coal burn hotter in colder weather?

coal burn hotter in colder weather?

PostBy: italia899 On: Fri Oct 27, 2006 10:49 am

Hello,

I believe the above is true but I wanted to get an experts' confirmation. My stove is reaching temps of 300-400 degrees in this 40-50 degree weather and wanted to know if those temps will increase in colder weather assuming damper and draft are at optimal settings. Thanks.
italia899
 
Stove/Furnace Make: Brunco
Stove/Furnace Model: Hearthglow

PostBy: SMITTY On: Sat Oct 28, 2006 7:43 pm

The chimney will pull a stronger draft. You'll be able to run the same temps with the damper closed a bit more.

How much stronger the draft will pull obviously depends on what type of chimney you have. I have a masonary chimney in the center of the house, & it will draft 2 appliances even in 60* weather.
SMITTY
 
Stoker Coal Boiler: Patriot Coal - custom built by Jim Dorsey
Hand Fed Coal Stove: Harman Mark III (not currently in use)
Coal Size/Type: Rice / Blaschak anthracite
Other Heating: Oil fired Burnham boiler

PostBy: Cap On: Sun Oct 29, 2006 9:28 pm

Smitty--

Why will a flue in the center of a structure provide a better draft than a flue on the external wall of a structure? I thought the difference between the inside of the flue and the outside is what created more or less draft. Greater temp diferrential, better draft? I read this on the following link.

But I continue to struggle burning coal in a 30' x 6" ss liner on warm & especially damp days. So I am not sure what to do next.
Last edited by Richard S. on Sat Nov 30, 2013 3:17 pm, edited 1 time in total.
Reason: <removed dead link>
Cap
 
Hand Fed Coal Boiler: Harman SF 250, domestic hot water loop, heat accumulator


PostBy: coaledsweat On: Sun Oct 29, 2006 10:00 pm

Exterior chimneys give up their heat to the atmosphere quickly while interior ones are inside the house and retain a lot of heat. The warmer chimney will produce a greater draft because the gasses stay warmer.

You should not have a draft problem with a 30' chimney, something is wrong if you are having trouble burning coal. Details? Lighting, keeping it going? Stove?
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: LsFarm On: Sun Oct 29, 2006 10:16 pm

Cap, can you pull that SS liner insulate it and reinstall it?? If you have a draft around the outside of the SS liner, it will be cooling off sooner too.

Do whatever you can to keep the air in the chimney as warm as you can. If the stove is just barely warm, and the SS liner is absorbing the heat from the gasses, by the time the gasses get to the top of the chimney, they may not be any hotter than the 60* outside air, therefore no draft.

You may have to keep a hotter fire than you would like in order to keep the flue gasses hot.

Just some ideas. Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: Cap On: Mon Oct 30, 2006 11:55 am

Coaledsweat, Greg--

I have the 6" liner fit tightly inside of a 8" square telecotta flue. No room for insulation unless I was to jam insulation down from the top between the liner in the corners of the telacotta. But this would not be neat. But what you say makes sense now to me. If I try and burn a soft/light coal fire, I'll have trouble. When I really let it rip, it'll burn real nice. Reading your post from over the w/e stands true with me too. If I let the fire begin to go dead around the edges, it is too late to refill, will only smother out the fire. It definitely takes some nursing it back with some oak blocks.

I have a accurate Ashcroft temp gauge on the stack pipe. If I keep my exhaust temp at 250 F or better, I have a real nice hot coal fire. If it settles down below 225 F., it is time to throttle up the draft.

Coalsweat, I am using a hand fired Harman SF-250. Look for it under the *pictures of stoves*. I also recently installed a hot water coil in it which is really working good, maybe too good. Check out the thread.
Cap
 
Hand Fed Coal Boiler: Harman SF 250, domestic hot water loop, heat accumulator

PostBy: coaledsweat On: Mon Oct 30, 2006 7:50 pm

I thought S/S was a no-no with coal?
Can you seal the bottom of the liner to the chimney and pour an insulating cement around it? I would think if air can run up between the liner & the flue it could have a negative impact on the liners draft.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: SMITTY On: Sun Nov 05, 2006 10:12 pm

I was told by the company that I bought my pipe from that 304 SS will last 5-7 yrs., & 316 SS will last 15-20 yrs. burning coal.

Both figures are only with a regular, annual cleaning throughout the pipe's life.
SMITTY
 
Stoker Coal Boiler: Patriot Coal - custom built by Jim Dorsey
Hand Fed Coal Stove: Harman Mark III (not currently in use)
Coal Size/Type: Rice / Blaschak anthracite
Other Heating: Oil fired Burnham boiler