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Garn vs outside wood boiler

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Fredman, Dec 22, 2007.

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  1. Fredman

    Fredman New Member

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    I would like to know if any of you had a outside wood boiler and switched to a Garn? I have a Wood Master and it is fine except for the smoke. I have a 1500sq. ft. and 1 1/2 car garage that I am heating, poorly insulated, but working on that. I go thru 12 cords of firewood a year. Would I use less than that with a garn?

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  2. Eric Johnson

    Eric Johnson Mod Emeritus

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    Hi Fredman. Welcome to the Boiler Room. I get to the U-P on business occasionally and just love it. Ski and Sauna.

    I think you'd use about half as much wood with a Garn or other gasifier in an outdoor location. I have an EKO in a cinderblock boiler room in my barn, and it works really well. I replaced an old conventional indoor boiler that was probably as inefficient as an OWB, and I've noticed a big difference between the two. Along with smokefree operation, I get a lot more heat out of the same amount of wood. We're burning more than half as much wood, but heating a lot more space and keeping it warmer, longer.

    The only gasifier you can buy right now that comes ready-to-install outside is the BioMax being sold by http://www.newhorizoncorp.com. I've heard that Econoburn is about ready to start selling an outdoor version of their gasifier: http://www.alternativefuelboilers.com/faq.htm.

    There are probably a dozen other brands of gasifiers available, including the Garn, and at the moment they all require some sort of building or other enclosure if you're going to put them outside. But I expect that to start changing pretty soon.

    Poke around here a bit and I think you'll get a better idea of what people are using and thinking about getting. Feel free to start threads and ask questions.
  3. brad068

    brad068 Feeling the Heat

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    Well Fredman, its no secret that I'm a big fan of Garns. First off, when you say "12 cords" do you mean 12 - 4'x4'x8' rank or do you mean 16-24"x4'x8'. Some folks definition of a full cord and a face cord are the same. So far I can tell you that I have burned 2.5 face cords since mid september with my homemade unit. It is heating my repair shop which is 12'h x 40'w x 48''l. The overhead door opens and closes a couple times a day and it stays @ 70*F. The boiler is inside the shop through this winter, and will be placed in its own structure big enough for boiler, wood storage, and solar panels on the roof before next heating season.
  4. Fredman

    Fredman New Member

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    That is full cord 4 x 4 x 8. So what is the process to fire it everyday? Does the fire go out and new one has to built? How much power has to be supplied to it? 120 or 220, amps? Does the unit give off heat?
  5. Eric Johnson

    Eric Johnson Mod Emeritus

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    Are you asking about the Garn, specifically, Fredman, or any gasifier?
  6. Fredman

    Fredman New Member

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    Any that I can put in an buiding that can heat 5000 sq. ft.
  7. Eric Johnson

    Eric Johnson Mod Emeritus

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    They'll all do that. The thing about a Garn is that the hot water storage is built in, so you're talking about a much bigger piece of equipment than more conventional gasifiers like EKOs or Tarms or EconoBurns, which you can hook up to separate tanks. So the Garn needs a pretty big space, and it needs to be insulated if the space is unheated.

    I'm running mine without a tank at the moment, and I'm usually throwing wood onto live coals, so there's no need to start a fire from scratch. But it's not hard to do. With hot water storage, you should be able to load most gasifiers once or twice a day in cold weather. Because I'm not using a tank at the moment, I make more frequent, smaller fires. The boiler burns clean and completely.

    As for radiant heat, there's not as much as with a conventional wood-fired boiler, mainly because gasifiers are really well insulated and the stack temps are much lower. With my old boiler, stack temps in excess of 1,000 degrees were common. And that throws out a lot of radiant heat. The EKO has stack temps closer to 300 degrees. Big difference. My boiler is in a small cinderblock room that's roughly 3 feet wide, 7 feet deep and about 6 feet tall. It probably stays around 120 degrees in there.

    My boiler came with a three-prong wall plug for connecting to a 120v system. Of course, I hard wired it with BX and conduit. Everything associated with the wood boiler is on a dedicated 15-amp breaker.

    As to what you can heat, here's my heat load in a climate that's similar to the UP. You could argue that my boiler is oversized, but with storage and some infloor radiant in the greenhouse, it's going to be perfect. I expect to burn about 10 full cords of dry beech per season, plus a little more during the summer for hot water. If you're anywhere near Indian River, you can check out a couple different types of gasifiers at Cozy Heat. There are probably some gasifier dealers in the U-P, but none that I'm aware of.

