Garn Boiler Feedback Please

im glad to see im not alone in the fundamental , basically addicting game of wood heating, I have read and appreciate, meaning feel your pain in this pursuit and can`t abstain any longer. My name is tom caldwell, live in nw ct. and am held hostage by a garn model 1900,actually very satisfied. I would welcome any inquiries .

Welcome to Hearth.com and the Boiler Room, Tom. Glad you could make it.

The Garn is an interesting approach, especially considering the onboard heat storage. And you gotta like the fact that it's manufactured in the U.S.

You might want to start a Garn thread. I think Google will deliver the interested parties.

Eric, i view the garn as a sleeper, highly engineered , repeatedly tested , however almost mideval in appearance, id like to say classical in approach. It still took me approx 1 year of trial and error to integrate properly into existing oil system and I could probably pipe a whole new system with the spare parts on hand, a child takes less time in the womb, and my wife is very patient.All kidding aside i chose it for its simplicity but am always thinking of a better mousetrap.

installing the garn, considering its size was pretty easy, it comes with 3 explicit manuals that i had sent a month before arrival, so there were not many suprises. Mine is located in a rehabed 2 car garage, set in place with a forklift, then piped, filled, test run for leaks, insulated and a metal stud/sheetrock enclosure built. This took approx 3 weeks of nights, you do not need the final enclosure if you are not going to be storing firewood next to the unit. Before arrival i had completed the underground pex piping 300lf 1/1/4", and mounted the flatplate heatexchanger. The size of pex and heatexchanger were predicated upon the firing rate of the existing oil boiler to "mask". i knew the firing rate of the oil boiler to 140k/btu/hr, so this was on paper my minimum requirement. Because the oil boiler will continue to run at the same firing rate until the zones are satisfied, i needed to know the btu requirements for each zone, one at a cold start and two at a running state after say 3 minutes. the combined cold start of all zones is unlikely, so i combined all zones running after 3 minutes and calculated a maximum btu/hr requirement , approx 275k btu/hr. through field testing with a taco 13 circulator i determined the piping head loss, flatplate could now size a hx and helped calculate wich circulator/flow rate would be needed. Also for my own curiosity i wired a old analog alarm clock to the oil burner relay, kept track of the daily time totals multiplied by the firing rate to roughly calculate a 24 btu consumption, the divide by 24 to determine a average 1 hour btu requirement, approx 77kbtu/hr. The 24 hr total 1,848,000btu represents what on a below 0 day i would need to generate and store. The garn model 1900 holds approx 2000 gal, hence between a low storage temp at 130 and a high boiler temp of 185, basically 55 degrees of boiler storeage twice a day. At a average burn rate of 400kbtu/hr, it is just under 5 hours a day. this is the worst case unless i add more zones. realistically throughtout the winter in nw ct. approx 6000 degree days, i burn 2 times a day for 2 hours. My house is a 80 year old 2800 sqft moderately insulated with cast iron radiator and baseboard, comprised of 4 heating zones, a 5th zone for a indirect fired hwh, a 6th zone for a 750gal gunite hot tub, 100kbtu/hr shell/tube hx, and a 7th zone for 500sqft radiant floor in my shop. the plumbing warehouse has my visa on file. I know my requirements are over the top, but if you got it wood is good.Selecting the garn size , they only make 3 was determined by the storage requirements, would suspect most choose the middle size that i have. Spring and fall i fire once a day, summer i burn same as winter i heat a 20,000gal gunite pool with a 250kbtu/hr shell/tube hx, maintaining 85 deg. Because the garn is burn and store there are no problems with overfire/idle/smoke anytime.I burn medium sized split cordwood, lumber scraps and old wood fencing and a occasional biobrick. Starting the fire being air infused is very easy, load approx 50 to 80lbs into primary burn chamber with a few crumpled news pages , light ,turn control timer for 2 hrs close door and walk away. after 45 minutes reload about 40 lbs, done. I nnstalled a thermocouple in secondary burn chamber and record temps of 1900 to 2100+ f. temps, remove ash once a week and brush tubes twice a year.I have not had any warranty issues as yet, and yes you can climb inside storage tank . I treat the water with a nitrite addmix and test twice a year,simple test kit .my monthly wood consumption averages 2/1/4 cords. all in all i realized most conventional plumbers do not want to take the time to be involved,it is time consuming and some trial and error, and it is just more satisfying to do it your self, and that is one reason we are all here! Joe kohler, kohler and lewis in new hampshire who has garn experience helped with piping layout between the hx and oil boiler, check out his website.

alright i guess my above post was a little long winded, but the above issues are ones that evolve before, during and after installation for pretty much any wood to oil or other system. if you are like most of "us" it is just fun .

paula, i thought possibly all the info might have made you think twice about the garn, you are tougher than i thought! all kidding aside i could not be happier with mine. have you ordered it yet? are you sure the small one will have enough storage based on your daily btu requirement? i am not sure but i think there is approx $3000+/- difference between the 2 units,my info shows the 1500 round holds 1496 gal or 12,476btu per degree raised, with a 55 degree swing 130-185 degree, this represents about 686,000btu per firing. firing time depends on quality of wood burned, dry 2 hours, over 25% moisture figure on 3 hours. all this means is with dry wood firing once per day you would be able to deliver 28,590btu per hour average for 24 hours. firing twice per day will supply 57,181btu per hour average. with the 2000 round the once a day would be 34,993btu per hour average, firing twice per day will supply 69,987btu per hour average. If able you could fire the small one in the middle of the day, also if you have radiant heat you could draw the useable temp down to 100 degrees, thus increasing your storage charge. With pex supply lines , a non pressureized system and a possible npsh, (net pressure suction head) altitude dependant iwould not run the system above 200 degrees.
how close to the existing boiler will the garn be? will there be any underground piping? or will it only need to go through a wall, other things to consider,is your house well insulated, will you be putting a addition ,extra btu requirements some day to the system. how is your domestic hot water heated. these are all things to consider when sizing a storage system. start with wiring a analog clock to your oil boiler relay. every 24 hours record run time and reset, multiply daily run time by 140.000btu , this will give you a good idea of what your storage requirements will be on a daily basis. who have you contacted at garn, who is your sales person. thanks tom

