# Wood Chip Boiler



## jebatty (Mar 26, 2014)

Does anyone use a wood chip boiler, either dry chip or green chip, in a large residential to small/medium commercial application? If so, how has it worked? What's really good? What's not what was expected? etc.? A local school has an interest in taking a look at this because it has a local source of chips, both dry and green. Thanks.


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## tom in maine (Mar 26, 2014)

I built a chip boiler back in the '80's. Norm Smith, an Ag Engineering professor and friend of Dick Hill's told me not to try to build one because "You will burn your house down".
Well, that was enough for me. He had published a lot about chip boilers, so I built one and it worked fairly well.
I used green paper chips that were delivered into my basement. They molded as they dried in the warm basement.
Drying chips can be laborious and/or expensive.


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## jebatty (Mar 26, 2014)

Probably in the range of 350,000 to 700,000 btuh


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## foamit up (Mar 26, 2014)

Talk to Marc at BioWin, he advertises on her. he has a real good one. Foamit UP


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## jebatty (Mar 26, 2014)

I've got BioWin on my list and will make a contact as soon as I gather more info.


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## DZL_Damon (Mar 26, 2014)

The Froling chip units in that range look amazing. I'm not sure what they cost though for a full running unit.

There are many choices. Ram feed, underfeed stoker, pneumatic spreader stoker, chain stokers. They are a bit more maintenance intensive than a pellet unit. I have recently been working on a project for work for the same size system as the school. Undersizing would be best if turn down ratio is needed. Multiple units is the easiest way to do that.


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## STIHLY DAN (Mar 26, 2014)

P&M makes a nice one.


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## Karl_northwind (Mar 26, 2014)

Heizomat.  Imported and distributed by Marc, I'm the Upper Midwest contact.
Fully modulating, and the price is more reasonable the larger you go, so slight oversizing is actually more desirable, especially if you want the flexibility to burn greenish chips.

Emailing off list.


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## Boil&Toil (Mar 26, 2014)

I looked at the lopper/drummer website, asked for information on one of their chip burners (the smallest one) (and one or two of their stickwood boilers as well), and my mailbox has been sadly lacking any information. Must have been a couple of weeks now. No prices and not much detail on the website, won't send info when asked, looks like one more crummy heating distributor that doesn't actually want to sell product. Oh, Well...

Re: the heizomat - this from a year ago here:
https://www.hearth.com/talk/threads/heizomat-wood-chip-boiler-videos.108849/


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## flyingcow (Mar 27, 2014)

I know of one school up here has one running for a few years. The shoulder season, they do not run it. It needs the bigger heat load to be effective. Thats why we're looking at pellets with a cascading type of system, for our school. But we're very early on in doing this.

I'm on a school board in that region and see if i can get a contact number of who oversees this biomass unit. 

Just my 2 cents.


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## jebatty (Mar 27, 2014)

Really appreciate the info. This "project" is in the pre-feasibility stage, really early in the process, and I am collecting info for purposes of preliminary evaluation of  roundwood/cordwood, pellet and chip boilers systems.

Initially I am not overly attracted to chip boilers due to issues relating to variable chip size and moisture content, and my attraction is even less for hogwood boilers in the size range of interest. Cascaded pellet boilers are of initial interest, as are larger cordwood boilers with storage. The school currently is served by two 500MBtu propane boilers, with one normally sufficient to meet all demands, and the second for peak needs and backup. But the discussion also includes possible expansion of the system to serve an adjacent building. At least one, if not both, propane boilers would be retained as backup.

I will continue to collect info.


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## DaveBP (Mar 27, 2014)

KOB/Viessmann have a dealer up in BC. There may be others closer but for one more website try:

http://www.finkmachine.com/wood-boilers.html


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## Fred61 (Mar 27, 2014)

Several schools in Vermont heat with wood chip boilers but I don't know if there is any central source for information on the projects or if they are engineered separately. Some have been in place for several years so I believe they are past their experimental stage. I had heard rumors that they needed "graded" chips but I'm not sure about that. I keep my ears open for any information I can obtain.