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  8. Fredman

    Fredman New Member

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    So your boiler just heats the water and you store the hot water in a different location, if you choose to have a tank. How much water does your boiler hold? That is what threw me off when I saw how little water was in some of the boilers. My outside wood boiler contains 150 gallons. Now does the storage tank have a heat exchanger in it? The one thing about the Garn if it is self contained, that I don't have to have a tank taking up more room that I don't have now with no basement. Or if I went with the others I suppose I could just have the water tank in the same out building as the stove or do you have to have in the house? I am new to this and I like the fact that there is no smoke and I have the option to burn more than just wood in them.
  9. Hbbyloggr

    Hbbyloggr New Member

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    I've been looking at the Empyre Clean Burn to replace the Emprye 450 OWB some time down the road. As with anything " new" I like to watch for the results to come in to work out the bugs.

    This looks to be an outdoor stand alone version that would slide right in place of our OWB. The link is: www.profab.org

    They used to be affiliated with Cozyburn but I don't see any mention of that in this web site. Maybe they had a parting of the ways...I'm not really sure.

    Hbbyloggr
  10. Eric Johnson

    Eric Johnson Mod Emeritus

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    You're right about the onboard storage with the Garn. Personally, I prefer to have the boiler in the barn and my storage in the basement, and I like having the option of bypassing the storage at will. If your house is at 50 degrees and the Garn is at 50 degrees, you're in for a long wait before that 1,500 or 2,000 gallons starts providing any usable heat. But that's an unlikely scenario, especially considering that it would take quite awhile for the Garn to get that cold. But it's something to consider. With a bypass, you can heat the house directly anytime you want, and worry about charging up the tank (or not) at your convenience. But people who have Garns love them; I think it's just a different way to skin the cat.

    My EKO probably holds 60 gallons of water. Refractory-based units like the Greenwood and Seton have a lot less than that. All they have are some water pipes running through the refractory. But it works. All are clean-burning, high efficiency boilers. And, as you point out, you can burn corn cobs or pine cones or pellets, cherry pits, etc. in addition to dry wood. You can even burn soft coal in the EKO--and presumably in the others as well.

    A nonpressurized tank needs a heat exchanger, and that's a major expense and/or engineering hurdle, considering the current price of copper. In the Garn, the firebox is the heat exchanger. Or, you can go with pressurized storage, usually in the form of a 500- or 1000-gallon propane tank. Then you don't need an hx, but you do need a pretty big expansion tank. You could use a hot water heater for that.
  11. Fredman

    Fredman New Member

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    How big is your house and how old is it? Do you heat the greenhouse all winter? and how warm do you keep your house and greenhouse?
  12. Eric Johnson

    Eric Johnson Mod Emeritus

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    The house is about 3,000 square feet, consisting of the original circa 1865 farmhouse with about four additions dating from the '50s through the mid '80s. I'd say the insulation is fair to good, within the obvious limitations, such as the 1972 Andersen glass door walls on three sides of the sunroom. My wife likes to keep the house between 75 and 80. No problem. Cast iron radiators throughout. The greenhouse doesn't have enough radiant at the moment, but it will get up to 70 on a typical cloudy winter day with the cast iron radiator and copper finned baseboard that's in there now, down to the 50s at night. When it's near zero, it stays around 60 if you keep the boiler firing. It hasn't gotten below zero yet, so I don't know about that. The primary heat for this house is a 193 K btu gas boiler that when I bought the house, kept the house and greenhouse warm all winter long. That was before gas prices doubled or tripled--I stopped paying attention when we got the first wood boiler 4 years ago. I've changed some things around in the greenhouse so it's different now. Next summer I want to put in infloor radiant in a slab. My point is that a 205 K btu wood gasifier seems like a good replacement for a 193 K btu natural gas boiler.

    Not knowing what your setup is, I'd say that a 60kw wood gasifier ought to be plenty. You might get away with a 40. I think nofossil heats a 3,000 square foot house with a hot tub in northern Vermont with a 25kw EKO. Says he only burns 4 cords a winter. Pretty impressive.
  13. leaddog

