DREAM BUILD

I sure wouldn't need to agonize long over the choice of a Garn or CB. I used to be just a Wood Gun person untill I saw how a Garn was built. The Garn I believe can vent Vert. or Horiz. The Garn is a boiler that really doesn't seem to have any problems, except you need to load it with wood.

If you can get a Garn for the roughly same price as the CB E model it is a no brainer. The Garn design has been around for many years and really trouble free from what I read. I got the literature and a quote ($8200) about 4-5 years ago but was not ready to build yet. We finally built our home last year but with I believe they were bring over $10,000 with the increases in the price of material. I opted for the EKO 40 for price alone ($5000) but the Garn 1500 would have been worth the 8200 definitely!

I'm not sure how your winters are, but I would want that load door inside the building. Solves your venting problem as well without putting in an expensive chimney.

I would consider heating the shop directly from the tank. Cheaper, simpler and works even if the power goes out.

Welcome to the Boiler Room!

To answer some of your general questions, the GARN 1500 should be plenty big enough for your proposed use. Remember, a GARN is different from just about all other furnace designs because of its integrated storage. Since you will be using tubing in your slab, you can run the temp of the GARN down to 130 easily, and get maximum utilization of the water temp. With a GARN you burn more to recharge the storage than as a means of direct heating.

With the GARN located as you have in your drawing, you have an ideal setup to take advantage of any standby loss you may have. If the tank is shedding heat into the heated space, you have little waste.

For the DHW, there are a couple of options. I would suggest a Superstor or similar indirect water heater. They have a coil in the DHW storage tank that you can circulate hot water from the GARN through. The DHW tank will be just another zone off of your manifold. No need to mix that leg, since you can heat your DHW tank up as high as you wish. Just be sure to use an anti-scald mixing valve on the DHW tank output to the kitchen.

As to wood storage, depending on your heat loss/load, you may be burning as little as once every couple of days, to as much as every day. Ready access to the fuel storage area should be considered. Maybe consider storing just a couple of burns worth in the GARN room in a plastic storage bin. That will cut down on the trips to the wood pile or shed.

The GARN is available with the vertical flue option, but I see no need for youto go that route. I would turn it around and load it from inside the shop area. You could even just turn it 90 degrees. You should be able to vent through a single 90 elbow without issues.

Best of luck, and keep us posted on your progress and decision.

I've never operated a Garn nor a CB e-classic. I investigated a Garn before I bought my GreenWood. The e-classic was not available then.

If you limit your choices to either a Garn or a CB, and then tell me that they are comparably priced, then as stated above, absolute NO BRAINER. The new-to-CB technoligy has been problematic if you read around a bit. Garns seem unconventional, but every story I have read about them seems like a sucess story.

Personally, I wouldn't go with either one, but if I had to go one or the other, I would NOT give te CB another thought!

Jimbo

You'll find the gasification boiler(biomaxx) with a storage tank will be about the same $$$'s as a garn(you'll save a few thousand if you build you're own tank). I'd tend to lean towards the garn and experiment with the corn cobs, as in throw a bunch in once fire is going. i think you'll find it'll take a fair amount of cobs to be effective and might be a PITA drying down a large amount like that to use a a single heat source. Just a thought, but my thoughts are usually wrong. BUT this isthe site to get some good info, I know there is somone here that has used biofuels for heat. Good luck.

STANG302 said:

Found something intruiging. Looking at BioMax Gasification Boilers and they say they can burn corn cobs. So that got me thinking and I do have the ability and resources to plant a few acres of corn. On top of that my parents plant 2 acres of sweet corn to sell and for the most part half goes to waste and could be used. So it could be done but how many bushels of corn would I need to suport 1-2 burns a day for the winter? Has any one gone this route?

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There is a thread on burning whole ear corn somewhere int this forum and with it links to other forums where ear corn is burned knowledgeably. From what I remember, as I was intrigued wit the concept, ear corn averages about 98 million btu's per acre (relegated by yield) and red oak is about 24 million btu's per 4x4x8' cord. Drying corn is not the problem that some think as it will dry on the stalk/cob to a desired 20% but weather, harbvesting, storage and handling can be a problem. Per bushel ear corn weighs in at about 40+/- pounds. I forget the actual cubic ft. per bushel but you can measure the Garn cubic displacement and learn the need for handling wood and corn to get your desired output.

Corn can be stored on the stalk but can be a bear to harvest with snow on the ground etc. etc so having storage facilities and alternative drying facilities could be a hassel. I have found cob corn is always at a premium in my area and aout as hard to find as winning lottery tickets. as most farmers deal in shelled corn.

