Johan’s wood boiler setup

Well, this is my wood boiler setup.
I felt a little weird making it because it was my first youtube video so if I sound a bit nervous it is because I am even though I have no idea why :laughing:

I made it in two bits, could not figure out how to pause the recording


Excellent presentation JohanM.
Showing us your wood supply says you are real serious and capable of expanding your wood-for-power.
Your voice sounds great. Good to meet you. And your voice in English allows Google/Youtube to CC into other languages. (why they cannot do Swedish is one of those mysteries worth a conspiracy theory)

Yes, a sophisticated whole home heating system alright. Your all-in-family able to use is a very valid reasoning.
But now you’ve a choice to make.
If you did go with vehicle wood gasification, with your own property wood harvesting you’d be using the limbs and branches wood portion then. Not impact your primary heating fuel source. Ha! But you will double your annual hours woods-work-sweating. Probably worth it for the pumps-fuels costs saved.
But. . . .the Big Butt . . .
If/when you lose Grid electrical power your all home heating wood boiler is not going to work. The drafting blower. The forced primary and secondary airs . . .blowers. Any water circulating pumps.

So maybe unless you already have PV solar like J.O. had added you might be wiser first setting up a wood-for power electrical generator back-up system. As a back-up they consume little wood annually.

Best Regards
Steve unruh


My own property wood can give me small growth alder, aspen and birch together with suitable limbs of pine and spruce so I think my best bet is a rebak like J-O’s for gasifier wood for the most part and I enjoy working in the woods, it kind of gives me peace in my mind

I knew when I bought the boiler that I needed a backup of some kind but it has not happened yet though, even if I bought a boiler that didnt use electricity I still have to run the circulation pumps to get heat to the whole house so I went for what I thought the best option, easy to use.

Unfortunately I havent got any solar, been thinking of getting it for a long time and now when everybody wants it I think it is overpriced just because they can. So I was too late jumping on that one.
And since electricity here in europe has gone up a lot in price during 2022, all generators are pretty much sold out (they are starting to have them in stock again now, market is probably filled).
So my thinking is to buy one or two never-used second hand one in spring or summer when they realize that they never used it and probably never will so they will sell it. Then I buy it. Hopefully it works that way.

And of course that one will be gasified, probably a downdraft charcoal gasifier then for the same reason (as hopefully also learned by my wife), most likely easiest to learn and operate without having to stand by it at all times. (well I will be until I feel that it can be left of course) and use it regularly so it will be second nature when the need is there.


Congratulations to your first video Johan! What Steve said - excellent. I never doubted it though.

I guess you can all imagine working with Johan there’s no lack of interesting topics for our daily conversation :smile:


Thank you
That is so true J-O, I am happy we ended up on the same shift, it truly is interesting conversations :smiley:


Well, apparantly it was possible to quote yourself, haha

I just wanted to say when I read what I wrote, that it does not necessarily need to be a downdraft charcoal gasifier to the generator. I perhaps need to get the gasifier in the car done and in use for a while before I can make that statement. I would of course rather have a wood gasifier on the generator too but I jumped to the conclusion that it would be easier with a charcoal gasifier on it for no reason at all, based on pretty much nothing. I have no experience in gasifiers yet. Sorry, my bad


With a raw wood system, I think the smallest that Ben Peterson sized his for is 500cc. Steve Unruh should remember off the top of his head.

Not that raw wood can’t power anything smaller, but it is easier on charcoal. Downdraft will give you peace of mind for any imperfectly converted pieces of charcoal, or let you blend in some pieces of wood.

Definitely utilize air preheat either way, cold air meeting hot nozzles will warp them over time.

Edit: For a truck or car you already have a great example of someone that can build a raw wood system for a vehicle and he even works at the same place!


Thanks Cody, i’m not sure what size engine/generator I’ll go for but I would suspect that I will end up with a 10-12kW one, then from what I read here on dow I would expect around 4-5kW from it, would that sound reasonable?
And I expect that must be a bigger engine than 500cc


I think we have perhaps touched that subject on a couple of occations at work :joy:


I would make a guess that you’d maybe have 7kw to work with. I think with my “9kw” generator I’ll be working with a realistic 4kw.


