How many acres of wood lot are needed to heat a house?

[unregistered168043]

I had this discussion with a person who says all you would need is an acre of wood land to heat a house, sustainably ( meaning you never run out ). I think you would burn through an acre in a few years and it wouldn't grow back fast enough to be sustainable.

I've heard estimates of 8 acres, and that seems more likely to me. What do you think?

[AuntKitty]

I've always heard 10 acres for a copiccing woodlot but I think it would depend on how cold the winters are where you live.

[SparkyMaine]

Yeah, would depend on how cold your winters are, how big your house is, and how well it's insulated.

We've got 11 acres of partly swampy land in Maine that has plenty of medium sized red maple, red oak, and some beech in the non-swampy areas. New 1100 square foot house that is very well insulated, and I don't expect we'll ever run out. Right now we only burn about a cord and a half a season, since we have a small stove that we only keep going when we're home (evenings, weekends, holidays). But, at the rate we burn, I figure 4 cords would be more than enough to keep us toasty for a long cold winter if we were home all the time, and I'm confident that the 11 acres would supply that no problem.

[Terri]

I have heard of folks up north who used a few cords.

My husbands uncle in Tennessee used 2 trees only.

It really DOES depend on where you live!

[thequeensblessing]

If you need firewood and you have a Davey Tree co. around you, contact them. They usually deliver a load of logs for free. My hubby works for them and he's always delivering free logs somewhere. He brings home logs that we use to supplement our 10 acres of woodland.

[TnAndy]

My understanding was always a cord a year could be cut off an acre, in an area with decent rainfall, and would be sustainable forever.

As to how many acres, that would depend on how many cords you burn thru.....and that would depend on location, house size/construction, efficiency of the stove, and so on.....

[suitcase_sally]

My neighbor has been heating with wood from his 10 acres here in Michigan for at least 25 years. He manages his wood very well. When he has two trunks coming up from one tree, he cuts one of the trunks and leaves the other to grow.

It depends on the type of wood and how big it is. We have an 80 acre woodlot and we can't possibly use all the dead and wind blown downed trees we've got. Last summer (2010) we had some bad storms that took down some HUGE black cherry, ash and popplle trees. Two of the cherry trees was enough for this winter and we are heating two houses.

[homesteadforty]

Originally Posted by TnAndy

My understanding was always a cord a year could be cut off an acre, in an area with decent rainfall, and would be sustainable forever.

As to how many acres, that would depend on how many cords you burn thru.....and that would depend on location, house size/construction, efficiency of the stove, and so on.....

This is my understanding (and experience).

[geo in mi]

You might take a look at this for a method of getting a better yield: http://www.countrysideinfo.co.uk/woo...ge/coppice.htm
Sometimes it works for me with cherry and maple.

geo

[flewism]

I say a sustainable cord an acre is the maximum you can expect here in the Midwest with a well managed woodlot. You eight acre estimate to harvest 4 to 5 cord a year is spot on, never run out and have some extra if required or desired.
Trees services are a great source for wood to process for firewood and I have a couple dropping wood or I pick it up.
My experiences;
1) You need to have an easy in and out for the truck.
2) You have to take the good with the bad, one time oak the next time cottonwood. We burn a lot outside so no issue there.
3) If it is bucked up, It doesn't come all bucked up in perfect 16-18" lengths. Their job is to get it down and on the truck as safely and quickly as possible.
I prefer they give me log length and I buck it to length.
4) Stoke the crew every once in a while with $50 for lunch money is appreciated.
5) If you have the ability to go get it on site, AKA truck and/or trailer, at times the phone will be ringing off the hook.

[SolarGary]

A similar question question came up before (just below in quotes), and I took a cut at estimating the BTU output from rapid growth trees. For a well insulated and tight 2000sf house, it came out to about an acre (details below). I'm wondering if any of the people who actually burn wood think this is possible?


"if one can grow as much wood as one uses in a year, then the heat is carbon neutral. Insulation and stove efficiency can help make this happen. By using solar to supplement the wood heat, or wood to supplement solar heat. These new passive solar haus would be easy to heat with less than acre of wood lot, one 8 inch tree a year would do it. If you grew fast growing hybrid popular it would be interesting to see how much land would be needed compared to btus."

Well said.

And, an interesting question—Just as a rough guess on the question:

The ref listed below says 5 tons of poplar per acre in the Ukraine (I’m sure we can do better


Taking a 2000 sqft house in a 6000 heating degree day climate (cold), and with R60 ceilings and floors, R30 walls, R4 windows, and 0.3 ACH infiltration, the yearly heat demand is about 39 million BTU, and of this about 17 million is met by internal heat gains (lights, bodies, dogs, ...) leaving 22 million BTU to be met with heating fuel. It could be less than this if some passive solar was used in the house design, but say no solar. Not sure that this home would meet Passive House Institute standards, but its a good efficient home.
http://www.builditsolar.com/Referenc...s/HeatLoss.htm

Could not find a value for heating value of poplar, but aspen is listed as 27 lbs/cf, 2290 lbs per cord, 14.7 million BTU/cord.
So, with an 80% efficient wood burner, it would take (22/14.7)/0.8 = 1.87 cords, or (1.87)(2290) = 4280 lbs of poplar(aspen) to heat the house.

With the 5 tons of poplar per acre, this would be less than half an acre—as a very rough estimate.

Seems like a good strategy for a pretty close to zero net carbon home.

