Gasifier- how to build or what to buy?

  • 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.

blackdogchainsaw

New Member
Jul 22, 2017
2
Indianola, IA
Long story short I’m looking into building my own gasifier to be my primary heat with Current LP furnace moving to secondary. The gasifier will placed in attached garage with room for me to drop pallets of wood next to it. Ease of use for both the wife and myself...

I’m mostly hoping you guys can point me to some build threads and some of the rough information I need to figure size, water storage needs, etc.


Sent from my iPhone using Tapatalk
 
My advice is this. My brother-in-law was a metallurgist and worked on medical devices for the heart. I was an attorney and did estate planning . He talked to me about a will and estate plan, and then asked if he could do that himself. I said, "sure" you can as soon as you gain an expertise in estate planning, and then I asked him if I could design and build my own medical device for my heart. He laughed. He never did his own estate plan.

So, as to your question, with the first one being about size and water storage needs. I suggest you do lots of research to gain an expertise in design and build of hot water pressurized boilers and hydronic hot water systems. You then may realize that your questions are very elementary, and I for one would not be willing to give advice to anyone on how to design and build a wood gasification boiler. Good luck.
 
  • Like
Reactions: TCaldwell
Its highly likely that you will spend far more time and money building a gasifier from scratch than buying one. On the other hand if you want to build a system around a commercial gasifier that's something that can be done and there are quite few build threads out on this site.
 
  • Like
Reactions: TCaldwell
Scouring this site you will find several build threads, primarily from fabricators usually deciding to build in unpressurized boilers based off a “proven design”, however not having experience with how that boiler actually is to be run. Then comes the rest of it, draft motor and fan, safety limit switches, gaskets, thermocouples, monitoring and control and much more.
The by part cost, raw materials, build time, the engineering time are just not realistic when you can buy a advanced and certified unit for less.
You will have enough hands on installing , piping and venting time to make the rest of your family wonder where you have gone!
I’m not trying to discourage your enthusiasm but unless your a certified welder who happens to hold degrees in mechanical, chemical and electrical engineering that also writes code, just buy one!
 
Coming from a person that built my own boiler I'll give you the best advice, RESEARCH.

I built mine based off a manufactured boiler, it's a "traditional" boiler but has a large heat exchanger and a refractory lined firebox. You can find my build thread on this site if you search. I'm finding that I'm changing things around almost every year trying to get a better burn, more storage, better efficiency, etc. If i could do it over, and had the money, I'd buy a garn.

As far as money goes, I built my boiler from scrap at my work place. I had about $500 in the boiler build and about another $2000 in the initial install. But i changed everything the next year by adding 750 gallons of storage.

My boiler build and also my storage install are on this site.
 
Also consider - any open flame stove, gasser, whatever is not allowed by insurance companies, building inspectors, etc in a garage where vehicles are kept - It'll have to be in it's own 'room'
 
Also consider - any open flame stove, gasser, whatever is not allowed by insurance companies, building inspectors, etc in a garage where vehicles are kept - It'll have to be in it's own 'room'

And would be a huge no-no with an insurance company anywhere in any structure that had anything to do with an insured space or area, if no CSA or UL sticker was present.
 
To all of you who have “concerns” above...

I’ve been laying bead long enough to make a boiler water tight and pressurized. Most of the wood units I’ve seen on the market don’t exactly have welds that look like long rows of “stacked up dimes.”

As far as insurance goes... my brother is my insurance agent and said as long as it’s installed to a similar units UL listing criteria, I’m fine. How the hell would insurance companies insure 1000’s of homes with outdated fire places and other appliances otherwise? UL is about the safety of the install and the safety of appliance. But the only thing the insurance company cares about is whether said appliance is installed correctly for use. They don’t want a bad install burning the house down. That being said my insurance will actually go down since I am removing 2 open flame fire places and replacing them with a concealed flame boiler that will have a large fire extinguisher on either side. Also I live on the side of a hill so there isn’t a spot outside to place a traditional boiler. We also go on several winter vacations a year and I don’t want to have to hire someone to feed my boiler when I’m gone. A smaller boiler system in the garage makes more sense to provide the bulk of the heat needed but ability to shut it down while were gone and not worry about something freezing and breaking.

As for a “building inspector”... the only thing our county has is a septic tank inspector. That’s it... no building code to follow. I will have another friend come and professionally run the wiring for the pumps. He’s an electrician by trade.

