Barometric Damper : Draft Pressure Setting

Re: Barometric Damper : Draft Pressure Setting

PostBy: titleist1 On: Wed Nov 06, 2013 9:16 am

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.


This is the part that i can't wrap my brain around - the keeping the draft in a particular range....

No matter what position my baro is in, further open or closed - depending on outside temps & pressure and my stove temp, my draft stays at .04 - except when wind gusts are happening and the baro is fluttering, the pressure moves slightly until the baro flap re-settles at .04. i don't have to move the weight on the baro to make it do this so does that mean mine keeps the draft in a < .005 range?

if i manipulate the weight on the baro moving it slightly like you mention i can control the setting on the mano to about a .005 granularity. that is about exact as you can visually tell where the oil is on the dwyer. but the further open i manipulate the baro the lower the reading on the manometer which is the opposite of what you and Larry see.
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: Lightning On: Wed Nov 06, 2013 10:32 am

So your barometric door starts to open at -.04? Then will open further without an increase shown on the mano?
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: tcalo On: Wed Nov 06, 2013 10:57 am

I have my baro set up to maintain a draft between .04 and .06. Anything below .04 and the door barely opens. At .06 the door is about halfway open. I've never seen it open anymore than 50% because it maintains .06 at this point. We would need some good gusts to open any further. Although it also depends on the stove temp and outside temps. The colder it it outside and the hotter I run my stove the more my baro door moves to maintain the required draft.
tcalo
 
Hand Fed Coal Stove: Chubby Coal Stove
Coal Size/Type: Nut Anthracite


Re: Barometric Damper : Draft Pressure Setting

PostBy: titleist1 On: Wed Nov 06, 2013 11:22 am

Lightning wrote:So your barometric door starts to open at -.04? Then will open further without an increase shown on the mano?


Correct. If conditions (outside temp, pressure or stove temp) cause the baro to open further (could be a little or could be a lot) the manometer reading stays at .04. (again, the reading is being taken between the stove and baro). The only time this was not the case was during the blizzard a couple years ago when the wind was a steady 40mph or so and the temp was low 20's the baro was open all the way and mano reading was up to .06. The wind seems to be the big factor at our house in pegging the baro because i have operated with outside temps at 0 with no wind and the baro was open about halfway and mano reading was steady at .04.

If conditions are steady (no wind gusts) and I manually push open the baro then my draft reading DROPS from .04 to maybe .02 depending on how far i open the baro. Does that translate to a sensitivity range of .02 in your experiment?
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: Lightning On: Wed Nov 06, 2013 7:10 pm

titleist1 wrote:If conditions are steady (no wind gusts) and I manually push open the baro then my draft reading DROPS from .04 to maybe .02 depending on how far i open the baro. Does that translate to a sensitivity range of .02 in your experiment?

Not really, I thought you would see a point on the mano where the door would start to open, then see a slightly higher reading when it was open further like a 45 degree angle,
tcalo wrote:I have my baro set up to maintain a draft between .04 and .06. Anything below .04 and the door barely opens. At .06 the door is about halfway open. I've never seen it open anymore than 50% because it maintains .06 at this point. We would need some good gusts to open any further. Although it also depends on the stove temp and outside temps. The colder it it outside and the hotter I run my stove the more my baro door moves to maintain the required draft.


Everyones setup will behave differently, I suppose there are too many variable to try to compare mano readings with baro door sensitivity....Thanks for everyone's input 8-)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: franco b On: Wed Nov 06, 2013 8:36 pm

While we are on the subject i just want to point out a clever selection of pivot bearing on the RC baro. It wants to be as friction free as possible. The usual solution is to use a vee notch and knife edge or some sort of bearing or bushing that the pivot rotates in. They used the simplest and cheapest and most friction free by utilizing a round pivot rolling on a flat surface instead of rotating within a bushing. Great design, cheap but good.
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: Wed Nov 06, 2013 8:59 pm

Oh yeah, I agree totally! There is an unmeasurable amount of friction on that pivot. Sometimes simple and easy is the best solution :D
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: 2001Sierra On: Thu Nov 07, 2013 12:18 am

SMITTY wrote: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:


I bought the Type M for my Keystoker 90, fussed with it for 3 years, would bind every so often. Just bought a R-C jury is still out if it is any better. I really think they all are junk :mad:
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: Fri Nov 08, 2013 3:55 am

2001Sierra wrote:Just bought a R-C jury is still out if it is any better. I really think they all are junk

Third year with my RC, I've never had a problem with it.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: dcrane On: Fri Nov 08, 2013 7:02 am

2001Sierra wrote:
SMITTY wrote: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:


I bought the Type M for my Keystoker 90, fussed with it for 3 years, would bind every so often. Just bought a R-C jury is still out if it is any better. I really think they all are junk :mad:


let the games begin :nana: I wonder what type they used back in the glory days of coal burning on the Glenwoods, Crawfords & Favorites?
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: Barometric Damper : Draft Pressure Setting

PostBy: titleist1 On: Sat Nov 09, 2013 10:03 am

some info to add to the mix.....

Baro was open about 1/4 way of the this morning so i held it closed and watched the mano reading climb from .04 to .05.

Temp here is 37*, no wind, stoker has been running for about 45 minutes the flue temp is approx 275* measured with a gauge/probe.

when i let it open again the mano dropped back to .04
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: Sun Nov 17, 2013 11:04 am

Since my last post to this thread I've used a toothbrush and brushed off the inside of the swinging door and also slightly adjusted my barometric damper to hold at a lower WC of 0.04" rather than the previous 0.05". It's windy here today, so I had a good chance to stand around and watch my damper closely in operation. Under the current wind conditions it just begins to crack open at 0.04", and the manometer indicates that it pretty much remains at 0.04" regardless of the degree (percentage/angle) of opening. clear up to nearly wide open. I know from past experience that at some combined level of cold temperature outside and high wind speed my damper will be overwhelmed and eventually climb above 0.04" (as I actually saw the damper wide open and the manometer hitting 0.11" on one rare very high wind occasion last winter, when the air rushing into the wide open damper sounded like a sucking vacuum cleaner), but from my observation today it appears that for more typical wind or cold temperature situations it is capable of holding quite steady at 0.04".

I do not see anything like Lightning's observation of the manometer monitored WC level of draft rising progressively as the barometric damper progressively opens.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (if I ever get it fixed)

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Sun Nov 17, 2013 11:45 am

lsayre wrote:I do not see anything like Lightning's observation of the manometer monitored WC level of draft rising progressively as the barometric damper progressively opens.


Yer right, this was one of those expiriments that didn't work.. I used a draft inducer to get the baro to open further at those pressure settings. I was approaching the baro as if it were a regulator, when in actuality it is a limiter :lol:
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper : Draft Pressure Setting

PostBy: lsayre On: Sun Nov 17, 2013 3:07 pm

It's windy enough here right now, but from 7:00 PM this evening until 7:00 AM tomorrow morning the NOAA has issued a "wind advisory" for our area, with heavy thunderstorms, hail, and possible tornadoes. This may be one of those nights when I wish I had 2 barometric dampers on my flue.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (if I ever get it fixed)

Re: Barometric Damper : Draft Pressure Setting

PostBy: Lightning On: Sun Nov 17, 2013 3:50 pm

lsayre wrote:It's windy enough here right now, but from 7:00 PM this evening until 7:00 AM tomorrow morning the NOAA has issued a "wind advisory" for our area, with heavy thunderstorms, hail, and possible tornadoes. This may be one of those nights when I wish I had 2 barometric dampers on my flue.


Yes, I saw the advisory too :o
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix