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Rationing wood

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by chuck172, Dec 1, 2008.

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  1. MaineMike100

    MaineMike100 Member

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    How much oil was used previously for both hot water and heat? Is the goal to virtually eliminate the oil by burning wood in the Tarm? I assume this is the case, so we could come up with a close approximation of the wood needed by adding the 5 cords burned previously in the woodstove to whatever amount of heat was previously produced by oil, converted to cords of wood.

    Your comment about the bedrooms being cool with the woodstove reinforces my previous point. With the Tarm you will be heating the entire house to a higher temp. than you did before... The good news is this means you will be much more comfortable, have better control etc. etc. The bad news is this means more wood, notwithstanding the efficiency differences between the stove and the Tarm.

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  2. NHFarmer

    NHFarmer Feeling the Heat

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    I figure I have used about 1 cord so far.No oil backup.I don't think thats too bad.My buddy has an outside boiler,1 cord per week,about 7 so far!!!!!!!!!.I am glad to have my Tarm
  3. Tree farmer

    Tree farmer New Member

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    I seem to get 10 to 11 hrs out of one full load during the past few weeks heating 2000 sq ft, though it has not been exceptionally cold yet. I have kept the stat at 71-72 just because I can - my wood is not overly dry from the damp summer even though the top was covered. Seems to be doing OK though. I have 7 cords to take me to the end of the cold season and hope there is some left over.
  4. chuck172

    chuck172 Minister of Fire

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    Tree Farmer, 10 to 11 hrs. on a full load is great. You're doing way better than me with my 500 gallons of storage.
  5. Nofossil

    Nofossil Moderator Emeritus

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    One of the differences that's taken me a while to wrap my head around is this:

    A longer burn is not a better burn.

    Back in the day, I used to prize big solid logs because I knew they'd burn all night and I'd be warm in the morning. In fact, a somewhat green log is even better because it will burn even longer.

    My instinctive tendency is still to split wood so that I have larger pieces.

    With gasification and storage, this is the wrong way to think about it. The most important question is this:

    What burn technique produces the most BTUs per pound of wood?

    As far as I've been able to determine, that would be a relatively short hot fire running at full output. Wood that's too large will prolong the fire, but deliver less effective secondary combustion and less total heat. When they tested the EKO in Europe, they used 2" birch chips and got 90% efficiency in a full-throttle burn. An OWB was tested here in the states with 4" oak timbers, idling 85% of the time to get a long burn. It yielded 17% efficiency. A major reason for storage is to allow you to do the efficient shorter burns.

    In your case, you may need more storage to meet your heat load over a long enough time to be useful.

    Once you have the most efficient possible fire, you want to figure out a schedule that takes advantage of your storage to give the best combination of comfort and convenience. There are compromises. On really cold winter days, I'll load the EKO before I go to bed even if the storage is up to temp. I know that will make the EKO idle a bit, but my storage isn't big enough to carry me all the way on a really cold day.
  6. VtRv

    VtRv New Member

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    What have those of you with storage found to be the most efficient way to recharge the tank. A quick fire to get the tank back up to max when it drops to say 150 degrees or wait and try to get the most you can out of the stored BTU's by letting it drop down to around 130 degrees then going for a longer burn to max it out. I haven't had mine up and running long enough to figure this part out. I've been basically letting it go down and then going for a longer burn in the evening to recharge it.
  7. sandman59

    sandman59 Member

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    I am in my first season with a EKO 40 (No Storage, boiler room 110 feet from house.) I have also used about a full cord of wood but our November has been colder than normal. I can usually fill the boiler to the bottom of the loading door opening and get a good nine hours of burner time (seasoned maple and apple.) I am also finding out that larger unsplit logs do not work as well as far as a quality burn cycle.