As for parts and build cost, let’s look at this from another angle... If I were to buy a “factory made” unit with all the bits and pieces; it would cost me just shy of 80-83% of what a geothermal system would cost. At that point I’d toss another $xyz$ into the pot, pay for someone to install geo and never worry about having to cut wood. Heating with wood is about saving money and my saw shop provides me the tools I need to make the wood. As for all the bells and whistles parts. I just took out a 200,000 BTU LP 3 zone boiler system from a shop that was going forced air. That should provide me all the extras I need including taco pumps, expansion tank, 30-40 brass ball valves, switches, flow control, etc. I also have access to all the old cast iron radiators I want for free and my neighbor was an industrial and residential boiler mechanic for the last 40 years. He told me to sort out my heating unit and he’ll help me put in the rest. He also has access to extra “spare parts” I might need for free.

So my cost for this system will be PEX, a few small parts, and the steel to build the boiler.
 
Last edited:
I know for a fact that if you install a boiler here that has no cert labels on it (CSA here), you will not have insurance coverage. Plain & simple fact. It is not all about the install.

I also looked into geo - a geo setup would have cost me at least 2x what my entire boiler install did, and that didn't include mods I would have to make to my distribution side to utilize the lower temp geo output. Which would have put it at 3x, roughly speaking. Plus a lifetime of very much higher electric bills every 2 months.

There is way more to building a pressurized boiler than just laying bead, starting with the up front design & engineering. I don't think I have seen any gasifier build threads so can't help you there - but good luck with things going forward.
 
If you don't mind, please keep us in the loop on your progress. Home builds are fun to follow. Don't forget the photos.
 
  • Like
Reactions: Chris Hoskin
Hi Blackdog
I would look at copying a Garn,or since i have one an Econoburn.
I have a big old oil fired boiler from an apartment building that was used by the US army oil pipeline pump station that i dismantled.I have thought about remolding it into a gasifier for my shop.
I say go for it,save some money and build you own.Chances are you may improve an existing design to meet your needs.
I have found a source for cast-able refractory and any other fire and heat related insulation,firestop,ect.I am going to try and cast my own nozzle for my Econoburn.Shipping cement bricks gets expensive.so if you have any problems finding those materials i can give you a source in Canada
Thomas
 
Seems the most important thing in a gassifier would be the nozzle size/firebox size/primary and secondary air amount and getting all of them to be sized properly to work right.

I cast in place a new nozzle for the eko every season,very easy to do, but I have found it has to be pretty close to the original size to work right.

This last time I used a piece of 3/4" foam to form the nozzle opening instead of 1",and had a bit of trouble getting a good flame at first.
It's getting better now as the nozzle opening wears a bit and increases in size.

Even these simple boilers like the eko probably have more design engineering built into them than a person realizes.
 
I read that you have been a welder for some time and you are confident in your abilities. That's good. I too used to hold ASME certs for pressure vessels tested to 350 psi air or over 1500 psi hyrdo. Confidence is good but have you seen a pressurized boiler failure video? If not you should watch one. My initial thought in building mine was go pressurized but then the thought of a failure scared me. Relief valves can be faulty, fail safes can fail themselves, and catastrophic failure is always an option. If you do build just go with a vented design. If you do a stand pipe up into a "bubble" on the top of your boiler then vapor water loss is virtually non existent. This is how a garn is vented and also how i vented mine.

You can always do what you want to do but a vented boiler is very safe insurance. And a piece of mind if you ask me.
 
One suggestion would be to put this in separate small shed that you don't need to insure and can hold at least a few pallets of wood and storage tank. No risk of damage or smoke in your home.
 
I built a pressurized gasification unit, worked great had it in a separate shed that was heating a house and a shop total of 6800 square feet. Until the structure caught fire from an overhead electrical service that was 50 plus years old. Insurance cover the homemade boiler also. I took a year off and plan on having it up and running this next season. See my thread below. https://www.hearth.com/talk/threads/homemade-and-engineered-gasification-boiler.149958/
 
I built a pressurized gasification unit, worked great had it in a separate shed that was heating a house and a shop total of 6800 square feet. Until the structure caught fire from an overhead electrical service that was 50 plus years old. Insurance cover the homemade boiler also. I took a year off and plan on having it up and running this next season. See my thread below. https://www.hearth.com/talk/threads/homemade-and-engineered-gasification-boiler.149958/
Glad to see you back around, check your inbox