Manual pipe dampers .. how, why, when

I re-did my stove pipes last week, removed the cheap non-functioning baro, installed the recommended Field Controls RC baro. While I was at it I removed the manual pipe damper, which made me nervous whenever I used it because Harman says THOU SHALT NOT HAVE A MPD! Anyhow I don't miss the MPD a bit, the stove now burns very steadily with no constant adjustment, like everyone told me it would. It's not quite as quick to fire up a new load of coal because the draft is limited, but not enough slower to be a bother.

Best thing about it is knowing there is a precision machine, drawing no electricity, working tirelessly on my behalf, managing my fire with no effort on my part. I love it when machines work for me free of charge! We don't have television for entertainment, so sometimes when it's windy I just stand there and watch the baro doing its job.

Thanks Santa! Well I have been using my MPD for two weeks off and on with the EFEL. Last started it Thursday evening, burned straight thru til last night. Burned out while away visiting. Burned slower and better. Big help having the Manometer to check draft at different stages of burning. Always stayed between the red and green arrows. Could adjust MPD and watch meter change. Even with the MPd FULLY CLOSED , the meter was right at the red arrow , not below.

Now with the Franco Belge, I don't have any damper at all. The nanometer did go past the green arrow when the wind started howling Sat evening. So I need something on the F/B. It does have an air intake auto adjust to keep from overfiring, but still I'm losing heat up the flue pipe. I guess it would be more except I using 4 inch exhaust pipe and that is helping to restrick the volume of exhaust.
Will see what I can get tonight after work at Stove and stuff! Jim

I was reading over the literature with the Condar Draft Kit (manometer) and found a couple of things, which I thought were interesting, but didn't know where to put them. So, here they are!

Quote:
"Chimney draft is created when room air is drawn into your stove or furnace to help burn fuel. Two main indicators of how your appliance is operating are flue gas temperature and draft. Draft, which is caused by a difference in pressure between flue gas and room air, is measured in inches or millimeters of water."

"Downdraft may occur due to unusual weather conditions, usually on warmer, damp days with no wind. Downdraft is usually temporary and always undesirable, as smoke and toxic flue gas may enter the room."

"Chimney draft is affected by wind and outside temperature. Windy or cold weather can increase draft and, in combination, cause a substantial increase, though rarely over .20 inches of water. A change to damp, warm weather tends to reduce draft, at times to the point of creating a downdraft. Downdraft can occur if the roof line of the house causes the prevailing winds to be forced down the chimney. A chimney cap will usually correct this."

Hi, Guys! As I understand dampers regulate air flow in chimney. Two diff ways: manual don't let too much air escape form stove and baro use room (warm by the way! ) air to equalize air stream.I have a Q? is it not enough to minimaize enter air in the stove by lower door? I think it's works same as manual damper only from bottom side of stove. About Baro- it use my heated air ($$$) to vaiste in to chimney What do you think? Serge.

spaserg wrote:Q? is it not enough to minimaize enter air in the stove by lower door?

A high chimney draft will increase the velocity of the air into the draft port. Even on low draft settings the increased chimney draft can easily place 4-6 times the air into the unit it would see under a normal draft. The stronger the draft, the higher the velocity, and the more air your fire sees.

This is my opinion, only! .. proven to myself, to the point, that I'm comfortable with it after 55 years of experience.

A baro damper is necessary on any "automatic appliance" to compensate for draft changes in the chimney.

A baro damper on a "hand fired" is more like a governor on an engine, it will set the "maximum burn" rate.

The MPD will, buffer the fire from external effects as well as, "help" retain the heat over the fire, and in the stove, while maintaining a more constant chimney temperature. A baro damper in conjunction with the MPD is the ultimate of "control" and "over-firing protection" ... on a hand fired appliance.

"Either could" be used or "neither could" be used, as well as, both can be used.

Dallas wrote:"Either could" be used or "neither could" be used, as well as, both can be used.

LOL, you should run for office.

"I don't think so, Tim "

I think the important thing to note with hand dampers is whether or not the appliance has a forced draft (draft blower) or not. A hand damper on a natural draft appliance is one thing, it's effect on the unit changes under a forced draft. It can cause the overfire draft to go positive. This is the reason you will hear some flack about them. Their improper use is risky. I am not against them as I use one. I just want you to be aware and safe.

Spaserg, you musht be the kind a' guy who geshts un argmint going amongsht da drunks in a bar -- hic ! -- then shlips off to the side to wascht the brawl. Why elsh would you revive thish battle after all thish time? Fr'm thish thread and othersh, you will find mosht forum partichipants DO use a baro, and ish not because we're all igrint and gesht pleashure from shending our $$$ up the chimbley. So schtop it!

rberq wrote:Spaserg, you musht be the kind a' guy who geshts un argmint going amongsht da drunks in a bar -- hic ! -- then shlips off to the side to wascht the brawl.

rbreq, "I" can't figure out what camp you're in and I don't know why you are giving Spaserg a hard time.

Your first post indicated you felt the MPD was the greatest thing in your life.

rberq wrote:CAUTION WARNING! Amen, brother! I'm new to coal this year, but i have a lot of woodburning experience. My coal stove installer put in both a manual damper and a baro. The baro is a cheap piece of junk and I have blocked it (discussed elsewhere). Lately I have been experimenting with the manual damper CAUTION! and I am astonished to report that EVERYTHING Dallas says appears to be true for my stove. Longer cleaner burns with significantly greater heat output from the stove. Less air over the fire (I can hear the difference when I damp it down a bit, because it audibly hisses in through the small secondary). My manual damper DOES have significant holes in it so even when in the closed position I can see no visible change in the fire at normal burn rates. Even so I don't dare run it "closed", but "sensibly" closed 45 to 60 degrees seems to help a lot. CAUTION!

And then later on, the MPD was the worse thing in your life!

rberq wrote:I re-did my stove pipes last week, removed the cheap non-functioning baro, installed the recommended Field Controls RC baro. While I was at it I removed the manual pipe damper, which made me nervous whenever I used it because Harman says THOU SHALT NOT HAVE A MPD! Anyhow I don't miss the MPD a bit, the stove now burns very steadily with no constant adjustment, like everyone told me it would. It's not quite as quick to fire up a new load of coal because the draft is limited, but not enough slower to be a bother.

Best thing about it is knowing there is a precision machine, drawing no electricity, working tirelessly on my behalf, managing my fire with no effort on my part. I love it when machines work for me free of charge! We don't have television for entertainment, so sometimes when it's windy I just stand there and watch the baro doing its job.

Do you have any clue what you are talking about?

Sounds to me like he figured out that manual dampers don't live up the the hype, and the automatic barometric damper does the job of controling draft as advertised.

Greg L.

Greg! Welcome back. I just didn't have my heart into that last post. It wasn't the same without you. Richard said, you were out for MPG, MPD or DNS or something ... I knew he meant you had gone to buy a manual pipe damper.

Dallas, some days I do have a clue, sometimes not. As to dampers, in my ignorance (which didn't stop my mouth) I was happy with the MPD, until I tried a good baro and (still mouthing off) I cast my old MPD into the pits of the town dump metal recycling bin. Not really trying to give Spaserg a hard time, but I was concerned lest renewing the controversy would disturb your recent tranquility. (Just teasing, now -- if I knew how to use Smilies I would put a big one here.)

I'd never buy a manual damper, I've figured out that they don't work, and there is an automatic version that DOES work, and it's automatic !! It even works while I sleep! Automaticly and safely.

Greg L..