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## Chris Hoskin (Mar 27, 2014)

The Fröling TX150 is a 500,000 btu/hr ASME boiler that can burn pellets or semi-dry (<30%) wood chips.  Like the P4 it can be cascaded up to four boilers, but it sounds like replacing one LP boiler with a single chip boiler and using the other LP boiler for peaking and back-up is a great plan.  Most are being used with pellets because the semi-dry chip is not yet widely available, but it sounds like this project might have access to them.  Chips must meet the G30/W30 spec.   See details about the boiler on our web site here: http://www.woodboilers.com/products/wood-chip-boilers/froeling-tx-150.html and a posting about a really cool four-boiler install on our blog here: http://blog.woodboilers.com/2014/03/featured-installation-four-froling-tx.html  Yes, that is a six foot and an eight foot step ladder next to the buffer tank (3000 gallons!).


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## Chris Hoskin (Mar 27, 2014)

Fred61 said:


> Several schools in Vermont heat with wood chip boilers but I don't know if there is any central source for information on the projects or if they are engineered separately. Some have been in place for several years so I believe they are past their experimental stage. I had heard rumors that they needed "graded" chips but I'm not sure about that. I keep my ears open for any information I can obtain.



It is my understanding the VT has more schools heated with wood chips than any state in the country.  Also that most are larger installations burning green chips.


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## Fi-Q (Mar 27, 2014)

I do not have a lot of information. But the hospital near buy just got there new chip boiler comissioned. There is a big bio tomatoes green house around here heating with chip boiler as well. And it was on the news lately that many schoold and public building in the matapedia valley are in the pre fesability stage as well.


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## Karl_northwind (Mar 27, 2014)

Chris Hoskin said:


> It is my understanding the VT has more schools heated with wood chips than any state in the country.  Also that most are larger installations burning green chips.


Wow.  that's pretty.  nice work. 

karl


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## jebatty (Mar 27, 2014)

Might there be a rule of thumb as to Btuh output when a green chip boiler, vs dry chip or pellet, becomes practicable?


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## Fred61 (Mar 27, 2014)

jebatty said:


> Might there be a rule of thumb as to Btuh output when a green chip boiler, vs dry chip or pellet, becomes practicable?


Comparison probably exists but I hope that they take into consideration that these chips will not dry themselves and resources must be added to reduce the moisture in a large scale operation. The extra BTUs might not warrant the cost.

Brought to you by someone who doesn't know squat about the process


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## Advanced Wood Heat (Mar 27, 2014)

Take a look at the Bio-Burner it comes in outputs of 100,000, 300,000 and 500,000 btu's and is made in Kentucky
It can burn everything from green wood chips to fine powdered saw dust..


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## flyingcow (Mar 27, 2014)

I drive tractor trailer. I've hauled clean wood chips, hog fuel, straight bark, sawdust,shavings, etc. This was in a 150 cu/yd open top trailer. 7 or 8 months a year it's alright. But the other 3 to 4months of the year(winter). It can be a big pain in the azz. Wait until you have to shovel a load off(by hand) because the walls/floor of the trailer weren't pretreated( with either diesel or antifreeze) enough to prohibit freezing in a big solid chunk. It freezes to the walls like JB weld.  I've seen loads sit in a heated garage for days before they loosen up.

To me, the extra cost to handle hog fuel, or even chips, just seems to be an added cost that you wouldn't see with pellets. Yes, you can park a live floor trailer inside a building and plumb it to unload as needed. But one way or another, you're going to pay $80k to$100k for that trailer.Plus have a heated facility to park that trailer in. 

But as fred says----Brought to you by someone who doesn't know squat about the process


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## PassionForFire&Water (Mar 27, 2014)

Below some pictures from the Heizomat container discharge system.
There are for sure more things to think about it with wood chips then with pellets.
The handling of wood chips is much more complex, but for anything over 200 kW it is a no brainer in my opinion.


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## flyingcow (Mar 27, 2014)

Where are these pics from? My concern/ with cost is I would think the fuel would freeze on the walls etc.?


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## PassionForFire&Water (Mar 27, 2014)

flyingcow said:


> Where are these pics from? My concern/ with cost is I would think the fuel would freeze on the walls etc.?



