Manual pipe dampers .. how, why, when

Re: Manual pipe dampers .. how, why, when

PostBy: Jimbitmen On: Mon Jan 06, 2014 6:27 pm

Just read this older post today, but what a lot of sense it makes. Dallas' "sensible amount" of draft hit the nail on the head when it comes to hand fired draft control. More draft=more combustion, but not necessarily more heat due to losses up the chimney. If you monitor flue temp, furnace temp, etc, you will find the best heating (of the dwelling) happens when a "sensible amount' of draft is present.
Jimbitmen
 

Re: Manual pipe dampers .. how, why, when

PostBy: WV Mountaineer On: Tue Jan 28, 2014 5:55 pm

I installed a 520 Warm Morning stove about 2.5 weeks ago. I use only the Manual Pipe Damper, no barometric thingy at all. I can't imagine doing it differently. All your heat is going out the flu if you don't use a damper. If you draft the coal from the bottom by opening the stove draft, turn the damper 2/3 the way off on the pipe, you get all the heat you need instead of letting it go out he pipe. Sometimes you need to get it hot, so you draft the bottom, open the damper and listen to it start to roar. I am not sure what part of this is misunderstood. You control the fire with both. You keep the fire hot with the bottom draft cracked but, force the heat to back up and radiate from the stove and the pipe versus going out the chimney with the damper. It isn't rocket science. Take that barometric thingy and throw it away if you have a barrel type stove. It isn't helping your purpose. Do it with a pipe damper and your stove draft instead. I been burning a stove for 40 years with a pipe damper only. So far, it has worked well. God Bless
Last edited by WV Mountaineer on Tue Jan 28, 2014 6:13 pm, edited 1 time in total.
WV Mountaineer
 

Re: Manual pipe dampers .. how, why, when

PostBy: freetown fred On: Tue Jan 28, 2014 6:12 pm

Same with my Hitzer WVM--When I have my MPD closed I can feel, with my hand near the top, more heat coming off it---YES, there is a time element involved in that test:)
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

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Re: Manual pipe dampers .. how, why, when

PostBy: lsayre On: Tue Jan 28, 2014 8:31 pm

What ever happened to: Volume of air in (and up through the coal bed to permit it to burn, induced via chimney draft) = Volume of air out (and up the chimney, bye-bye)? The simple logic of air volume in equaling air volume out must apply equally to both barometric dampers and MPD's. But on top of that, the barometric damper lets you keep your stoves draft sitting right at the stoves combustion efficiency sweet spot, which is something that Jimbitmen touched upon in his post above. You certainly can't say that for an MPD.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Manual pipe dampers .. how, why, when

PostBy: dlj On: Tue Jan 28, 2014 9:00 pm

lsayre wrote:What ever happened to: Volume of air in (and up through the coal bed to permit it to burn, induced via chimney draft) = Volume of air out (and up the chimney, bye-bye)? The simple logic of air volume in equaling air volume out must apply equally to both barometric dampers and MPD's. But on top of that, the barometric damper lets you keep your stoves draft sitting right at the stoves combustion efficiency sweet spot, which is something that Jimbitmen touched upon in his post above. You certainly can't say that for an MPD.


You are over looking a fundamental aspect of heating which is air-fuel mixing and heat transfer time.

With a baro, you control stove temperature by controlling your input air valves. So as you increase your air input, you also increase your volume of exhaust air going up the chimney with it's respective increase in chimney exhaust temperature (stack losses) as you do not control the back end.

Using a MPD, you run both ends independently. So you can increase your input air feed volume while controlling your exhaust. The result is longer mixing time in the stove, greater heat transfer dwell times, higher stove temperatures while maintaining lower exhaust temperatures.

Both devices have their pro's and con's - both have reasons why one would use one or the other or both on the same stove/chimney system.

