Woodgun without waterstorage vs. Tarm with waterstorage

[ceevictor]

Hi, this is my first post here. I'd love some feedback on my situation.

I want to add a gasification furnace onto my existing propane furnace (to use as back up). I have NO basement and very little room in the boiler room so I have no choice but to build a small insulated outbuilding for it and bury the line to the house. This all seems doable (although expensive!) but I know in the long run it'll pay itself off. The two funaces I've been looking at are the Tarm Solo Plus 40 w/ 822 gallon storage OR the stainless Woodgun without storage. Anyone have any info on comparing these two setups? Mainly concerning overall efficiency, ease of use, and reliability.

Let me say that the reason why I'm considering a unit without storage at all is because I would need to put the storage tank in the outbuilding with the furnace (15-30 ft from the house). The Tarm guy I spoke with says he's never heard of anyone doing this. I imagine it would lose some efficiency in this setup. I'm also not clear on how this setup would work in counjunction with my existing 55 gal. Superstor hot water tank. I wouldn't want to draw from the outdoor hot water for household use cause it'd take me 5 mins to get the hot water going, right? Anyway because of these uncertainties I thought the stainless Woodgun might be the way to go. Again, my primary concerns are efficiency, ease of use, and reliability.

Thanks for any insight you all could lend!

 

[Eric Johnson]

That's a dilemma.

If cost is not a big issue, I'd consider getting an outdoor gasifier like the Adobe, Black Bear or Blue Forge. The Blue Forge looks like a nice rig to me.

What kind of radiant heat do you have: cast iron radiators, baseboard, infloor radiant or something else? If you have ci rads, you might get away with a four-way mixing valve instead of a hot water tank. Or, you could go with a Garn. It has 1,500 gallons of hot water storage already built in. Just park it on a slab and build the insulated structure around it.

 

[ceevictor]

Cool, I didn't even know there we're outdoor gasifiers. I'll check them out.

My house is baseboard hot water and infoor radiant. That Garn sounds interesting.

 

[Eric Johnson]

The three I mentioned just came out in the past year or so. I really think that you need water storage with any gasifier--indoor or outdoor--for reasons that I'm just beginning to appreciate. Given that, I think the Garn might be worth a serious look, as it all comes in one package that you can put a shed or other small building around. A friend of mine has two (he runs a sawmill), and I'd be happy to hook you up with him if you get to that point. He's also a Garn dealer, but a straight shooter. Garn has a video on the Internet somewhere. Pretty impressive.

EDIT: I just remember one more outdoor gasifier. It's a modified indoor rig, very similar to what I have, but with an insulated structure and 500 gallons (I believe) of hot water storage included. You can get a bit more detail at:

http://www.newhorizoncorp.com

 

[webbie]

Don't forget to consider longevity - PROVEN longevity! Most earlier woodgun rotted out.....so they went to stainless....but that in itself does not guarantee anything. It would be a shame to spend this much money and not have something which will work for a few decades.

 

[ceevictor]

Good point. From what I've seen so far I'm feeling that water storage is best when using gasification. I liked that Garn from what I could gather off the website. With that unit I wonder if it'd be worth burning it in the summer for hot water use, or would I be better off using my propane?

Eric, I couldn't find anything at that link about a modified indoor rig, where did you find that?

 

[Eric Johnson]

For some reason, the New Horizon homepage comes up with an index instead of the html. I can't find it, either. However, the rest of the website is working, and you can check out the EKO and the BioMax specs, etc. The outdoor setup involves the BioMax, which looks to me to be very similar to the EKO. Both mfg. in Poland.

Try this:

http://www.newhorizoncorp.com/woodboilers.html

Actually, it's working now:

http://www.newhorizoncorp.com/

I did see a WoodGun at a recent trade show, stainless steel firebox, cyclone--the whole nine yards. It's built like a Sherman tank. However, the 130K btu model on display had a "show special" price of $10,500, which is about $4,500 more than I paid for my 205K btu EKO. It looks to me like the same technology in a beefier containment vessel. Since it's a downdraft gasifier, I think hot water storage is probably just as desirable as with any other wood gasification boiler.

Which brings me to my question for Craig: The New Horizon website says that you burn "up to 40 percent less wood" when using a hot water storage tank with a gasifier. That's another way of saying it would be less efficient, right? So isn't "inefficiency" just another word for smoke where gasifiers are concerned? If so, then would it not follow that a 91% efficient boiler would drop to something south of 60% efficient and have correspondingly higher emissions when used without a tank?

