Wood stove questions

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Travlin's picture
Travlin
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Joined: Apr 15 2010
Posts: 1322
Wood stove questions

 For emergency heating, and cooking, I am looking at a small wood stove.  I like the Four Dog model or the Five Dog model shown here.  http://www.fourdog.com/index.htm and here http://www.fourdog.com/index_files/steelstoves.htm  Here is a video. 

  After testing for function, it can easily be disassembled and stored, then set up quickly when needed.  Both models have an airtight door gasket and a baffle below the vent outlet, so they are efficient and controllable.  Here is a good review with details.  http://www.walltentshop.com/FourDogStoves.html

I have an old house with a chimney starting in the basement, where I would set up the stove.  The chimney has a metal liner and was used until last year to vent a natural gas furnace.  I will have the chimney inspected before getting the stove.  The city limits me to 2/3 of a cord (two “face cords”) of fire wood in my yard.  Coal seems hard to come by, but I can easily buy charcoal briquettes, or wood pellets, and store them in barrels or sacks in my garage or basement.  I considered kerosene heaters, but I don’t want to be dependent on petroleum.  This stove can burn scrap lumber if necessary.

Here are my questions for more knowledgeable members:

1   My basement is 765 square feet.  Do you think either stove would keep just the basement at least 60 degrees F when it is 0 outside?  No BTU heat ratings are offered, but here are the fire box sizes.  Four Dog: 2.55 cubic feet.  Five Dog: 3.5 cubic feet.

2   How long would 2/3 of a cord of good hardwood firewood last when used in my basement stove 24/7 at 0 degrees F?

3   How long would 20 pounds of charcoal briquettes last when used in my basement stove 24/7 at 0 degrees F?

4          How long would 20 pounds of wood pellets last when used in my basement stove 24/7 at 0 degrees F?

5          If you can’t say how long, what would be a proportional comparison of these three fuels?

6   The Wall Tent Shop says the stove will burn coal or charcoal, but suggests adding a grate to keep it off the metal bottom.  Do you think charcoal briquettes would work okay?  They can get hot enough to melt steel, so thin fire bricks to line the bottom might be needed as well as a grate.  http://en.wikipedia.org/wiki/Charcoal

7   I know wood pellet stoves use a different burning chamber design.  In a pinch could pellets be used in a standard wood stove with a bottom grate with a bowel shaped metal mesh to hold them?

Research note – “charcoal briquettes” are typically made of sawdust, chaff, brown coal, and binders.  http://www.madehow.com/Volume-4/Charcoal-Briquette.html

Anything else I need to consider?  I’d appreciate help with whatever you know about this subject.

Travlin

logBurner's picture
logBurner
Status: Bronze Member (Offline)
Joined: Sep 26 2008
Posts: 58
Some quick off the cuff answers . . .

Here in UK people don't bother selling by cords any more but rather by the ton, even though that usually means 1 cubic metre building bags. UK is bad for buying wood.

My tips / answers:

See http://thelograck.com/firewood_rating_chart.html and you will see that all wood differs. More useful info on that site. Main difference is properly seasoned wood v unseasined wood. I reckon you can burn 3 times as much unseasoned wood compared to seasoned stuff. Unseasoned wood means, frustration and forever tending to the fire. See the poem at the bottom of http://www.kentdownmushrooms.co.uk/Logs.html a good way to rememberr and it really is true. I can't remember if it is elm or

Our multifuel burner is approx 20 inches cubed and that is rated as 10 KW and I think you can go beyond that. Our living room is 5m x 8m (15 x 24 = 360 square feet), in a 24 inch thick stone wall cottage but the building is old and so a fair amount of heat loss. If there is no strong wind (less heat loss) then it has been -15 C outside and we can wear shorts inside. We open doors to scatter heat around the building but it doesn't travel around corners very well. Careful if you decide to dry indoors - a fair amount of water in a sack of logs and depends on building can lead to huge condensation.

Some stores here sell 12.5Kg bags of wood for £5 ($7??) and can burn 3 of those over a 16 hour period. The nets are like the ones seen half way down at: http://www.woodlogsscotland.co.uk/buy-logs-delivery.html. I reckon we need at least 5 cubic metres of good (Ash, Oak, beech, sycamore, . .) seasoned wood for a full 'winter' in UK (September to March) with different number of hours burning.

When I first got log burner I mixed in some coal anthracite I think) ferocious heat and seem to complement each other - it buckled the grate at the bottom of the wood burner. I was told if it ends in cite then don't use it they use that in foundries. I don't like coal - dirty. With Wood ash I can use in the garden (watch out for acidity levels!!).