    If I used to burn 550 gallons of oil, how much wood does should I expect to burn? I now keep the house at 72 degrees compared to 70 with the oil heat. I was hoping to be around the 5 cord area.
  8. WoodNotOil

    WoodNotOil Minister of Fire

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    I think the assumed equation in 1 cord of dry hardwood = 150 gallons of oil. So

    550/150= 3.7 cords

    With the luxury factor (higher house temp, longer showers, etc) 5 cords is probably in the neighborhood, but there are lots of factors at play. Like was the oil heating DHW as well?. . .
  9. MrEd

    MrEd New Member

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    I am monitoring this thread carefully, as I also am shocked at the quantity of wood I am going thru. I think I burned close to 2+ cords just in November.

    My storage is not on-line and my hope is that that will cut it down some, hopefully a lot.

    Everyday in the morning I am reheating the house from 58-60 back upto 72 or so, and seem to use a tremendous amount of wood getting it back upto temp; once the house is at 70-72, its very easy to keep it there. I'll need to keep more precise records, but seems to me I can go thru a fullload of wood in under 2 hours, and only then does the house start to respond. Most of my splits are small, maybe to small, but since I got a late start last year, I split things smaller than usual in order to help with seasoning - it worked and 90% of my wood is plenty dry.

    I do believe I am getting full gasification most of the time, stack temps never get higher than 600 for long, and never any visible smoke thru the chimney except at startup.

    I am also planning on insulating the attic, which can only help.
  10. chuck172

    chuck172 Minister of Fire

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    I knew you would chime in on this topic Ed, our installations have much in common. I know you'll be installing 500 gallons of storage soon. I'm curious how your your wood usage will differ.
  11. sandman59

    sandman59 Member

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    I just connected the side arm heater to my 80 gallon electric hot water tank, so that will also need to added to my previous fuel oil usage.
  12. Birdman

    Birdman New Member

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    I am new to the Tarm world. I have been burning for 4 weeks now. I am amazed at how little wood I am burning. And this is to keep my whole house at 70 and heating the hot water for 5 people. We use alot of hot water. Also my house is a log cabin and it is not tight. ... and I am heating a huge area with a cathedral ceiling. These estimates of 6 to 7 cord sound high to me? I have 4 cord of hardwood and 1 cord of dry pine in my basement for the rest of the winter. I have more stacked outside... but it just seems to me that I will not need more than what I have already in the basement. It is my first year... so I can be wrong. Last year I heated with a woodstove... nice one... and used 4 cord. I also used 750 gallons of oil. I am very pleased so far with the Tarm. I have kept the house at 70 in the past week ( day and night ) and my kids shower twice as long... with hotter water. Wife is very happy to have woodstove out.. since she likes it very clean. I have tweaked some things on the system .. and am looking forward to some cold weather to see how teh Tarm does. the coldest it has been is 15. It has also been 48. I am very curious about the pressurized storage and how it would help me. I am burning twice a day right now.... sometimes 3... depending on temp. Sometimes full load... sometimes half load.. depending on weather. Still... i have burned maybe a third of a cord in 22 days? I am hoping to hear more from others as to how a typical day goes with storage. Nofossil has been helpful. others with storage want to chime in ?
  13. WoodNotOil

    WoodNotOil Minister of Fire

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    Not to burst your bubble man, but 5 cords sounds a little low for the winter with the kind of heat loss you are describing. Your 750 gallons translates to 5 cords of dry hardwood plus the 4 cords in your woodstove would put you at 9 cords. I am thinking 7-8 in your application would be a little more realistic. Depending on weather conditions, you will use a lot more wood when the temp gets consistently low. January is the month I burn the most wood each year.

    As for storage, it allows you the flexibility to fire when it is a little more convenient, but is most useful in the shoulder season and for DHW in summer. You will find in the coldest weather without storage you will have to fill 4 times a day (mostly partial loads) to keep the fire from going out and the boiler able to supply heat to the house. Nothing is worse than the fire being out and your wife complaining the house is cold! (or the alternative... burning oil!!!)
  14. rickh1001

    rickh1001 New Member

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    I just wanted to chime in, as I am starting to get a handle on our wood usage. Coming off oil for the first time, it is somewhat shocking to realize how much wood it takes to keep up with full time heating of the entire structure. It is a lot different than just burning a wood stove off and on.