Long story shortened.. Found some and burned it in my EKO40 was not a flash fire but not a long burner either and ear handling was a bit of a hassle not being set up for it. Would like to have a couple of tons for a fair assessment.

Generally speaking, drying down corn has been very difficult this season. Up in this end of the country(lower bushel/ton per acre), they've called it a bad year, bushhogging it into the ground. Too expensive to deal with. Heatermans' region sounds about the same. He's in the same ballpark region you're in. And these farmers know how to grow it and it still went bad.

We've had plenty of rain but some are getting a good harvest. Probably have their own driers. Bushel shelled corn is different than ear corn because the ear can be left on the stalk and dried via cold weather patterns as the ears usually turn down and the husk prevents water from wetting the kernels. The problem with that approach is snow can plug the corn heads while harvesting and then the deer and other critters consume more of the product. There is a lot of low land corn grown in this area that the farmers plant knowing they may have to harvest in the snow because the ground is too wet and soft in the fall. Usually they won't mess around with ear corn and that makes ear corn hard to find.

STANG302 said:

Found something intruiging. Looking at BioMax Gasification Boilers and they say they can burn corn cobs. So that got me thinking and I do have the ability and resources to plant a few acres of corn. On top of that my parents plant 2 acres of sweet corn to sell and for the most part half goes to waste and could be used. So it could be done but how many bushels of corn would I need to suport 1-2 burns a day for the winter? Has any one gone this route?

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The GARN is also rated to burn cob corn. However, unless you have ready access to A LOT of free corn, it is probably not worth the trouble, no matter what you burn it in. Search this forum and the GARN forums and you will find several threads within the last year with details on the Btu content, storage and handling, etc. I considered this option too, and may burn some corn in my GARN if some falls in my lap, but I am not going to farm it for heat.

Heading out to shell the last 50 acres of corn we have, then finally get back to working on my garn room.

I'd forget about burning corn in the garn. I've gathered up about 5 bushel of ear corn from places we can't harvest, corners where it gets knocked down and random times when it jumps out of the corn head. Took alot of time to do, but was waiting on the semi to be loaded anyway.

They are right about getting corn to dry down this year. Harvest alot of corn this year at 23% moisture, very hard to dry with the propane grain dryer. Dry corn is 15%, i've read that 14% burns best.

I'd be putting the loading door inside. It's gonna be COLD when you are making that Garn work the most.

STANG302 said:

Your right on the corn. Just is not as easily accessable and usable as wood. Just finding all kinds of alternative options I've never considered before has been educational for me.

As for the garn it may be an option to put it in its own room with wood storage. Off in the corner and vent it straight out. So, the heat loss on the garn is enough to heat 1000sq ft if left bare?

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LOL - if you leave a GARN bare in a well insulated 1000 sq ft room, you will have yourself a very large SAUNA No need to leave it bare, just use less on the side facing the room.

Since you are doing in-slab radiant, look at the information of the radiantcompany.com. They recommend a slab insulation plan that leave the center of the slab uninsulated http://www.radiantcompany.com/details/grade.shtml Since the perimeter (about 8 feet I think) is insulated, this makes for a HUGE heat sink in the center of the room. At first is seemed strange but after thinking about it the thermodynamics make sense. I used them to size my wood floor radiant system and they were very helpful. I second the suggestion for the loading door in the shop. Stack your firewood on pallets then bring it in to the shop with forks.

Hunderliggur said:

Since you are doing in-slab radiant, look at the information of the radiantcompany.com. They recommend a slab insulation plan that leave the center of the slab uninsulated http://www.radiantcompany.com/details/grade.shtml Since the perimeter (about 8 feet I think) is insulated, this makes for a HUGE heat sink in the center of the room. At first is seemed strange but after thinking about it the thermodynamics make sense. I used them to size my wood floor radiant system and they were very helpful. I second the suggestion for the loading door in the shop. Stack your firewood on pallets then bring it in to the shop with forks.

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I have seen a LOT of discussion on the Radiant Co, and their idea of putting a hole in the insulation - they have a lot of good info on their site, but IMHO the idea of putting a gap in the middle of the floor makes absolutely NO sense for the vast majority of installs - especially those close to rock, or on damp soil - you will NOT get the heat back out that you dump into the ground under all but the rarest of circumstances, so why not keep it in the slab where it belongs? You are right though, it does make a huge heat SINK in the middle of the room - and I don't want to sink my heat or the money and work I use to make it...

Far as I'm concerned, this is another one of those places where the same question Sigienthaler asks about those peddling various "miracle insulation" materials (i.e. "bubble wrap") for underslab applications is appropriate - Namely, if it doesn't work as advertised, will the Radiant Co. come out and pay to fix it? Given that there is no PRACTICAL way to fix a slab, I'd rather spend the extra couple hundred bucks on the foam needed to do the job right...