Our burner is surrounded by thick stone + brick chimney and that acts as a heat sink \ store and stays warm over night. I don't burn junk wood or anything else, I just use wood.

HTH

Damnthematrix's picture
Damnthematrix
Status: Diamond Member (Offline)
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Posts: 3998
you call that a stove?

Sorry.......  couldn't help myself!  I never realised you could get wood stoves that small.  What is the point of a stove with no oven though..?  Just asking.

I'm going through my own AGA saga right now (might rhyme more with UK followers..)

I bought this old AGA stove, almost twenty years ago...

I knew nothing about AGAs, just thought they were like any other wood stove.  After moving it three times (and it was moved, as in one piece I mean, at least once before I moved it) to then find out you're supposed to pull them apart first, and rebuild them on site.

As it turns out, I was extremely lucky that almost no damage was done in any of the moves.... apparently, you can even break their backs!  Except that a part known as the manifold was broken, and another called the auxilliary air duct was totally rotted out, such that I could not fit the brand new custom made stainless steel flue we just paid $500 for!  GROAN.........

This thing is as old as me, and never been pulled apart before I'm sure....  all the bolts are rusted together, and after three weeks of trying to soak the bolts that hold the top down in penetrating oil unsuccessfully, I decided to drill them out.  Having learned my lesson with the top bolts, I just angle grindered the rusty bolts that joined the broken manifold to the top oven, and now I'm faced with having to empty the stove of its diatomaceous earth insulation of which there will be several cubic feet I'm sure, just to replace a four or five feet of two inch pipe....

I have my fingers seriously crossed now that I can get the manifold welded up..... because I sure as hell don't want to waste that beautiful flue!

A dismantled AGA looks like this...

Aga rebuild Aga rebuild
Aga rebuild Aga rebuild
Aga rebuild Aga rebuild
Aga rebuild Aga rebuild
Aga rebuild Aga rebuild
Aga rebuild Aga rebuild
Aga rebuild Aga rebuild

 

 

logBurner's picture
logBurner
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Joined: Sep 26 2008
Posts: 58
Amazing!

Wow, wow, wow! That is impressive - fair play to you :) Good luck with that lot.

dshields's picture
dshields
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Posts: 599
I have one

I have a wood burning stove.  The link leads to it below -

http://www.englanderstoves.com/30-nc.html

I live in far NW NJ.  It gets cold here.  The NC-30 will keep my house warm at 0 degrees F with say a 20 mph winf if I run the internal fan system and tend it basically constantly.  We burn 4 cords of wood a winter - a cord being defined as a file of split and stacked wood 4' X 4' X 8'.  We collect wood in the summer and fall and usually go into the winter with 2 cords chopped and stacked.  We have a gas powered hydraulic splitter.  We have chain saws and a truck to collect and haul wood in.  We end up buying 2 cords each winter from a saw mill about half a mile from where we live.  Having the saw mill there is very cool.  The will only does hard woods, no pine or other soft woods, as they produce high end furniture products.  We only burn seasoned hard woods - mainly oak and maple with a sprinkling of cherry and walnut.  Some times it amazes me as we burn wood that other people would make expensive stuff out of.  last year 200 dollars cash would purchase a delivered small dump truck full of non-split wood.  Once split it would be between a cord and a cord and a half and ready to burn.  You can also pay 20 dollars at the mill and fill up a pickup full of scraps.  There is a huge pile of scraps all the time but you load them, haul them, and cut them.  It is a lot of work.  Our house is 3000 sq ft.  My advice is -

1) Buy the biggest wood burning stove you can get.

2) Get a boat load of wood.  Look for saw mills in your area.  Go talk to them.  See if you can get scraps.

3) Buy some fans.  You will need them to move the air around your house.  They do not have to be big and noisy.

4) Do not put the stove in the basement.   The basement is not going to freeze as it is under ground.  Put it on the first floor.

5) Get a splitter.  It will be very difficult indeed to split enough wood for a winter with an axe.  If you do you will be in the best physical shape of your life.

6) Do not get an insert.  Just do not do it.  Get a sand alone stove.

7) Do not get a pellet stove no matter what they tell you - big mistake - they would love to sell you a pellet stove.

8) Coal - i have burnt some coal.  I have never had a strictly coal burning system so I am not in a position to help you there.  However, every winter a buy a few (say 5) 50 pound bags of Pennsylvania anthracite coal from a an energy company near me that sells, coal, wood, oil, and gas.  It is difficult to get coal started but it burns hot and it burns for a while.  I buy lumpy coal.  I throw it in the stove on top of a bunch of wood coals, say 5 pieces the size of half a pear on cold nights.  It smells.  Get ready for the smell.  Coal smells.

