Barometric Damper : Draft Pressure Setting

Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Tue Nov 05, 2013 7:22 pm

I recently moved the weight out on my baro door to make it more sensitive to draft. Under normal conditions (no high winds or extreme cold) my baro won't allow my draft to exceed a -.035"wc. I like to keep my draft pressure between a -.02 and a -.035.. I took pictures of it at various draft pressures. The pictures are increments of -.01 starting at -.01 and the last pic is at -.05.. I used a MPD and draft inducer to manipulate my draft pressures.. I was wondering if others that use the Field Controls RC see the baro door open at the same angle with same amount of draft as in the pictures.

Heres at -.01"wc.. The door is nearly completely shut but not up against the stop on the baro housing.
baor01.jpg
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The next pic is at -.02"wc
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Here is -.03"wc
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Here is -.04"wc
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Here is -.05"wc
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Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: mozz On: Tue Nov 05, 2013 7:51 pm

Is it level? Looks a bit off. Also, if you take it off and clean all the buildup on the weight and flapper, it will move easier. Scrubbed mine with a small wire brush this year and it swings like it was new. My 5" baro pegs wide open all the time, draft is too much with chimney going through the center of the house when it is cold out.
mozz
 
Stoker Coal Boiler: Axeman Anderson 1982 AA-130 Steam

Re: Barometric Damper : Draft Pressure Setting

PostBy: franco b On: Tue Nov 05, 2013 7:52 pm

I think the observations you make are great, but in this case I don't think you will get an answer because it first requires the calibration of barely opening at .01 and running up to .05 which most will not have either the manual pipe damper or adequate chimney to achieve.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea


Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Tue Nov 05, 2013 8:13 pm

mozz wrote:Is it level? Looks a bit off. Also, if you take it off and clean all the buildup on the weight and flapper, it will move easier. Scrubbed mine with a small wire brush this year and it swings like it was new. My 5" baro pegs wide open all the time, draft is too much with chimney going through the center of the house when it is cold out.


Oh yeah, It's perfectly level both ways. I used an oblique camera angle to show the door position the best. I keep it clean too, I brush fly ash off it with a tooth brush about every two weeks lol. :)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Tue Nov 05, 2013 8:20 pm

franco b wrote:I think the observations you make are great, but in this case I don't think you will get an answer because it first requires the calibration of barely opening at .01 and running up to .05 which most will not have either the manual pipe damper or adequate chimney to achieve.

Thanks Franco :D I was hoping that maybe someone would chime in with what their door position is at say a -.03 or -.04 as compared to my door's position. Just curious to see if people run theirs this sensitive or if they need more negative draft to achieve the same door position.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: lsayre On: Tue Nov 05, 2013 8:26 pm

I can't contribute here because I have the Type M damper. Mine is just beginning to crack open at 0.04" of WC.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Tue Nov 05, 2013 9:05 pm

lsayre wrote:I can't contribute here because I have the Type M damper. Mine is just beginning to crack open at 0.04" of WC.


I've considered trying a type M. So if it's just beginning to open at -.04, what pressure is it at when it's at about a 60 degree angle?
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: 2001Sierra On: Tue Nov 05, 2013 9:58 pm

I have looked into the Fields site. I wonder if the weight should be on the left side, so it will behave differently. I would call them, as their online resources do not clarify.
2001Sierra
 
Hot Air Coal Stoker Stove: Keystoker 90 Chimney vent
Coal Size/Type: Rice
Other Heating: Buderus Oil Boiler 3115-34
Stove/Furnace Model: Keystoker 90 Chimney Vent

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Tue Nov 05, 2013 10:09 pm

2001Sierra wrote:I have looked into the Fields site. I wonder if the weight should be on the left side, so it will behave differently. I would call them, as their online resources do not clarify.


One side is for a horizontal pipe, the other side is for a vertical pipe. Why it would make a difference I don't know. I found that the side it's on currently, reacts more sensitively than the same position on the other side. The path for the weight seems to be inclined slightly more on this side also. I have a diagonal pipe so I guess it's just "pick one" hahaha.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: SMITTY On: Wed Nov 06, 2013 12:07 am

I had my Type M on the oil boiler set to .02 .. so, it was open constantly - just at varying levels depending on the wind gusts.

