Multiple unit options Garn

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

True North

New Member
Sep 14, 2017
3
Muskoka Canada
Hello Ladies and Gents

I have read (and learned) a lot reading these forums lately, and finally mustered the courage to post for the first time.

I would like to ask opinions regarding multiple Garn Boiler installation options for a project that will begin within the next two years, starting with the workshop, followed 1-2 years later with our retirement Home.
I am contemplating:
2 Garn whs 2000's or
3 Garn whs 2000's or
2 Garn whs 3200,s

Our family recently purchased lakefront property in Muskoka Canada - 2 hours north of Toronto. Very similar climate as Northern Michigan or Minnesota. This will eventually become our full time home.

Old buildings will be torn down & two new large buildings constructed.

1 - Workshop
Approx 7,500 sq ft total - 16-18 ft ceilings
Approx 5,000 sq ft kept at 50*F, balance at 70*F
Storage, woodwork shop, Garn boilers, & firewood stored here
ICF Insulated Concrete Form walls (R28) with approx R50 roof
Radiant floor heating through out

2 - Main house
Approx 16,600 sq ft total
6,000 sq ft main floor w 11' ceilings - 33% is open to ceiling (28').
2,500 sq ft second floor w 9' ceilings
6,000 sq ft basement w 8.5' ceilings
2,100 sq ft garage (oversized 6 car w shop area)
ICF Insulated Concrete Form walls (R34) with R60 Roof
Radiant floor heating on all levels and garage
Main house kept at approx 72*F, and garage @ 50*F

House has due south exposure, and will have "substantial" glass floor to ceiling windows overlooking the lake.

Will have multiple LP in both buildings for appliances and fireplaces, (and a couple 60K BTU+ wood burning fireplaces)

Will consider electric heating element options in chosen Garn units

We have 75 acres of heavily wooded land, and as I grow older I hope to gather logs for the next 30+ years God willing.

Site Location:
Cottage will be along the lakeshore, and the workshop (where we plan to locate the GARN unit(s)) will be approx. 250' behind, and 50' higher elevation. Terrain is heavily treed, and rocky.

Questions:

I would like to have a system where one burn per day should be sufficient on all but the coldest few weeks of the year.

Based on criteria above and your expert opinions, should we install:
Two WHS2000 units?
Three WHS 2000's
Two WHS 3200's

I believe one of each could actually be ideal from a capacity perspective, but I think this could cause unnecessary complexity to the system

The 2000's are approx 17K USD, and the 3200's are 42K (ouch!)

Will the 3200's possibly last longer as they have thicker construction?

Also I like the idea of the electric backup heat (we may be away on vacation for a few weeks during the winter)


We are looking for a system that we will not regret in the future in terms of size...... We prefer to spend a little more up front, than regret buying too small in the future.

Any thoughts on the above would be greatly appreciated.

Sorry for the novel

Cheers
 
Sounds like a great project, have you checked with Dectra about who your district rep is, they probably are associated with contractors that can calculate heat load from your architectural plans to determine your best garn approach.
 
I know zero on the Garns. I am however, duly impressed with your future plans! Sounds like some dreams coming true. Enjoy.
 
I'm a big proponent of wood heat and I see Garn as top shelf units. Not to discourage you but have you honestly assessed your return on investment with that heating system? If you're not experienced with burning wood from your property understand that it is a time commitment. If you're willing to invest the time every year and the money up front, I say go for it. BTW: you can't beat in-floor radiant either.
Sounds like quite a place and budget!
Good luck.
 
Please do not yell at me, I know this is primarily a wood burning forum.

With what you are planning or examining a pair of EFM DF520 Coal stokers making single pipe steam at 2 PSI will be much more efficient making heat and more effective for all you heating and domestic hot water needs and there will be much less plumbing to do.
The EFM coal stokers can burn soft coal as well.

Steam heat is very efficient and cost effective especially with needs involving larger heating loads.
 
There could be other factors involved, possibly he's into renewable fuels and it's a family endeavor, personally there is nothing better than the smell of a gasifiying wood fire.
Not to take away from the heating aspect of coal.
 
I would likely reconsider the electric elements if you will be relying on them for extended periods. (And the few weeks you mentioned is an extended period). At least run some numbers on how much $$ of electricity they will burn through in a day. That gets really expensive really fast. Do you have access to NG? LP on site for other uses? An oil burner might also be a consideration.