If you have any questions on this stuff send me a private mail and we can discuss.  I am very happy with heating with wood.  Even if the power goes out and you have a big stove (remember no inserts) you can keep your house from freezing.  Especially if you have a generator and some fans. 

 

logBurner's picture
logBurner
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Posts: 58
Some questions and responses . . .

1) Buy the biggest wood burning stove you can get.

Yep :)

2) Get a boat load of wood.  Look for saw mills in your area.  Go talk to them.  See if you can get scraps.

Make it a ship load if you can. Wood will last up to 5 years. Fuel is expensive.

3) Buy some fans.  You will need them to move the air around your house.  They do not have to be big and noisy.

This is major advice. I used a fan (a little noisy unfortunately) and that stops 40 degree C in living room and 8 degree in furthest room. You can always turn off when people assemble in living room. Cold spots are the biggest nuisance with a log burner. Hence do not dry wood next to log burner, seems smart but condensation can become a problem.

4) Do not put the stove in the basement.   The basement is not going to freeze as it is under ground.  Put it on the first floor.

Mmmmm not sure, heat rises?? My Daughter lives in a top floor flat and also a new build but heat from lower flats helps considerably YMMV

5) Get a splitter.  It will be very difficult indeed to split enough wood for a winter with an axe.  If you do you will be in the best physical shape of your life.

In uk called a maul as well. DS is right you ain't going to do it with an axe. I love splitting wood, therapuetic.

6) Do not get an insert.  Just do not do it.  Get a sand alone stove.

DS do you mean the iron bafflers at the side of the burner? Our Burner has those. The only reason I have left on is that they hold the top baffler and I was wondering if that can catch any smoke heading up the flue and make day to day cleaning easier.

7) Do not get a pellet stove no matter what they tell you - big mistake - they would love to sell you a pellet stove.

Agreed. Wood grows. Pellets are made. Some energy needs to make those.

8) Coal - i have burnt some coal.  I have never had a strictly coal burning system so I am not in a position to help you there.  However, every winter a buy a few (say 5) 50 pound bags of Pennsylvania anthracite coal from a an energy company near me that sells, coal, wood, oil, and gas.  It is difficult to get coal started but it burns hot and it burns for a while.  I buy lumpy coal.  I throw it in the stove on top of a bunch of wood coals, say 5 pieces the size of half a pear on cold nights.  It smells.  Get ready for the smell.  Coal smells.

LOL - compare smell of coal with say Apple wood! Burning apple, or cherry you just feel like opening the wood burner to let the smoke into your home, really it is that nice. If wood is seasoned to the point where you can get the fire going with a few pieces of paper and three or four pieces of kindling you are doing things right. You also know when you can reduce air flow and watch flames creep up at an incredibly slow rate. Look at the smoke coming out of the chimney, seasoned wood and you see virtually nothing. Unseasoned and you can expect a huge amount of soot building up. If you use very sappy wood like pine then watch out for tar building up.

Also, don't use drift wood from salt water the chemicals NaCl can cause problems with mortar in the chimney apparently (even if lined I think affects steel). If you can combine burner with central heating system via a backboiler then go for it. I don't know the maintenance costs on those things but huge amount of energy from wood burners and certainly a large amount is wasted: -10 outside and walking around the house in shorts. We had snow on the roof for weeks so our place is not too bad for heat leakage but around the chimney we had some melt, 16 hours a day of must be several hundred degrees going up the chimney no wonder!

Has anybody used chimineas for use in the allotment to keep frost off??

dshields's picture
dshields
Status: Platinum Member (Offline)
Joined: Oct 24 2009
Posts: 599
logBurner wrote: 1) Buy the
logBurner wrote:

1) Buy the biggest wood burning stove you can get.

Yep :)

2) Get a boat load of wood.  Look for saw mills in your area.  Go talk to them.  See if you can get scraps.

Make it a ship load if you can. Wood will last up to 5 years. Fuel is expensive.

3) Buy some fans.  You will need them to move the air around your house.  They do not have to be big and noisy.

This is major advice. I used a fan (a little noisy unfortunately) and that stops 40 degree C in living room and 8 degree in furthest room. You can always turn off when people assemble in living room. Cold spots are the biggest nuisance with a log burner. Hence do not dry wood next to log burner, seems smart but condensation can become a problem.

4) Do not put the stove in the basement.   The basement is not going to freeze as it is under ground.  Put it on the first floor.

