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Wood boilers

tank idea, what did you use to insulate the tank? I checked the price on the Fralo, like everything else they increased. I like the idea of a pressurized system. Now I have to decide if im going to put it underground or maybe above grade in the same shed as the boiler. If I put it underground it would leave more room for wood in the shed but leaving it above grade has advantages too. Hmmmm how do you have yours and in what type of piping configuration.


  • Wood boiler question

    Anyone here have experience with wood boilers? Gasification or standard types. Preferences, problems, recommendations?
    Was looking at the Ecoburn unit made in USA, but I really have nothing to compare it with. Also looking at the Biassi cast iron for simplicity. Thanks
  • Wood Boilers

    Tarm Solo 30 gasification boiler. Nice unit,followed Mfg. instructions for installation,works great.
  • Chowdahead
    Chowdahead Member Posts: 59
    Wood boilers

    HS Tarm also know as BioHeat, Eko, Woodgun to name a few
  • Wood Boilers

    This is a Tarm Solo 30 gasification boiler.
  • hot_rod
    hot_rod Member Posts: 21,868
    what's in your wallet?

    The EconoBurn is a nice heavy duty, and heavy, built in the US gasifier. I have heard nothing but good reports.

    Bio Energy had some beautiful wood and pellet boilers in a nice trailer display last week at REX. The Austrian built Froeling is quite a piece of equipment. I think the TARM name is gone but that boiler is still being sold with a nice looking upgrade to the "jacket"

    I have an EKO from Poland. A beast, no super model good looks but it works great, easy to clean, efficient. I have a 40KW with 500 gallons of buffer tank, pressurized.

    I believe EKO has an office in NY somewhere now. I met Anya Orlanska operations manager for the US operation, at the ASHREA show this spring. They had a booth at the show, a very knowledgeable gal.

    Snoop around at the "boiler room" at www.woodheat.org to get a feel for what is hot and what is not. Some good feedback from long time wood burners over there.

    I believe there is a wood and fireplace show in Vermont every summer or fall, lots of the manufacturers are in attendance. Also some of the FarmFest and county fairs are good places to see equipment. Take a truck and trailer it's a good place to find "show special" cash and carry prices.

    Get that wood split and drying. Gasification burners need dry wood to burn efficiently. 12- 18 months worth of dry time is suggested.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Hot Rod

    When the heating call is satisfied and the boiler shuts down, how long will the wood be able to relight itself and does it smoke much during this period? Also do you feel the buffer tank is a necessity?
  • nick z.
    nick z. Member Posts: 157

    It might depend on your application. Are you adding it to an existing system? or are you starting from scratch?
    I've only hooked up a couple of outdoor boiler and they both worked very well.
    I've installed a Tarm Bio heat whcich was an amazing piec of equipment.I would say with this unit a storage tank is necassary.
  • Yes I am adding

    it to a radiant system that is run by a geothermal water to water heat pump. I use a 40 gallon buffer tank on the geo and that buffer tank has a coil in it. Originally I was going to use the coil to feed excess solar into the heating system, but since then I have found that really isn't worthwhile. I am looking to install this wood boiler in a shed behind the house and if need be I was thinking of burying a 500 gallon Fralo septic tank with spray on insulation in an open system configuration. I am unfamiliar with how often you have to load them and how often do you clean them and are they hard to clean?
  • hot_rod
    hot_rod Member Posts: 21,868
    temperatures in a plastic tank?

    It's possible to see 180- 190F in a wood boiler buffer tank. Is Fralo ok with that? I've looked at some HDPE tanks, most limit you to 140F continuous.

    I've used concrete septic tanks with an EPDM liner for extra protection. The square tanks are easy to insulate with sheet foam, them maybe seal it all with closed cell spray foam, maybe a DIY kit from Tiger Foam.

    I'd say at least 6" of foam for an in ground tank. Below frost level?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hot_rod
    hot_rod Member Posts: 21,868
    yes to the buffer

    unless you can be around to feed the fire and adjust the burn to the actual heatload.

    Mine just pulses the fan, at low speed to keep a fire going when it reaches setpoint. i've only had one over-temp condition.

    500 gallons buys me about 6 hours of heat at design once the fire has gone out.

    The buffer tank will store energy for days without burning, and absorb any over heat conditions on a mild day.

