How much firewood do I need?

[svirden]

Greetings, I'm new here and hope for some experienced responses to my question!

I just moved into a little 450sf cabin in Homer, Alaska. Appears to be relatively well insulated with spray foam between the studs, though I don't know about the ceiling or floor (cabin is raised off the ground). There is electricity to the cabin, and a modern medium-sized woodstove.

Because of the last couple of weeks of great weather and bright sun coming in the windows, the cabin has been plenty warm until nearly midnight without lighting a fire.

But now that is changing and we need to buy firewood. The only wood left in the region is spruce. Based on your own experiences and the facts I've provided, how many cords do you recommend for a winter of heat? We'll work mostly from home and so will want heat 24 hours a day. We're told that locals start thinking it's cold around minus 10F, which is not uncommon.

On a side note, do you have any tips to keep the fire going throughout the night? We can collect coal from the beach here, and I'd think one fist-sized chunk might keep heat in the box until morning. But I'm not sure it's okay to burn coal in the woodstove. Your thoughts?

Thanks so much!

[MadTripper]

I'm not sure on the coal question. You would need to look at the manufacturer info to find out. I plan on burning a little coal in our stove this year but wouldn't tell anyone to do the same unless it was designed for it.

As far as wood goes, Spruce is pretty shotty for burning but I understand that is the only choice for some. I plan on burning about 6 this year but I have some good insulation and I'm in Pennsylvania. A rough guestimate for your situation would be double to triple that which would be around 12 to 18. I'm not familiar with anyone living in your area on the boards but maybe someone will chime in. If it were me, I'd probably try and get at least 20 cord of spruce this year and hopefully, you overestimate. (I could be way off but overkill is insurance you probably would rather have than running out in early March)

As far as keeping the fire going, I posted somewhere here as to my method although this was with a Kodiak double door. About 20 minutes before I was either going to bed or leaving for a duration, I'd pile on some kindling and wood, as much as I could fit. Open the draft all the way and let it get roaring. Fill any voids that may have burned down after the 20 minutes, and close your vents to the proper setting which in my case, all the way and then cracked 1/2 to a full turn depending on outside temp. I could get about 14 hours pretty steadily using that method. Keep in mind, we are blessed with lots of good hardwood in my area so there will be several variables for you to deal with. You might just be better off getting in the habit of tending to the fire every night/early morning.

Tripper

[svirden]

TWENTY cords of wood to heat a small cabin for 6-7 months?!!

Really?!

I just talked to a guy who said he burned four last winter to heat his single-wide trailer. Hard to know how to compare that to a cabin, tho.

Would love feedback from lots of people on this, please!

[ozarksnick]

I think 20 cords would be enough to heat your home for at least two years, even in Alaska.

I used 2-3 in southeast Kansas last winter and my home is not well insulated and pretty drafty.

[AlchemyAcres]

As a general rule-of-thumb I use 1/3 of a cord of hardwoods to heat 500 sq ft for two weeks (northern PA on the top of a very windy hill).....4 to 4 1/2 cords total, depending on the year.

Spruce has little better than half the potential BTUs of the better eastern hardwoods.

To extend your nightly burn time, use large pieces of firewood in a stove that allows you to stand them up on end against the sides of the stove so the logs burn mostly on the end rather than the sides, that will increase the burn time considerably.

~Martin

[WileyCoyote]

I don't know how much help I'll be. We just moved from a 1000 sq foot FHA all electric home, toa 100 yr old, 1750 sq foot ( including the cement block basement and wood beam/plaster first floor and upstairs) wood and propane heated house.We have a very small stove, tucked into a corner of the westernmost room. The house is heavily built and well structured for the climate, and we have spent the summer putting in thicker doors, insulation, window glazing and caulk to seal every cranny and opening. Some of the windows are fairly new and double insulated; most are the old fashioned beveled glass; all have storm windows. Every room including the stairwell has ceiling fans. I tell you all of this because air flow is important in heat transference; particularly cold air from unsuspected openings, especially in the floor and north walls. If you have large windows that help heat the house, they can also cause heat to escape if they are not sealed around the glass, the frames, or do not have storm windows.

