Chimney Draft Failure

Re: Chimney Draft Failure

PostBy: jpete On: Fri Mar 22, 2013 2:53 pm

Lightning wrote:
jpete wrote:My chimney drafts like a pile of mud so toward the end of the season, I have to foil over the baro to make sure ALL the air goes the way it should.


On warmer days try running more secondary (over the fire) air. I've been able to maintain a draft even when it's approaching 60 degrees outside by doing that.


Wish I could. No adjustable secondary air on a Harman Mk II. :(

Maybe I'll finally get my Chubby running and give it a shot next year. :)
jpete
 
Hand Fed Coal Stove: Harman Mk II
Coal Size/Type: Stove, Nut, Pea
Other Heating: Dino juice

Re: Chimney Draft Failure

PostBy: Ctyankee On: Fri Mar 22, 2013 3:28 pm

I had this web page tagged for my basic info. Maybe someone might find it helpful/interesting too.

http://www.engineeringtoolbox.com/natur ... d_122.html
Ctyankee
 
Hand Fed Coal Stove: Hitzer 503 insert
Coal Size/Type: nut and pea

Re: Chimney Draft Failure

PostBy: lsayre On: Sat Mar 23, 2013 7:21 am

Ctyankee wrote:I had this web page tagged for my basic info. Maybe someone might find it helpful/interesting too.

http://www.engineeringtoolbox.com/natur ... d_122.html


Good website link! I wonder if something like this exists online scaled in feet, degrees F., and inches of water column?
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (if I ever get it fixed)

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Re: Chimney Draft Failure

PostBy: dlj On: Wed Mar 27, 2013 12:42 pm

my main problem with this web page is regarding the temperature that is generating the draft.

A system using a stove is a closed system. I have seen when starting with no fire, draft has to be established. In those cases, I usually take newspaper and start a small fire in the stove with them. It has never taken long for the draft to start even when initially the draft is reversed at start-up. This used to happen to me a lot in the fall during start-up in one house I used to live in. Start small with newspapers and not a lot of smoke comes in the house prior to the draft being established. A fire, even banked way down, is hundreds of degrees - going strong - in the thousands of degrees.

I have run fires inside a house also with open systems, like fireplaces. I used to have an open fire in my kitchen where I could cook next to my stove. I've barbecued in it in the middle of summer and outside temperature was above the inside house temperature. In the most difficult scenarios, I had to hold the burning paper up into the entrance to the chimney with tongs until the draft would be established.

Natural draft up a chimney with no fire and the natural draft up a chimney with a fire are distinct in the temperatures you need to use to calculate the draft.

fwiw

dj
dlj
 
Hand Fed Coal Stove: Vermont Castings Resolute
Baseburners & Antiques: Glenwood Baseheater #6
Coal Size/Type: Stove coal
Other Heating: Oil Furnace, electric space heaters

Re: Chimney Draft Failure

PostBy: Lightning On: Tue Oct 29, 2013 6:16 pm

Thought I'd revive this thread with some observations I made today.. I had an opportunity to get some numbers with the mild daytime temps.

First picture, was at 4:00pm when I got home from work.
250 degrees over the load door, 158 degrees on the pipe and a -.015 of draft pressure.

I decreased the primary air at the ash pan door about 25% from where it was.
I increased the secondary air in the back of the furnace by 50% from where it was.

Second picture, an hour later at 5:00pm.
244 degrees over the load door, 160 degrees on the pipe and a solid -.02

My conclusion is that the decrease in primary air with an increase in secondary air with a low fire and mild temperatures outside gave me 2 favorable results.

1) Decreased the temperature of the furnace 6 degrees (favorable since its 75 degrees in the house) and increased the flue pipe by 2 degrees.
2) Improved my chimney draft by -.005 :lol:

Though its a small improvement, I haven't yet had a draft failure since using this technique. The numbers show that more heat (which is being carried by the extra secondary air) is going up the chimney to help maintain draft.. :D
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Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Chimney Draft Failure

PostBy: michaelanthony On: Tue Oct 29, 2013 6:30 pm

Well professor Phineas J Whoopie, Sherman here. Now considering the path of the sun and the direct drop in temperature during the 60 minute interval it appears you experienced a draft increase of .0008333/minute...soooo is this observation an indirect result of mechanical indifference :? :lol:
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: Chimney Draft Failure