    You will learn to load the boiler according to the weather forcast. If a warming trend is coming do not stuff it full of wood :)

    A lot depends on how close you size the boiler to the load, and how often you are at design condition.

    The biggest mistake is oversizing the boiler, then they tend to shut down and smolder a bunch. Some buyers go larger sizes just to get a bigger firebox, not a good idea.

    Heating with cord wood is a bit of work.

    I let mine go out and cool down for a good cleaning. Then with a cleaning brush and shop vac I can get a real good cleaning.

    How often depends a lot on the wood you burn. Some woods generate a lot of ash. I tried some walnut once and got more ash than heat :)

    Soft woods and old pallets, same thing. Dry wood is critical. Cleaner burn, more BTUs and less cleaning.

    I enjoy the wood burning ritual. cutting, splitting, hauling, etc. It's good exercise. But by April I'm often turn the LP valve back on!

    Siggy has a good 2 piece article on wood piping and controls in www.hpac magazine, a couple months back you can still download it as a PDF there.

    Here is a picture of the Froeling that was running at the REX show last week. it's a pellet version but shows the quality of the unit.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Joe Billow_6
    Joe Billow_6 Member Posts: 69

    I have used square paint totes. 2" foam to line them and then slide your square buffer tank in and fill the small gap with the spray foam. I use the big cans with the reusable gun and a peice of clear hose to get to the bottom. The plastic tote with the galvanized cage protects the tank and fittings while in the ground and during backfill.
  • Steve Ebels_3
    Steve Ebels_3 Member Posts: 1,291
    I like Econoburn a lot

    We have installed a few and they work very well. Extremely heavy and well made along with being one of the very few that is actually ASME rated as a pressure vessel. Nice to see a US company put out a product of that quality. Their factory support is on a par with Viessmann judging from my interaction with them. (That's saying something!)

    I would recommend installing any brand gasifier with sufficient storage and a good dump zone. Adequate storage makes more difference than can be described. A gasifier is just a completely different animal when you can give it longer burn times.

    Speaking of burn time...............if you want to check out a horse of a different color look up www.garn.com and study those for a while. They operate on a completely different principal in that the fire burns continuously until out and the heat is stored integrally in the 1500 gallons of water that the unit holds. Yes, it is very big. The thing with a Garn is that even though it was designed back in the early 80's, it beats the emissions spec for 2010. My state (Michigan) basically patterned their emissions laws based on the Garn after studying many of the gasifiers out there. There is virtually no smoke and they operate with a negative draft combustion air flow so you get nothing blowing back in your face when you open the door to load or peek. Of all the product I sell, my Garn customers are the ones with a perpetual smile on their face. A little tougher install due to the size but well worth it. I have Garn units heating everything from a 1,800 sq ft single family home to running 8,000 sq ft of infloor plus 1,000 gallons of hot water for a dairy farm. They work like nothing else I have ever used in wood fired equipment.
  • My supplier called Fralo

    about a a year ago when I inquired about using them for solar storage. Your right, the temp rating is also based on pressure and they only test to 140 but they told me using it with no pressure I could exceed 160, which is fine for me because my radiant rarely needs 120. I plan to use the 2 part closed foam spray or the 2 part insulation I have seen triangle tube use to insulate their phase three units. I plan to set it 2 feet under, they have those screw in manhole lids in different lengths. I really haven't worked out all the details but it seems pretty straight forward.. Ive said that before lol. I helped my neighbor, a union steamfitter pipe in a wood boiler 10 years ago, it was a used outdoor boiler, I believe a Taylor, since then replaced with a central outdoor boiler( not the new gasifier)anyway we used 1-1/2 well pipe and the boiler is 200 feet from the home, He runs that thing all year for hot water, heat and swimming pool. He has friends who are in the tree cutting business and they drop off mountains of wood...pine, poplar, anything, and that PE well pipe is always 180 degrees and it is still the original pipe. So I figure it is worth a try, If it holds up and I can insulate it cost efficiently it should be a cost effective storage system since the tanks are reasonable and are made up to 1600 gallons.
  • I called Econoburn

    I am going to see their unit in July, I like the idea that it is made in USA. I wasnt sure but I am glad you and hot rod say good things about them, makes me feel like it wont be a wasted trip. Not that I have counted out the other units, price will play a part here too. That Garn unit is huge! My home only needs 36000 on a 0 degree day.
  • Steve Ebels_3
    Steve Ebels_3 Member Posts: 1,291