    We are heating a converted 35X70 foot barn, half of which has a 13 ft high ceiling with only minimal insulation. In addition, there is a 30X40 ft conventional farmhouse 50 ft away, again, not with the greatest insulation. So I am heating a total of 2,450 sf + 1,200 sf = 3,650 ft - not to mention the basement of the barn where the furnace is located. Last year on oil, we went through a total of 1,700 gal for both houses. Using the 150 gal/cord estimate, that puts me at 11.3 cords of wood equivalent energy. Figuring a heating season of roughly October through April, or 7 months, that would average 1.6 cords/month. Of course, October is a lot different than -20F in January.

    So far, my wood consumption has been right in line with the equivalent oil I used last year. I started the Eko 60 early October, and now at the beginning of Dec, I have just finished off 3 cords of dry wood. In the coldest weather coming up, I am figuring on about 2 cords/month.

    What is interesting is that the Eko efficiency is holding up. The unit is burning very cleanly, and the matchup of the wood usage to previous oil consumption tells me the unit is keeping up good efficiency.

    The point though, is that 11 cords is a heck of a lot of wood - a lot more than I am used to dealing with for the normal woodstove and fireplace. It is a lot easier just to have the oil truck keep the tanks full and burn oil. Large quantities of wood take a lot of effort, not to mention running down to load the boiler every 4-8 hours. No one ever said burning wood was easier, but it is a lot more fun, and requires a continuous effort. I am getting used to the idea of seeing massive stacks of wood everywhere I can fit them in the basement, and just keeping the Eko happy with load after load of wood.
  15. Birdman

    Birdman New Member

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    Yikes. I am hoping not 9 cord. I am figuring I will use more when it gets colder... but.. It is December 2 today. I figure I have 14 weeks left (after this week is done)of tarm... then maybe I will use oil from Mid-March on? I am praying I will not have to use 9 cord from here on out. Even 7 seems high to me? I think of the 750 gallons of oil I used in the past... alot of it was to heat hot water.. even in the summer... and to heat my back bedrooms during the winter. I will not use the tarm in the summer to heat hot water.. so maybe I will still use 250 gallons per year? All estimates. I have also been tring to find places to reduce the heat loss this year form the house. Also.. take off a cord... from the past year for woodstove?... as i used alot last year.. and at times... i had it too hot... above the 70 constant temp i am getting now.. and teh Tarm efficiency is better than the woodstove? And i used the woodstove earlier and laterpast March 15th) last year as compared to Tarm this year. I still think 5 cord will do me. I hope I'm right.... I really do not want to use more than 5-6 each year. That just becomes too much work. I am really thinking if it is over 5 cord... I will just use oil the rest of the time. oooohh... dangerous words on this site. Hope that did not offend the purists on this site.
  16. chuck172

    chuck172 Minister of Fire

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    I've estimated that one wheelbarrow per day
    =20 loads/days per cord
    150 days of heat
    =roughly 7 cords of wood
    taken further:
    1 wheelbarrow = 30 pieces of wood
    =15pcs in the morning and 15pc's in the evening
    My plan for now will be to load the TARM with 15pieces in the morning and 15pieces in the evening just for shits and giggles.
    At least it will be somewhat of a routine which I think I need.
  17. Birdman

    Birdman New Member

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    150days of heat? For NJ? and won't there be days when you don't need to fill it up like that? Sounds like you could get away with alot less.. and still be happy and warm. However.... I like your idea of just doing it.. to see how your experiment works. Keep us posted!
  18. Birdman