PostBy: Rigar On: Tue Oct 29, 2013 6:45 pm

michaelanthony wrote:Well professor Phineas J Whoopie, Sherman here. Now considering the path of the sun and the direct drop in temperature during the 60 minute interval it appears you experienced a draft increase of .0008333/minute...soooo is this observation an indirect result of mechanical indifference :? :lol:



....i think the increase in draft has to do with the approaching I-SUN comet. (just my 2 cents) :lol:
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Chimney Draft Failure

PostBy: Lightning On: Tue Oct 29, 2013 6:48 pm

I'm sure it could have been tidal effects of the moon too. :lol:
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Chimney Draft Failure

PostBy: joeq On: Tue Oct 29, 2013 6:53 pm

Do you know what your furnaces recommended draft is suppose to be per the manufacturer? My stove is suppose to be about .04 for "theoretical" max. efficiency. I don't think mine would stay lit with a draft as low as yours.
joeq
 
Hand Fed Coal Stove: Surdiac Gotha 513
Stove/Furnace Make: Oil fired
Stove/Furnace Model: Thermopride

Re: Chimney Draft Failure

PostBy: Lightning On: Tue Oct 29, 2013 7:14 pm

According to the plate stamped on the side of the furnace, it says not to exceed a -.05. It doesn't state a range to stay in. I like to keep mine between -.02 and -.03. It runs -.01 at times when it's warm out.

Yours would stay lit with less draft pressure just by opening the primary a little more.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Chimney Draft Failure

PostBy: Loco627 On: Tue Oct 29, 2013 11:22 pm

Just out of curiosity, how high an outside temp have you folks kept burning? A week like this week where it was highs in the 40s, but is forecast for low 70s for a day two before dropping back down. Can you manage to maintain a draft at those temps or do you eventually have to give in and start over when temps drop again?
Loco627
 
Hand Fed Coal Stove: DS Machine Circulator 1500
Stove/Furnace Make: DS Machine
Stove/Furnace Model: 1500 Circulator

Re: Chimney Draft Failure

PostBy: Rigar On: Wed Oct 30, 2013 5:38 am

loco

...i have a stoker feed furnace....and have no problems burning thru warmer periods
( shoulder seasons)
unless its 70 plus degrees outside...i just let it idle...(like pilot)
unless the house calls for heat...the plenum wont even get warm.
I have seen stack temps as low as 88 degrees (IR thermometer)

some members burn all year...boilers i would assume- for DHW
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Chimney Draft Failure

PostBy: Rob R. On: Wed Oct 30, 2013 5:42 am

Loco627 wrote:Just out of curiosity, how high an outside temp have you folks kept burning? A week like this week where it was highs in the 40s, but is forecast for low 70s for a day two before dropping back down. Can you manage to maintain a draft at those temps or do you eventually have to give in and start over when temps drop again?


Depends on your chimney performance. I run a stoker boiler year-round. The draft gets very low in hot muggy weather, but there has always been enough to keep the fumes going in the right direction.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Chimney Draft Failure

PostBy: Loco627 On: Wed Oct 30, 2013 6:42 am

Rigar wrote:
some members burn all year...boilers i would assume- for DHW


I forgot all about boilers. That would make sense, they need to run all summer.
Loco627
 
Hand Fed Coal Stove: DS Machine Circulator 1500
Stove/Furnace Make: DS Machine
Stove/Furnace Model: 1500 Circulator

Re: Chimney Draft Failure

PostBy: Lightning On: Wed Oct 30, 2013 7:14 am

Loco627 wrote:Just out of curiosity, how high an outside temp have you folks kept burning? A week like this week where it was highs in the 40s, but is forecast for low 70s for a day two before dropping back down. Can you manage to maintain a draft at those temps or do you eventually have to give in and start over when temps drop again?


I've been able to keep an idle thru a warm day (70's outside) so low that the snap switch on the top of my furnace air jacket doesn't reach 115 degrees to turn the blowers on.. Meanwhile holding 120 degrees on the pipe and a -.01" WC of draft pressure..

Of course this is with my primary nearly closed and my secondary nearly wide open, and a window open at each end of the basement to keep air pressure neutral.. :lol:

This scenario is the lowest I can maintain.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

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