What am I doing wrong? Too much coal being used

Re: What am I doing wrong? Too much coal being used

PostBy: stoker-man On: Thu Feb 21, 2008 2:17 pm

It might be possible to have a positive draft if your air is set too high and the chimney is too small, but it would be at both sides. The draft over the fire is the most important measurement; taken at the door.

Your fire must be stoking and the chimney warm when you do these tests.
stoker-man
 
Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove

Re: What am I doing wrong? Too much coal being used

PostBy: Wood'nCoal On: Thu Feb 21, 2008 11:35 pm

I'm not familiar with the meter you are using, but on my Dwyer I'm actually using the portion of the scale which reads in positive increments for the reading. It's interpreted in negative inches of water column. The negative scale is too short to use. The draft reading will increase if you hold the baro's flap closed, will decrease if you hold it open.
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Scale reads positive but reading is actually negative pressure.
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Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: What am I doing wrong? Too much coal being used

PostBy: e.alleg On: Fri Feb 22, 2008 12:58 am

I think he's just reading the scale wrong, if the chimney had positive pressure then I think he'd be complaining of a smell and a massive headache.
e.alleg
 
Stove/Furnace Make: EFM
Stove/Furnace Model: 520

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Re: What am I doing wrong? Too much coal being used

PostBy: stoker-man On: Fri Feb 22, 2008 6:45 am

He's using the Bacarac draft meter. The scale is exactly the same as Wood n' Coal's meter, except, the positive side of the scale is on the left.

I don't understand why there is such an emphasis on the positive side of the Dwyer scale when stoves require negative drafts.
stoker-man
 
Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove

Re: What am I doing wrong? Too much coal being used

PostBy: coaledsweat On: Fri Feb 22, 2008 8:41 am

stoker-man wrote:I don't understand why there is such an emphasis on the positive side of the Dwyer scale when stoves require negative drafts.


There are two hoses on the Dwyer, changing them reverses your reading from positive to negative.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: What am I doing wrong? Too much coal being used

PostBy: stoker-man On: Fri Feb 22, 2008 8:46 am

On the scale picture, it appears that there is a negaitve sign on the left side.
stoker-man
 
Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove

Re: What am I doing wrong? Too much coal being used

PostBy: Wood'nCoal On: Fri Feb 22, 2008 8:50 am

stoker-man wrote:He's using the Bacarac draft meter. The scale is exactly the same as Wood n' Coal's meter, except, the positive side of the scale is on the left.

I don't understand why there is such an emphasis on the positive side of the Dwyer scale when stoves require negative drafts.


Only because the Dwyer meter is intended to be connected in a different application, for example on a forced air system to monitor the air flow through a filter. The high side tube is connected to a point before the filter, the low side after. If the filter is after the blower it will read positive pressure. As the filter becomes clogged the reading on the meter will begin to climb.

Since the negative side of the scale is so short we just use the positive side, in effect using the gauge backwards, since it's not positive pressure, but negative pressure (vacuum). The same would be true in a forced air system with the blower after the filter, since it would be all negative pressure.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Visit Lehigh Anthracite