Coal fired water heater ?

PHM

I used to burn a lot of wood: wood stoves, wood furnace, and then more recently I built myself a convection tube bodied, three pass, air tight, wood stove with secondary air.

I'm tired of it, don't use it, and am going to haul it out of the basement. Might try to sell it but it will probably go for scrap.

I also have a Hot Pot coal-fired 'laundry stove'. Two-lid with a water jacket.

And a Hercules coal-fired water heater. Sort of looks like a really fat curb-side fire hydrant. Also, as you might suspect; with a water jacket.

So now that I'm projecting to hooking up one of the little coal burners I would to ask for your opinions.

Do you coal-thinkers think that using the little coal units without the water jackets filled will be a problem? Of course a modern heating boiler cracks from being dry fired. But these little things are from before pumps and auto fill valves, and so forth. So the possibility of them being operated without water seems like it would have been obvious to the manufacturers - right?

Or must they be filled with water before firing?

EBEBRATT-Ed

They need water to prevent damage. Be careful with those and make sure you have a relief valve

Larry Weingarten

Hi, is it this sort of heater? This is a sidearm for domestic water heating. What are you looking to do with it... space heating like a wood stove, or? I can't imagine the cast iron reservoir would appreciate being dry fired because of unequal thermal expansion. Water inside would do a lot to mitigate that problem. Firing it slowly would probably work, but that's another thing to always remember.

Yours, Larry

Jamie Hall

I have one sitting around here somewhere. Cracked, They will if they are fired with not enough water in them -- they have to be full. The advantage is that the leak from the crack will damp the fire at least...

STEVEusaPA

PHM...is this the world famous Poodle Head Mikey?

PHM

Jamie Hall: I am willing to bet that a cracked unit could be easily repaired with some Silver King and a water circulating pump.

PHM

Larry: Much like the one you posted; yes.

So the design intent of water heaters such as this was to heat a hydronic coil mounted inside a tank of domestic water?

PHM

EBEBRATT: I would connect it an atmospheric / open system - so no relief valve.

With a cast iron radiator as a 'tank' I could always touch-test for low water level.

Larry Weingarten

Hi, There was no separation of waters. The water you bathed in flowed through the cast iron sidearm heater. The heater was just hooked up low and high on the tank, so convection drove it. The heater needed to be low in relation to the tank. Tanks were often uninsulated, so you could just feel the tank to know if you had enough hot water.

Yours, Larry

retiredguy

I will stick with a tank type water heater fired with gas, propane oil or electricity, anything but a solid fuel fire. My reason is that I have seen so many "accidents" when a home owner used a solid fuel water heater in the home. In a small town near Indiana, Pa an accident happened that I was told destroyed the house with some of the family inside. Pardon my negativity but I saw too many horrible and preventable accidents in my 40+ years.

PHM

Yes. Larger than Life and apparently still twice as dangerous.

I am done experimenting with my square tube body, 3-pass wood stove / convection furnace, with secondary air, and a massive-thermal-mass fire box: A 67 fire brick chamber.

But I have a little coal fired Hot Pot 'laundry stove' with a water jacket with a cracked grate - and this coal fired Hercules water heater I'm tinkering with.

It's all novelty / personal amusement grade stuff to get the Hercules up and going. My wood shop activities produce a lot of scrap wood, and tossing some hard coal on the fire seems like a cool thing. A Tagaki tankless supplements the hydronic solar panels I built so there no good reason to heat domestic hot water with coal.

I was casting about for a cast iron radiator to hang from the basement floor joists higher than the little water heater and have a open gravity system. Run the radiator 3/4 full and leave the air vent out. Maybe tap in a 18" boiler sight glass for water level - since I already have one just sitting here.

On the other hand; I already have a four 2FPI 3/4" tube evaporator coils - from the bottom of open display GEM cases. 1 1/8" suction - and I can header the 3 distributor tubes inlets to 1 1/8" copper. And plus; it weighs 30 lbs. rather than 300 lbs.

Hey: Do you know anything about projecting coal-firing BTU output from the unit's grate size?

PHM
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STEVEusaPA said:

PHM...is this the world famous Poodle Head Mikey?

PHM

Yes; it looks a fair amount like yours. But it's all one piece - no draw bolts between sections like yours.

EBEBRATT-Ed said:

They need water to prevent damage. Be careful with those and make sure you have a relief valve

MikeAmann

I can tell you COAL BURNS HOT.
And you need a very hot wood fire just to get the coal started.
And oh, the black dust everywhere.
This seems like way too much undertaking just to make a little bit of hot water.

retiredguy

If you are going to burn coal in a residence, choose anthracite instead of bituminous (soft coal), peat or cannel coal since these produce a lot of soot and are dirty.

hot_rod

Ever lived downwind of an inefficient coal burner?