OK, I reread the above - LP will be on site. So I would likely use a condensing LP boiler for backup heat.

I would also likely consider or evaluate a divorced boiler/storage setup. I can get lots of used LP tanks here, big ones - at a budget of about $1/gallon. Using your figures above, 2 - WHS 2000's would cost you 34k USD. If you back out what using used LP tanks would cost for storage, that leaves you at 30k USD for the boiler component (estimating conservatively again). That will get you a couple of very nice Frohlings with money saved (there are Canadian dealers). Or Varms. ;) And if you run it all pressurized, you will eliminate heat exchangers and all that goes with those, and perpetual water testing & treatment regimes. You should also be able to incorporate other heat sources easier - like a backup LP boiler. Or even a pellet boiler if you have a decent pellet source there.

[Or even Leons coal boiler - if you have a source of coal. Which I doubt - something that gets overlooked at times.]

Whatever you do - with the scope of what you are talking about, get some professional design input. This is a big one - bigger = more potential for something to go off the rails when it comes to system functionality.
 
  • Like
Reactions: TCaldwell
There is another beast of a boiler to consider. Lopper is the name. Combined with decommissioned propane tanks as Maple1 has suggested, equals or outdoes the Garn. The Garn boilers are top shelf for sure but the Loppers have models rated up to 2.7 million btu's and they are Lambda controlled. They use 10mm and 20mm boiler plate. A member here has installed and used a Lopper boiler for a couple of years now, their thread can be viewed here: https://www.hearth.com/talk/threads/long-time-coming-installed-a-lopper-drummer-45-boiler.121101/

If my memory is correct, the Lopper site had more details available previously or I just cannot navigate as well at this time. The Lopper website can be viewed here: http://www.loppernorthamerica.com/drummer-cord-wood-boiler.html
 
Some interesting info can be found at the Lopper website under the Technical/Resources tab (case study). Here is a snip from that webpage which, as you can see, includes the consulting engineers info.

Lopper.JPG
 
Thank you for the reply,

Yes, I have contacted Keith from Dectra (Garn). Keith is an engineer and was very good to talk to. Keith also asked me to have my architect calculate my "heat loss", and said we could go from there.

I did not ask Keith who the rep in my area was,........ but he did say that as we get closer we may be able to visit a Garn homeowner in our area.



I am looking for more of a ballpark idea at this point to make sure I am not under sizing, and to get a comfort level that this system will work with our plans and lifestyle.

As the shop will be constructed first, I want to plan an appropriate sized area in that shop to locate the Boilers and a couple months of indoor cord wood supply.

Based on all that I have researched, I have two options that will likely satisfy my family's needs:

3 Garn 2000's @ $51,000 + delivery (USD) for the units
2 Garn 3200's @ $84,000 + delivery (USD) for the units


Any opinions on these two options ???

The 3200's are significantly more costly upfront.
Will they provide significantly more storage in the real world ???
Will they last longer due to the heavier metal construction ???

Additionally, for those that are using electric backup to heat the tank (during off peak hours)..... is this sufficient to keep the BTU's up if the homeowner is away for a week or two.

Thank you
 
Have you examined burning anthracite coal at all? I stopped burning wood after 33 years of dealing with it.

Just as an example the AHS S500 has 115 gallons of water and is tested for 500,000 BTU 14K+tax+frieght The AHS S1000 has 220 gallons of water capacity and is rated at a million BTU and $27,000.00 plus tax and frieght from this specific dealer.
 
A lot of good information ...... Thank you

To answer a few of your questions, I am not that concerned about cost up front. As for the time investment, I think I would really enjoy loading the boilers.

We installed a new wood stove (Hearthstone Heritage w glass door), in the old cottage (temporary), and I love loading it.....even at 3:00am! The smell, and visual is so beautiful and relaxing - that is what got me thinking about wood heating.

I am fortunate that I can afford up front costs, and want to purchase the best products out there. This project is not low budget, as I expect it to run 3-4MM - Not a snob at all, nor am I trying to boast, - as a boy coming from Slovenia (45 years ago) our family frequented the second hand store many many times. I had no problem with the clothing, but was teased by a bully at school for a while. He went a bit too far once and I retaliated a bit too aggressively. (I was a strong farm boy that eventually played University Basketball and Football - I'm 6'6" now, and was always the biggest in my class). At that time I was new to Canada, and could hardly speak English.... That bully pushed me into a wall, and I was concerned that the resultant blood stain on my new T-shirt would not go over well when I got home. Out of fear more than anything I did what Donald Trump says he will do to North Korea - I didn't ease up on the bully until there was half the school huddled around us, and two teachers prying me off. That bully got me suspended from school for a week, and believe it or not became my best friend after that!