These are from Heizomat installs in Germany/Austria. I did see some installs 3 weeks ago.
The containers can receive some form of heating in the bottom. Heat rises.
The floor is a movable floor, it "walks" the wood chips to the front where a solid auger discharges them.
So, again as with wood pellets the Germans/Austrians are 10/15 years ahead of us for what concerns medium scale wood chips boilers.
All is mechanically sound and most of the issues we can/will think off are addressed.
There are between 15 and 20 top notch "biomass" manufacturers in Austria/Germany alone.
Each of them sells at least 500 to 1000 medium scale systems per year.
It's impressive and scary at the same time.
For us here in North America to catch up it's a matter of opening up to the technology that is available right there and get it over here, rather then trying to reinvent the wheel (pellet boiler)


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## heaterman (Mar 27, 2014)

PassionForFire&Water said:


> These are from Heizomat installs in Germany/Austria. I did see some installs 3 weeks ago.
> The containers can receive some form of heating in the bottom. Heat rises.
> The floor is a movable floor, it "walks" the wood chips to the front where a solid auger discharges them.
> So, again as with wood pellets the Germans/Austrians are 10/15 years ahead of us for what concerns medium scale wood chips boilers.
> ...




The sad thing is that the code and rating agencies will never allow that to happen without collecting their "tariff" and making the Euro's redesign and reengineer an already superior product. 
Just. Sad.


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## Willman (Mar 27, 2014)

Check out the scheduled bus tour for the North East Biomass show. Many schools and such have gone with chips over the recent years.

http://nebiomassheat.com/program.php


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## JP11 (Mar 28, 2014)

My sister in law's husband runs a BIG chip boiler for a textile manufacturer.  He says his actually runs better on chips that are a little less dry.  I know that they spent just as much on their storage with live floor as they did on the boiler.  it was around 4 million bucks I think.

JP


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## peakbagger (Mar 28, 2014)

http://www.biomasscenter.org/resource-library/publications

I would suggest looking through these publications. If I had to pick one, the Wood-Chip Heating Systems: a Guide for Institutional and Commercial Biomass Installations" is a good read.

Some general comments about wood chip applications is they do not scale down well. There are a lot of moving parts in the wood feeding system no matter what the size. The chips are non uniform and but usually in roughly 2" chips. If you are moving tons per hours, the chips flow pretty well but if you are try to move small volumes, the chips clump. Wood chips are generally green and wet when delivered. Let them sit too long and they degrade and sometimes catch fire or mold. If you handle them wet, they tend to be a problem in winter where they are right on edge of freezing, its real easy to get to the point where the chips freeze in clumps if the conditions are right. Many of VT installations very quickly had to switch to "premium" wood chips supplied by one or two suppliers at a premium cost as they couldn't handle the standard grade chips. Chips can be very deceiving, from 20' away they look like uniform chips but get closer and you frequently will find buried under the outer layer sticks and staves which can really foul things up. 

Most of the small institutional biomass chip installations were heavily subsidized so they could afford to put the system in. The general preference for small institutional or commercial units are pellet boilers. Pellets may be more expensive but the scale down far better than a biomass plant.  I have heard second hand from fairly reliable sources that the amount of day to day attention from the plant staff is a lot higher than they were told when the system was built to the point where the staff has to be increased or diverted to deal with wood handling issues.

Another aspect is depending on the size you could get into the EPA boiler MACT regs which is something you really want to avoid


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## heaterman (Mar 28, 2014)

peakbagger said:


> http://www.biomasscenter.org/resource-library/publications
> 
> I would suggest looking through these publications. If I had to pick one, the Wood-Chip Heating Systems: a Guide for Institutional and Commercial Biomass Installations" is a good read.
> 
> ...



That would depend on the level of automation and design of the boiler to a large degree. Different moisture levels of the fuel demand a different grate system also. Setting up for one and actually trying to burn another would be disaster.


