Baro damper when loading coal

Baro damper when loading coal

PostBy: rberq On: Thu Dec 06, 2007 7:40 pm

I have blocked my shoddy barometric damper because it looks like it might fall apart, so I have never used it. (First season burning coal.) I intend to install a new, higher-quality damper soon. When I add coal to my stove, I generally open the air inlet wide to get lots of draft and air flow for a few minutes. Will this still work with a baro damper, or will the baro limit draft so that it's hard to fire off the new load of coal? Should I devise a clip of some sort to lock the baro closed while I reload?
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

Re: damper when loading coal

PostBy: bigchunk On: Sun Dec 09, 2007 4:22 pm

well i have a baro metric damper on my stove pipe and it is opened just a little bit its using what room air it needs . some times its not opened at all . it depends on the weather and how hot the fire is burning the baro is set to a certain setting i did not set it my instalers did. when i open my ash door it will open then close on its own. normal . when i reload i have been doing it after i shake down the ashes. and after i take the ashes outside . the damper is closed sometimes when i reload, it does it on its own. i dont mess with the primary air after i reload i keep it at the same settings. i try to bank it in the front a little bit in a corner. if i see that i covered the coal from front to back and side to side realy abundantly then i know im gonna get some gases bulding up and i keep my eye on the glowing embers they will start working there way up to the new coal i just put on. then at some point if i open the door a little bit it will ignite somewere sometimes one little flame sometimes the whole top will just come to life. then i will open my secondary draft so i can close my door it takes a second to do this. then i will get a feel for the time to close my secondary draft again. the damper sometimes isnt even opened . when that fresh load catches i can just walk away.
bigchunk
 
Stove/Furnace Make: harman
Stove/Furnace Model: sf250 magnafire

Re: Baro damper when loading coal

PostBy: rberq On: Sun Dec 09, 2007 10:20 pm

Thanks for the info. I wish my stove had an adjustable secondary inlet like you describe. It has a fixed opening around the glass of the door, that lets air in above the fire. It works so-so. Sometimes I do like you, open the door a little to get the gas to ignite, then when I close it enough air comes in so the gas keeps burning by itself. What I don't like is, I can't close off the secondary later on when it's no longer needed. So when a wind gust comes along, or there's too much draft, it sucks excess air in above the fire where I don't think it does any good. A working barometric damper would help that. I am contemplating blocking the built-in door vent and retrofitting a damper on the stove side above the fire for secondary air. But that won't be this season, and I'll have to study the idea a bit before I second-guess the engineers at Harman.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

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Re: baro

PostBy: bigchunk On: Mon Dec 10, 2007 10:06 am

could you send a pic of your set up so we could see the stove. you could put the pic of your stove in the stove pic section. that would be great thanks.
bigchunk
 
Stove/Furnace Make: harman
Stove/Furnace Model: sf250 magnafire

Re: Baro damper when loading coal

PostBy: rberq On: Wed Dec 19, 2007 8:09 pm

I withdraw my original question. I replaced my shoddy baro with the recommended Field Controls model RC, very carefully installed it level and plumb, set it to the max .08 draft, and it works fine. Plenty of draft when loading the stove with new coal, though not as much as with the old baro blocked.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

Re: Baro damper when loading coal

PostBy: coaledsweat On: Wed Dec 19, 2007 8:28 pm

rberq wrote: set it to the max .08 draft, and it works fine.


That seems like a lot, normally coal fired units max out at .06. Not saying its wrong, I am curious as it seems high to me.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Baro damper when loading coal

PostBy: Wood'nCoal On: Wed Dec 19, 2007 8:37 pm

rberg,

I think you said it's a Harman stove. Harman recommends .06 to 1.0" WC for the draft. I run mine at .05" WC. I reduced it from .06 to try to extend the burn time. You really don't need .08. My stove burns fine and produces lots of heat at this setting. I also found out that the chimney drafts a lot more that I thought, with a full fire burning the baro will open to the limit of it's travel and stay almost at that point for quite a while.
To me seeing the baro open that much doesn't mean all my room temp. air is going up the chimney, it means I'm saving $$$ by burning coal with the correct amount of draft! :)

My baro usually closes when I open the loading door, it resumes operation when I close the door. I run the ash door draft vent anywhere from 3/4 turn to 3 turns open, depending on the amount of heat required. I will sometimes open the vent more after adding coal until the fire is well established.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Baro damper when loading coal

PostBy: rberq On: Wed Dec 19, 2007 10:30 pm

Yes, it's a Harman. The instructions that came with the stove say .06 MINIMUM draft, with .06 to .10 being the suitable range. So I set it at the mid-range, .08. Also since I don't have a manometer I wanted to err a little above the minimum. Seems to burn well, and I don't get the audible whistle of excess air into the over-the-fire air inlet like I was getting before installing the baro. I will experiment later with slightly lower settings.

Like you, I generally run the air inlet between 3/4 and 3 turns open, though very rarely beyond 1 1/2 except when firing up new coal. I also have noticed that the baro closes when I open the ash door or open the air inlet to its max. It makes sense. Think of the chimney like a straw that you are using to suck up a thick choclate shake. That's like having the air inlet closed down, so there's a lot of suction in the middle of the straw where the baro is. But once you pull the straw out of the ice cream -- like opening the ashpit door -- there's no resistance to new air flowing into the bottom of the straw, hence very little vacuum in the middle to pull the baro open.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

Re: Baro damper when loading coal

PostBy: Wood'nCoal On: Wed Dec 19, 2007 10:46 pm

rberq wrote:Yes, it's a Harman. The instructions that came with the stove say .06 MINIMUM draft, with .06 to .10 being the suitable range. So I set it at the mid-range, .08. Also since I don't have a manometer I wanted to err a little above the minimum. Seems to burn well, and I don't get the audible whistle of excess air into the over-the-fire air inlet like I was getting before installing the baro. I will experiment later with slightly lower settings.

Like you, I generally run the air inlet between 3/4 and 3 turns open, though very rarely beyond 1 1/2 except when firing up new coal. I also have noticed that the baro closes when I open the ash door or open the air inlet to its max. It makes sense. Think of the chimney like a straw that you are using to suck up a thick choclate shake. That's like having the air inlet closed down, so there's a lot of suction in the middle of the straw where the baro is. But once you pull the straw out of the ice cream -- like opening the ashpit door -- there's no resistance to new air flowing into the bottom of the straw, hence very little vacuum in the middle to pull the baro open.


Since this place is poorly insulated, I usually need more heat out of the stove, right now it's set at 2 turns. I will leave it there for the night. You said the baro closes when you open the ash door. That shouldn't happen. Do you mean the loading door?
I probably should have gotten the Mark II, for the additional BTU's, but once I get the Alaska done and installed in the cellar (which is at about 55 degrees now) it should ease the load on the Harman. We also burn the wood stove at the other end of the house as needed.

The Mark I really does put out the heat, though.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Baro damper when loading coal

PostBy: rberq On: Thu Dec 20, 2007 9:55 am

Nope, I meant the ashpit door. Though it also happens when I open the loading door, or when I suddenly open the air inlet all the way. The chimney is producing suction on the stove and the baro damper, so air tries to come in to fill the partial vacuum. It's kind of like electricity, the air will come through the path of least resistance. So if all the air needed can come in easily via the ash or loading door, or via the open air control, then it will not pull any through the baro. Of course that's only a momentary situation. If I leave the ash door open until the chimney is roaring, then there's so much draft (suction) that the baro will open. Conversely if you have a good draft going and suddenly close down the air inlet, the baro will open wider to satisfy the sudden extra vacuum, momentarily, until everything gets back to steady-state again.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

Re: Baro damper when loading coal

PostBy: rberq On: Sun Dec 30, 2007 2:45 pm

Answered my own original question. I set my baro back from .08 to .06 (per the baro weight scale, not measured with a manometer). The stove burns even better, but draft is marginal for firing up a new charge of coal. I made a simple clip (out of a paper clip) to hold the baro closed for the first 5 or 10 minutes when loading. This increases the available draft significantly and once I have good over-the-fire flames (to avoid "the explosion"), then I remove the clip and it's back to normal.

Call me impatient -- but it's a great time-saver when I'm trying to get out the door to work in the morning. Plus it makes me feel more useful, sort of like driving a standard shift instead of an automatic.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

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