Is Garn worth the extra $$$

As you stated, the advantage of the Garn is primarily that it is all in one. It is probably comparable in cost to buying both a gasifier and commercial storage without all the need for plumbing and controls to connect it together. The downside is that it needs its own building and buried lines. You certainly can build your own storage and save a bunch of money. Plumbing the whole system yourself can save tons as well. There are also some differences with the round firebox and draft fan, but I will let Garn owners speak to that...

Welcome to the Boiler Room, whtmtnbiker.

Depending on how creative, motivated and lucky you are, you may be able to save some $$ by gathering the materials and vessels to build your external storage system. However, if you are not so motivated or lucky, you will spend about the same for the external storage + gassifier as you would for a GARN with integral storage. Yes, the GARN is a gassifier, but a totally different design from the downdraft units most other manufacturers offer. External storage does require additional piping, pumps and controls over the GARN integral system.

Another point to consider is that the heat transfer from the GARN firebox and heat exchanger piping to the storage water is the most efficient means to accomplish this, since there are no transfer lines or additional HX in the storage tanks. for external storage there are also decisions to be made with respect to pressurized and non-pressurized systems. I am sure others will fill you in on whatever details you may still need in that regard (assuming you have already searched and read the copious number of threads on the subject). The GARN is an unpressurized system.

I am not sure what WNO was referring to specifically in his reference to the round fire box, but the draft inducer fan on the GARN is another of it's many great design aspects. When starting/loading/reloading the GARN, the draft fan is pulling a large quantity of air through the fire box and heat exchanger piping. That means no smoke in your face or in the room when loading with a fire going.

If you have not done so, feel free to check out my installation blog via the link in my signature below. There are also some operational videos for you to see.

Best of luck with whatever system you choose (but you know which one I am rooting for . . . ;-) )

I was referring to the round shape of the firebox. I have heard that it prevents bridging of the wood...

WoodNotOil said:

I was referring to the round shape of the firebox. I have heard that it prevents bridging of the wood...

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OK - thought that might be it, but did not want to "assume". I have only had one incidence of bridging, and it was unique to the large splits I happened to throw in for that particular burn. It also did not seem to affect the burn, either, as I only discovered it when checking on the state of the burn - the splits were glowing and burning nicely with all that air supply!

I have an Econoburn 150 and am building storage; I am very happy with the Econoburn and have no regrets (there's no way I could've shoehorned a Garn into my 1830 farmhouse cellar, and I did not want to create a new separate outbuilding for the purpose).

But I agree with the comments above that, by the time one gets into all of the ancillary plumbing, pumps, controls, etc., a Garn is likely no more expensive than a downdraft gasifier + storage.

Jim K-

Thanks for that link to your GARN install. Really really nice job (I'm sure you heard that before!). I've gone with a corn burner, but it's still instructive to see how you did your install. Wish I would have seen that before I did mine!

Regards-

What it came down to for me was the storage issue. Buy the garn, storage is done. Buy another unit and you got extra work to do.

For me, I have enough work to be done with replumbing my existing boiler room that I didn't want to prick with the other. I expect it might cost me an extra 3 or 4 thousand for the Garn. 3 or 4k over 30 years is peanuts.

I never let the cost change my decision. Pick the unit that works best for YOUR situation. Don't be too frugal with this process, quality counts.

Good Luck!

RowCropRenegade said:

I never let the cost change my decision. Pick the unit that works best for YOUR situation. Don't be too frugal with this process, quality counts.
Good Luck!

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Those sure are true words- in general, cutting to the chase to get what you'll really be satisfied with, and that will serve you well for a long time, is a lot less expensive in the long run than getting the cheap option first and upgrading several times to eventually get to where you want to end up.

There's a great old expression I heard somewhere once about "being too poor to buy cheap stuff."

whtmtnbiker said:

My first is what's "bridging"?

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It is when the wood gets caught on each other and doesn't fall down during a burn. What happens is all the wood in the middle burns out leaving a bridge of wood above it. In a down draft gasifier bridging affects the gasification as there is no wood over the nozzle which is in the bottom of the fire box. I believe in a Garn everything exits out of the back of the firebox, so it is not an issue.

She's also figured out a formula adjusting my project estimates...double the cost and triple the time allotted. Hate to admit it but she's usually right.

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I am guilty of the same thing!

I will attempt to address the title of the thread from my personal biased perspective. I agree that the overall installation cost involved in adding storage to a downdraft gasser will be similar in price to the installation of a Garn. I can't say that for sure... I have never installed a Garn, but it makes sense from a market perspective.

