that it's a top loader, there never is any problem with smoking up the cabin when you add wood because it has a good draft.

I miss that little stove!