Baffle on draft

Baffle on draft

PostBy: Wiz On: Mon Dec 24, 2012 10:56 am

Running stove for the past four months with basically one issue that has me totally baffled. ( Draft) Boiler is in work shop that's not insulated or airtight. No matter what setting I use on baro weight or air shutter opening size it doesn't change manometer draft. On high side of meter it runs -.03, switched it to low side +.03. The only way for me to achieve -.01 is to hold baro wide open. In doing this or just setting baro weight to less restriction it's only pulling heat out of shop. Next question is Keystoker says draft to be set at -.02, now using manometer correctly is this reading from high side or low side. I thought colder weather would've resolved issue but nothing change. Greatly appreciate advice , I've got no more hair to pull out.
Wiz
 
Stoker Coal Boiler: Keystoker Ka 6
Coal Size/Type: Casey Junk Coal :(

Re: Baffle on draft

PostBy: Rob R. On: Mon Dec 24, 2012 11:25 am

Keystoker's recommendation of -0.02" is to be taken at the firedoor, not the breech.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Rice/buck
Other Heating: Dad's 1953 EFM Highboy

Re: Baffle on draft

PostBy: KLook On: Mon Dec 24, 2012 11:29 am

So, you have to much draft for the baro to reduce? This is helped by the non airtight building not hurt by it. I would reduce the chimney at the top or put in an evil MPD and close it down some. Between the baro and the Keystoker.

Kevin
KLook
 
Stoker Coal Boiler: Harman VF 3000
Coal Size/Type: rice, bagged, Blaschak
Stove/Furnace Make: Harman (Back In Maine)
Stove/Furnace Model: VF 3000


Re: Baffle on draft

PostBy: Wiz On: Mon Dec 24, 2012 11:58 am

Keystoker's recommendation of -0.02" is to be taken at the firedoor, not the breech.
... I'm checking at fire door

I would reduce the chimney at the top
I'll give this a try.
Wiz
 
Stoker Coal Boiler: Keystoker Ka 6
Coal Size/Type: Casey Junk Coal :(

Re: Baffle on draft

PostBy: Lightning On: Mon Dec 24, 2012 3:08 pm

Hey Wiz, I'll try to help ya with some of that confusion. On the mano, (I assume its the Dwyer model 25) most of us use the positive side of the scale (I believe its the low side) to read negative pressure. You want negative pressure so carbon monoxide can't leak out. I think a manual damper between the baro and stove is a good suggestion.

Now, air tight room verses not an air tight room. An air tight room (the room your stove is in) should inhibit a strong draft since make up air isn't able to replace the air that the baro is taking out. I think this issue got some high profile on another thread somewhere lol. How can I prove this? Well, on warm days I open vents in my furnace room to the outside to aid a lazy draft.

When its windy I'll close my manual damper about 80% if my baro can't maintain less than a .05" WC as read on the positive side of the scale, knowing its actually negative pressure. The only reason for hooking them up "backwards" is so we have more scale to use, since the negative side only reads down to -.05.

I hope I've saved you some hairs :)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: Baffle on draft

PostBy: Rob R. On: Mon Dec 24, 2012 4:19 pm

Do not use a manual pipe damper on a stoker.

What do you get for a reading at the door after the stoker shuts off?
Rob R.
 
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Rice/buck
Other Heating: Dad's 1953 EFM Highboy

Re: Baffle on draft

PostBy: Wiz On: Mon Dec 24, 2012 7:09 pm

On the mano, (I assume its the Dwyer model 25)
Yes your correct.

Do not use a manual pipe damper on a stoker.
I'm using Fields Control R-C

What do you get for a reading at the door after the stoker shuts off?
When stove shuts down manometer jumps to -.05 then back to ..-.02

Today I added rain cap and reading on manometer using low side I now have on idle .02 stove running ..02 and stove off .02 .... I've put fields control to 4 to get more resistance. Had it at 2 and with no wind it would swing open constantly.

No matter what I do to air shutter on stoker it doesn't change draft. So at least I got it to be .02
Wiz
 
Stoker Coal Boiler: Keystoker Ka 6
Coal Size/Type: Casey Junk Coal :(

Re: Baffle on draft

PostBy: Lightning On: Tue Dec 25, 2012 11:34 am

Lightning wrote:I think a manual damper between the baro and stove is a good suggestion.

Rob R. wrote:Do not use a manual pipe damper on a stoker.


Yep, Rob is right..
I wasn't thinking about a positive pressure possibility in the firebox caused by the combustion blower.
Good call :D
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: Baffle on draft

PostBy: 331camaro On: Sun Dec 30, 2012 6:34 pm

hey wiz i just set mine today, how far open is your air shutter on the stoker motor? i have mine half open and the secondary fan door all the way open. my building is sealed up pretty good other than overhead doors if you nudge the baro at all you can see the fluid move in the gauge. i wonder if your uninsulated building is the culprit.
331camaro
 
Stoker Coal Boiler: Keystoker k6
Coal Size/Type: rice

Re: Baffle on draft

PostBy: Wiz On: Sun Dec 30, 2012 9:36 pm

hey wiz i just set mine today, how far open is your air shutter on the stoker motor?
Air shutter is 1 inch and secondary is 1/2 open. I insulate the ceiling but concrete walls are not. Going to insulate work shop walls this summer. Yes fluid does move in manometer when baro opens and closes.
Wiz
 
Stoker Coal Boiler: Keystoker Ka 6
Coal Size/Type: Casey Junk Coal :(