wood stove or gasifier?

  • 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.
Status
Not open for further replies.

jklingel

Feeling the Heat
Hearth Supporter
Oct 23, 2007
279
Fairbanks
I've been thinking, which can be dangerous. I am really interested in having a wood gasifier in my new house (5200 sqr ft), but I am a little concerned about the time it will take to pay for one. Here is the skinny. We WILL have an oil boiler in the house, as per The Boss. Period. End of story. That will run $6-7K. So, if I add a gasifier and water storage, I'm probably looking at another $7K, or more. Sheez. Is it therefor not a viable consideration to put in a good quality but much cheaper wood STOVE and just get what heat out if it that I can? (Wood will be pretty cheap, btw.) I cringe a little at the maintenance a stove will be (cleaning chimney, dumping a lot more ash, doing gymnastics to get heat upstairs...) but they are pretty robust, simple machines. ANY AND ALL boilers/heaters will be in my basement, and I have been reading things like "don't put a wood stove in the basement; a stove needs to be on the level it will heat", etc. Oh, sigh. What is a guy to do? I don't think I want to go w/ a compromise of having an OWB, as it looks like that will not save that much $$. It looks like one extreme or the other will be the way to go (stove or gasifier). An HS Tarm oil/wood boiler sure sounds simple to do, but the boiler itself is $12.8K, plus shipping, and I have not heard back from them on the cost of their water storage tanks (versus building my own). So, is a stove even worth considering? For info, our design temp here is -51 F, and our degree-days number is 14,260.... if that helps form an opinion. A Greenwood, FOB here, will be about $7500, and a Blue Forge will be about $11.2K FOB here (and 250K btu rating). Hmmmm. Opinions/suggestions? Thanks. j
 
As you suggest in your post, you're making a series of lifestyle choices and it really boils down to what your priorities are. That's a big house in a very cold climate. It's going to take a lot of btus to heat.

You might want to check into how The Boss feels about wood being brought into the living space, dust, ashes being hauled out, etc. If you get one stove for that big house, it's probably only going to heat a small part of it. That's fine if you want the living room to be nice and warm and you're not fussy about the rest of the house, but it's going to take a lot of expensive oil to keep everything tolerable, regardless. You'll also need a good chimney right above the stove.

With a wood-fired boiler, you're married to firewood. No way around it. Even if somebody dumped loads of dried, split wood in your yard, you're still going to spend hours stacking, hauling and restacking. If you have no stomach for that, then a boiler probably isn't a great idea.

I would get a cheap oil-fired boiler (the price you quoted sounds excessive for the boiler alone; that must include the radiant units and piping as well) and a good indoor gasifier and have them hooked up at the same time. That will save you some money. My goal would be to never use the oil, except perhaps when you go on vacation. If you can get a good supply of dry wood and can figure out how to store and handle it, then you will be able to heat your house and hot water exclusively with the wood boiler. What do you figure the payback is on that in your situation? One year, maybe. Two?

Hot water storage is a big turn-off to most people considering buying gasifiers, since it adds considerably to the price of the project. I've found that HW storage is not a requirement, but it would come in handy and make things a lot easier. However, I think if you sized your boiler right (that's a big house), you could get by without the storage for one or two seasons, and then make the investment as the opportunity arises. You might want to sell the other occupants of the house on the virtues of abundant, cheap heat and hot water before suggesting that you spend a couple thousand more for your convenience. Lower upfront investment; more work and planning on your part.

OWBs are fine in some situations, IMO, but they burn about twice as much wood as a comparable gasifier and can produce a lot of smoke under certain circumstances, many of them beyond your control. Check out the excellent post in the thread about comparing OWBs for some well-reasoned details, both pro and con.
 
Hard to add much to Eric's post. I've been down the same road - started out with oil boiler, but built the house and boiler room with space for a wood boiler. Finally added one - an EKO gasifier, and a year later added the storage tank.

In my deliberations, I always place high value on the Wife Approval Factor (WAF). With a wood boiler, the house is heated with the same baseboards, controlled by the same thermostats, no firewood in the living quarters, endless hot water. This translates to outstanding WAF.

I've got my system set up to automatically transition between heating modes, and I have wifely buy-in on the comfort / cost tradeoff. Here's how it works:

If we're heating with wood, the house is heated to 72 degrees - that's her warmest desired temperature. When the wood boiler goes out, the system switches automatically to heating with the storage tank, and the thermostats set back to 70 degrees.

When the storage tank gives out, the system switches to oil and the thermostats set back to 68 degrees. We never let this happen unless we're away for a few days.

Our house is well insulated and well sealed, so it's not drafty. Our last house required 75 degrees or so to be comfortable. YMMV.
 
Amen, Bruthas'!!

Gotta luv the WAF . . . the payback is priceless!

One thing I would say, to concur with Eric. . . When I bought my Viessmann, I hadn't planned appropriatly for the Wood fired Hydronic. I could have gone much less expensive on my oil boiler, put the saved money into either water buffer/thicker concrete mass/additional WAF (aka Shoes!).