Things to think about... storage seperate from the boiler allows the ability to install your system in stages. Boiler now, storage later when finances/time permit. Granted, this option is meaningless for folks who need to have extra long cycle times right out of the gate. Also, storage seperate from boiler allows you to disconnect from the storage at any time, and pump heat directly to the exchange points. A handy feature that might help out if you get behind firing the boiler and need heat in a hurry. This would be an issue only if you want to use absolutely zero dollars in fossil fuels as backup.

One last thought... and I would actually like to hear some input on this from the rest of you. I surmise that a storage tank seperate from a boiler will last longer than the boiler itself since the tanks will not have to endure the stresses and corrosion inherent in fireboxes. In the case of a boiler that incorporates storage into it's design, you will effectively have to replace both storage and boiler at the same time when the boiler goes bad after 20 or 25 years. (Maybe the Garn are said to last longer than that?) If the two are seperate, you would likely only have to replace the boiler, which will cost about half the price. I posted this idea in another thread, but it didn't seem to go anywhere. I don't know how many people will even consider looking 20 years into the future... or whether you can expect a closed system storage tank to last much longer than that anyways... though I think if properly installed could last quite a long time.

cheers

When I actually get the final figures, I think the cost of a garn will be about the same. I like what I got, but was quite curious when I started getting info on a garn. My Innova is in a garage (whoops, meant to say wood, storage building) that would have easily held the garn. I love the idea of my unit in an outbuilding. All my mess is out there. And if i need a little quiet time, love to watch the flame.
I think it was piker did mention about quick turn around time on heating house. With my schedule, we build a fire in the afternoon. 3 or 4 ish. Nobody home until then, house will cool off on the cold days(below zero). Room temp about 62ish. Start fire and in about 45 minutes I'll have 160 degree water running thru my baseboard. Starting to heat house up pretty good. Another 20 to 30 minutes and i got 180 soon to be 195 degree water flowing thru the baseboard. This is when the drapes and anything hanging off walls starts flapping. Now we're cooking. Also any heat not being used will go directly into storage. I do not know if a garn would be able to do the same thing, as quick. BUT with the smallest garn I would have about 1500gals of storage versus the 820gal I have now. So that might not be an issue.
One important note, make sure you have a installer well versed on control/valve work(plumbers are not heating contractors, at least most aren't). If available, follow the manufactures directions on installation. If you have a unique setup, contact said manufacturer, and have them advise you on your problem. My installer has put these type of systems in before and he followed Tarms' layout, and it worked the first time and haven't had any issues since. Also if I have any problems in future, should be easy to diagnose with the support staff.

Hopefully by the time my garn wears out fusion technology will be here....

I hope my mechanic skills will be improved by the time I wear my unit out. I'll build a knockoff maybe. Put the door off the old unit on it.

My old oil boiler has run over 40 years, why can't these wood boilers do the same? Maintenance is key with any piece of machinery.

Rust is the enemy!

Piker said:

One last thought... and I would actually like to hear some input on this from the rest of you. I surmise that a storage tank seperate from a boiler will last longer than the boiler itself since the tanks will not have to endure the stresses and corrosion inherent in fireboxes. In the case of a boiler that incorporates storage into it's design, you will effectively have to replace both storage and boiler at the same time when the boiler goes bad after 20 or 25 years. (Maybe the Garn are said to last longer than that?) If the two are seperate, you would likely only have to replace the boiler, which will cost about half the price. I posted this idea in another thread, but it didn't seem to go anywhere. I don't know how many people will even consider looking 20 years into the future... or whether you can expect a closed system storage tank to last much longer than that anyways... though I think if properly installed could last quite a long time.

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This is a totally uneducated guess, but I would think that the Garn would have less thermal stress as it heats up and gets cooled down than my EKO. The reason is that when I'm burning I don't start to send water to the storage till it hits 187 degrees which almost empties the boiler and refills it with 140 degree water. The 140 degree water is actually hotter than that as it picks up heat from the heat exchanger right away, but this is the temp that it enters the boiler. This cycle repeats many times until I shut down. With the Garn, it heats up the whole tank all at the same time so you start at your recharge point and burn it till the fuel is done. Maybe I'm wrong and 40 degree fluctuation many times does nothing to the steel and ceramics.

sdrobertson said:

Piker said:

One last thought... and I would actually like to hear some input on this from the rest of you. I surmise that a storage tank seperate from a boiler will last longer than the boiler itself since the tanks will not have to endure the stresses and corrosion inherent in fireboxes. In the case of a boiler that incorporates storage into it's design, you will effectively have to replace both storage and boiler at the same time when the boiler goes bad after 20 or 25 years. (Maybe the Garn are said to last longer than that?) If the two are seperate, you would likely only have to replace the boiler, which will cost about half the price. I posted this idea in another thread, but it didn't seem to go anywhere. I don't know how many people will even consider looking 20 years into the future... or whether you can expect a closed system storage tank to last much longer than that anyways... though I think if properly installed could last quite a long time.