Im a bit tyed up at the moment so forgive me for not saying hi on the other thread, l will do it here. Hello and welcome!

What Steve sayd. Your English is excelent. But your boiler setup makes me want to hide behind the barn :smile: we do have one thing in comon thugh, you used the oil tank for wood storage and l used it to build my stove. Some obsolete technology doing some good still…

Going charcoal or wood, realy depends on your fuel sorce mainly. What you describe maybee seems more like a wood fired thing to me… a downdraft charcoal and wood gasifier are not much different or more dificult to build. Its true thugh, its usualy easyer to convert a downdraft charcoal gasifier to raw wood thain opposite


Ok, thats more than I expected. But I also know that I am careful with my estimations. Its nicer to become happy than dissapointed I guess


Thank you Kristijan.

You have absolurely nothing to be ashamed for, I really really like your mass heater with an integrated stove. If I could go back in time fifteen years knowing what I know now, I would probably have made different choices in our house, a mass heater for example. But it has to be included into the house, not really something to just chuck in there without a major rebuild so thats most likely not going to happen unfortunately.

Well perhaps the generator will be on wood, but I still have to find one and it will have to wait to be converted until the car is running on wood and the operator has learned to run it properly. Me, that is.


On the use at least a 500cc electrical generator it is three hard experienced learned things.
First: Having enough gas demanded for system loading to create the gasifer internal heats for stable operation when using raw wood fuel chunks.
Second: Then only having to make reasonable sized wood fuel chunks. Mini-woodgasifiers must have mini-chunks. Micro-wood gasfiers micro-wood chunks. Dutch John has this information with pictures still up on his site:

Third: the larger engine electrical generators will have good factory DC electric starting capability. My own wife will not use any of my set-ups unless she can turn-key electric start them.
In fact we are for 7 days, and still having late winter snows, ice and winds. My wife is set up and capalbe of operating, pull starting my gifted to her little suitcase Honda 2000 Inverter generator. On stabilized treated gasoline. My elder sister next door is set up the same on her little pull starting 2000 watt Yamaha suitcase inverter generator too. On treated stabilized gasoline.
Neither would be able to hard torso swing pull over a 5500-6500 or larger unit.

Your sophisticated whole-house boiler controller unit is not going to like weird synchronous generator waves, and sagging voltage when it may be struggling on variable batch woodgas JohanM.

Why I’d suggest an electric starting more expensive engine driven inverter-generator. Converted it then to long term storage bottle LPG instead of degrading gasoline. And then a charcoal gasifer as the more than 24 hours needed fueling back up. Gary Gillmore here on the DOW did this first charcoal fueled inverter generator back almost 10 years ago now. Dave in Australia uses his charcoal fueled inverter generators a lot to supplement his PV solar in his cloudy rainy season.

You proofing all of course. Writing the operations pictograph placard for other family members.
Ha! Ha! One of the ultimate vehicle woodgasification challenges . . .can your wife operate it too?
Steve Unruh


You make a lot of good points Steve, thank you
Converting a generator to lpg and have a gasifier as backup is an extra step that I would probably never have thought of, here is where experience and trial-and-error come in (which I have none of in generators), very nice suggestion

Is an inverter generator enough for sensitive equipment or does it need to run through something like a battery first?

I will look at too


Inverter generators will play nice with sensitive electronics


That would be my hope, my wife is pretty capable, the only things she hasnt seen through that I sent her way is dealing with rats and numbing-and-bleeding an animal for slaughter, butchering she will help out with though. But I dont blame her, some people dont want to and I will not make her.
Sorry, a sidenote blabbering.
But yes, my wife sure will try

I hope I am not offending anybody talking about slaughter and such, thats not intended


So no other equipment besids the inverter is needed to make a good sinus curve? (Just want to make sure)


Yes they’re fine on their own. Inverter generators use an inverter to clean up the sine wave

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Thats good, thank you. :slightly_smiling_face:

Now that we are talking Johan’s generator needs, I am wondering about your ramp generator hookp J_O. Did you ever make a report on how it works? Is that an efficient way to go seeing you already have the gasifier and the wood?