I went on to higher education (mostly to play football), and worked my tail off for most of my life. I got really lucky many times, but never met a man that got to work earlier, or stayed later than I did...... I loved every job I ever had, and eventually made far more money than anybody really needs - but I never forgot where I came from. Today I employ a lot of people, including a half dozen with various disabilities and am proud to have them on my team!!

I am giving you too much info, but I think it gives you a window into what makes me tick.

This is also a way to be somewhat green and self sufficient. I like the idea of cleaning up our property of dead trees, and buying additional cord wood from a local guy.

Most people in this area heat with Propane (usually 1,000 gallon tanks). We will have a large propane tank to operate our kitchen stove, and a number of fireplaces. We will also have a couple large wood burning fireplaces for the beauty and smell.

Our hydro rates here are about 17 cents per KWH, but are reduced to about 9 cents in the overnight hours. I was thinking that if I could program these electric elements in the Garn boilers to operate only in these off peak times, this could work for a week or two per year when we are away - we could also adjust the thermostats to trigger at a reduced temp ie 55 degrees.

Don't think I want to go the coal route, but will read up on it to educate myself a bit more.

Could a Propane heater (with a separate water storage tank) be installed into the same water lines as the Garn system, and be programed to come on only when the main system is not able to satisfy demand - ie vacation, or extreme cold snap?

Cheers
 
Where in the Mustoka region are you located? Close to the lake and moderated winter temps? ... or inland with colder temps? Your latitude is about 45* north, south of my home (and location of Deep Portage) in Minnesota at about 47* north, and a long ways from any moderated Great Lakes temperature. So, I suspect your average winter temps are warmer than I experience, and your heating loads are less.

With that said, I mention Deep Portage (DP) because it has a single Garn WHS3200 which has 3200 gal of internal storage and it alone can heat 56000 sq ft down to winter temps of about -10F in an old, not well insulated building, and using fan coil units, not in floor radiant. To do this, the Garn must supply hot water continuously at a temp of about 150F with outside temp down to around -10F, and in the 135-145F range at outside temps around +20F. On a continuous burn basis the Garn WS3200 has average output of about 500,000 btuh, and it can maintain a continuous high burn for up to about 18 hours (100 lbs/hour) using well seasoned mixed hardwoods, and then it must be allowed to mostly burn out and empty hot coals before it can start another continuous burn cycle.

Your plan with radiant floor and ICF buildings should result in a need for hot water much cooler than DP requires and a much lower heat load than DP needs. For example, my personal shop maintained at about 55-60F (located at same latitude as DP) has a radiant floor and is supplied with 100F water. I suspect you will not need many if any continuous burn periods, and a Garn in your situation should be able to meet your needs on a batch burn basis, a type of operation for which a Garn is well suited. Based on DP experience, a single Garn WHS 3200 with its internal storage could work well in your situation. However, your mixed elevation needs, unless the Garn is at a higher elevation, probably will require a pressurized system, and that will require a heat exchanger, as the Garn is an unpressurized boiler. That will add an expense and ongoing maintenance issues for your system.

That said, DP also has a Wood Gun E500 (WG) gasification boiler which on a continuous burn basis can meet the DP heating need down to about -20F and it can operate continuously and does not need to operate on a batch burn basis. DP has a 4000 gal hot water storage tank that primarily serves the WG. A single WG E500 or equivalent with similar system storage also should work well in your situation. The WG also has the benefit of being able to supply 160+F hot water on a continuous basis, something which the Garn is not well suited and may not be able to do, because of its batch burn operating method. The WG is a pressurized boiler and no heat exchanger should be required.

There is the obvious benefit of having two hot water boilers, as you will be better assured of needed heat if one boiler needs maintenance during the heating season and needs to be shut down for more than a brief period. A condensing hot water LP boiler as backup and to use during absences may be a very good choice. Such a boiler modulates well, operates well so long as return water is 120F and below, and no storage should be required. You also will need to consider backup emergency electrical needs, such as with a generator backup system.

