Setting up an Outside Boiler to Burn Coal

Carbon12 · Post by **Carbon12** » Fri. Feb. 14, 2014 1:55 pm

Sweet!

Also, this:

Hand Feed to Stoker Conversion Slab Heating Project

Seems it's been done a couple times.

windyhill4.2 · Post by **windyhill4.2** » Fri. Feb. 14, 2014 2:56 pm

Ours is rated at 600 k for whatever that is worth,i still think it would be too complex a conversion to try for enough efficiency to be worthwhile. I did not research it but believe it was Ls farm that put an underfed pot in a wood stove,but a much smaller firebox than ours.

Carbon12 · Post by **Carbon12** » Fri. Feb. 14, 2014 3:14 pm

THAT,.......is a big boiler! What did you have in mind to replace it?

windyhill4.2 · Post by **windyhill4.2** » Fri. Feb. 14, 2014 8:43 pm

I've been researching the Van Wert 800 & like what I found about that unit,have to figure out how to do the conversion,build a shed where the owb is or build onto shop & run more pipes to the pit under the owb to connect all the pipes,then build a cover over the pit to protect & keep heat in the pit pipes .

LsFarm · Post by **LsFarm** » Fri. Feb. 14, 2014 10:02 pm

Do a search on the forum for 'Iron Fireman' .

Greg L

Carbon12 · Post by **Carbon12** » Fri. Feb. 14, 2014 10:50 pm

Could you build a shed next to the OWB? Would it make sense to feed the hot water from the coal boiler into the wood boiler to keep all the controls intact? That way you'd have the wood boiler as back up, just in case.

windyhill4.2 · Post by **windyhill4.2** » Fri. Feb. 14, 2014 11:19 pm

Our owb is not a boiler,its an open system,like a big tea kettle (to borrow a phrase by Rob ?) so joining is not an option & the condensation in the cold owb firebox would be very bad,not to mention the lost BTU's thru firebox & out the stack.We have looked at various options & have decided its either burn wood in the owb or replace with coal boiler which is the option we hope to pursue as $$ allow.

Post by **Lightning** » Sat. Feb. 15, 2014 3:52 am

windyhill4.2 wrote:Our owb is not a boiler,its an open system,like a big tea kettle

Open? How so?

lsayre · Post by **lsayre** » Sat. Feb. 15, 2014 6:09 am

Lightning wrote:
windyhill4.2 wrote:Our owb is not a boiler,its an open system,like a big tea kettle
Open? How so?

Perhaps he means it is vented to the atmosphere (open), and not pressurized (closed). If so it probably heats a fairly large reserve tank of water via a heat exchanger.

Post by **Lightning** » Sat. Feb. 15, 2014 7:18 am

Oh ok. That's neat. Is that so it can't boil and burst?

lsayre · Post by **lsayre** » Sat. Feb. 15, 2014 7:21 am

Lightning wrote:Oh ok. That's neat. Is that so it can't boil and burst?

Most likely. I think its done because a wood fire is not very controllable.

Post by **Rob R.** » Sat. Feb. 15, 2014 7:25 am

Outdoor wood boilers are "open" because that allows them to not be classified (and regulated) as a pressure vessel. If they were built to the same standard as an ASME boiler like an EFM or Axeman Anderson the cost would be a LOT higher. It is all about making them cheaply, there is no performance advantage to an open system.

Post by **Lightning** » Sat. Feb. 15, 2014 7:44 am

Ah I see.. Thanks for the explanation.

windyhill4.2 · Post by **windyhill4.2** » Sat. Feb. 15, 2014 7:45 am

Thank you,Rob. You said it much better than I could've , the thing that convinced me to go with an open system was the advertising done by lots of the stove makers."Our unit is not pressurized & cannot burst spraying you & your family with boiling water". Sounded good & safe,but ours rarely sees temps above 190* anyway,wood fire is less controllable only because coal burners generally use a more consistent draft & burn. OWB uses forced draft to quickly get fire built up,then shuts draft off completely until water temp drops & the cycle repeats.

artbaldoni · Post by **artbaldoni** » Sat. Mar. 01, 2014 10:40 am

OWB successfully burning coal for the last 2 weeks. Using a mixture of bit nut and red ash ant nut. Johnson A419 contoller set at 180° with a 2° diff. Loaded at 2100 last night with 8 coal shovelfulls. Tended at 0800 this morning and dumped ash. By the looks of things I will get an 18 to 24 hour burn in sub 20° ambient temps with the house at 72°. Heating 3000 well insulated sq' and dhw.

https://www.dropbox.com/s/oa8oq7t8p90d6fb/2014022 ... 070122.jpg