MPD & Baro on a Glenwood 8?

Looking for some input from G6 or 8 owners, please.

My buddy Tony's chimney is so strong we are having to run with the MPD closed, the check damper fully open and the secondary air half open. If this is not done the stove accelerates like a rocket. I'd like to add a second MPD and possibly a Baro. I'd set the Baro to run at say .8 then we could use the MPD's to get the draft down to say .2 - .4 Right now all the MPD will drag it down to is .5 - .6

Tony's chimney is in the center of the house. It's all of 30 tall. It is a 6in clay liner inside 12 in block. The outside portion easily goes several feet above the peak.

Any 6 or 8 owners run this type setup?

Did Wilson hide a turbo in the back pipe ?

FYI. That elbow mounted check damper is used by both the #8 and the #6. For the #8's size/volume of coal burning it is kinda on the small side and will have less affect on an #8 than it does on the #6.

Couple of things to consider. Is he ever going to use wood in it ? If so, I'd be more tempted to put in a second MPD rather than a baro. Plus, he may not like having to deal with the baro during refueling,....unless that's the stove where the mag ended up. Then it should not be much of a problem.

Is he burning stove size coal ? If so, mixing in, or switching to all nut will help tame the draft quite a bit.

Paul

Scott ... I'm not the most knowledgable person on this site but I have run a number 6 for a few seasons. It's pulling that hard in base heater mode ?? That's really something. I've talked to emery a few years ago and he mentioned installing 2 mpd for it was hard to slow it down. Especially during windy cold nights. I have a ss chimney that's about 18 ft in total that goes through my ceiling and out my roof. I can easily control my draft strength. The wind makes my manometer go haywire. Btw. Tony has the most ideal chimney set up for the best draft conditions. Not sure what's going on there

Your right Paul. Nut coal def slows down the draft. That's my prefered sized in my glenwood

Paul,
Good point on the "wood" issue & the Baro, that slipped my mind. Yeah, he could throw some nut in but we just split 45,000lbs of stove size I've told him to save his fines for that use if necessary.

Kev,
Interesting Emery told you that as it lends credence to the second MPD. Yes, in base mode. The chimney is ridiculous, it pegs my draft gauge so hard it seems like it will bend the needle!!! It would not surprise me if the air space around the liner is filled with vermiculite. How long could you run your 6 @ say 400 without tending and still recover/reload successfully?

Scott,

i think you are going to have your hands full with taming that flue.

is the .05-.06 you are seeing while it's in direct draft or Base mode ?

if base mode, i'd say you need at least 2 MPD's and the Baro. ( provided he doesn't have infiltration issues )

i just checked my 3 MPD's while in Base mode after tending. the MPD closest to the outlet of the base chamber is a solid plate that bypasses around an 1/8" gap all the way around. this MPD is never open more than 45*. the second and third MPD's are the usual type with opening across the middle along the shaft, each are dead centered in the pipe as well.

with all of them open as far as each will go i'm running in Base mode at -.06. by closing the bottom one it will drop it to -.03 but if there is any wind above 10 mph it will run up to what ever.

if I leave the bottom one open at 45* and close the other 2 they will each drop the pressure by .01, .02 combined. sometimes this is desirable on a fickle day when the temp. could go up to 50+ and I want the flue to be moving CO out but don't want to go direct draft.

closing all of them will pull the pressure down to .02 under low wind, .03 with wind, and they will pretty much hold it right there right up to 35 mph. after that I can reduce the primary to compensate.

there is one fully closing MPD in the direct draft collar so that it doesn't allow more pressure while in base mode.

hope that helps,
steve

Thanks Steve.... yeah base mode. No "infiltration" issues (primary air leaks). His wife could vacuum the house with this chimney.

Scott ... I can consistently get 17 to 19 hr burn times in the temp range. But as most on here recommends , 12 hr tending is safe and as well as simple. Plus I'm sure most here don't mind poking around w the stove a little. But you can forget about these babies sometimes. So little fuss and quite as heck.

Thanks Kevin. He wants to get consistent 24+ hr burns at 400 with one tending every 24hrs. His work/life schedule right now prevents him from12 hr intervals. I think slowing down the vacuum cleaner will do the trick. And it's time to install the mag

scalabro wrote:Paul,
Good point on the "wood" issue & the Baro, that slipped my mind. Yeah, he could throw some nut in but we just split 45,000lbs of stove size I've told him to save his fines for that use if necessary.

Kev,
Interesting Emery told you that as it lends credence to the second MPD. Yes, in base mode. The chimney is ridiculous, it pegs my draft gauge so hard it seems like it will bend the needle!!! It would not surprise me if the air space around the liner is filled with vermiculite. How long could you run your 6 @ say 400 without tending and still recover/reload successfully?

You know all that bagged coal that's loaded with small bits and fines that guys are complain is stalling their stoves, ...... you just discovered the perfect stove to burn it in !

Yup, using two MPD's is an old time draft-tamer trick.

See if you can swap some stove for nut - even the junky nut with a lot of small stuff mixed in would help. I'll bet there's guys nearby that would love to swap to be able to mix in some stove. Or, throw in some pea coal with the stove. If it still needs more to hold it back, then try adding a second MPD. If that doesn't do it at least you don't have a lot of money wasted on solutions. You can always add a baro later if nothing else slows it down.

Paul

scalabro wrote:

Looking for some input from G6 or 8 owners, please.

My buddy Tony's chimney is so strong we are having to run with the MPD closed, the check damper fully open and the secondary air half open. If this is not done the stove accelerates like a rocket. I'd like to add a second MPD and possibly a Baro. I'd set the Baro to run at say .8 then we could use the MPD's to get the draft down to say .2 - .4 Right now all the MPD will drag it down to is .5 - .6

Tony's chimney is in the center of the house. It's all of 30 tall. It is a 6in clay liner inside 12 in block. The outside portion easily goes several feet above the peak.

Any 6 or 8 owners run this type setup?

Maybe a second baro would calm it down, not unheard of.

scalabro wrote:Thanks Kevin. He wants to get consistent 24+ hr burns at 400 with one tending every 24hrs. His work/life schedule right now prevents him from12 hr intervals. I think slowing down the vacuum cleaner will do the trick. And it's time to install the mag

That mag will give him about 18 pounds more of stove, about 20 of nut. But, I think the problem with 24 hour tending might be ash buildup before it ever runs out of coal ????

Paul

If I may, FWIW - If it were me, I would put in a baro below the MPD. With the MPD in the closed position and as it's nature of being a restrictor, the baro will require VERY LITTLE room air to satisfy negative pressure down as low as you want it to go.. I know many people frown on the whole MPD above the baro thing but I never encountered any problems with that arrangement. If you put the baro above the MPD I suspect it will be wide open most of the time swallowing copious amounts of room air and it may not even be very effective with what you want to achieve, which is a steady but low negative pressure in the stove.

This was what I learned in my experimenting with both devices in the same pipe.

Merc300d wrote:Your right Paul. Nut coal def slows down the draft. That's my prefered sized in my glenwood

I had looked into getting bulk stove for the #6, but after talking to a few 6 owners, plus running about 5 bags of stove through the range and seeing how it reacts with my almost 40 foot high chimneys that draw so well, I decided to stick with nut for both stoves. And nut coal gives me about 10% more fuel density then stove size in the same firepot.

Paul

Hahahahaha no way Paul we have waited too long to get our grimly coal filled hands on Lehigh!! And I guess we'll find out about shaking after 24...he's not having problem now running 300-350 for 24.

In 5 years after we runout of coal we'll buy some nut

Good points Lee but he may want to use wood in the stove in the shoulder months.