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## ewdudley (Mar 28, 2014)

peakbagger said:


> Most of the small institutional biomass chip installations were heavily subsidized so they could afford to put the system in. The general preference for small institutional or commercial units are pellet boilers. Pellets may be more expensive but the scale down far better than a biomass plant. I have heard second hand from fairly reliable sources that the amount of day to day attention from the plant staff is a lot higher than they were told when the system was built to the point where the staff has to be increased or diverted to deal with wood handling issues.



I'm sure there are plenty of these systems that do in fact pay their own way, but it's hard to ignore the prevalence of installations that would never would have gotten rolling without plenty of tax dollar lubrication.


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## DZL_Damon (Mar 28, 2014)

peakbagger said:


> I have heard second hand from fairly reliable sources that the amount of day to day attention from the plant staff is a lot higher than they were told when the system was built to the point where the staff has to be increased or diverted to deal with wood handling issues.



I was promised all I had to do was press the green button and remove a wheelbarrow of ash per year. Our daily duties would not be effected anymore than any other boiler!

We've hired an extra guy, and a 10 yrd container of ash goes out once a week in the winter. However, the plant did pay for itself in fuel savings in 3 years.


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## Como (Mar 29, 2014)

I looked into this some years back.

The local High School went Biomass with Gas back up. I forget the name, Swedish design US manufactured. 

In Germany, UK etc you can chip for the year, where I am you would end up with a solid lump. The school chips every 2 weeks or so and use containers that look like roll on roll off, essentially they do not chip more than they can store inside.

From a cost perspective the material handling costs make it not costs effective for household use for most.

Wood here dries pretty quick and I doubt moisture levels would eve be near 35%.

Logically you would have a central chipping operation for multiple customers, I think I saw a co op operation like this in Ireland. Outsource the collection, chipping and supply of the product. I think some of the Irish cases I saw they just charged you by the energy consumed, they supplied everything.


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## flyingcow (Mar 29, 2014)

_*Wood here dries pretty quick and I doubt moisture levels would eve be near 35%.*_

My only simple thought, when chips or biomass are in a pile, they don't necessarily dry. I've seen a few mega plies catch fire on their own.


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## Como (Mar 30, 2014)

I will have to find my moisture meter, where I am now is the opposite extreme to where I have lived most my life. High altitude arid plenty of sun, after a couple of years wood is down to single digits, too dry? nobody bothers storing under cover.

The chip systems apart from the local school I have seen have been in very different climates, low altitude, wet occasional rather than constant freeze risks. There the norm seemed to be to chip late summer and store under cover for the winter.


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## peakbagger (Mar 30, 2014)

The biomass chips available in the northeast that are affordable to burn (see the BERC report I referred to earlier) are in the 40 to 50% range. The chips are quire green, some of them are chipped directly as they are cut and may end up on the pad in less than 24 hours.

Everyone dreams of sawmill residuals but the pellet plants snap them up as they tend to be drier. The pulp mills tends to grab the good chips, so what get sold for biomass fuel are the dregs no one else wants.


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## flyingcow (Mar 30, 2014)

Good post peakbagger. I've hauled hundreds of loads(35 ton per trip) out of various chip mills, stud wood mills, hog fuel loads, etc. Nothing sits on the ground for long. Maybe a day or two. Only time it sits is if the mill wants it to ferment for a reason. Sawdust/shavings can't sit for long, turns bad quickly.

The only thing left is bark and low quality crap. Which will be bought quickly if you've got a cogeneration plant or plants within 200 miles or less.


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## Troyboy (Evoworld USA) (May 3, 2014)

jebatty said:


> Does anyone use a wood chip boiler, either dry chip or green chip, in a large residential to small/medium commercial application? If so, how has it worked? What's really good? What's not what was expected? etc.? A local school has an interest in taking a look at this because it has a local source of chips, both dry and green. Thanks.


Hello jebatty. We make an Austrian designed two stage chip boiler in Troy,NY. Company name is Evoworld. The boilers are being built at Troy Boiler Works. They are ASME code and getting labled this Spring. They burn 30% and under chip 2 1/2" and down. I have plenty of information on the system. Product range is from 80MBTU to 1.7MMBTU. How do I get information to you to you?


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## jebatty (May 4, 2014)

Thanks for the info. I am waiting for more preliminary info before proceeding further.


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