Gary


From: http://www.hemphasis.net/Paper/paper.../hempvtree.htm
“In Ukraine, poplar wood grown for pulp produces 5.1 tons/acre/yr, and dry stems of hemp produce 3.24-4.05 tons/acre/yr. This is 4-5 times more than indigenous forests in Ukraine, and approaches the increment of the most productive plantations of fast growing poplars. The Ukrainian Institute of Bast Crops expects hemp to yield an average of 5 ton/acre of dry stems. The cost of transporting hemp pulp, dispersed over larger territories than wood, removal of the ash content, and the lower pulp yield compared to wood pulp make non-wood pulp more expensive. However, the Ukrainian Institute compared the labor costs of growing and harvesting hemp and poplars in 1992 and found the costs were comparable. “

Heating value for woods: http://www.builditsolar.com/References/woodhvrs.htm

[lonelyfarmgirl]

Our house is 3000 sq. feet. We have heated floors in the basement, heated floors in the 3 car garage, and a 1200 sq. foot shop with heated floors and a forced air furnace, just like the house. We also heat our water with wood. We are very well insulated here, but I am a freeze baby. We had 7 acres of woods and a couple thin line fences that had the occasional downed tree. Our outdoor wood furnace has a box that is 3X3X5 (I think). We get super cold here and heat the house from Mid October to end of May. We also burn the rest of the year to heat our water. For 3 months, DH fills the stove 3 times a day, and twice a day for 4 months and once a day the rest of the year. Add a huge maple syrup evaporator, wood fired, that we run steady for a week or 10 days, plus we roast 6? pigs a year, which is also done with our wood. We have never even remotely come close to using even half the wood around for firewood. The woods is very healthy, we have never cut down a live tree, only dead fall. I don't really know how much we use, but our wood shed is 28X30, and we fill it darn near to the ceiling, and we use a good majority of it in a year.

[Common Tator]

It depends on the density of your woods too. Our place is in the mountains, on a heavily forested north slope. Hubby is usually too busy to think about firewood, so I started letting a woodcutter cut at our place, as long as we directed when and where he cut, and he left us a third of what he cut. That saves on hubby's sore back, and chainsaw blade, since the wood is aged oak. Our property (42 acres, about 30 acres woods) supports us and has provided truckload after truckload for the woodcutter, and that is just the dead oak tree.

Hubby also drags large branches to the house and cuts them up too. We have far more than we need.

[haypoint]

How many gallons of gas will it take to go from my house to my friend's house?
If you can figure that out, then you'll be able to figure out how many acres to heat your house.

First of all you don't list your location. Some places keep a fire going for 7 months, others 7 weeks.
You don't list how much wood you need to heat your house. If you didn't know that, perhaps the size and amount of insulation and how cold you keep it.

You don't tell where this acre is or what kind of trees grow on it or how mature they are, sizes, etc. Again, climate, soil type and drainage are important factors.

An acre of mature Ash in Kentucky could supply a 500 square foot well insulated house, kept at 58 degrees for many winters.

An acre of poplar in Indiana could supply a 3,000 square foot old farm house for about two winters.

[lonelyfarmgirl]

Ours was maple, hickory, ironwood, ash and elm, some oak. no pine hardly at all, but you dont put that in a stove anyway.

[elkhound]

the forestrys rule of thumb is a health acre of woods produces one cord of firewood a year.

[goatlady]

Of course you do, lfg! for 17 years in the Black HIlls of SD that is the ONLY tree that grows there and pine is all I burned for 17 years there with no problems what so ever. Here in AR. I burn at least 50% to 60% pine for the last 6 years with no problems. Pine burns fast and hot and that very hot burn keeps the pipes clean for me. I get on the roof every year, take the spark arrestor cap off, run the brush up and down a few times and end up with maybe a WM plastic grocery bag with 1 or 2 cups of soot in it. No creosote, no gunk, pipes are slick and clean. But it all depends on what is available for fire wood.

[blufford]

Originally Posted by goatlady

Of course you do, lfg! for 17 years in the Black HIlls of SD that is the ONLY tree that grows there and pine is all I burned for 17 years there with no problems what so ever. Here in AR. I burn at least 50% to 60% pine for the last 6 years with no problems. Pine burns fast and hot and that very hot burn keeps the pipes clean for me. I get on the roof every year, take the spark arrestor cap off, run the brush up and down a few times and end up with maybe a WM plastic grocery bag with 1 or 2 cups of soot in it. No creosote, no gunk, pipes are slick and clean. But it all depends on what is available for fire wood.

I thought pine and other evergreens burned cool and gunked up the chimney.

[cmtigger]

Originally Posted by blufford

I thought pine and other evergreens burned cool and gunked up the chimney.

It's pretty common where I live to burn pine. Most of what grows here is pine, cedar and oaks, so you burn what is around. Basically it burns faster than the oak, but nobody around has had issues with burning it, you just won't have a log burn as long as a harder wood.

[Ravenlost]

Yep...to many variables to give a definitive answer.

We have two acres of mature hardwoods...mostly water oak, sycamore, elm and sweetgum. Our house is over 3000 sq. feet. We only have a fireplace, but try to heat the house with it.

So far we use about a cord and a half a year, but we're in North Mississippi so don't have horrible winters (although we do get in the teens). In the seven years we've been here we haven't had to cut down a tree yet...not a living tree. We've been able to harvest downed trees and dead ones. This year we're burning a large elm that died a couple years ago. If it doesn't get us through the winter there's a huge dead oak to be cut down. There are also several downed trees in the woods just waiting for hubby.

Anyway, that's been our experience.