From my experiance only, keep the wood and any by products out of the house. Once you get the hang of it, having the hydronic outside will only mean three trips a day to the unit.

if your house is >5,000, I'd guess your payback is less than 3 years.

Jimbo
 
>5,000 in Fairbanks, Alaska!

I think Janinne is pretty hot, too. Too bad her husband doesn't agree.
 
I am still in the process of building my home. I originally wanted to get the Tarm oil/wood boiler. However after looking into it further. Realized that if I wanted to get the most out of it. I would need water storage as well. I live in Ct and would not be able to utilize all of the Btu's out of a batch load on an average day. My local dealer wants $10k for that unit wich was already really stretching the budget. But then another $4k for water storage knocked it out for us. So I decided on a quality oil boiler (Buderus) and quality wood stove for now. Later I would like to do the add on Tarm for $6k plus water storage. This will of coarse be after we absorb some of the hit from building our home. Just sharing.

Now my quesition for some of the current owners of wood boilers. If you have water storage. Did you build it yourself? How much did it coast and what is the construction like? Are there plans available?

James
 
James04 said:
Now my quesition for some of the current owners of wood boilers. If you have water storage. Did you build it yourself? How much did it coast and what is the construction like? Are there plans available?

James

Built it myself out of a stainless tank I bought from a local scrap dealer. Blow-by-blow description on my web site. The section on heat storage is a little sketchy, but you can see what I did.
 
50% of the reason I didn't go with Tarm was they quoted me $7.2 for the tank. I WILL do storage at some point, but it WILL

1)Not give me standby loss during the summer
2)Incorporate solar so that I can re-sell 3/4 of the tank of oil I bought this fall
3)Not cost 7200
4)reduce idle time on the GW, which will stretch my wood pile
5)be at least partly funded by Uncle Sam

So, are you saying you will buy an extra appliance (woodstove) now, that will be obsolete when you later buy what you really want?
 
Modified concrete cistern in the basement. Still working on the heat exchanger. Everything homemade. I've probably got $500 in the tank between the insulation and the liner and the concrete block. Lots of time. The hx will be another $500.

Interesting discussion about putting a spiral hx in a square tank. I never thought about that and not being a math or physics type, I'm not even sure if it's a valid concern. But I am pleased to point out that my hx is going to be rectangular, so I think I'm covered in any event.
 
Tarm's tank prices are a rip off. I bought a Solo 40 boiler from them and built my own 750 gallon tank. I used concrete block with a EPDM pond liner and insulated with Celotex. I was framing the house at the time so it was easy, I used one wall of the foundation as the end wall of the tank. Another option is to use a pre-cast septic tank they come in all sizes and shapes. If you are building new it can be placed so the top is flush with the slab.
 
So, am I the only one that lives in the North because I hate the heat?!?!!!

What are all you people planning on doing with the standby losses??
 
Standby losses on the tank? Mine's in the basement and my boiler is oversized, so I guess I'm not too worried. Two inches of good foam all around, six inches of reinforced, poured concrete (no contact with the foundation, BTW), and the block wall is filled with vermiculite. Nofossil's is outside, but he's got enough insulation to contain a nuclear reaction.
 
ISeeDeadBTUs said:
So, am I the only one that lives in the North because I hate the heat?!?!!!

What are all you people planning on doing with the standby losses??

I've got about $800 or so in my tank:

$400 for the tank itself and welded-in fittings
$150 for copper - lots of it used / reclaimed
$250 for insulation. Lots of insulation.

My tank is outside under the deck. Like everything in the system, the location is a compromise.

Pro:
- Catastrophic failure doesn't flood the basement
- Larger tank is possible than I could fit in the basement
- Allows solar panels with thermosiphoning during the spring / summer / fall
- Standby losses don't heat the house during the summer

Cons:
- Have to rainproof and varmint-proof the enclosure
- Longer plumbing runs
- Slightly lower WAF
- Standby losses don't heat the house during the winter

It has a multilayer insulation system intended to reduce radiant as well as conductive and convective heat loss. My standby losses are a little tough to calculate because I'm always pulling heat from the tank, but it appears that I'm in the ballpark of 1-2 degrees per day with a temperature difference of 120 degrees between the water and the outside air.

Not perfect, but I can live with it.
 
The heat's got to go somewhere . . . solid insultion only slows the conduction. And it does nothing for convection nor radiation. This means it slowly releases it's heat, for hours, days . . . .

Great in the winter (right now my basement zone doesn't come on, and that's just a 20gal boiler and a 50 gal DHW tank) but in the spring/ summer, that would suck!
 
ISeeDeadBTUs said:
The heat's got to go somewhere . . . solid insultion only slows the conduction. And it does nothing for convection nor radiation. This means it slowly releases it's heat, for hours, days . . . .