Mmmmm not sure, heat rises?? My Daughter lives in a top floor flat and also a new build but heat from lower flats helps considerably YMMV

5) Get a splitter.  It will be very difficult indeed to split enough wood for a winter with an axe.  If you do you will be in the best physical shape of your life.

In uk called a maul as well. DS is right you ain't going to do it with an axe. I love splitting wood, therapuetic.

6) Do not get an insert.  Just do not do it.  Get a sand alone stove.

DS do you mean the iron bafflers at the side of the burner? Our Burner has those. The only reason I have left on is that they hold the top baffler and I was wondering if that can catch any smoke heading up the flue and make day to day cleaning easier.

7) Do not get a pellet stove no matter what they tell you - big mistake - they would love to sell you a pellet stove.

Agreed. Wood grows. Pellets are made. Some energy needs to make those.

8) Coal - i have burnt some coal.  I have never had a strictly coal burning system so I am not in a position to help you there.  However, every winter a buy a few (say 5) 50 pound bags of Pennsylvania anthracite coal from a an energy company near me that sells, coal, wood, oil, and gas.  It is difficult to get coal started but it burns hot and it burns for a while.  I buy lumpy coal.  I throw it in the stove on top of a bunch of wood coals, say 5 pieces the size of half a pear on cold nights.  It smells.  Get ready for the smell.  Coal smells.

LOL - compare smell of coal with say Apple wood! Burning apple, or cherry you just feel like opening the wood burner to let the smoke into your home, really it is that nice. If wood is seasoned to the point where you can get the fire going with a few pieces of paper and three or four pieces of kindling you are doing things right. You also know when you can reduce air flow and watch flames creep up at an incredibly slow rate. Look at the smoke coming out of the chimney, seasoned wood and you see virtually nothing. Unseasoned and you can expect a huge amount of soot building up. If you use very sappy wood like pine then watch out for tar building up.

Also, don't use drift wood from salt water the chemicals NaCl can cause problems with mortar in the chimney apparently (even if lined I think affects steel). If you can combine burner with central heating system via a backboiler then go for it. I don't know the maintenance costs on those things but huge amount of energy from wood burners and certainly a large amount is wasted: -10 outside and walking around the house in shorts. We had snow on the roof for weeks so our place is not too bad for heat leakage but around the chimney we had some melt, 16 hours a day of must be several hundred degrees going up the chimney no wonder!

Has anybody used chimineas for use in the allotment to keep frost off??

Yes sir - by insert I mean a wood burning stove you insert into a fireplace so only the front of the stove is effectively attached to the room.  These waste a huge amount of heat.  The heat just goes up the chimney.  Also, all the ones I have seen depend on electric fans built into them to push heat into the room.  If the power goes off you are done if you do not have a generator.  A stand alone stove is much better.

Pellet Stoves - same problem - they need electricity to work.  No electric and you are done.  You also correctly bring up the issue of the pellets themselves.  If there are no pellets to be had you are also done.

 

Dutch John's picture
Dutch John
Status: Bronze Member (Offline)
Joined: Oct 10 2008
Posts: 50
Stove size
dshields wrote:

 My advice is -

1) Buy the biggest wood burning stove you can get.

If you mean a mass heater, I fully agree. But not in case of a lightweight cast iron stove. Each stove has a small range where it burns both clean and efficient. A mass heater (masonry) runs a hot clean fire, while the mass accumulates the heat, releasing this slowly over time. Operating a too big cast iron stove means either heating cleanly, but with the windows opened or having a dirty too small fire. Or waste efficiency by excess combustion air, stealing the heat an releasing it by the chimney.

Always buy a stove on which you also can cook. Always season your wood. Start growing your own wood if you do not live near a forest. Last year we passed the tipping point of being payed to cut someones tree down and have the wood, to now pay for it. We live in a country in which 99% of the homes has access to natural gas, but people are hoarding wood...

Regards, DJ

joemanc's picture
joemanc
Status: Martenson Brigade Member (Offline)
Joined: Aug 16 2008
Posts: 834
Wood Stove Inserts

There's another longer thread on burning wood...

http://www.peakprosperity.com/forum/heating-wood/40655?page=0#comments

As for the Wood Stove Inserts, I don't agree with your statement about wasting heat. Now that my house is fully insulated, my wood stove insert is able to fully heat my 1400 sq. ft home easily. I also got the Ecofan to push air if the power goes out. I'm happy with my insert. But I would like to get another free standing wood and cooking stove at some point. It's on the list.