Click to expand...

This is a totally uneducated guess, but I would think that the Garn would have less thermal stress as it heats up and gets cooled down than my EKO. The reason is that when I'm burning I don't start to send water to the storage till it hits 187 degrees which almost empties the boiler and refills it with 140 degree water. The 140 degree water is actually hotter than that as it picks up heat from the heat exchanger right away, but this is the temp that it enters the boiler. This cycle repeats many times until I shut down. With the Garn, it heats up the whole tank all at the same time so you start at your recharge point and burn it till the fuel is done. Maybe I'm wrong and 40 degree fluctuation many times does nothing to the steel and ceramics.

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Not an expert, but it sounds like you aren't plumbed properly if that is what your EKO is doing... You should have a mixing valve in a pipe running from the boiler output to the input, so that you are looping the water around the boiler and heating up just the bit in that short pipe, until you are up to temperature, and then SLOWLY mixing in small amounts of your house / storage water (or water from your heat exchanger) to maintain a constant temperature in the boiler... If you are cyclically pumping hot water out and refilling with cold, that is a bad thing... You want a relatively steady rate of cooler water coming in, getting heated and leaving, so there will be a temperature gradient from the input to output ports, but the temperature at any given point in the water path shouldn't change significantly. (or at least that's my understanding of how it's supposed to work - If I'm way off base, I hope one of the pro's will jump in and tell me...)

Gooserider

Isn't the Garn cheaper than one of the boilers in the 200K btu class and a 1500 gallon commercial storage solution? $8K+ for the boiler and $7500 for the storage vs $12K for a 1500? Or is this too simple an analysis?

Maybe the integration of solar water heat in the off season is more expensive with the Garn because of the integrated storage?

It seems that it is only more expensive if you plan on starting without storage or intend to fabricate a storage solution?

SolarAndWood said:

Isn't the Garn cheaper than one of the boilers in the 200K btu class and a 1500 gallon commercial storage solution? $8K+ for the boiler and $7500 for the storage vs $12K for a 1500? Or is this too simple an analysis?

Maybe the integration of solar water heat in the off season is more expensive with the Garn because of the integrated storage?

It seems that it is only more expensive if you plan on starting without storage or intend to fabricate a storage solution?

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The Garn 1500 is a 350kbtu with 1420 gallons. You are correct that for that btu output and the amount of gallons of storage that is a good price. However, very few of us need 350k, so if we were not going with a garn we would get a smaller boiler. The size of the Garn is fine because you just end up going longer between burns. As I said before, if you have a place for one of these units and the money, it is hard to pass it up.

SolarAndWood said:

Isn't the Garn cheaper than one of the boilers in the 200K btu class and a 1500 gallon commercial storage solution? $8K+ for the boiler and $7500 for the storage vs $12K for a 1500? Or is this too simple an analysis?

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The Garn is a bare steel boiler, so the costs of insulating it and building an enclosure need to be factored in. The Garn is also atmospheric, so a large heat exchanger (or multiple small ones) needs to be installed in most situations.

Installed cost of a Garn should be similar to a comparable boiler/storage combo, if done professionally.

Joe

Is the additional heat exchanger to isolate water that is exposed to oxygen from the distribution system or to keep the boiler from filling above a desired level if part of the distribution system is above it? Can the heat exchanger be avoided with appropriate materials in the distribution system and locating the boiler above it? I assume another exchanger is required for DHW?

SolarAndWood said:

Is the additional heat exchanger to isolate water that is exposed to oxygen from the distribution system or to keep the boiler from filling above a desired level if part of the distribution system is above it? Can the heat exchanger be avoided with appropriate materials in the distribution system and locating the boiler above it?

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It's a combination of the two, in some cases (systems with large amounts of yellow metals and the like), but mostly it's to prevent system from draining back into the boiler.

That's why I said "most situations," as some cases will not require it. For example, I drew up plans for a Garn to heat a greenhouse using radiant heat, which meant there was no piping above the water level of the Garn.

SolarAndWood said:

I assume another exchanger is required for DHW?

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Yes. Typically, an indirect water heater is used.

Joe

Thanks Joe. The boiler will sit above the entirety of the new distribution system. No heat exchanger and no stack makes a huge difference in the $$$ comparison.