I can certainly say that my MPD controls my chimney draft extremely well...

dj
dlj
 
Hand Fed Coal Stove: Vermont Castings Resolute
Baseburners & Antiques: Glenwood Baseheater #6
Coal Size/Type: Stove coal
Other Heating: Oil Furnace, electric space heaters

Re: Manual pipe dampers .. how, why, when

PostBy: freetown fred On: Tue Jan 28, 2014 9:26 pm

Larry, if your baro works well with your particular set up, it don't get no better then that. Me??? I'll stick with my 50 yrs with a MPD never having any kind of issue what so ever. With wood burning or my current coal stove for 6 seasons
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: Manual pipe dampers .. how, why, when

PostBy: lsayre On: Tue Jan 28, 2014 9:30 pm

So you can increase your input air feed volume while controlling your exhaust.


How can you provide more air feed (initially more O2 rich) in without simultaneously having more air (now CO2 rich due to combustion) exhausting up and out the chimney? And as to retention time within the stove, the volume of flow in/out combined with internal baffle and flow path provided by stove design is the only driver that can dictate that. You can and do intentionally moderate the volume of air flow through the coal bed via either method. Both methods therefore must simultaneously moderate the exhaust. One method maintains the flow of air more uniformly though, and that is the barometric damper. In the end a manual pipe damper moderates draft, but it provides no means by which to uniformly moderate draft fluctuations.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Manual pipe dampers .. how, why, when

PostBy: Lightning On: Tue Jan 28, 2014 9:56 pm

Great..
Another genius that thinks the hundreds of us using baros are all wrong dumb stoops.. :(

Trying to change this mindset is futile :lol: ...

Some people know what's going on and some people think they know what's going on.

Some people with an open mind can be taught that the baro and MPD both slow down gases by reducing negative pressure in the fire box.. While other people just can't "see" how something that "is not there" (baro) could possibly "hold heat in a stove"..

I've learned to live with it.. :P

Dr. Phil said that it's OK to "agree to disagree"....
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Manual pipe dampers .. how, why, when

PostBy: dlj On: Tue Jan 28, 2014 10:05 pm

Lightning wrote:Great..
Another genius that thinks the hundreds of us using baros are all wrong dumb stoops.. :(

Trying to change this mindset is futile :lol: ...

Some people know what's going on and some people think they know what's going on.

Some people with an open mind can be taught that the baro and MPD both slow down gases by reducing negative pressure in the fire box.. While other people just can't "see" how something that "is not there" (baro) could possibly "hold heat in a stove"..

I've learned to live with it.. :P

Dr. Phil said that it's OK to "agree to disagree"....


Missed something here, oh right you just claimed to be a genius

Have fun out there...

dj
dlj
 
Hand Fed Coal Stove: Vermont Castings Resolute
Baseburners & Antiques: Glenwood Baseheater #6
Coal Size/Type: Stove coal
Other Heating: Oil Furnace, electric space heaters

Re: Manual pipe dampers .. how, why, when

PostBy: titleist1 On: Tue Jan 28, 2014 10:06 pm

Lightning wrote:Trying to change this mindset is futile :lol: ...


Its like talking religion, politics, tastes great / less filling, Ginger or Mary Ann, etc..... :P
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Manual pipe dampers .. how, why, when

PostBy: freetown fred On: Tue Jan 28, 2014 10:47 pm

I don't think there is any mind set to change, God knows baro's & mpd's have been beaten to death here on the FORUM. Most guys I've talked to made a choice on what info they had gotten. Some tried one unsatisfactorily & went to the other. Seems simple enough to me. I'm personally a salesman, what I try to do on here is share my experience which for the most part, I've learned on here:) PS--Mary-Ann
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: Manual pipe dampers .. how, why, when

PostBy: dlj On: Tue Jan 28, 2014 11:37 pm

lsayre wrote:
So you can increase your input air feed volume while controlling your exhaust.


How can you provide more air feed (initially more O2 rich) in without simultaneously having more air (now CO2 rich due to combustion) exhausting up and out the chimney? And as to retention time within the stove, the volume of flow in/out combined with internal baffle and flow path provided by stove design is the only driver that can dictate that. You can and do intentionally moderate the volume of air flow through the coal bed via either method. Both methods therefore must simultaneously moderate the exhaust. One method maintains the flow of air more uniformly though, and that is the barometric damper. In the end a manual pipe damper moderates draft, but it provides no means by which to uniformly moderate draft fluctuations.


