Manual pipe dampers .. how, why, when

No one has mentioned the biggest objection to barometric dampers, pointed out by my wife: BATS might come down the chimney and out through the damper into the room. Never mind that bats don't fly around in the Winter, that there are no bugs for them to eat, that they might not like the smell and temperature of flue gases. IT STILL COULD HAPPEN!

I'd imagine if the gases didn't kill them the heat would. Isn't going to take much CO to kill a bat. Go up by your chimney and take a deep breath... I'm kidding of course but having been around a chimney that was being used by a coal stove I can tell you it's not all that pleasant.Certainly possible when not in use in the summer but you could just secure it somehow. For that matter it's probably a good idea to remove your pipes in the summer anyway to help prevent corrosion, plug the chimney up.

Greg has sited the MPD as "unsafe", but hasn't indicated what, in his opinion, makes them unsafe.

A baro damper could be considered "unsafe" if looked at in the right light. If it were to get stuck in the closed position, which mine did, it would not act as was intended, when needed. Additionally, the flue pipe integrity is compromised by adding the baro on the side of the flue pipe. You wouldn't think of assembling the stove pipe with a bunch of loose, air infiltrating, joints.

No bat in its right mind is going to enter a chimney if there is a coal fire at the other end of it (one with rabies may not be thinking clearly though).

A few items, which I have found regarding MPD. Couldn't turn up a thing on their "un-safety".

http://www.vogelzang.com/Manuals/pb65lMnl.htm

Install flue pipe draft damper (#20) into the top end of the first straight section of stove pipe (see Fig. 1) exiting the stove before the stove is used.
Drill two 1/4" holes centered on either side of the pipe section 6" from the top end of the pipe (see Fig. 1).
Remove the handle from the damper then slide the damper into the pipe.
Align the damper with the holes drilled in step 9a and insert the handle through the holes and the damper.
NOTE: THIS DAMPER IS NECESSARY FOR THE PROPER OPERATION OF THE STOVE AND TO MEET EPA EMISSIONS REQUIREMENTS FOR HEATING APPLIANCES. IT MUST BE IN-STALLED BEFORE USE. (NO EXCEPTIONS)

http://www.marinestove.com/manual.htm

A flue damper shall be installed in the pipe 14” above the cook
surface of the stove. The damper is a critical component which
will enable the user to control the stove’s draft.

Do not install a "Little Cod" without a damper.

Insurance Information Institute
http://www.nnins.com/pdf/woodstovesafety.pdf

DAMPERS
If a wood burning stove has an automatic draft regulator controlled by a thermostat, the
manufacturer's instructions for installing it must be carefully followed. Alternately, a manually
operated damper can be installed on the pipe near the stove. This damper should not obstruct
more than 80 percent of the pipe area.
A second damper higher up on the vertical section of the stove pipe is advisable to permit shut
down the stove in case of a chimney fire. You can have this made by a local sheet metal comp
or a tinsmith.

I have read all of the points of view posted in this thread with interest. IMO one members passion for a particular way of doing things does not and should not replace the manufacturers instructions for installation and operation of a coal burning appliance.

I am into the science project aspect of coal burning as the next guy (maybe more than most ) but I have to add some words of caution here, Please do not take advice on this Forum as a replacement for advice from the manufacturer and seller of your particular unit.

Having said that please carry on with the discussion.

PS bats do get into our bedroom in the summer since we leave the door open in the evening while we are watching TV, my remedy is to just hide under the covers till they leave. My wife just laughs at me and tells me to go and get it out of the house.

LsFarm wrote:Manual dampers ARE unsafe. The cheap little tension or friction springs loose tension with heat and age, the 'perfect setting' on the manual damper slips in the middle of the night... or a lump of creosote or fly ash falls on the damper and does the same...

If you have a manual damper and a warm front comes through at 3AM, you need to get up in the middle of the night to open the damper or the reduced draft will allow you to have the CO 'rolling out of every crack in the stove and baro'.

Greg L

So what part of the above did you chose to not read prompting your comment: 'Greg has sited the MPD as "unsafe", but hasn't indicated what, in his opinion, makes them unsafe. " I think I clearly stated why the manual damper can be unsafe.

Then you posted manuals from wood stoves. From stoves that are at best marginal for burning coal. Vogelzang, isn't that the manufacturer that makes the cheap potbelly stoves sold at HarborFreight? 'Little Cod' What is that?? and from the wood institute. [so what?]
I'm sure if I dig deep enough that I can find documentation to support just about any viewpoint. Elvis has been documented to be alive !! Just search and you can find hours of proof.

Ending with a quote from a previous message:
"I'm glad for you that the manual damper you installed has apparently made your stove work better. But each and every chimney, chimney type, inside or outside, stove, new design or old design stove, quality of house, house location, elevation, prevailing wind, etc, etc makes each chimney and solid fuel appliance a unique situation. A properly set up barometric damper eliminates a handfull of these variables and makes the burning experience much more consistant and reliable."

Stay within the guidelines of the forum, don't post potentially dangerous information. Err on the side of safety: manually closing off the draft to a coal stove has the potential to be unsafe. A great deal of experience and expertice is needed to use a manual damper safely. This is the entire focus of my comments: I fear that a new coal burning member will try to use a manual damper and create a safety issue for them and their family.

I have spent hours exchanging PMs with new members helping them to learn how to burn coal. I have helped people that have never used a solid fuel stove of any kind or fuel. I fear that someone will get CO poisoning from the improper use of a manual damper.
Properly used by an experienced stove/furnace/boiler opperator, a manual damper CAN help fix issues with an instalation that has way too much draft. But experience and expertice are critical for the safe use of the manual damper.