paula the garn is large, have you seen one in operation yet? It does seem to disappear behind the metal stud face wall. Mine is located in a rehabed detatched 2 car garage, the other half is for wood storage.I have seen a garn barn as dectra`s plans show and the wood storage is outside, a bummer when its cold. You are welcome to check out my install if you are interested. Since you were able to provide martin lunde with your particulars he can size and sell you a flatplate hx, i bought mine from him. As dectra also offers a piping design layout for a fee. Most of his regional salesmen are engineers, mine is jim fink who performed a hydronic analysis of my operating layout. I should have hired jim from the get go, i would have saved alot of time. I will say martin is very accomodating during the inquarry process, once you recieve the contract from the salesman, that person becomes your contact with garn , and your representative for martin. it seems to work. I will post my phone numbers on my bio.

"I’d rather spend $6,000 on a proven design like the Tarm and set it up like they suggest. Then you get a 20-year warranty."

Just a quick note on the Tarm Warranty. If it is not installed by a professional then there is no warranty. I have one and installed it myself but I'm confident enough with the company that I'll be ok.

It's in the fine print.

Eric

Thanks for that clarification, Eric.

I don't think you really find out what any warranty is worth until you make a claim. Like you, I tried to establish a working relationship with the dealer and the importer, in part because they were very helpful, but also because I wanted their approval of both the design and the installation. Any warranty implies a partnership of sorts, and I want it to be a close one with these guys.

How's it working out with your tank?

eric v , what is unproven with the garn

That quote
"I’d rather spend $6,000 on a proven design like the Tarm and set it up like they suggest. Then you get a 20-year warranty."

wasn't mine but Eric Johnson's. I only used it to refer to the warranty on the Tarm.

I looked at the Garn and came real close to buying it. I had the budget for it but chose the Tarm because I could put it inside the house (in a new addition for it).

My other factor for choosing Tarm was they have been around 80 some odd years.

I e-mailed Garn a few times and then he stopped returning my e-mails, I'm sure he is real busy.

But, I like the concept of the Garn very much.

My tank issue is still with me but I've been to busy too collect some good data. This weekend I'll take some good data.

I'm leaning toward the fact I have too much copper coil and the water returning to the boiler is too cool to pass through the termover valve. Just an early guess.

Eric

I said that somewhere, but now I can't find it, and it's kind of out of context. Presumably I was offering advice to someone who I thought might have more luck with a mainstream unit, like a Tarm. The Garn is a great boiler, but for a variety of reasons, probably not for everybody. Sometimes it's hard to read someone's qualifications or motivation from a post or two. Sometimes it takes awhile to figure out where they're coming from.

I am sorry to take your quote out of context, that certainly was not my intent. I only meant to refer to the Tarm Warranty. In fact your comment had nothing to do with any specific boiler at all.

Again, I apologise for the error.

Eric

no hard feelings taken, i agree they are not the most progresive when it comes to public relations. Actually i looked hard at tarm,felt that they have a quality product, 2 reasons i looked on 1, short wood 2, the heat storage set up seemed complicated and as expensive as the boiler, they all have there drawbacks.

paula, you might call switzers custom woodburning system, dundee ny 607 243 8689 , gary builds and installs gasifing boilers, i visited his shop . builds pressurized and non pressureized storage boilers based upon your requirements

i notice on the garn web site it can be a direct vent out a wall are there any other gasifiers that can do that? I've seen this boiler at a lumber jack show and it is impressive and huge. i do believe it is a complete package of clean combustion and water storage but man what a big gasifier.

The Garn venting is pretty darn impressive. I couldn't believe it when I saw that video. My friend with the sawmill has a couple of Garns and a Central Boiler. He uses the CB to burn green slabwood (no chipper for some reason). I suspect another reason he runs the CB is to get that woodsmoke ambiance around his millyard. It contributes to the atmosphere, so to speak.

The EKO is supposed to be vented into a Class A chimney. I suspect the same is true for Tarm and similar designs. Mine goes into an 8" Duratech.

remember the garn has basically not been changed for almost 25 years, a few modifications now and then, it was designed by a combustion engineer,and is still one of the few boilers independently tested. they are made in outside of minneapolis and are more common in the mid and west. is it the most efficient boiler out there, i doubt it , probably the most efficient and simple burn and store made in the u.s., yes it is large. check out the herlt german gassifiers, with thier controllers aside from the puke green and telletubby shape i would on paper think they might take the cake. www.donegalorganic.ie

eric, i second your view on the gassification/induced burn in secondary chamber issue. the garn falls in the later, but still reaches similar temps as down draft gassifiers through refractory nozzles.

that is a good looking true gasifier. i like how the ceramic covers all the firebox area to dry out the fuel better. ill try not to use gassifier for all the boilers i talk about it is just too easy to call them all that. i do understand the differences everyone on the forums talk about.

it has been 5 days, is the garn dead? it basically incorporates secondary burn, thermal storage , a solar port in one unit.

TCaldwell,

I took pictures of my homebuilt Garn principle boiler and emailed them to this site. I don't know for sure if they made it. I'm still learning on my computer. I could of built any boiler but I personally think that the Garn system is bulletproof! I just didn't have $12,000