Best Indoor Furnace for 40' Reefer Kiln?

[Rose Lane]

We are considering building a Firewood Kiln from a 40’ reefer container.
Oak Farm Firewood in England documented their build and we’ll use their notes as a starting point (available on youtube)

One thing we like about it is the Wood Fired Gasifier Furnace they put inside the container.
Oak Farm uses the 60kW Angus Hot Air blower, this unit is not available in the US as far as we can tell.

So, what’s the best alternative?
Here is the high level spec we are trying to meet:

60kW / 200k BTU (this is based on Oak Farm’s Unit, open to comments on sizing)
Indoor (putting the Furnace inside the container makes it self-contained, a pro if we ever decided to move it)
Wood Gasification
Computer Controlled (but simple as possible)
EPA 20 approved (buying new)
Hot Air Furnace

Looking forward to suggestions / ideas!

 

[salecker]

Hi
Just curious as to the need of a firewood kiln?
You should be able to use any furnace,as no codes will be followed?
Thanks

 

[brenndatomu]

Seen this locally recently...not fancy, but not much out of pocket $ to get started either...double barrel stove in an old steel shed.

 

[clancey]

I think those idea's are neat...If I have to move I might very well check into some of those idea"s that's if I still have energy to get up off my chair...Wonderful reading...old clancey

 

[Rose Lane]

Hi
Just curious as to the need of a firewood kiln?
You should be able to use any furnace,as no codes will be followed?
Thanks

We have a requirement for hundreds to 1k cords of kiln dried firewood per year, thanks!

 

[Rose Lane]

Seen this locally recently...not fancy, but not much out of pocket $ to get started either...double barrel stove in an old steel shed.
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Looks great for a back yard project, too small and inefficient for our requirement. we are planning to use IBC cages though

 

[SpaceBus]

I think you would be well served with a Drolet Heat Commander. These units are very efficient and clean burning.

 

[JRHAWK9]

soooooo, what do they use to dry the wood to burn in the furnace which dries the wood?

 

[brenndatomu]

soooooo, what do they use to dry the wood to burn in the furnace which dries the wood?

That's why I thought the double barrel stove was such a good idea...burn 'er hot and run the junk through 'er...splitter trash, nuglies, etc etc...it's almost like free kiln fuel!

 

[clancey]

Ha Ha---Stop being such a stickler you old thing--lol JWH ---Heck buy one and just plug it in---lol never much thought about how you would heat that one---good idea brenndatomu use the double one....Love it...old grumpy clancey ...

 

[brenndatomu]

I think you would be well served with a Drolet Heat Commander. These units are very efficient and clean burning.

That's what I thought too...but I think with the size of operation that's being talked about, it would take several of them, at least...I wonder if it wouldn't be better to install a large gassifier OWB and use that to run hot water to the various containers...run simple water to air heat exchangers with a fan mounted right on/against it inside each container...

 

[SpaceBus]

That's what I thought too...but I think with the size of operation that's being talked about, it would take several of them, at least...I wonder if it wouldn't be better to install a large gassifier OWB and use that to run hot water to the various containers...run simple water to air heat exchangers with a fan mounted right on/against it inside each container...

That's the next step if the HC is not big enough. A google search says 310,000 BTU output and his specs call for at least 200k. I would think an indoor downdraft gasser would be better than the huge outdoor style, but it will take a serious HX to utilize all that output burning at full tilt. Might be a bit too much output to be honest.

 

[brenndatomu]

A google search says 310,000 BTU output

Yeah, but only like 30-40k BTU per hour...I have a feeling that they want 200k per hour/per can.

I would think an indoor downdraft gasser would be better than the huge outdoor style, but it will take a serious HX to utilize all that output burning at full tilt. Might be a bit too much output to be honest.

Outdoor unit is only trying to keep itself at 180*...especially a modern gasser...they idle almost as cleanly as they run.
Its probably gonna take a decent sized unit to run several cans @200k ea...assuming that's the right number.

 

[Rose Lane]

I think you would be well served with a Drolet Heat Commander. These units are very efficient and clean burning.

Drolet Heat Commander is on the board!
that is one that we've been eyeing...

