Unpressurized Storage for Wood Gun

[emesine]

I am thinking of installing a wood gun, but I’d like to add storage at some point. I am building new construction, so there are no limitations on tank sizing, etc. I will probably start with a wood gun only, then add storage at some point in the future. I have two questions:

1. Will a wood gun be damaged by allowing cooler water (110 degree water coming in from my radiant flooring) to enter the boiler? I have read posts on avoiding the “condensation temperature.” The wood gun is SS, so I imagine condensation is no problem.

2. How do I add non-pressurized storage to the plan? I am not sure how to rig things such that the wood gun works while it is firing, but the storage takes over as soon as the wood gun shuts down.

Thanks!

P.S. Depending on how complicated this gets, I might just put in a GARN!!

 

[Hydronics]

There is a company in Maine who makes and sells open storage tanks -search for "Tom In Maine" I believe.

I'm glad to see someone at Hearth is looking at the Woodgun, being stainless it should never need replacing. I wouldn't get too hung up with storage, I'm not convinced that wood consumption would decrease enough to warrant the expense and complexities.

I'd give Woodgun a call regarding return temps. I wouldn't think corrosion would be a major concern but the thermal stress of return water going suddenly from 180 to 110 when the zone opens should be avoided with any boiler. I have radiant but have it set up to mix the return water with some supply water prior to going to the wood boiler.

 

[flyingcow]

Control work will take care of the return temp. Most if not all wood boilers will have a loop set up to maintain water temps returning into boiler. there are good books on this stuff, someone here should be able to provide you the titles. properly designed systems will work correctly.

As far as storage goes, it's nice to have. I fire a load of wood every 2 days, hopefully will go to 3 when it warms up some more. I walk out, start a fire, and leave. 10 minutes of my time if i hurry. No more worrying/dealing with the boiler. Also, this allows the boiler to run wide open, because there's enough thermal storage, it's heating the tank back up to temp. This will make the wood burn more effiecently, thus burning less wood. But it's probably not much, so installing a tank just to save on wood consumption, isn't the reason for the extra $$$$'s. If you're putting in radiant system, these tanks will love it. Radiant and thermal storage is a good pairing.

 

[emesine]

Flyingcow-

Can you share your piping and control setup for your piping/boiler? I would like to add storage- as stated above more for convenience than for efficiency- I just can't work out exactly how to do the piping and controls. The only thing I can figure out is to run the wood gun directly into a large unpressurized storage tank using a large pump/ heat exchanger, then heat the house using the hot water in this tank. There is probably a better way!

The exchanger would have to be pretty big; I estimate it would take 15 gal/minute to pump the heat out of a wood gun running at 1.5k btu (E180).

Thanks!

Andrew

 

[flyingcow]

Well....my system was installed by a pro, because i know very little about this, as far as installing. I/we used Tarms layout and their controls. Don't know how to post it on this computer thingy. It was more pricey than DIY , but if/when I have problems, I'll call Tarm and should be easy to trouble shoot.
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For the first loop, which brings the boiler up to temp before sending it to the system(to house) is a Termovar Loading Unit #4832s. This has a circulator and mixing valve all in one. I think it works sweet, but I just drive a truck for a living. Upon firing my boiler, in no more than 45 minutes I'll have 165+ water heading into my system. Climbing quickly to 195+
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Hot water heads to house(per Loading Valve) goes to storage tank or to heat the house directly. This is done with a Termovar Diverting valve #K6640a. Once boilers out, it will pull the heat I need from the storage tank.
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I'm sure this hasn't been much help, but it's the best I can do. This site will help you greatly. Very good and knowledgeable people on this site. Do a few search's on here. More than worth your time. Wood Gun should have some customer service to help you directly. They might have their own controls and layout. Other competitors do, each has their preferred layout/controls. Econoburn has some great service, Tarm, etc.
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Now my tank was manufactured by www.americansolartechnics.com . Really like it, the HX coils are another generation above anything else. Call and talk to these guys. Worth your time. Tom( he is on this board from time to time, as "Tom In Maine") has years(decades?) of experience with these tanks, he also is very experienced with solar heating systems. Which is what I want to eventually hook into my storage tank for heat.
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I wish I was more help, but this is the place to be for your questions.
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Also, very important.......wood has to be seasoned. If you don't have, it do it now. If you can, buy/cut 2 years of wood, that way you have one years ahead. Don't put it off. If you buy seasoned wood, use a moisture meter, and explain this to the dealer. You want 20/25% moisture. This site will also help you with others experience/knowledge on using sub par wood.
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Good bunch of people here. You should get good responses from this thread, because I'm sure I've mis-spoken on any one of these subjects. It's what I do best.
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[Singed Eyebrows]

Hi Emesine; I'm certainly no boiler expert. That said, you might want to use a mixer, Laddomatt 21 or ESBE to keep the boiler temps constant because as was mentioned, the expansion & contraction isn't good for any boiler & a stainless WG wouldn't be an exception even with the many stays. You mention running without storage & a stainless WG alone might be all you ever need. I can't answer your non pressurized storage question because I'm not sure if it stratifies the same way as pressure storage. You are going to run off the WG & change over to storage & if I understood Nofossil correctly, this is not the way to do it. You run off your storage, not the WG directly. Others can answer if a non pressure tank stratifies decently so you don't need to heat a large tank completly before getting hot water. Garn sure looks like a great boiler now that I know how they are built. I don't envy anyone needing to choose between a Garn & a stainless Wood Gun, Randy

 

[ihookem]

Singed eyebrows, do you like Woodgun more than Garn? Just wondering. I am thinking of getting a Woodgun. I better hurry cause in a few months it's going to get cold again.

