Need Tips for Burning Slow in the Warm Weather

PostBy: coaledsweat On: Fri Jan 05, 2007 12:45 pm

Well I can tell you one thing about running a hand fired in this warm weather, don't try to run a smaller bed of coal. If anything you may want to go deeper. It seems that the thinner the bed the less control you have and it tends to get harder to shake the ash and a poor burn at the bottom. The thicker bed allows a more even burn, better ash and a lot more control and stability running down low because you can run the ash deeper and stop shaking when you see a hint of glow. You use less coal too.
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

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PostBy: LsFarm On: Fri Jan 05, 2007 1:54 pm

Coaledsweat: Going deeper is what we are talking about. The BTU output of a stove is determined by the area of the fire. Reducing the firebox size by building a new 'back wall' to the firebox makes the fire area smaller. This will allow a deep, but smaller area of coal to burn.

This is the same as using a Harman Mark I instead of a Mark III, a much smaller fire area, but still the same deep bed of coal.

The one problem that can occur is if the amount of heat is so little that the chimney can't create enough draft to pull air through the coal bed and the fire goes out. A good tall chimney reduces this problem.

Mark Cap has been running a reduced firebox since last season if I remember correctly. I have had a reduced firebox in my boiler since last season. It works fine, allowing me to burn a much smaller amount of coal in a much deeper coal bed. This is how I get 12 hour burns.

A stoker burner in a LeisureLine, Keystoker, Alaska or Harman does the same thing, the coal bed will be only ~7" wide by an inch deep, at a low fire setting, but will increase to 7" wide by 5-6" deep at a high output setting.

Greg L

Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: barley master On: Thu Jan 11, 2007 8:18 am

all this talk about making the fire box smaller just has me shakin my head. were lookin here to slow down the heat rate of your stove on a hand fired unit. if you have to make the fire box smaller then you have to let it go out to do that, then relight it, what a waste of time and energy that is (at least for me). just learn how to fire it and youll master that stove. if its still too warm then like said earlier open then windows. because of current temps now you will be kicking yourself because you have to make the firebox bigger to get the heat required to keep everyone toasty which means shutting the unit down again and removing the bricks. if your able to leave the bricks in all the time then your stove is oversized for what it has to heat but it will still do the job. I don't know about you guys but I only like to make one fire a year per stove. oh and all I had to do when the temps dropped was to go over to that window and close it :)
barley master

PostBy: Gary in Pennsylvania On: Thu Jan 11, 2007 9:52 am

barley master wrote:just learn how to fire it and youll master that stove......

Last week we had temps in the mid to upper 60's.
I had my hand fired Harman insert a-goin' ....
I close the draft knob completely....then back it out just a quarter to a half turn - NO MORE! The outside box temp will linger 200-250 degrees.
Just make certain that the freshly added coal is caught well by the bed before you draft it so low.
Gary in Pennsylvania

PostBy: coaledsweat On: Thu Jan 11, 2007 11:11 am

I'll go along with that. I think it is a lot easier in weather like this to operate a boiler than a stove in these situations too, as you can adjust there temp settings. A draft blower will also make it a little easier I think as the fire can just about die and the blower livens it up every now and then.
The thing that bugs me about stopping and starting extra fires to change the box size is it takes about 100-120# of coal to load up a new fire which pretty much negates any savings doing all that work to save a couple #s a day.
The other day we had a high of 72F and I had no trouble with my boiler going overtemp. I just cut the draft way down for the day and back up in the late afternoon and she was happy.
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: LsFarm On: Thu Jan 11, 2007 3:37 pm

Gary: a lot of chimneys won't draw well enough to keep a fire going at extremely low settings like you are using. You are lucky to have such a good drawing chimney.

Barley. I'm certainly not advocating changing the firebox size everytime the weather changes for a day or two. But if a person's stove is just too big for the application, then why burn extra coal when [if] it is possible to reduce the firebox size to better fit the application??

I do everything I can to minimize the quantity of coal I burn. Because I'm a 10 hour drive one way to the breakers. Or I can pay $300+ a ton in my state. Nope, not me, unless I'm desparate. I can't take two days off work to do a jaunt to Pennsylvania after coal.

So I reduced my firebox to burn an optimal amount of coal. If the trend is for it to be cold, I can easily increase the box size without letting the fire go completely out.

I'm certainly not going to open windows and warm up the neighborhood. That defeats the purpose of burning coal in the first place. If I had money to burn, I'd just crank up the thermostat and pay $1200-$1500 a month for propane.

I agree that for short term warm temperatures just opening the windows is a method to keep the house from being uncomfortable. But if I wanted to heat my place during two or three weeks of 50*days/35* nights with a hand fired stove, I'd size the firebox to fit the heat requirements, not burn excess coal and open windows. I'm too frugal [read cheap :) ]

This is mostly a moot point anymore, the temperatures in Michigan are trending towards 'normal' 20's in the day, teens at night. Forcast for 12* Monday night.

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

PostBy: drhntr855 On: Thu Jan 11, 2007 5:03 pm

Hi Guys, I blocked off the back of my Hot Blast and didn't the result I was looking for. With all of the fire in the front and the fans and fan control in the back I had plenty of heat in the front of the furnace but not enough in the back to make the distribution blowers come on even when I turned the fan limit all the way down. I think if I had done the opposite it would have been better but then loading may be an issue. I let it go out this morning and will go back to a full fire box tonight. I like the idea and it makes sense to me. Maybe in the spring I'll try again but in reverse. Probably in a boiler it's not as much of an issue what part of the fire box is hot.

Coal Volume per day

PostBy: drujinin On: Thu Jan 11, 2007 5:56 pm

I burn right around 50 lbs a day when its cold, but I think my house maybe considerably tighter than some of your farm houses.
Hand Fed Coal Stove: Hearth-Mate Series 2480
Coal Size/Type: Nut

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PostBy: coal_kid On: Thu Jan 11, 2007 10:40 pm

Wow my thread picked up when the weather turned, I had a 14 degree low last night. I’m happy I didn’t have to shut my stove down to take out firebrick.

Personally I think I have mastered burning low… 35-40 lb a day is the lowest I can burn without risking the fire going out. 10 lb am, 10 lb eve, ~15-20 lb before bed.

I run it low heat spring combustion air, and -0.03 draft on the chimney. I experimented with different banking methods and found one that works for me. What works best for me is to have the back of the firebox where you can almost see red… high in front so it’s still mostly fresh 8 hours later. My stack temp would be about 200. (My outer-most grates are stationary, so pilling it up on the outside makes too much ash where I can’t move it.)

I’d bring up the fire with a -0.06 chimney draft and combustion air wide open until I’d see 300-350 degree stack temp. Load it up, get the stack back to 300-350 again and start shutting it down slow. Maybe a 20 minute ritual, which works good when it’s cold too.

I only burnt about 60 pounds yesterday with a 14 degree low, thats a 1600 sq ft house kept up nice, built in 1950. I did burn away alot of my base, so my fire is low in my firebox tonight.

PostBy: short On: Sat Jan 13, 2007 9:53 am

coal kid, on the front of thr loading door on your stove there should be a slide damper. on warmer days open this damper,the fire will draw air across the top of the fire ,cooling it. that is the purpose of that damper.

PostBy: coal_kid On: Sat Jan 13, 2007 10:00 pm

On the feed door there is a slide damper. I experimented with it and that did slow the fire down enough for me on our hot 60+ degree days last week. I found I can keep a fire just going with that open to where my draft is -0.03. I didn’t want to go any less. I haven't had to do that for a few days, now that we are back to November type weather.