We had a bad storm day here awhile back; the north wind was whistling around the house, and the temps dropped down to 30, but with a steady 40 mph wind pushing the rain like needles it felt a lot colder. We decided to check out the stove to see how it worked (we had to replace the stovepipe and sealed some leaks around the chimney). We started a fire at 3 PM with three big handfuls of small tinder, and put on three pieces of 2 in diameter kindling; like MadTripper, we opened the vents and the flue and got it roaring, then put on a single 'big log' 22 inches long (as long as the stove takes), waited for it to catch with a good fire, then closed all the vents and the flue. Within a half hour the first floor temp (in the kitchen, on the same floor) had risen from 65 inside to 70. As the cast iron got too hot to touch (it didn't get that cherry glow to it because it was underfed), the temp went up to 75. Without adding another log, the temp was at 71 at 5 o'clock the next morning still. The stove was cold and had nothing but ash, all the wood had burned.

We had a fan on low blowing from the 'stove room' into the rest of the house, and had the ceiling fans reversed to 'winter' on low. This setting pushes the warm air down from the ceilings toward the cool air closer to the floor. All rooms stayed at about the same temperature all night. The basement stays at a comfortable 67 degrees; it is well-sealed and the egress has a new door and insulation around it because it faces north. It also has a second door at the foot of the basement stairs that is also insulated, so that the 'dead air' is trapped between the two doors.

As you can see there are all kinds of variables; it would be really hard to say, yes this size stove and this much wood will work. I know it is going to get a lot colder here, and we'll get a lot of snow, tho it won't be Alaska temps or snow by any means, and I will need more wood when we have to deal with that. It also depends on what you call 'comfortable' - 60 degrees? 70? with a sweater? socks? slippers or shoes? Quilt coverup? If you like to walk around nekkid you'll need more wood! ;) Or even if you want to step out of the shower and not see your breath...70 was 'way too warm to sleep in, but it was an experiment. :)

But - I lived thru the winter in the NM desert in an uninsulated house with a woodstove and no electricity, and it was chilly in that house all winter, no amount of wood would get it warm no matter how red the stove got. The wind whistled thru the walls constantly there. I know where the term 'pneumonia hole' comes for, for windows, after that!

I think I might check under that house and see what you can do to keep the wind from sweeping under it or even blowing snow under it, and check all my windows and doors and make sure they were tight and sealed and insulated; with storm windows or even plastic sheeting over them if necessary. (We'd put the plastic INside, not out; it lasted longer out of the weather.) The more tightly you seal that house, the less impact airflow has on your heat dissapation, the less wood you will need.

And I am uncomfortable with coal simply because of the residue it leaves behind in the pipes and chimneys; I am all about clean-burning because I am basically lazy and HATE to clean a chimney. ;D I'd burn it if it was all I had, but I'd think of another way to heat if I could. That and nothing beats the smell of a good wood fire, or the taste of it in your food. ;) City people pay big money for that - coal-flavored, not so much. We have about two cords, and access to much more on the back of the property in the dump area, so we are not hurting this year. We are going to try to avoid using the nice propane heater; but it is there for a fallback if we need it. The previous owners installed it for when they went away for a week or more at a time, so that they could set the thermostat to keep the pipes from freezing, but for two years prior to moving out, the owner used only the woodstove. It's good to always have a fallback - be it coal, or propane, or even an electric or kero heater if you must. They all have potential failures - lack of wood, lack of coal, high cost, or even if the electricity goes out! We have electricity too but I still bought a gallon of kero last week on sale for the lamps, just in case.

[MadTripper]

Like I said, I'm definately guessing but we are talking about Alaska which has about 2 months longer winter than I have and dealing with wood that has half the btu's. *I'm trying to err on the side of caution. *If this is the first winter the original poster is spending in this type of environment, the last thing they would want is to run out before the cold weather does. *Besides, whatever is left can be stored for next year and by then, they will have a good idea of an exact amount. *I'll do some more research and see what I can dig up.

Tripper

Although this doesn't give a sure number, idealy, you want half of your wood stash left in mid-February. You might find some better answers specific to your area by searching www.hearth.com.

Chris

[sawyerob]

Homer is one of the milder climates in that area, depending how far up the hill and back in you live. There's lots of dead spruce up on the hill side that folks are glad to get rid of. There's also birch in the area too.

Then there's coal on the beach, and between Homer and Clam Gulch there's always coal on the beach. Thing is, you have to wash that coal VERY good or it stinks when you burn it. Take a sledge hammer to break up big pieces so you can handle them.

But, it's better to go to the dump in Homer and get coal there. There's an excelent vein of coal there that is of excelent quality.

Homer gets some really nice sunny winter weather, no reason wood can't be cut then too...

SR

[MadTripper]

Well if there is birch available, I'd stock as much as I could. I like burning birch, mostly black but occasionally a white as well. It takes a while to season however the heat is great. White birch has bout 27% more heat output than spruce and black birch has about 67% more.