    leaddog Minister of Fire

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    I have the eko80 that I installed this year. I replaced my outside boiler and I'm burning less wood and have alot less smoke. The advantage of a gasifier is less wood and less smoke. But they do need DRY wood. I liked my owb be cause I could burn anything that I could pick up so I didn't spit anything. I also could burn some less that dry stuff. I could fill it once a day and forget it and those points are what sold them. BUT, they SMOKE<SMOKE alot and that isn't good for anyone even out in the country. The handwriting is on the wall and the old type owb are on the way out. All the major manufactures are working on some type of gasifcation unit. I wouldn't recomend anyone to buy an old style owb now but go to a gasification unit. They take some getting used to as you have to burn them different. Dry wood, tend them more often, Storage is better( the more the better) and learn how to start a fire to make them work. I think the hardest part getting used to is when you start a NEW fire it takes some time. You have to getsome coals going with small pieces, then put a few more small, larger pieces inand get it gasifing and then after afew minutes you can fill it up and go away. It's just a change off habits and you get used to it. But you don't get all that smoke that is bad for your health and all the other people for miles around. I know that alot of people think that they are not near anyone so it doesn't make a difference but years ago I flew small airplanes and the first couple years in the fall when people were burning leaves there was a haze any place you flew in Michigan. You could smell it and at times was very thick and cut visability way down. Then most towns banned burning of leaves and it was like nite and day different. Mort of the pilots talked about what a difference it made. You didn't notice it as much on the ground but in the air you really noticed.
    We here in the usa are so far behind other countries in useing the technology that is out there. I can't under stand why the gov. isn't really pushing solar water heating. The vacum tubes can be used any where here and give a huge boost. I googled solar water heating and come up with hits all over the world but here in the usa very few. China is manufatureing them and exporting them all over but no one here is noticing. Yes the gov will give a tax credit but it has to be done by a certified installer and they inflate the price so much that the tax credit isn't worth it. Most people that can hook up there boiler could install one of these.
    The gov is pushing some atternative heating but it is pushing more to corn because it helps the farmers, and there is a lot of better sources than corn. But the big oil and farmer have more clout.
    Sorry I'll get off my soap box now
    leaddog
  14. Fredman

    Fredman New Member

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    It's all about politicians and which big company owns them to get away from renewable resources and go with oil companies

    Well my house is 1500 sq. ft. cement block, along with the garage. I am planning on building a 30 x 50-60 shop either next summer or the next. I have a above ground 28 ft. pool I would like to heat in the summer and a hot tub in the winter. What size do you think I might need?
  15. leaddog

    leaddog Minister of Fire

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    Well here is my take on it. It depends if you are planning to heat the shop as that is a large area and if you do put in radiant for sure. If you went with the garn I would say that you only need the smaller one. It has the storage built in and there is different ways to insulate it but you will need to insulate for sure as you are going to run it in the summer. Heaterman is a dealer in Nothern Lower Michigan
    If you go with an eko I would think you would want the 60 or 80. There is so many variables and I don't know your situation so it depends. If you cut your own wood you can use longer longer wood in the 80. The 60 takes 24+ and the 80 takes39+. The 80 will hold more so you can get longer fire times. Dave at cozy-heat is just South of the bridge and I have found to be very good to work with. Either way I highly recomend storage. If you are going to build a shop I think I would put my storage next to the shop In the ground. I have been thinking about this and putting it in the ground would work very well. you could use poured or cement blocks or even treated lumber walls. You would have to insulate it well with foam or foam board and line it with epdm to keep it from leaking. The advantage is you could make a 2000 or larger tank and not have the pressure problems forcing the walls out. With a larger tank you wouldn't have the sq-ft in walls per gal so the heat loss would be less. I believe the larger the tank the better as long as you insulate well as then you have more flexabity on when you fire the stove.
    If then at some time you want to add solar you can go with more panels pipe it into a smaller tank to keep the temp up and put all the overflow into your storage. That way you can use even more of the sun.
    Just some thoughts. explore all the allternatives as every ones ideas and capabilitys are different.
    leaddog
  16. Eric Johnson

    Eric Johnson Mod Emeritus

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    I'd say a gasifier is perfect for heating a swimming pool. You'd be running a series of long, hard burns and that's when they're most efficient. Plus you'd get your hot water all summer long. My neighbor has a pool about 150 feet from my boiler. I'd like to hook him up and bill him for the wood used. I bet he spends many thousands heating that thing with gas. Ditto on the in-floor radiant. Because you can use water temps down around 80 degrees, I think, you get a lot more mileage out of a storage tank, because you don't have to recharge it at 130 degrees. Just drain it all the way down to 80 and then you get a more efficient recharge because the water you're heating is that much cooler. To look at it another way, the cooler the water you can get away with, the more btus your tank can hold. And that's a beautiful thing.
  17. Fredman

    Fredman New Member

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    I thought about radiant heat but then decided against it. I am going to get a couple floor cranes and I am not sure where I am going to put them in my shop. The foundation on them are 4 feet down and 4 feet square plus the steel racks are mounted to the floor also. It would be nice to have warm feet but I would probably only have my shop set on 55-60 anyway, so insulated boots are fine. Thanks for all the help and information
  18. duncanheat

    duncanheat New Member

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    Hello there. I love all the information you guys are honestly giving. I'm in the market for a wood boiler but I wanted some opinions on which one would a good make and model. I have a 3000 sq. ft. built in the 1910. I've been reading comments on GW and EKO and I'm concerned about the GW cracking inside but I really wanted to have an inside boiler. thanks for any help...
  19. Eric Johnson

    Eric Johnson Mod Emeritus

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    Welcome to the Boiler Room, duncanheat. Hopefully we can help you decide what's best for your situation.

    The EKO and Tarm and Econoburn and BioMax and Wood Gun are all indoor boilers.
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