75 acres of land for supplying your heating wood needs is substantial, but it may not be sufficient over the long term. An actively managed wood lot with mixed age species should be able to supply about 1 cord/acre on a continuous basis. What portion of your land will be maintained as "heavily wooded," be actively managed to achieve mixed age status, and be available for heating wood supply? You likely have the potential of many years wood supply, but maybe not for the long term, and you may need to consider future wood purchases.
 
  • Like
Reactions: Karl_northwind
Congratulations on your choice to burn wood, it's really a lifestyle and today there are many boilers that will fit your needs. Keep in mind your building a small commercial heating system, multiple boilers, multiple buildings, heating and electrical backup, all tied with a degree of automation control. You want to make sure your all parties involved have a track record and can possibly show you examples of their work.
 
A lot of good information ...... Thank you

To answer a few of your questions, I am not that concerned about cost up front. As for the time investment, I think I would really enjoy loading the boilers.

We installed a new wood stove (Hearthstone Heritage w glass door), in the old cottage (temporary), and I love loading it.....even at 3:00am! The smell, and visual is so beautiful and relaxing - that is what got me thinking about wood heating.

I am fortunate that I can afford up front costs, and want to purchase the best products out there. This project is not low budget, as I expect it to run 3-4MM - Not a snob at all, nor am I trying to boast, - as a boy coming from Slovenia (45 years ago) our family frequented the second hand store many many times. I had no problem with the clothing, but was teased by a bully at school for a while. He went a bit too far once and I retaliated a bit too aggressively. (I was a strong farm boy that eventually played University Basketball and Football - I'm 6'6" now, and was always the biggest in my class). At that time I was new to Canada, and could hardly speak English.... That bully pushed me into a wall, and I was concerned that the resultant blood stain on my new T-shirt would not go over well when I got home. Out of fear more than anything I did what Donald Trump says he will do to North Korea - I didn't ease up on the bully until there was half the school huddled around us, and two teachers prying me off. That bully got me suspended from school for a week, and believe it or not became my best friend after that!

I went on to higher education (mostly to play football), and worked my tail off for most of my life. I got really lucky many times, but never met a man that got to work earlier, or stayed later than I did...... I loved every job I ever had, and eventually made far more money than anybody really needs - but I never forgot where I came from. Today I employ a lot of people, including a half dozen with various disabilities and am proud to have them on my team!!

I am giving you too much info, but I think it gives you a window into what makes me tick.

This is also a way to be somewhat green and self sufficient. I like the idea of cleaning up our property of dead trees, and buying additional cord wood from a local guy.

Most people in this area heat with Propane (usually 1,000 gallon tanks). We will have a large propane tank to operate our kitchen stove, and a number of fireplaces. We will also have a couple large wood burning fireplaces for the beauty and smell.

Our hydro rates here are about 17 cents per KWH, but are reduced to about 9 cents in the overnight hours. I was thinking that if I could program these electric elements in the Garn boilers to operate only in these off peak times, this could work for a week or two per year when we are away - we could also adjust the thermostats to trigger at a reduced temp ie 55 degrees.

Don't think I want to go the coal route, but will read up on it to educate myself a bit more.

Could a Propane heater (with a separate water storage tank) be installed into the same water lines as the Garn system, and be programed to come on only when the main system is not able to satisfy demand - ie vacation, or extreme cold snap?

Cheers

Loading the boilers is the easy part. Are you ready to properly process/put up that wood before you even get to putting it in the boiler(s)? That might be in the 30 cord per year area if you are contemplating that much boiler capacity - it all needs cut and split and then seasoned for a couple of years.

A Garn is an open boiler. The rest of your system and most any other heater (i.e. LP boiler) will be closed/pressurized. So you need heat exchangers wherever they meet. So won't likely be able to plumb a LP boiler directly to a Garn - there would need to be a HX in between. If that's what you mean. But the same HX could likely be used, if you are thinking about keeping the Garn warm when the fire is out for a long time - it would just be transferring heat from the rest of the system to the Garn, rather than vice versa, in those periods.

You/we really can't accurately answer or respond to your boiler question without an accurate and thorough heat loss calculation. jebatty likely has the best input above that you can get, without those important up front design calcs. That is a huge pile of investment $$ to be doing without some accurate numbers to work with.