    Birdman New Member

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    Boilerman... why don't you insulate and save yourself 4 cord per year? alot less work.
  19. chuck172

    chuck172 Minister of Fire

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    150 days of heat is Nov. through March.
    If there are days where I don't need to burn, GREAT!
  20. rickh1001

    rickh1001 New Member

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    Birdman,

    Insulation is coming along next year. Actually, as we have converted the barn over the past 10 years or so, I have been careful to heavily insulate the walls whenever possible - sometimes filling in as much as 12" with insulation. Half the barn is a conventional ceiling, and that section has decent insulation, about 10" in the ceiling. Next year, I plan to cover the fiberglass bats in the ceiling with plywood, then load another foot of cellulose on top. The problem is the half of the barn where we put in the 13 ft ceiling. It is just 2" tongue and groove. We use the floor space in the summer. In the winter, I throw 6" of fiberglass on it, just to keep some heat in. It is not so easy bringing a 100+ year old barn up to modern standards! If I had to do it again, we could have built 3 houses for the work that went into converting the barn. I keep working on tightening it up every year, but in the end, it is just a massive structure that takes a lot of heat, no matter how well insulated I get it. Actually, the 13 cords of wood it looks like it will take to heat isn't too bad, compared to the outdoor wood boilers. Our neighbor has a small, well insulated house, and he goes through almost the same amount of wood using his OWB. Every weekend he is out cutting and splitting another load of logs, while his OWB is pouring out smoke. Everytime I look up and see my clean exhaust I smile at how efficient it is. The only mistake I made on the installation so far, is I should have more like 1,000 - 1,500 gal of storage for such a large heating load. The 500 gal storage doesn't last long, so I really am running the EKO more or less continuously. Next summer, I will add a 1,000 gal LP tank.
  21. Jim Post

    Jim Post Member

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    There are lots of ways to skin the wood rationing cat and here's our approach this year.

    1) delay tarm use until shoulder season is nearly over. November 7th this year....
    2) turn down the thermostat....set as low as it goes....58....house stays at 62.
    3) bypass the sidearm heat exchanger on hot water heater....keeping 40 gallons of water at 180 degrees when we only need 120 is wasteful.
    4) put shrinkwrap plastic on the inside of windows....first time we've done it and it makes a big difference.

    We don't have storage. My wife can load the tarm when/if I'm not around.

    Using the above steps we have decreased our wood consumption considerably from previous years...

    jp
  22. egghead2004

    egghead2004 New Member

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    My house is only 7 years old and this makes a big difference. Then again I have Crestwood windows and doors...they all suck, major drafts around the window panes themselves, not around the window casings. On cold days you can see the condensation form on the plastic where the cold air is hitting it.
  23. wantstoburnwood

    wantstoburnwood Member

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    I called my wood guy tonight after reading all the posts and ordered 2 more cords. I think I am too worried about running out and having to burn (oil) for 2 months from march to april. I have burn't 1 cord already and it has been mild. I am heating my dhw and 2800 sq. ft + 28x 24 garage.
  24. 8nrider

    8nrider New Member

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    after reading these posts i can not wait to get the old tarm 55 fired up. it still looks like another month or so. i cut the thimble in the stack and started on the iron. i believe it is going to save me wood. i'm running a hearthstone, fireplace, 360 sq. ft. radiant floor of propane hot water tank. but then again when your family is a bunch of pyros they will find a way to burn the wood anyway. maybe i would be better off burning oil and blocking off the 3 fireplaces.
  25. chuck172

    chuck172 Minister of Fire

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    I've fallen into a burning pattern that starting to show some hope. I load the boiler up in the morning (about 4-5:00AM) with 10 pc's. Heat the house, re-charge the 40 gallon superstore and 500 gallon storage tank.
    I'm good then till about 7-8:00PM. While I'm watching my neighbor Lou Dobbs on CNN, I'll load up another 10pc's of wood.
    I'm keeping a log of time, storage, and outside temperatures. I know its really not that cold yet but at least I'm starting a routine that I can build from.
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