Why buy a Eko or Tarm over a Greenwood or Seton?

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tigermaple

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Jan 3, 2008
88
Fingerlakes, NY
This forum seems biased toward Eko and Tarm. Maybe because of the banner ads you see above. I believe this view is unwarranted. The GW/Seton is clearly the superior unit IMHO. The simple design with less to go wrong is key. Less motors and fans to fail, plus a natural draft is what I'm getting at. I'm not even getting into the fact that I save DAYS of labor by not having to split wood and test it with a moisture meter. They are American made and don't need water storage(not that storage would hurt). What gives? I know the GW/Seton are not perfect, lack of access door to clean heat exchanger and condensation, for example, but these can be fixed or lived with. The overall performance between the two groups seems the same, but I have no empirical evidence to present.
 
Just a thought...........If you get on the web and research wood boilers and pellet boilers you'll find that most of the really good gasification technology out there comes from Europe. Specifically Germany, Austria and to a lesser extent some Danish and Eastern European countries. Just about everything you'll find incorporates the same basic technology with a few different ideas and control twists thrown in by the various manufacturers.

There are a couple reasons for this. Number one being that they have been doing this on a larger scale than we have for a long time. Hence, they've learned a few things along the way. Number two would be the issue of environmental concerns. The pollution and emission laws for wood burners over there are pretty stringent, while here in the US we can't even agree on a basic set of rules that apply to all regions of the country. When the playing field isn't level you wind up with a mishmash of one manufacturer claiming this and another claiming that about their products. It's no wonder most of the good Euro companies are waiting for the dust to settle here before they bring their products over. (Viessmann and Froling come to mind immediately) I have had conversations with both companies and lack of uniform standards in the USA is one of the reasons they refuse to introduce their fine products here.

When it comes to wood burning, control is everything and if you look at some of the products from the two companies mentioned you'll find they are both forced negative draft units that incorporate some pretty sophisticated control technology. Similar to what you'd find on a best quality gas or oil boiler. There's not a single one that is natural draft as it's very difficult to achieve good emission results under field conditions with that type of combustion control.

As for being able to burn whole unsplit logs, some may feel that's an advantage due to the perception of longer burn times. The flip side of the coin is to burn wood cleanly you want to burn it hot and fast so split wood beats "round" wood hands down. Again...the emission laws across the pond are written in stone and the manufacturers over there have figured out ways to meet them. You'll also find that storage is of such importance that many of the governments there actually offer tax subsidies for "buffer" tanks.

You have to wonder why there is nothing like a Seton or Greenwood made over there.

Just a little food for thought.
 
This may not be an apples to apples comparison, but it reminds me of the days when to compete against Japanese car makers, U. S. companies came out with units like Aries, Reliant, Escort, Tempo, Cavalier, Citation. Remember those Jewels??
 
Ran the wheels (and everything else) off 3 Reliants back in the '80s. Company cars. Junk.

Anyway, we try not to have a bias. About all a banner ad gets you in the form of consideration is me pointing out that it's there from time to time. Other than that, I don't care what people buy or use. I just want everyone to be successful and burn less oil and gas.

I think it pays to point out that the Seton-style design is completely different from the Tarm/EKO/Econoburn/Biomax, etc. Two chambers vs. one; water vs. refractory; pressurized vs. non; bottom vent vs. top; natural draft vs. blower; firetube vs watertube, etc. Both have their pros and cons, obviously.

I've used both induced-draft boilers and natural draft designs. And while I like the simplicity and self-reliance of natural draft, I prefer the performance of a fan. I think it's one less variable to worry about.

But I don't think I know enough about either to say which is superior. I like what I've got and hope everyone else feels the same way.
 
This is my first season with the Seton W-130 and difference in time in restocking your wood lot is absolutely amazing . Any rounds up to 16'' in dia go right in covered and ventilated storage . I still drag my 25 year old hydraulic splitter out for the big stuff . I like the height and size of the loading door , makes it very easy to roll the logs in without bending your back . Anthony
 
As Eric says, sponsorship doesn't mean much - Greenwood has been a site sponsor for a while (not ads in this room, but elsewhere) and Tarm is not currently a site sponsor, etc.

Any bias is only individual and is probably based on the fact that there are vastly more Tarm and Eko units in operations at this point in time. As some people here know, I sold Tarm for 20 years and was the US Importer for a 5 years. That makes me somewhat knowledgeable in their models - so you might see that I answer Tarm questions and not Eko or Greenwood.....

Strangely enough, in all the years I sold Tarm I never heard of the Seton design......our competition was only OWBs at the time (1990 or so) and maybe a little Wood Gun (eshland).

So rest assured that we (mods or site owner) have no dog in the fight except a desire to see satisfied users and clean burning (high efficiency). The whole idea of these forums is to be able to find out about all those other brands and designs and help each other with the nuances.
 
I actually put a deposit down on a Tarm, but after reading the manual, decided against it. Though I have a GW, I wouldn't say it's better nor worse than Tarm/Eko ('specially seeing that I've never run either). But as Eric mentioned, TOTALLY different machines. Both have advantages/disadvantages.

A big reason I favored the GW was the ability to handle 'less than ideal' wood. But let me tell you something. When we were getting wood last fall, I took what seemed like the BEST Oak, hard maple and some ash, and put this inside the outside furnace room. Then, about two weeks ago, I decided to incapacitate my Stihl for a few weeks, and had to go to burning the best stuff. Let me tell you it is amazing burning dry, clean, warm hardwood. Yes, it's getting warmer outside. But we had two mornings in the low teens, and when you put this wood on a coal bed and close the load door, it sounds like a jet is taking off!

But I don't care who the manufacturer is, when it gets 60* during the day, if you don't have storage, nothing works that great.

Jimbo
 
Heaterman,
I understand fine European design as I have Bederus oil boiler and many euro woodworking tools. Plus a car of euro design. All my chainsaws are european. The rest of the stuff I own, beside the GW, less than 10 years old is made in china. My point is maybe we got this one right. I like this furnace concept and believe with further simple tweeks it could really shine.
 
Craig and Eric,
Sounds like Greenwood should advertise here. This site seems to get a lot of hits from people interested in buying. The info here is awesome for newbies and veterans. I agree Eko or seton better than oil.
 
Jimbo, Almost all the wood I burn is damn near perfect because I'm lucky enough to have plenty of woods and saws. Nothin like dry rounds in the GW. I know how hard it is to burn your best wood though. It's like a safety net for the killer cold snap. What's wrong with the saw? I didn't think stil's broke.
 
Is a Ford better than a Chevy better than a Toyota better than a Porsche better than a Yugo, etc.? Each has it market, price range, options and features, pros and cons, devotees, trashers, and "fit." Just figure out what's best for you and hope no buyer remorse. I'm very pleased with what I have after one full season now of operation. I'll tell you more in 5 and 15 years down that long, winding log road -- and all the while not burning a fossil fuel or paying the oilman.
 
One thing that would sway me toward the Eko would be the variable speed draft fan. Modulation is a wonderful thing in a boiler!

Chris
 
As an EKO owner, I don't feel that I have any brand bias. I do know that I've been very impressed by the efficiency and performance of the forced draft gasification. I'm ending this season right at 4 cords, and I'm pretty well convinced that there isn't any other wood burning solution that would be significantly better for my needs.

It may be the case that there are other solutions that would be just as good, though. My brother built his own forced draft gasifier and saw a 40% reduction from his wood consumption with his previous conventional wood boiler.

As to whether any of the natural draft designs can achieve similar performance, I don't have the data. In cases where simplicity is critical, the natural draft approach may be the better choice.

It also seems to be the case that a forced draft gasifier only makes sense if you can provide it with dry enough wood split small enough. They're pretty unforgiving about green wood, and they don't generally like a load of all huge rounds.
 
The more I use the Greenfire the cleaner I burn. The only time I see or smell smoke now is on startup or reload. If it is real cold I see steam or white smoke similar to an oil boiler. I agree the ability to burn green unsplit wood is sweet. I can't wait to see what dry rounds will do next year!!! C'mon winter 08!!! LoL just kidding... relax...
I wish I could try other gassifiers to have a comparison...
 
The ability to burn green unsplit wood may be sweet, but it dosn't come for free. It takes heat to burn that moisture out of the wood, so you will not see the same efficiency burning green wood as you would if it were dry.

It's the same story with the OWB's. Everyone raves about being able to burn green wood, but they are burning double the amount of wood to get the same amount of heat.
 
Yes that is a given and we all know it. The point is I can burn green if I have too and the boiler burns very clean. OWB's can burn green but are very dirty. Big difference. That is why I said I cant wait to see what dry wood will do next year... Even burning green I am willing to bet I am not burning any more then y'all are burning dry wood. I know my wood consumption is probably 1/3rd to 1/2 less then the Memco or Buderus smoke dragons burning dry wood.
 
Blend in 25% wet wood with 75% dry and there is little drop in performance. A 50/50 mix will cause significant loss. I have to get my system rigged up like nofossil so I can give out real numbers.
Sparkle,
Your gonna be very happy with dry rounds, I hope your family likes a warm house.
Nofossil,
Do you weigh your wood loads ever to get efficiency readings?
 
tigermaple said:
Nofossil,
Do you weigh your wood loads ever to get efficiency readings?

Of course.....

I had a thread earlier that covers this in excruciating detail. Of course, you have to measure moisture content as well as weight, and you have to take detailed measurements of the heat that's produced over the course of a burn.