Is there a reason(s) you are focused only on Garn? Have you fully considered what comes with using an open boiler when the rest of the system is closed? If so - that is OK, just as long as it is fully considered.
 
Anthracite coal can be easily delivered from Pennsylvania with a quick call to any of the mines. They have haulers that haul for them. I used to have a coal stoker stove in my old house and it was great. I was going to buy a stoker boiler for my new house but came across a wood boiler for a price i couldn't turn down. At times I wish I had gone stoker boiler like my friend has but oh well. I use around 7 cords of wood per year with my gasser and I buy my wood log length and process it. That is enough work for me, I would need to put in tons of time to haul wood out of the woods and then process it. I can't see processing 30 cords per year, that is just to much. With a coal stoker you load the hopper every few days and you can store truck loads of coal in a relatively small space, it also doesn't go bad. It can get wet or covered in snow, it doesn't matter. I would seriously consider it looking at how much heat you need per year.
 
Isn't there a guy, como in Colorado that was heating a hotel with 2 garns, I can't seem to find the search to bring up his threads, maybe some insight there. I'd be skeptical about concluding wood useage at this point, I could be wrong but who here with a garn approaches 15 cord a year? I burn 1/2 that
 
Isn't there a guy, como in Colorado that was heating a hotel with 2 garns, I can't seem to find the search to bring up his threads, maybe some insight there. I'd be skeptical about concluding wood useage at this point, I could be wrong but who here with a garn approaches 15 cord a year? I burn 1/2 that

If 15 cord a year will do it, then I don't see the need for all this boiler power. One 2000 should be lots.
 
If 15 cord a year will do it, then I don't see the need for all this boiler power. One 2000 should be lots.

He's planning to heat over 20,000 sq. ft. up North and I bet he's got an acre or two of glass to look out of, no single wood burner is going to be able to handle that heat-load. Whatever the answer, times it by 2.
 
He's planning to heat over 20,000 sq. ft. up North and I bet he's got an acre or two of glass to look out of, no single wood burner is going to be able to handle that heat-load. Whatever the answer, times it by 2.

Yes I get that - but what goes hand in hand with that is a LOT of wood. Hence my 30 cord guess - which I suspect is an underestimation. And without proper heat load calc, all we're doing is guessing.

If multiple boilers are needed, so is a metric crap ton of wood. If a metric crap ton of wood isn't needed, then one boiler will do. So there's still lots of unknown here.

I burn around 6 cords per winter with my little 40kw boiler. That's only burning average 6 hours per day. So I could likely run through 15 cord of wood per winter quite easily if I was burning steadier. So failing to see the need for all this boiler power unless said metric crap ton of wood is also needed - and due consideration for perpetual yearly metric crap ton of preparation of it.
 
It's funny how you can very easily have a home that is too small for a boiler. Really anything that you can heat with a woodstove, say up to 3000 SF. Then you can quickly get to the point where the home is too big for a boiler mostly due to the metric craptons of wood required.

The multiple building thing makes the most sense.

I expect the OP in this thread will be mostly dependent on conventional furnaces and fuel despite his best intentions. Which is why I would be looking at one big boiler to just reduce the dependence on the conventional furnace while still being able to enjoy the wood burning hobby and not too many metric craptons of wood. Nothing wrong with using the boiler for 50% of the demand.
 
It's funny how you can very easily have a home that is too small for a boiler. Really anything that you can heat with a woodstove, say up to 3000 SF. Then you can quickly get to the point where the home is too big for a boiler mostly due to the metric craptons of wood required.

The multiple building thing makes the most sense.

I expect the OP in this thread will be mostly dependent on conventional furnaces and fuel despite his best intentions. Which is why I would be looking at one big boiler to just reduce the dependence on the conventional furnace while still being able to enjoy the wood burning hobby and not too many metric craptons of wood. Nothing wrong with using the boiler for 50% of the demand.


Very true, I think the amount of wood needed for this load will quickly turn the wood collecting hobby into a burden he may not be prepared for. Heat the shop with wood and the house with propane or vice-versa but have backup systems for both. Another option is a commercial scale automated chip burner that can easily be sized to heat both buildings, it may take more infrastructure planning and machinery to manage and load the chips but in the end it will be much more automated. Bio-Burner has large models that can burn wood chips, pellets or sawdust.