    Operating with water temp in a 1500 Garn dropping from 190 to 140* at a steady 36,000 btu load would mean you only have to fire it about every 18 hours. Storage does that for you.
  • It looks like a really nice

    unit but I just dont have the room in my shed. I wen to their web site and I like it but it just is to large for this install. I want to try underground buffer tank with a smaller unit in the shed, that will give me some room in the shed for wood. But thanks for the info.
  • Where do you

    get those at Joe?
  • Steve Ebels_3
    Steve Ebels_3 Member Posts: 1,291

    What water temp are those rated for?
  • What type

    of tank did you use for your buffer?
  • What type of tank

    Are you guys using for storage/buffer? Im not sure about the plastic tank because the lower temps mean larger storage to hold the same BTU,s. I have a 500 gallon skid mount oil tank. What pressure do you think I could use in that or maybe run it open?
  • hot_rod
    hot_rod Member Posts: 21,868
    old LP tanks

    are commonly used for buffer tanks. About a buck a gallon around here. I have a 500 and 300 I bought used. ASME rated vessel.

    But, oh that smell. I soaped and flushed 4 times and still had the smell. Finally moved it far away and let it air out for a few months. But the gravel driveway smelled for about a year where I washed it.

    I've heard a quart of OxyClean will do a 500 gallon and leave it odor free. It has soda ash and hydrogen peroxide as some of the ingredients.

    I tried a pallet tank in my yard. At 160 it got so soft it started to bulge through all the squares in the metal frame work. I contacted a manufacturer of those tanks 140F max at 0 pressure. it's just HDPE, unless they make them from a better product now.

    With a wood boiler you want to load a tank to 190F to leverage a large delta t. And have some overheat capacity, up to 220F under some pressure.

    Best bang for you bucks in an un-pressurized tank may be a concrete septic tank. You can get them from 500 to 1200 gallon around here. They deliver them and unload in the hole. Some go nude, but I always lined the ones I used with EPDM roofing. pack it full of copper coils. I know some guys use pex for the coils. they tell me you need 3 times as much to get the same transfer as copper. Don't know how scientific that sizing method is.

    Tom Lane claims 2.4 lineal feet of 3/4 copper per 5 gallons of storage (solar)

    The contractor from PA that did the seminar at ASES used .08 square feet per gallon for HX. Or 80 square feet for a 1000 gallon tank.

    The SST website has some coil sizing info also. They build collaspible un-pressurized tanks.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hot_rod
    hot_rod Member Posts: 21,868
    If I were to do it again

    I would stand the tank on end. It would stratify better especially if you dump solar into 'er.

    I have seen several on end, one guy welded the tank onto an old truck rim for a base. Another had 3 legs welded to the side.

    Lp tanks come in a lot of different sizes and diameters. Around here the 300 gal. run about 8 feet long, 10 feet for the 500 gallon.

    Boiler and hearting fluid is in the tank, to add solar you would need a hx to glycol the panels.

    Or like Siggys he uses the tank as a drainback from the solar, heat off it via plate HX.

    Mine is up on 4X4s under the legs and a 4" of rigid foam around it as a square box.

    Underground would be tougher to insulate, i would spray a closed cell foam 6" or so, maybe a few 2" layers of rigid below the tank.

    Critical to underground tanks is keeping ground water away from them, even with spray foam you'd want to keep the area around it dry. maybe a sump hole next to it to monitor condition, a piece of 12 plastic culvert pipe perhaps.

    Here are some pictures of horizontal 500 and 1000 gallon LP tank systems. 1000 gallons are very heavy to handle, you really need a crane truck to do it safely.

    The plastic pallet tank with fin tube hx is one I built and luckily tried in the driveway first. The plastic actually bulged through all the squares at 160F!

    Also the 500 gallon concrete tank I had in my shop for one season. The water got some sort of bacteria over summer and smelled like a sewer. couldn't get rid of the smell. It's now out in the field as a water trough for the cows!

    I'll hunt for the vertical mounts.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Great pic Hot rod

    That looks like the way im going to go! I could get a 300 gallon in the shed lengthwise but not vertical. Thanks for the pics.
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