 

[webbie]

The tank vs. no-tank thing is impossible to put a number on - consider someone who has a high heat loss and uses the boiler hard during the cold months...and might also have a lot of radiation and a mixing valve. They are probably seeing over a 70% total efficiency. I think the lower numbers would be for someone who does not need as much heat on a constant level......

and, the reason for storage is also that the boiler does not degrade as quickly...which is, of course, a good thing. I think they are trying to push people into storage because it means a happier customer and a longer lasting unit.

As we also know, the numbers on brochures and web sites are thought up by.....well, by people like me! Always put your best foot forward - a marketing creed.

 

[ceevictor]

That looks interesting, although I couldn't info on it, just the pics. It looked like a propane tank on the back? or could that be the storage? Thanks for the links.

 

[Eric Johnson]

I think I read somewhere else that the 500 gallon storage tank is below the boiler, but that might be a misinterpretation of what was being said. You can call Zenon Pawlowski at New Horizon and I'm sure he'll be happy to tell you all about it. The tank on the back might be expansion, though that's just a guess as well. If it's rigged up with a pump and an expansion tank, then it's close to a self-contained system.

That's one I'd wait until I got some field reports before jumping into. But maybe he's on to something. The other outdoor gasifiers mfgs. make some interesting and possibly dubious claims about their units' abilities to burn green wood and do it smoke-free. I'd have to see that with my own eyes to believe it.

 

[ceevictor]

Yeah, there's so many options and claims it's hard to sort through. I'll call Zenon and pick his brain. by the way, how much wood do you burn a season and how often are you loading?

 

[Eric Johnson]

I don't know because I just hooked it up the other day. Only ran it once. You can check out the installation thread in the Gear forum.

My hope is to burn 10 full cords and load it twice a day. That's heating an 1865-vintage farmhouse with several better-insulated additions and a single-pane glass greenhouse. Plus domestic hot water. The greenhouse might kick that up by a couple of cords. My old boiler, which was a conventional, 150,000 btu/hour smoke dragon consumed around 16 full cords annually, and that was without the greenhouse. So I'm figuring half the wood consumption, since I think the EKO is probably twice as efficient.

 

[ceevictor]

Makes sense. Did you consider using the Garn? Also, any idea how much it costs?

 

[Eric Johnson]

If you look at the thread, my boiler room is only 34 inches wide, so a Garn was totally out of the question. The Garn must be six or eight feet wide. My dealer friend says they retail for around $12,000. I'm not sure what the output is. The Blue Forge sells for about $9,000. Stuff's pricey.

I did consider the Tarm Solo 60, but since all my wood (some 40 cords) is all cut to 24 inches, the 20-inch limit on the Tarm pretty much doomed that option. The Tarm has a better warranty (20 years vs. 5) and a proven track record, and the prices are not a whole lot higher. I'm not sure if they have a mechanical heat exchanger cleaner like the EKO and BioMax, but that's an important feature, I think. I hear that cleaning the heat exchanger tubes by hand is a dirty job, and something you have to do periodically.

Given the exchange rate and higher shipping costs, I suspect that imported equipment is going to become more expensive moving forward.

 

[ceevictor]

Anyone know anything about these units that are built ready to go outdoors? they look just like the outdoor wood furnaces but use gasification.

Here's one I found

http://www.wdheat.com/Gasification E3400.htm

It'd be nice not to have to build a shed unless I need to.

 

[wg_bent]

I figured the industry would get around to making those. The older OWB's just pollute too much.

 

[ceevictor]

So I just talked to Rick from Seqouyah, they make that outdoor unit I linked to earlier. The only approved unit they have available is too big for my needs (320,000 BTU) my existing propane is 120,000. He claimed that the larger unit will not use more wood then a smaller one, does that make sense? Actually, other then the higher price, he's saying it's better to use a larger unit because I can load it less often (firebox is 44" long!). It holds 250 gallons of water. These units are brand new so who knows what kinks need to be worked out.

 

[Eric Johnson]

I'd want to talk to someone who has run one under actual battlefield conditions for a year or two before making that kind of financial commitment. And on my kind of battlefield. The concept of "bigger is better" doesn't jibe with my understanding of wood gasification, but there are a number of different companies working very hard trying to make outdoor wood gasification a reality, so who knows?