 

[Rose Lane]

Yeah, but only like 30-40k BTU per hour...I have a feeling that they want 200k per hour/per can.

Outdoor unit is only trying to keep itself at 180*...especially a modern gasser...they idle almost as cleanly as they run.
Its probably gonna take a decent sized unit to run several cans @200k ea...assuming that's the right number.

We were planning on cooking One 40' can at a time.

 

[Rose Lane]

Yeah, but only like 30-40k BTU per hour...I have a feeling that they want 200k per hour/per can.

Outdoor unit is only trying to keep itself at 180*...especially a modern gasser...they idle almost as cleanly as they run.
Its probably gonna take a decent sized unit to run several cans @200k ea...assuming that's the right number.

If the Drolet comps out in performance to the Angus 60kW it makes the cut.

 

[JRHAWK9]

200kBTU/hr = ~30lbs of wood/hr @100% efficiency = ~118 hours of burn time/cord of red oak.

There is not a 2020 certified wood furnace around capable of anywhere near 200k BTU/hr.

You'll need at least -FIVE- Kuuma/Caddy/Drolets all burning in unison to get that kind of output, all pretty much running full tilt.

You would be trying to use residential heaters in an industrial/commercial application.

 

[brenndatomu]

If the Drolet comps out in performance to the Angus 60kW it makes the cut.

Its not even close...as far as I can tell that 60kW equates to ~200,000 BTU/HR...the Heat Commander is 310,000 BTU over 8 or 10 hours.
Beat me to it @JRHAWK9

 

[Rose Lane]

200kBTU/hr = ~30lbs of wood/hr @100% efficiency = ~118 hours of burn time/cord of red oak.

There is not a 2020 certified wood furnace around capable of anywhere near 200k BTU/hr.

You'll need at least -FIVE- Kuuma/Caddy/Drolets all burning in unison to get that kind of output, all pretty much running full tilt.

You would be trying to use residential heaters in an industrial/commercial application.

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Can't argue with that clear and concise assessment. So the Drolet is out. I was hoping it would be possible to do on a Kuuma - no luck.

 

[Rose Lane]

Its not even close...as far as I can tell that 60kW equates to ~200,000 BTU/HR...the Heat Commander is 310,000 BTU over 8 or 10 hours.
Beat me to it @JRHAWK9

Ok - im in total agreement - what is the unit that has the capacity to do the job?

 

[brenndatomu]

what is the unit that has the capacity to do the job?

Well, I know the HeatMaster G10000 is real close there...195k/hr x 8hrs.

 

[SpaceBus]

Its not even close...as far as I can tell that 60kW equates to ~200,000 BTU/HR...the Heat Commander is 310,000 BTU over 8 or 10 hours.
Beat me to it @JRHAWK9

Yeah, I see now where I misunderstood! That's a huge heat load. Are there still European style downdraft boilers available state side? Might have to use an outdoor unit.

 

[brenndatomu]

Are there still European style downdraft boilers available state side? Might have to use an outdoor unit.

Yes, some can be bought here still...and any 2020 approved owb would work...although only a few qualify for the tax credit
The HeatMaster line is approved for indoor or outdoor use too.
Just FYI, I think all the remaining EPA approved boilers are downdraft gassers...it's really a genius design!

 

[ABMax24]

By my math a 40ft reefer would hold 20 cords of wood packed completely full. Let's say using totes you can get 50% packing efficiency, that's roughly 10 cords if wood. Moisture to evaporate from the wood depends upon species, but let's use 1300lbs per cord. That's 13,000 lbs of water that need to be evaporated from the wood. Even a well designed kiln is going to waste 40% of the heat without evaporating any water. At 960btu/lb and 40% waste we need about 17.5 million btu to dry 10 cords. With a 200,000 btu heater we are talking 4 days at full output to dry the wood, and basically a cord of wood to fuel that heater.

I'm really not sure what to use for a heater, but I think you're looking at commercial units for this. Or a custom built unit that clearly wouldn't be emissions certified if that's an issue.

Where's @SidecarFlip? I believe has experience with boilers of this scale.

 

[stoveliker]

I think @peakbagger (also?) has - but he has other things on his mind right now.