Manual Pipe Dampers .. How, Why, When

SWPaDon wrote:

warminmn wrote:The last 21 pages of this topic are all right, and they are all wrong, as every situation/stove/burner/chimney/location/coal is different. Is that a safe answer?

Almost

I knew I'd be wrong!

Damn, I think ya nailed it W!

freetown fred wrote:Seeee, I told ya!

Gee FF...I thought I was real middle of the road on that one!!

That's not as easy to do as people might imagine T! But yep, ya done good.

I was in the General Store the other day and noticed that the Coal fed Pot Belly stove has a Manual Damper. I asked the Proprietor why he didn't have a Barometric Damper on it? He looked at me like I was from a different time period.
I went over to the Schoolhouse to deliver Supplies and noticed that the Coal fed Stove in there had a Manual Damper too?
What gives?
I went back over to the Store and the Proprietor said, "Young Feller, You need to understand a Wood Stove Damper is solid, no hole in the middle of it. Now a Coal Stove Damper has most of the middle gone out of it. The reason is that coal will smoother and die if there isn't some draft to draw air through it.
So he sold me a Coal Damper and a Ton of Coal and I went home!
Point is...........?
My Coal/Wood Combo Stove has a built in Damper, I run it tight as it isn't fully shut. The stack runs less than 200 degrees based on the Magnetic Thermometer.
Admittedly, if we were to get a big wind, it MAY flare up at night, but I figure there are BIGGER World problems than to worry about Heat loss. Especially when the curtains are moving when the wind blows!

Nice D, sounds like ya ran into a bunch of common sense!! Question--have you had many FLARE-UPS since 2006??

we have baro and a MPD on the furnace and the MPD on the stove in the back
I run the MPD at about 1/8 to 1/4 closed on both
a lot of timez I lock-out the baro on the furnace with a bit of wire if I need it to go hotter quickly
all the baro does is cool the stack temp which reduces the draft
it makes up volume with cooler denser air which slows the draft down

closing the MPD accelerates the AIR because you have the same volume moving though a more restricted space which improves effienecy

rjc862003 wrote:closing the MPD accelerates the AIR because you have the same volume moving though a more restricted space which improves effienecy

If the volume were the same it would not show lower draft numbers and the firing rate would not slow.

To set either baro or MPD a manometer is very helpful in seeing what is happening.

The guy at Hitzer told me I needed an MPD. Hitzer does not require an MPD but RECOMMENDS a pipe damper be used. He also told me I should try running my 254 with a 'half moon' ( I love modern Amish Thermodynamics terms!) on the ash door vent and the MPD fully closed.

The stove burns on this setting, but I can touch the pipe (Amish Thermometer) about a foot above the stove, and it's not very hot, about 200 judging from my epidermals . I ran it last night with the damper at 60^ and a 'full moon' on the ash door damper and it kept the house at 72 when it was 33 outside.

RRBoy wrote:The guy at Hitzer told me I needed an MPD. Hitzer does not require an MPD but RECOMMENDS a pipe damper be used. He also told me I should try running my 254 with a 'half moon' ( I love modern Amish Thermodynamics terms!) on the ash door vent and the MPD fully closed.

The stove burns on this setting, but I can touch the pipe (Amish Thermometer) about a foot above the stove, and it's not very hot, about 200 judging from my epidermals . I ran it last night with the damper at 60^ and a 'full moon' on the ash door damper and it kept the house at 72 when it was 33 outside.

Epidermal thermometer.... I love the term! There are a lot of people that do it the same way but now we have a scientific word(s) for it. Half moon, full moon, whatever keeps you warm is good

RRBoy wrote:I can touch the pipe (Amish Thermometer) about a foot above the stove

Amish Thermometer Love the term.
Other things being equal, lower pipe temperature means less heat is going up the chimney and more is staying in the room. As long as the stove is burning adequately lower is good.

I use a barometric damper, not MPD, because with my particular stove and chimney combination the baro provides good control. The only problem I had with an MPD was when the stove was burning fast and hot, and I closed down the MPD, the plentiful flue gases couldn't get past the MPD fast enough and stayed in the room for me to breathe.

Who was "the guy" at Hitzer? What does the user manual say about MPD vs. baro?

It doesn't compare them RB--it's pretty much a common sense thing--if a completely closed MPD isn't doing the trick, I bet a 2/3 closed one would. Again, different set-ups, different needs-- Just sayin. I've never seen a SOLID MPD that closes down so tight it don't let gas's escape--BUT, never looked for one. Mine is just what I refer to as a regular MPD which I keep around 1/2 closed at all times, even when tending--YEP, I've got a hellatious drawing chimney--plus, my HITZER has a baffle set up & the bi-metallic thermo. All is good!

I'm not sure what the guy's name was that I talked to, but he never said anything about a barometric damper, only a manual pipe damper.

I am very new to burning coal (3rd day) so I am trying different settings. So far, so good though. I have it just smoldering, I'd say. I've been shaking every 12 hours or so, and keeping it topped off about 3x a day.

Right now the ash door damper is just open slightly and the MPD is about 3/4 closed. It's 32 outside and 70 in the back part of the house....it's underwear temperature in the kitchen adjacent to my stove room.

Sounds real good R, if it ain't broke, don't fix it. No need to add some gadget just cause it's available, just more crap to go wrong!!!!!!!!!!!!

If it's working, it's working. Sounds like you are off to a good start.