 

[Singed Eyebrows]

Hi Ihookem; We both need to get going with our installs. As I mentioned that is a really tough choice. I believe the WG has 2 major advantages over the Garn, the fact that it is stainless & it is compact & can fit in a basement. It also is cheaper & can run without storage. Now that I know how the Garn is made I sure wouldn't mind owning one of these. It has to be a very safe boiler with that large water jacket, a WG without storage will overshoot about 10 degrees sometimes more so if you also figure storage with the WG you are probably at the price of a Garn. As for boiler life the Garn seems last way longer that any carbon steel gasser I've read about. I know this is clear as mud so far as for a choice. If you were talking carbon steel WG or Garn for outside install & the price was not a concern I wouldn't hesitate to buy a Garn. I think the Garn is very possibly a better designed boiler all around. I would probably lean toward the WG because of the stainless, not by much though, Randy

 

[Como]

I contacted WG and they sent me info

Price

500 is about the same as 2x2,000

Options

WG has feeder, can add oil/gas for back up. Does not have storage.
Garn has Storage, can add electricity and solar.

Pressuriation

Garn is not, WG is and can be certified at a cost.

I agree it is a hard call.

 

[muncybob]

WG has a feeder...for pellets or something other than wood splits/rounds? For what it's worth, I have spoken to several WG owners in the last year or so and they cannot say enough good things about the WG, but both said go with SS! I also spoke with a WG SS owner that has also has a steel version at his shop and that thing is going strong after 20 years....but he still highly rec. the SS. I wish I had the room for a Garn though.

 

[emesine]

I've looked into the feeder for the WG. It is very high quality and can burn anything you like. It would be a beautiful wood chip burning set-up, which, IMHO, would be one heck of a lot better than burning cord wood. The problem is that it would add probably 20K to the price of the set-up once you modify the boiler, put on the feeder, put on an auger for the feeder, and put in a storage bin for the 20 tons of wood chips you would burn in a season. It just isn't practical for home use, unfortunately. It might be a nice set-up if you and your sons live on the same property.....

Andrew

 

[Singed Eyebrows]

I've thought further about the life expectancy advantage of the stainless WG over the Garn & realized if the Garn does fail after many years it can probably be repaired quite reasonably. I had in the back of my mind that if the Garn corroded through it would need to be replaced. It appears that any resonably handy person with a sawzall & grinder could remove an end plate & slide the whole thing out. Maybe there is more welded to the other end than I am aware of. This looks like a very rebuildable boiler in any case. The outer shell is unpressurized so any decent welder could weld the end cap back on & then probably good for another 25 to 30 years. So Garn vs stainless WG? I think it's only down to size & possibly price the way I see it, Randy

 

[ihookem]

Singed Eyebrows,I think a Woodgun is cheaper even if it's stainless. There is a Woodgun dealer arounfd Plymouth.The guy told me he will install any wood burner. He just charges accordingly but likes the Woodgun enough to be a dealer around Plymouth, Wis. He told me 8900 for the stainless and 6700 for the carbon 100 Woodgun. He told me he thinks the carbon will last a long time but would be a little more carefull about treating the water. Carbon has a 6 year warranty and stainless has a 20 year warranty.

 

[Singed Eyebrows]

Hi Ihookem; I'm surprised. This is less than WG quoted me directly. Have you talked to the dealer recently? WG was supposed to have a price increase although they weren't sure how much it would be. I also think the carbon steel will run a long time if run with a mixer & storage. I would not run a carbon steel WG the way it is designed to run because if you have any gasket problems(door or rubber intake flap) on idle you will rot the plates. I do not know what plate steel WG uses, they wouldn't tell me, so maybe it's been improved. Treating the water is not going to help as they were being eaten through from the fire side. I'm not sure you are comparing apples to apples. I believe the Garn is about 350,000 btu for the small one. If you price this against a 350,000 btu stainless WG the Garn might even be cheaper. WG makes a 230,000 btu max output & a 500,000 btu max output/ & a half million stainless WG has to be a fortune. My friends stainless E140(140,000 btu max) listed for about $11,500 with some options. Hopefully I'm still on thread here & apologize if I'm not, Randy

 

[emesine]

That's exactly the quote I got a few weeks ago directly from the factory (we don't have a rep for Indiana). I have their price list if anyone is interested.

 

[ihookem]

You're right, Garn is huge, my quote on the WG was for the 100. It puts out 100,000 btu and that's a btu fart in Garn terms. I only need 100k btu's though, my house calls for 64k btu's @ -10 f.

 

[Como]

500,000 btu max output/ & a half million stainless WG has to be a fortune.

26k plus change for the ASME certified.

 

[Hydronics]

I wouldn't compare garn output directly to other boilers, keep in mind that a 350k Garn isn't designed to have all the output used by the heat load. The high output is for recharging storage.

Not to throw a wrench in the works but you could almost buy two carbon eko's for the price of a Garn or WG. Don't take me wrong, Garn & WG are high quality units but it's something to consider.

 

[ihookem]

Ok then how much is an Eko 25 or and Eko 40? I don't think I have a dealer in 500 miles of me though. I would also have to have it dropped off somewhere and have it loaded on my trailor and then I can't get it off. I will consider it though.