The oil burner is very abusive to it though. Each time the burner kicks on, the thing slams shut with force. So much force that I found it stuck shut more than once. Pisses me off - that damn thing was expensive! Should've left the cheap ass one on there .... :roll:
SMITTY
 
Stoker Coal Boiler: Patriot Coal - custom built by Jim Dorsey
Hand Fed Coal Stove: Harman Mark III (not currently in use)
Coal Size/Type: Rice / Blaschak anthracite
Other Heating: Oil fired Burnham boiler

Re: Barometric Damper : Draft Pressure Setting

PostBy: titleist1 On: Wed Nov 06, 2013 12:29 am

i guess don't understand how you are setting up your testing at different pressures with the different openings or what you are trying to determine. :?

my baro position and the mano readings are the opposite of yours. i do not have a draft inducer or a manual damper. my manometer is connected prior to the baro. after the stove has reached firing temp (as opposed to idle temp) if I intentionally close my baro to the position you have in your first pic my draft will read roughly .06 depending on how cold it is outside. if i force open it up to the position you have in the last pic the draft will drop to about .02.

if i leave the baro to work on its own, it will maintain a .04 reading on the manometer while being open varying amounts from all the way closed to just about wide open, depending on the wind.
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Barometric Damper : Draft Pressure Setting

PostBy: lsayre On: Wed Nov 06, 2013 7:08 am

Lightning wrote:
lsayre wrote:I can't contribute here because I have the Type M damper. Mine is just beginning to crack open at 0.04" of WC.


I've considered trying a type M. So if it's just beginning to open at -.04, what pressure is it at when it's at about a 60 degree angle?


By 0.05" it is about wide open. It is incredibly sensitive.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Wed Nov 06, 2013 7:46 am

Thanks Larry, That's good information. So the type M keeps your draft in a narrow range which is what you want. The RC keeps it in a slightly wider range.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: michaelanthony On: Wed Nov 06, 2013 7:55 am

Lightning wrote:
One side is for a horizontal pipe, the other side is for a vertical pipe. Why it would make a difference I don't know. I found that the side it's on currently, reacts more sensitively than the same position on the other side. The path for the weight seems to be inclined slightly more on this side also. I have a diagonal pipe so I guess it's just "pick one" hahaha.


Haha, I was looking at mine as well curious which side to use because mine is set up at a 90* called a bull nose and I came to the same conclusion...whichever side you need to get the results you want! HA!
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly coat rack
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Wed Nov 06, 2013 8:54 am

titleist1 wrote:i guess don't understand how you are setting up your testing at different pressures with the different openings or what you are trying to determine.

my baro position and the mano readings are the opposite of yours. i do not have a draft inducer or a manual damper. my manometer is connected prior to the baro. after the stove has reached firing temp (as opposed to idle temp) if I intentionally close my baro to the position you have in your first pic my draft will read roughly .06 depending on how cold it is outside. if i force open it up to the position you have in the last pic the draft will drop to about .02.

if i leave the baro to work on its own, it will maintain a .04 reading on the manometer while being open varying amounts from all the way closed to just about wide open, depending on the wind.

I realize the mention of using the draft inducer and manual damper to manipulate the draft pressure may have confused some people :( . I was trying to get a reference for where others set their weight on their baro door during "normal" burning conditions. So the pictures at -.04 and -.05 don't really apply since I used the inducer to exceed the drafting strength of the chimney. It seems that with my set up, my baro will keep the draft inside a particular range, for example between a -.02 (where it starts to open) and a -.04 (where its approaching a 45 degree angle) which is a .02"wc range.

Larry says his stays in a .01 range (-.04 starts to open to a -.05 where its almost wide open) a narrower range for a more consistent draft pressure. I likey :)

Its amazing how sensitive a hand fed is to draft pressure (mine seems to be). My furnace ran between 260-263 degrees all night long. This morning I saw my baro was holding draft at a -.02"wc with the baro door open at about a 60 degree angle. I decided this was a hair weak (I have a fiddling issue :lol: ) SO, I moved the baro weight toward the door about a 1/16 of an inch so it would hold it at a -.025"wc.. This small adjustment in draft caused my furnace temp (measured over the load door) to increase 12 degrees (from 261 to 273 degrees) over the period of an hour.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix