Manual pipe dampers .. how, why, when

Appreciate the comments Dcrane, Lightening, I usually don't get frustrated about things but I feel like there is an attack on us MPD's...I will say that before diving into a decision to go with Baro vs. MPD, do a lot of research, read, read, read, take out the sensationalism and just look at facts, not someone agenda, as they can confuse people. It's like sitting around the piers and listening to several fisherman argue on which way is the best way to fillet a fish. I get the use of and why people want to use both. If I had a modern stove design, I'd look into a baro, but with this hand fired, built correctly, only so much air can go through this unless I open the bottom up. No need for me, the bottom air vents are closed...when I first started running I wanted to see how it would react and I'd get it up to 700-750 and I'd lose burn time. I have a big old farm house and I switched from years of burning wood because the house was cold in the morning. Really only getting 4-5 solid hours of burn time. My farmhouse is 4,000 square foot so it wasn't cutting it. The longer burn times and the 600 degree heat output is great. I have the two MPD's for safety and to keep stove temps steady. The main MPD is closed and the secondary is about 80% closed. Stack is double walled all the way up and really warm to touch/not hot or burn to touch. If I didn't have really tall ceilings or a lot of square footage, I'd run the stove cooler. Although this Herold 116 wants to run at 550-600 closed down. I like the air control with the two MPD's and thought about using a Baro and MPD but I can burn wood also, on cool spring and fall days and I don't want to have to deal with creosote making a baro stick. I use kiln dried wood for burning because mostly I use coal.

BPatrick wrote:I have the two MPD's for safety and to keep stove temps steady. The main MPD is closed and the secondary is about 80% closed.

Wow, 2 MPDs? in line with each other? you must have an industrial leaf vacuum for a chimney ... kidding of course.. Would be interesting to see what that chimney draws with a manometer. I've never known anyone to use 2 MPDs...

Bottom line with baro vs mpd is pretty much whatever blows smoke up your skirt--if you're happy with 2, so be it--maybe one more would work betterer???? Sugggestions are only given through personal experience, but bottom line is that nobody is in anyone else's house to really know. YES--safety being the primary issue

BPatrick wrote: I have the two MPD's for safety and to keep stove temps steady. The main MPD is closed and the secondary is about 80% closed.

If these 2 MPD's are on a horizonal run,make sure you keep the pipe clean in between them from fly ash build up.

The primary MPD is closed and the secondary isn't all the way closed. We have good draft. I'm in an old farmhouse built in the 1860's and the secondary one set at 80% is just in case massive winds from a snow storm type blizzard would creep up...there would be a safety to slow down the draw. We've had 55-60 mph winds a few times this year with storm and the stove runs the same. It runs steady. Emery's friend built one hell of a stove and my air intake at the bottom is usually closed. The top door has mica windows and a slot with two small airholes. I have them open a 1/4 to burn off the gases from the stove and I have blue flames for a long time, its beautiful to watch. Anyway, this stove sets in and runs between 500-600 I prefer 550 as it keeps the house warm. I'd open up the airholes more than a 1/4 to keep around 500 and if I have them around 1/8 the stove runs at 575-625. I run the airholes all the way open during a 35 degree day and the stove runs at 400-425 for around 17 hours.

MPD= Instant, gruesome death from CO, often within seconds of even looking at the MPD control lever. I've heard of CO deaths in people without an MPD just from reading this thread. Bad, bad device. The devil incarnate.

Baro= Excellent, superb,totally awesome device, greatest invention since the wheel, can heat an uninsulated 5000 sq ft house to 90 degrees with a Folgers can of nut for 6 winters in a row in northern Alaska. Basically the single greatest technique mankind has yet found since mastering the art of fire. Strike all of that if you EVER burn a stick of wood, a chimney fire will immediately break out and before you can dial 911 your home will be a smoldering heap of cinders. Also before installing have a pryotechnics professor from M.I.T. come out with 14 different gauges and testers to adjust draft based on the Mayan lunar calendar.

Pretty much sums up this thread so far.....

Yeah, most are strong minded about their choice of draft control. The ones who benefit the most realize the advantages of properly using both of them at the same time. ... Why be divided.. Unite, and see that they are better together

I choose to look at the positive side.

MPD's are good and helpful in some installations....

Baro's are good and helpful in some installations.....

Both are good and helpful in some installations.....

Each Stove / Chimney / House / Topography / Wind Characteristics are different and only you can determine which works best for you.

You need to learn the personality of your set up and see what works best with a little experimentation.

Solid fuel is a hands on system and not for everyone.

