Baro Damper Question

Cap, one of these nights you will be gone on a work trip, and the weather will cool off, and the wind pick up. Without a baro damper, your tall chimney will pull so hard on your stove it will burn the coal up in one night. The function of the baro is to stablize the draft.

During warmer, calm weather, if you have low or inadequate draft, your baro won't do anything but sit there untill the draft exceeds it's setting. It sounds like you have inadequate draft since you like your baro covered with tin foil. If covering it with foil improves your draft, then you need to examine why you have inadequate draft. You have a tall chimney if I remember correctly, lined with a 6" SS liner.. Too long of a run of 6" will slow the velocity and draft. Personally I would want a 8" chimney with your SF250, especially if you are burning the full firebox.

I had a 6" stack originally, and had smoke in the room issues everytime I opened the door to load coal. Changing to an 8" chimney cured the problem Much greater capacity for draft and hot smokey gases.

Is your liner smooth or corrugated?? If corrugated, has it accumulated a layer of fly ash??

Greg L

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Cap wrote:Interesting! Having read the .pdf file...

Direction for hand fired units---"Close ash pan door for mild weather". Can I assume then, the ash pan door is to be open for cold weather? And allow the RC Control"s barometric damper control the draft?

But why would I leave my door open for more than 5 or 10 minutes to stoke up a fire? That would be insane.

This baro is likely designed for older systems or much larger "plants" as they put it. Little or no need for a small hand fired Harman the way I see it.

Cap
tHE ANTI-BARO..IT'S BEEN FOILED

Cap, I think their description of the ash door is where most old big units got there air, the draft control. That info is very dated. The priciples remain the same whether it is a small or large fire, its your heat.

rberq wrote: But there are other not-recommended locations that forum members have used successfully.

That's true, but the more you stray from the recommended install, the less likely it will perform properly. If your a little wrong its just a few extra lumps of coal your out. If your a lot wrong.........

Cap wrote:Interesting! Having read the .pdf file...

Direction for hand fired units---"Close ash pan door for mild weather". Can I assume then, the ash pan door is to be open for cold weather? And allow the RC Control"s barometric damper control the draft?

But why would I leave my door open for more than 5 or 10 minutes to stoke up a fire? That would be insane.

This baro is likely designed for older systems or much larger "plants" as they put it. Little or no need for a small hand fired Harman the way I see it.

Cap
tHE ANTI-BARO..IT'S BEEN FOILED

Mark, It says "close ash pit draft door" not "close ash pan door". I interpret "close ash pit draft door" to be a reference to the adjustable air inlet or draft control usually found on the lower portion of a hand fired unit, usually the "ash pit" or "ash compartment". What say you?

My baro works fine. Maybe I'm impatient It just doesn't allow my unit to create a large amount of heat. With the setting (or weight) on the highest set point, the draft is .07" wc. I have to use foil to create a stronger draft thus more heat. With my ash pit damper wide open and foil on the damper, the draft max's out at 1.5" wc. Right now, I just loaded the unit for the night, ash pit damper wide open, draft sitting at 1.3 wc. Once I damper her down to two turns out from tight, the draft will settle down to .07" wc.

I understand I run the risk of burning dry but it's more hassle than it's worth . And besides, burning dry is a good thing every now & then. Gives you a chance to clean out all of the waste. Now if I go away, maybe I'll pull the foil. My wife likes it cold. I'm a fairy, I like it warm.

Notes: I did clean the liner last Nov. It was coated with fly ash. I do have a 6" corrugated. I do not get any smoke in the room with the door open. The 8" square flue allowed the draft to collapse after 6 or 7 hrs of operation when the fire was on its downswing. I can easily maintain the lightest draft . I just cannot control the upper 25% with the baro. So, it's been foiled. My firebox is 18" x 13" or 20% reduced with a 8" piece of SS C-channel and firebrick.

Sounds like you have a pretty good handle on this coal burning thing!

If you can't get a hot fire with .07" wc, then your grate is clogged with ash, or your heat exchanger between the fire and the flue is clogged. Have you ever cleaned the fly ash out of the Harman's heat exchanger around the tubes??

My machinist buddy GregWhite here in Michigan with the Harman SF150 cleaned about half a 5 gallon bucket of fly ash out of his Harman's exchanger after one season.

If you need a .13" wc draft to get a good fire, you are either expecting a fresh load of coal to go from black to red coal in 5 minutes [very impatient ] or your grates and or exchanger are clogged. A .13" draft should just about suck pieces of coal up the flue.

Greg L

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Mark,
In thinking about it, what Greg mentions has merit. The draft readings just don't seem right. I'm not familiar with the insides of your stove, but with that much draft the pipes should practically be glowing. That much draft with my Mark I would get the pipes really hot and send lots of heat up the chimney. I know with my stove ash will accumulate at the bottom of the baffle, which is also where the outlet collar is. The manual for the stove does mention cleaning out the pipes, but fails to say anything about this area of the stove. That's why I switched the elbow to a tee with a cap for easy cleaning. The installation instructions shows an elbow.

Maybe the unit isn't burning as hot as it could due to the size of stove coal I've been burning? Very large chunks. Lot of air passing thru the bed?
Quite warm today, high 40's, throttled in damper to one turn from tight. .078" w.c. Fire burnt all day untouched.

Maybe. As I mentioned before, the only time I burned stove size was coal that was very low quality. My stove seems to do best with pea, but I'm going to try a 50/50 pea and nut mix to see if I could get a little longer burn time.

I burn stove when it gets real cold, that stuff always burns hotter and faster for me.

I just edited my last post in this thread. It should have read "pea and nut mix" instead of "nut and stove mix".