Denny Johnson's picture
Denny Johnson
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Joined: Aug 13 2008
Posts: 348
Travlin.........you may find

Travlin.........you may find this forum helpful

http://www.hearth.com/econtent/index.php/forums/viewforum/2/

Travlin's picture
Travlin
Status: Diamond Member (Offline)
Joined: Apr 15 2010
Posts: 1322
Thanks

Everyone – Thanks for your replies.  You are all obviously experienced and offered good information.  Here are some specific thoughts.

Damnthematrix – “You call that a stove?”  Well yeah.  I was looking for a compact source for emergency heat, not something big enough to live in! Wink Your AGA stove is an impressive unit for primary use.  Judging by your photos, I’m not sure your firebox is any larger than the 3.5 cubic feet of the Five Dog model I am looking at, though the AGA unit would be more useful and efficient for everyday use.  I don’t feel the need for an oven for an emergency stove, however, they are offered as an option by the Four Dog company, and water heaters too.  http://www.fourdog.com/index_files/bushgear.htm  Thanks for the photos and interesting story.  I hope your repairs go well.

Dshields – The Five Dog model I cited has the same size fire box as yours, 3.5 cubic feet.  However, your stove has an advanced design to pre-heat incoming air, circulate it for optimum combustion, and insulate the firebox, so it would be more efficient.  I am looking for an emergency heat source, so I decided to set it in the basement, because it will minimize heat loss compared to being above ground, and the flue is easily accessible.  To place it on the first floor requires removing furniture and going through a wall to get to the flue.  For longer term use that would be an option, and a larger more expensive stove like yours would make sense.  Judging by the size of your house, climate, and wood consumption, I guess 2/3 of a cord of good hardwood might carry us one month in the depths of winter, especially with some charcoal in reserve.  But that is just a guess and I’m not confident about it.  My city limits me to 2/3 of a cord of stored firewood at one time.

Dutch John – You made a good point about matching the size of the stove to the space to heat.  That is easy to overlook.

Anyone – I will pursue the links provided, but would still appreciate your thoughts about my questions 2 and 3.  Let’s use a different approach.  How much dry hard firewood, or charcoal, would it take to heat my 765 square foot basement for one month to 60 degrees F 24/7 when it is 0 degrees F outside?  You don’t have to be an engineer.  Informed guesses are welcome.

Travlin

Dutch John's picture
Dutch John
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Joined: Oct 10 2008
Posts: 50
Heat loss calculator

Travlin,

Your last question cannot be answered, because one needs to know the R-values of walls, floor and ceiling to calculate the heat losses. You also need to know the efficiency of the used stove, which can be as bad as 40% or as good as 90%. The moist content of the wood if of importance. Too many unknown numbers. 

Regards, DJ

Damnthematrix's picture
Damnthematrix
Status: Diamond Member (Offline)
Joined: Aug 10 2008
Posts: 3998
the AGA saga
Travlin wrote:

Damnthematrix – “You call that a stove?”  Well yeah.  I was looking for a compact source for emergency heat, not something big enough to live in! Wink Your AGA stove is an impressive unit for primary use.  Judging by your photos, I’m not sure your firebox is any larger than the 3.5 cubic feet of the Five Dog model I am looking at, though the AGA unit would be more useful and efficient for everyday use.  I don’t feel the need for an oven for an emergency stove

LOL!  I did receive some good news this morning (our time)... Following some emails, a really nice guy from the UK rang me, and we spoke for 25 minutes (ain't technolgy grand...?) AND... he has all the parts I need to fix my cooker!

AGAs don't actually warm rooms up much.  They are full of insulation to keep the heat IN, thus reducing the amount of fuel used.  Our house is heated by the sun in winter, and only needs tiny amounts of "topping up" to allow us to run around in T shirts in winter!  But by all accounts they are the ultimate thing to cook on, or rather "in" as it is the ovens that excel here for slow cooking.  Can't wait to make my bread in it soon.

Travlin's picture
Travlin
Status: Diamond Member (Offline)
Joined: Apr 15 2010
Posts: 1322
A guess is good
Dutch John wrote:

Your last question cannot be answered, because one needs to know the R-values of walls, floor and ceiling to calculate the heat losses. You also need to know the efficiency of the used stove, which can be as bad as 40% or as good as 90%. The moist content of the wood if of importance. Too many unknown numbers. 

Dutch John

I understand what you are saying.  I’m just looking for a guess.  It tells me a lot if someone heats a 1,500 square feet frame house with a high efficiency stove, and uses 1/3 of a cord of dry hard wood per month.  My basement is about half that size.  It has a concrete floor, and stone walls, so it will leak much less heat.  If my stove is only half as efficient I would guess that 2/3 of a cord would last me at least one very cold month.  I’m just trying to get some reference points like Dshields provided to base a guess on.

Travlin

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