Bottom line: My system efficiency is about 55% - that is, of all the heat value that's in the wood that I burn, 55% is measurable output delivered to heat loads in my system. The rest is heat leakage from pipes and the boiler itself, or lost up the chimney as water vapor, hot flue gas, and so on.
 

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Nofossil,
I'm glad your on our side. I love how every wood boiler mfr raves about 85-95%.
Any ideas on further performance boosts or are we topped out? I hate to think almost half the wood I burn goes up in smoke even if all is running near perfection.
Keep up the good work.
 
tigermaple said:
Nofossil,
I'm glad your on our side. I love how every wood boiler mfr raves about 85-95%.
Any ideas on further performance boosts or are we topped out? I hate to think almost half the wood I burn goes up in smoke even if all is running near perfection.
Keep up the good work.

The devil's in the details. It's a lot easier to get 90% efficiency if you assume that the available energy is 6500 BTU/lb rather than 8600 btu/lb, for instance. Combustion efficiency is different than unit efficiency, which is different than system efficiency. A lot of the heat that I'm not catching in my 56% is heat that still goes into the house, so it's not lost. My actual efficiency would be worse if the unit were in an outbuilding, though.

I've made some improvements to my system that I hope will get me another 5% or so. I just need a couple of loads of consistent wood to do the tests. Haven't had that in a while.
 
Isn't there about a 1,000 pound difference between the Seton/Greenwood boilers and the EKO/Tarm's.
That seems to be a big deal to me. How does one install that in a basement? I guess they can go in the garage.

I think the large amount of thermal mass in the Seton/Greenwood boiler takes a while to heat up and cool down.
That heat capacity is great if you want to burn green wood. Most of us usually don't.
You can slide with that issue if the house is big and drafty or otherwise has a large heat load during the dead of winter.
It would seem to be an issue during the fringe months when you only need a little heat.

Yes, you should have storage with the Eko/Tarm, but that heat is in an insulated vessel and you can control it very effectively.

I would buy a TARM or EKO in a heartbeat over the others. I would rather buy an American made product, but the design
of the Euorpean boilers are mature and well proven. You can't ignore that.
 
My votes for tarm or eko. Ever hear of a viesmann vitolag wood gasifier? anyone running it in the states? When the emission laws finally change you will see usa manf offer european technology. Is econoburn and garn it? I smelled a bad outside boiler everyday on my drive to work. smelled up the whole neighborhood. I felt like stopping in and telling him to go to this site and read up on efficient boilers. I finally put a down payment on a 822 storage tank for my tarm solo 40. I'll post pictures when up and running. Thanks to all who have helped me get educated!> sweetheat
 
I forgot about the Garn. That was based on Dick Hill's work. Spoke to the fellow who does them years ago about tanks. Of course, he did not need any, given his design. Really a little more for a giant heat load like a school or such. I remember seeing the Viessman in literature.
Like all their stuff, it is for German Techno Junkies. Very impressive and pricey.
 
nofossil said:
tigermaple said:
Nofossil,
Do you weigh your wood loads ever to get efficiency readings?

Of course.....

I had a thread earlier that covers this in excruciating detail. Of course, you have to measure moisture content as well as weight, and you have to take detailed measurements of the heat that's produced over the course of a burn.

Bottom line: My system efficiency is about 55% - that is, of all the heat value that's in the wood that I burn, 55% is measurable output delivered to heat loads in my system. The rest is heat leakage from pipes and the boiler itself, or lost up the chimney as water vapor, hot flue gas, and so on.

Nofossil - Your graph showing all the temps in your system over time is awesome. I especially appreciate looking at it to get a feel for your heat exchanger performance. I noticed that you need to cycle the storage zone and that during the periods where the zone is on the boiler ouptut temp goes down very quickly. This indicates to me that your heat exchangers are certainly good enough, if not better than they need to be, during that stage of the heating process. However, I would guess that the most demanding part of the process for the HX is at the end when the tank is getting near the boiler output temp, due to the smaller heat delta available to drive the heat transfer. I can see on your graph that the tank temp starts to rise less rapidly near the end as expected, but that it still gets up to temp pretty darn quickly. It looks like there is no need for better heat transfer, which means that your HX should server as a good example for the one i am designing. Granted, you have a different boiler that I will be getting, but I can scale the HX based on boiler BTU. I checked your web site, but you didn't indicate the size tubing for the boiler HX. What size tubing and what total length do you have?
 
Tom G; I do not think the viessman's technologoy is any more anvanced than the tarm or eko, it's just not sold in the states. something about the UL listing costs. Insurance! There are more but are not sold in the usa. Vigas of austria is another gassifier. My hats off to the europeans who have seen the light and advanced much farther than us. We would still be sitting around a camp fire if not for there techno junkies! sweetheat
 
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