Tripper

[RenieB]

We have used between 4-5 cords of wood a winter but I think with the stove we have we will use less. I have kept the fire going all night by filling it with larger peices of wood just before going to bed and have been able to just add some kindling in the morning and it would start burning then add the larger stuff. I wouldn't use coal unless the stove is made for it as burns a lot hotter.

RenieB

[JAK]

A big part of it is being willing to let the cabin temperature drop at night, even to below freezing, as long as the cabin is built for it with respect to location of any water pipes and so forth. Then its just a matter of how often you are inside and how warm and busy you want to be. The very coldest days/nights you might have to stay in and keep the stove going, but most days even in winter you might be out and about. It sounds like you have a small enough space to heat up quickly, but you will soon get used to not getting undressed until a good hour or two after you get the stove fired up, and then spending the late evening walking around naked until you are ready to turn in. Have fun.

Good spruce is OK to burn as long as you do it efficiently, be extra sure that it is good and dry, and keep an eye on your flue. It actually has more BTU/pound, though less per cord. A little coal mixed in might be a good thing, but I would never use just coal. It is tempting to try and build a fire in such a way to burn all night but I think in practice it is better to try and burn it efficiently and let your place warm up and cool down, and adjust your clothing and lifestyle accordingly. If you incorporate a hot water tank that can help retain some heat also. Storing some wood inside is also a good way to capture and retain some heat and give the wood a final drying out before you burn it.

Lets estimate that over the heating season you might have 50 days of 20 pounds, 50 days of 40 pounds, and 50 days of 60 pounds, and 50 days of 80 pounds, for a total of 4-5 cord. That doesn't seem like much to some folks that like to heat bigger homes and keep them warm 24/7, but it would be more than enough to keep me busy. Depends alot on how well you are insulated and how tight it is, and how cold tollerant you are, and how often you are home.

[MadTripper]

It actually has more BTU/pound, though less per cord.

Just to clarify, all wood has the same btu per lb of dry weight which, in a perfect environment of 0% moisture and only oxygen in the atmosphere, 1lb of wood produces about 8600 btu's. This is why wood is typically measured in cords which is a measurement of volume and not weight. Wood is considered seasoned for heating purposes when it has around 20% moisture content. Less moisture is better because the wood doesn't have to use energy to cook off the remaining water which also adds creosote to your chimney.

Tripper

[AlchemyAcres]

The type and model/brand of stove makes a HUGE difference too.
If you're lucky to find a Fisher SINGLE door wood stove....the baby bear, moma bear or the popa bear....you're lucky...some of the best stoves ever made. The logs are perpendicular to the the door...they burn better and they hold a fire better.
The double-door stoves are best left for scrap...the logs are parallel to the opening and they just don't work as well....they never ever naturally draft as well...they use more wood and they SUCK, big time!!!! LOL Most, if not all, double door stoves are the same!!!!
Look for a Fisher mama or papa, if you have a tiny cabin look for the baby bear.


~Martin :)

[JAK]

Just to clarify, all wood has the same btu per lb of dry weight which, in a perfect environment of 0% moisture and only oxygen in the atmosphere, 1lb of wood produces about 8600 btu's. *This is why wood is typically measured in cords which is a measurement of volume and not weight. *Wood is considered seasoned for heating purposes when it has around 20% moisture content. *Less moisture is better because the wood doesn't have to use energy to cook off the remaining water which also adds creosote to your chimney.

Tripper
More resinous woods, like most softwoods, have more BTU per pound. This is because the resins have more BTU per pound than the cellulose and lignin.

[JAK]

http://www.consumerenergycenter.org/home/heating_cooling/firewood.html

8000 to 8500 Btu per pound for non resinous woods.
8600 to 9700 Btu per pound for resinous woods.

[MadTripper]

http://www.consumerenergycenter.org/home/heating_cooling/firewood.html

8000 to 8500 Btu per pound for non resinous woods.
8600 to 9700 Btu per pound for resinous woods.

Interesting. *I guess the benefit still comes down to how many lbs of spruce vs. how many lbs of birch you can fit into the firebox and how well it is seasoned. *Is the original poster still following this thread? *If so, have you asked any locals about firewood usage?

BTW, this is the link that talks about all wood having the same btu content.

http://www.gi.alaska.edu/ScienceForum/ASF12/1249.html
*

Tripper

[flatwater]

To many veribles for an accurate amount. Depends on insulation , your habits, cooking on a wood stove , how long is the winter, how good is your stove etc: etc: 4 to five should get you through. Give it a try then you will know for sure.
Flatwater