Greg L

I have never seen one of the springs on a MPD fail. If it were to get weak, I would expect it to be noticed and corrected. I wouldn't expect it to fail instanteously in the middle of the night ... a baro damper, maybe. A MPD is a lot more solid and "positive", than a baro damper, which could also become contaminated by creosote or fly ash. Do you check your baro damper for proper operation at least twice a day?

It sounds to me like you are hollering "WMD" (weapons of mass destruction), but I've not seem any evidence.

Well there is some valid points on both sides of this issue, anybody reading this just be aware of the possible dangers and that's not to say its going to be dangerous in all circumstances or even in a majority of them but the possibility does exist. I'm not taking sides here.

Let me start my saying that after reading the post that was locked, I couldn't help feel a little embarrsed. You guys were acting like a girlie man with a stoker instead of a real man that shovels and shakes.

Now my take on the hand damper vs. baro question.

I have both on my stove and each has their place in the operation of the stove. It’s still early in the season and my flu's draw hasn't even gotten close to what it will be in a few weeks. Right now I don't use the manual damper at all. The flu is drawing right around a .06. We are still getting highs in the high 30s and low 40s. I have no problem getting a good burn out of the stove by using the air only. If I used the manual damper now I would be ok at night, but could lose the fire during the day when the temps got up there and my air cut way back.

Now let’s move ahead three weeks. 0-10 for a low and 20 for a high and a lot of winter wind. Now I've got a flu that's drawing like crazy. I couldn’t imagine getting a very efficient burn without a baro. The flu will range between a .06 and a .09. Could even go higher. Now when it 5-15 degree outside I've got the air open and that stove is cranking. Now is when the manual damper comes into play. I've got a good draft so I can close that damper down and leave the heat in the stove and a baro that will make sure my draft remain a constant .06.

If I had to choose between two, hands down the baro.

I will also tell you this. If I had a flu that was week or had any issues with it, the last thing I would want on there is a manual damper. Greg you are correct a manual damper can be dangerous, but I think a good drawing flu minimizes any issues that may arise and if the damper fails close, that should kill the fire and still carry the products of combustion up the flu. Again that only with a good flu, a week flu with a failed manual damper could be fatal.

Well that my take on the subject and guys lets be nice, I don’t like seeing threads locked.

Don

When the leader locked the other thread on this, I understood he was concerned and so was I. (Richard, if I'm out of line here, yank this!)

Let me preface this with the fact that combustion by-products kill people. Check and double check everything and don't take chances. If you know what your doing, be careful! If you don't know what your doing, find someone who does even if you have to pay them.
I had to know what is going on with this deal so I went down and played with old Nellie. The results suprised me. What I did was check the draft at three separate places. First at the stovepipe, prior to the baro. Next, at the draft door on the combustion fan. And lastly, I checked the overfire draft. I tested each point with and without the draft blower going.

Open or closed, the MPD had no impact on the draft feeding the fire. This was true with and without the draft blower.
Open or closed, the MPD had no impact on the stovepipe draft with the exception of when the blower ran. Open, the draft would climb very high, very quickly. Closed, the draft would bump up slightly, stay fairly steady and rise very slowly over time. This would confirm what I thought earlier, that the boiler will run the draft motor longer at a lower load as it should.
Now comes the big surprise, the overfire draft. When testing it with the MPD open or closed it had no impact on the overfire draft, which I thought was rather odd. Then the blower came on. BINGO! the draft went neutral instantly. I watched it for a while and noticed that the draft was going positive as the blower continued to fan the fire up.

I don't know about all the other chimney/solid fuel units out there, but mine proves if you don't have an airtight unit with a decent draft, you can kill yourself. I don't want that to happen to anybody, so check everything and be safe. Learn as much as you can and get the tools you need to run these things right. Burning coal is supposed to be a warmming experience, not one that leaves you stone cold.

Sorry, I don't know how the other thread ended. I couldn't get past the preposterous "Elvis is dead" claim.

Just a quick note:
It's all about safety! Should I say it again...
Please follow the instructions in the manual that is for your stove or furnace/boiler. If you don't have the manual, find one.
Everyone (including sales people and professional installers) have their own opinions about the right way to do things. That doesn't mean they are always right. The manufacturer of the appliance should have the last word on what's the right and wrong way to do installations and what equipment to use.
It's all about safety and not waking up dead or on fire.
Thanks!

And so is the EFEL, burned all night and was easy to shake down and get back up to full speed in the morning! I guess the real test will be when I get home after work? I have been able to get it to burn overnight but almost always died the next day, unless I was around to tend every 4 or 5 hours! Like in the other post, when driving a Model T you can't drive it like a new car! Got to keep adjusting the choke and fuel mixture settings!

What was your reason for opening this, again?

I had two experiences over the last several days.

I coaled the stove, let it sit there with the MPD open until it got going. When I closed the MPD, poof!, the hot gases above the coal ignited (secondary combustion). Due, I suspect from containing them and allowing them to get hotter. The other thing, I accidentally forgot to close the MPD at one point. When I went downstairs to check things later, I found the room to be cooler than normal .. cooler than I would have expected, due to the warm temps outdoors. My conclusion of this event , was that the MPD being open, allowed a good amount of the heat to rise up the chimney.

Merry Christmas! Have a safe Holiday season.