Gooserider

In terms of slab insulation or leaving a space in the center:
IF the soils are good, it MIGHT work in your favor.

To quote Clint Eastwood, "Are you feeling lucky?"

It is not worth the risk since there is no simple recourse if something does not work right.
In my book, you need to insulate everything and insulate well. If not, you are burning more fuel.
This is how I get away with a cord of wood for space heating and keep it 70-72F in the winter.

The concept of leaving out some slab insulation might never be visible but I can guarantee that you will probably be burning more
wood, oil, gas or whatever.

The area under the slab is always going to be cooler than room temperature. It ain't worth the risk.
Insulation also segregates the slab from subgrade moisture by physically separating it, not just trying to isolate it with a couple mils
of polyethylene plastic.

Just a quick note , adding storage to a separate boiler is not that expensive. I paid $600 for my 1000 gal tank and a couple hundred for expansion tank.All in all I have about $ 8000 in to my system . I also built a 28x32 barn to hold the eko and tank wich leaves me with 24x32 to play. and wood storage under the shed roof to the back. total cost under 17k. I don't think I could install a garn for that .I think the Garn is an awesome machine but I keep reading that a gassifier and storage will cost the same , simply untrue from my experience.

Who here uses a Pellet Boiler? If so are you useing storage?

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Not sure about using a pellet boiler, but at least in theory, there is less benefit to storage with a PB, because a PB acts much more like a fossil burner in that you can modulate how much fire you have, and turn it on and off fairly quickly - unlike the way a cordwood burner operates. Remember, it is best to keep your BTU's as fuel, not as storage - we only do storage with cordwood burners to act as an "impedance match" between the way a cordwood burner operates most cleanly and efficiently with a flat out, high heat output burn and the slower demands of the typical house load... Since a PB can slow it's burn down to just a trickle of pellets, or even go out entirely and automatically relight, it can far more easily match it's output to the moment by moment house load.

Also one odd idea that poped into my head. Does any one have there storage setup underground? Is there any benifit or am I thinking crazy?

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There are people that have done it... It can work, but one needs to be really fussy about insulating and keeping ground water away - the two big problems are that many insulation options aren't compatible with burial, as they degrade with moisture, and that while ground temps are typically higher than air temps so you have less ΔT to drive temperature loss, the fact that most soils have FAR higher thermal conductivity more than makes up for it - so you need extra heavy insulation. If you have ground water, that makes the problem even worse, as water can penetrate any flaws in the insulation, and is massively conductive... IMHO you are probably better off above ground, ideally inside a structure you are trying to heat anyway (so as to take advantage of any heat losses) or possibly outdoors with real good insulation and weather proofing.

Another question about storage. Can Poly tanks or cement tanks be used?

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Poly tanks tend to be problematic, as most have temperature ratings at or below what we see in a thermal storage system. Otherwise they'd be fine. Cement tanks will work as long as they are properly built for the large mechanical loads involved, and people have used them, as long as they are well insulated and sealed... The amount of heat that the cement will store is not all that great however, so it can be better to insulate on the inside, given the challenges of adequately insulating under a large and heavy cement tank... Note, my understanding is that concrete septic tanks are NOT suitable - they are built assuming burial in dirt, which provides external support for the walls - they can't take the pressures of a full load of water w/o being buried... To do a cement tank that will work safely takes LOTS of rebar and some significant engineering...

Just a quick note , adding storage to a separate boiler is not that expensive. I paid $600 for my 1000 gal tank and a couple hundred for expansion tank.All in all I have about $ 8000 in to my system . I also built a 28x32 barn to hold the eko and tank wich leaves me with 24x32 to play. and wood storage under the shed roof to the back. total cost under 17k. I don’t think I could install a garn for that .I think the Garn is an awesome machine but I keep reading that a gassifier and storage will cost the same , simply untrue from my experience.

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The cost comparison between a Garn and a Gasser + storage install is a bit of a mixed bag, as there are a great many variables involved, and the answer about which is more expensive will very much depend on the situation... My understanding is that the assumption of the two being comparable is based on having an existing structure (or building comparable structures) and having the installs done by the relevant professionals, using new materials... Obviously if one gets some of the materials at a better price, (and that was a much better than average price for the 1Kgal tank) it influences the equation. The simpler plumbing of a Garn is going to cost less than all the boiler / storage stuff if done by a pro, but DIY has the advantage of "free" labor, etc... Bottom line is that it's only an approximation, and that each potential purchaser has to run the numbers to see which option is better for their specific case... However I think it is reasonable to say that as a first approximation, it isn't that far off - so it is definitely worth looking at both options.

Gooserider