Great in the winter (right now my basement zone doesn't come on, and that's just a 20gal boiler and a 50 gal DHW tank) but in the spring/ summer, that would suck!

Not going into an in-depth discussion about emissivity an cell convection here - another topic, another thread. For now, assume that insulation systems can deal with all three, and evaporative loss as well.

Insulation slows but of course does not totally stop heat transfer. However, slow enough is good enough. Some folks don't heat the storage tank in the summer, so the basement heating effect might not be a problem. I run mine up to 150 or more with the solar panels, so outside is good in that respect.
 
I also have looked at inserts , wood stoves / furnaces and gasifiers and because of the mess , smoke, risk of fire with the indoor units I have decided to install a gasifier in a shed behind my garage. The cost is alot more than the other options but it will burn longer create less smoke and keep the mess and risk of fire out side where I like it.
The payback will be longer, I figure 5 to 6 years at current prices but due to the fact I will not be moving anywhere and the unit should be able to run another 10 plus years beyond the payback we will be way ahead. I know this is not the best option for everyone ( my Brother in law heats his small house very nicely with a wood stove that he got used for 400.00 so his payback was like 3 months) however it looks like the best option for our family.
 
Ahhh, the small house/large workshop option! If only it wern't for the WAF, this would be the best option :coolsmirk:
 
Nofossil,

Thank you. Very cool web site. How much does the Eko 25 go for? How much was that SS tank. I would love to have a similar setup.

James
 
James04 said:
Nofossil,

Thank you. Very cool web site. How much does the Eko 25 go for? How much was that SS tank. I would love to have a similar setup.

James

I bought the EKO back when Zenon was getting established. I got it for what you could call a 'fire sale' price ;-)

I think I heard that it was around $5K now, but Hew Horizons and other dealers could give you real prices.

I figure I have about $800 in the storage tank between the cost of the tank itself, the plumbing, and the insulation / enclosure.

If you're interested in a similar setup, I and others will be glad to offer help and guidance. In the case of my system, it's important to understand how much infrastructure I already had in place for developing the controls - not for the faint of heart. The cost of a system like this grows quickly if you can't do it yourself.

I've had many people ask what I would charge to build them a copy of what I have. The answer is that I couldn't do it for a reasonable price. If I charged myself my own normal hourly rate for designing and building this, I'd be broke and the payback would be on the other side of forever. If it weren't fun for me to do this sort of tinkering, it wouldn't make sense.
 
Roger that, and I don't even have any controls.

The best pricing I've found on EKOs is at: http://www.cozyheat.net. I believe that includes delivery east of the Mississippi, to a commercial address with a forklift. At least that was the deal when I bought mine last summer.
 
Thanks for all the info and opinions. $3K for a Tarm storage tank is a tad high; I'll have to build one, I guess. What the hey: it's only lots and lots of work. My only concern would be getting it "right" but I think some of you guys have that figgered out already, too, so I'll copy your designs. Gotta just love stealing people's R&D; sounds like Bill Gates and Windows... Yes, 5K sqr ft in Frb scares me, but my wife wants a one-level house for when we really get into geezerhood, and I need a little basement, at least. I've always figgered that if you are going down 4' for footers you may as well go down 8' and use the volume. This will give me 42' of basement wall exposed to the cold, but I will need access for projects and stairs to a dungeon won't cut it... oh, sigh. (I may just design it so I have a 6' wide tunnel leading into the basement. Dunno.) The prices I listed in the original post are pretty accurate; my son just put in a Viessman smaller than I'll need and paid about $5.5K for it. The other prices are from dealers. I will have to check on these EKOs, too. All the wood will be in the basement, accessed from the outside, so no sweat w/ my wiffie complaining about carp/dust/etc. Lots of decisions to make, lots of reading to do. Thanks again for all the info. I better get back out and try another "leg brake" on my chain saw if I am going to get this place cleared. BTW: Janinne is OK (no idea who she is) but she is not up to par w/ our governor, IMO. No there is one fox-assed woman! later. j
 
TCaldwell said:
james 04 have you looked at the garn?, it is all incorporated. www.garn.com , I live in ct if you want to see.

I have looked at the Garn before. But if I recall they were enormous and expensive. Do you know what they are going for? Although I couldn't possibly do any thing now. It doesn't hurt to start looking at all the different options.

James
 
IN LOVE! I just looked at the Garn web site and fell absolutely in love. Gotta have one of those muthas, come hell or high water. I just emailed them for more info.... hang on, the price tag may burst my bubble, and the shipping will probably be catastrophic. FWIW, I re-analyzed my previous statement about how spendy a gasifier AND a good oil boiler will be; hell, they will be less than what I hope to sell my USED riverboat for (20' SeaArk, not a humongous river boat). Ever heard of a riverboat paying for itself? I think I just turned my brain around....
 
jklingel said:
Ever heard of a riverboat paying for itself? I think I just turned my brain around....

I guess that means you don't have a casino on it.
 
Status
Not open for further replies.