You can always connect up to NG, fill the oil or propane tank write out the check each month and turn down the 'stat!

titleist1 wrote:Both are good and helpful in some installations...Each Stove / Chimney / House / Topography / Wind Characteristics are different and only you can determine which works best for you.

I think that says it all.

I can support this from personal experience. My original Franco-Belge installation 28 years ago had an MPD and a baro damper, in that order, between the stove and the chimney. With that stove and my chimney, had I not had the baro, on a windy day my fire would have burned into the coal hopper, even with MPD nearly closed. I assumed it was automatic, every coal stove install had a baro.

When my DS 1500 was installed, I was concerned about not having a baro, but neither DS Machines nor the installer recommended it. Since then, we've had days with sustained 30+ mph winds and gusts near 50. With the MPD closed, the DS thermo control adjusts and keeps the stove burning steady without overfiring. I'm perfectly happy with no baro on this stove.

But I'm also sure somebody on the other side of the mountain from me, with the same stove but a different chimney and wind conditions, might well need one.

I believe I'll not comment on the personal attacks, but will say, :
LOOK AT THE DATE of a thread and read the entire thread/subject before you hit reply and add a comment..
This thread started in 2007 !!

IF a person reads the ENTIRE THREAD you will see that the drift of the thread changes over the years..
To comment on the first page or two of heated and emotional posts is like going to a 2007 political thread and commenting on it 6 YEARs later..

What isn't evident in reading this thread from the begining is that at the time, in 2007, there were very few people on the forum,
many first time burners who wanted a cut and dry setting for a MPD.. 'how far should I close the MPD.. I lost my fire', I can't keep the fire hot',
I burnt up all my fire in 4 hours, and the house was not warm etc,etc etc.. A baro is a set it and forget it control for an over-drafting chimney..
So a baro was strongly advocated for inexperienced burners.
As the years go by, as a burner gains experience, and mpd is often added with much success, Or a baro is tried with success or sometime no success.
A baro never adds draft to an under-drafting chimney. The entire draft control and exhaust airflow control issue is badly misunderstood by many.

This entire 6 year thread can be distilled down to a few lines:

MPD's work well for an EXPERIENCED burner, and for burning WOOD, and for NON-AIRTIGHT stoves.
They also work well with stoves with a BUILT IN thermostatic draft control, like most Hitzers, some warm mornings and others.
If your stove is not airtight, then a MPD is a necessity, because your stove is out of control with air leaks.
If you can't shut down the fire with the stove's air controls in the stove's body or doors, then your stove leaks, is not airtight,
and needs the 'bandaid' of an MPD in the flue pipe

OLD stoves, like the base burners, base heaters, Oak with indirect draft need a stronger draft, and even have 'check dampers' which
must be used with caution for the potential of CO leaks into the living space.

People who got on the forum and wanted a set it and forget it draft will use a baro with success. Many modern stove manufacturers
state to NOT use an MPD, but to use a BARO to control draft. These modern stoves, if maintained, are airtight and are able to
control exhaust flow rates. with their ashpan door draft controls, therefore an MPD is not needed.

The combination of an MPD followed with a BARO above the MPD is the ultimate control.. ONe controls draft and the other
controls exhaust flow rate through a leaky stove.

Over the years, many people have discovered that they do just fine with one or the other or with both or with neither..

The entire issue of draft control vs exhaust flow control is badly misunderstood by many.

[b]EVERY CHIMNEY, STOVE, HOUSE, PREVAILING WEATHER CONDITION, PERSONAL PREFERENCE IS DIFFERENT.[/b]

Enough,
Greg L

someday im going to be able to speak as well as Greg might want to give a link to my new thread How Barometric Dampers Function, Why use a Barometric Damper which explains that Manual Dampers serve a differant function then Baro Dampers (they cannot be compared to each other).

BPatrick wrote:I like the air control with the two MPD's and thought about using a Baro and MPD but I can burn wood also, on cool spring and fall days and I don't want to have to deal with creosote making a baro stick. I use kiln dried wood for burning because mostly I use coal.

Careful....

Chimney fire = Bad
Chimney fire + Baro = Insanely bad.

Richard S. wrote:

BPatrick wrote:I like the air control with the two MPD's and thought about using a Baro and MPD but I can burn wood also, on cool spring and fall days and I don't want to have to deal with creosote making a baro stick. I use kiln dried wood for burning because mostly I use coal.

Careful....

Chimney fire = Bad
Chimney fire + Baro = Insanely bad.

Agreed!!!

so where do i set my manual draft wide open or closed a bit it buns beutiful but fast?

perch wrote:so where do i set my manual draft wide open or closed a bit it buns beutiful but fast?

that would depend totally on how much heat you wish your stove to allow into your living space.