You are dealing with differential pressures. The advantage of the baro is it maintains a constant pressure. So as you open the input side of the airflow, the volume, and velocity of gases flowing through the stove and out the stack, also increase. Now, over a defined range of flow rates, this can be very advantageous allowing a stove to run quite efficiently, at least those stove/chimney systems that run best with a baro.

What will happen however, especially on the side where you are pushing combustion to regions above the "sweet" spot is that you begin dropping more rapidly in overall heating efficiency of the stove compared with running a MPD in that situation.

As you state above, "the volume of flow in/out combined with internal baffle and flow path provided by stove design is the only driver that can dictate that" - but the MPD is part of the internal baffle and flow path of the stove. Hence using an MPD, in fact, you can change this function. This function is set using a baro, and is variable using a MPD.

You also state above, "One method maintains the flow of air more uniformly though, and that is the barometric damper. In the end a manual pipe damper moderates draft, but it provides no means by which to uniformly moderate draft fluctuations." I completely agree with you. However, given the fact that when using my MPD, I typically run with it either closed, or nearly closed, the fluctuation in pressure has essentially no effect on my stove/chimney system as far as fire control or heat output. The driving factor is the limited gas volume allowed to pass the MPD. What I can do, and in fact was doing earlier tonight, was running with my bottom door on my stove wide open, my stove in base burner mode and the MPD 3/4's closed resulting in my stove temperature running around 850F and my chimney temperature running about 255F. You cannot get that kind of temperature differential running a baro. You might get your stove running up around 850F, but your stack temperature will be pushing 400F.

I'll repeat myself for those who feel I somehow fall into one "camp" or the other: the baro and the MPD are functional units of a stove/chimney system, use of one or the other, or combining both together, may provide a particular stove/chimney system to perform optimally.

dj
dlj
 
Hand Fed Coal Stove: Vermont Castings Resolute
Baseburners & Antiques: Glenwood Baseheater #6
Coal Size/Type: Stove coal
Other Heating: Oil Furnace, electric space heaters

Re: Manual pipe dampers .. how, why, when

PostBy: Lightning On: Wed Jan 29, 2014 12:19 am

dlj wrote:I'll repeat myself for those who feel I somehow fall into one "camp" or the other:

I wasn't referring to you.. :) But if you wanna throw stones from over there that's ok with me.. :lol: :P
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Manual pipe dampers .. how, why, when

PostBy: dcrane On: Wed Jan 29, 2014 6:08 am

Ok... who pulled this shyt storm back up (i want names! :mad3: ) LOL

I feel both DJ & Larry are right... DJ is right because in some cases a MPD closed holds a draft extremely well (and he is having zero efficiency loose of a baro taking his heated living room air to throw out his chimney to maintain his draft at a very optimal level. Larry is right because in some cases this simply cannot be achieved (the draft is so erratic or so strong at different times it can suck a gold ball through a garden hose... as they say LOL). Therfor... Its a rigged debate that cannot be won since it applies differently to all people.

P.S... Mary Ann (all day LONG!)
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: Manual pipe dampers .. how, why, when

PostBy: WV Mountaineer On: Wed Jan 29, 2014 2:26 pm

I'm pretty sure Lightning was referring to me So here is all I am going to say on it. Use what suits you. But, do not mistake your opinion or your assumptions on reality. It was -9 here this morning. It is 1 degree here now. I heat a 2400 square foot home, built in 1970 with no upgrades, on 65-70 pounds of coal a day. My thermostat says 83 degrees right now. My electric bill last month was $56. This month is going to be even cheaper. I type this in a pair of gym shorts in the upstairs of my home. The stove is in the basement. I'll put another 5 gallon bucket of coal in my stove around 9 pm tonight. When your stove with the baro thingy does that as efficiently as mine is dong it, I'll listen. Make no mistake though, after your post stating your position, I'll never coin you as a genius, sarcastically or not.

I wasn't being a smart guy on my first post. But, the genius term you coined me with might suit me in the home heating department because, a MPD and controlled air intake in the form of a stove draft, works real well in my case. Much better than a baro thing. :^)
WV Mountaineer
 

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