Average Stack Temp. ??

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Joined: Thu. May. 01, 2008 7:12 pm
Stove/Furnace Make: Hitzer
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Location: Nottingham,Pa

Post Thu. Aug. 07, 2008 5:22 pm

Could some one give me an idea of the average stack temp. after the draft regulator on a coal furnace. Is it comparable to that of a oil burner. Thanks for the help!

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Stoker Coal Boiler: Axeman Anderson 260
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Location: Michigan

Post Thu. Aug. 07, 2008 5:50 pm

I have no idea what the temp of an oil burner's flue is..

For a hand fired stove the temp can vary from ~250* to 8-900* or even higher at times
A stoker is usually around ~150-300*

My AA boiler when idling is around ~120*, but will reach 400* after a 10 minute burn in the dead of winter. This is measured about a foot above the boiler's exhaust.

Most will run around 4-500* when making heat.. higher if the appliance isn't able to extract as much heat from the firebox to the surrounding room.

Greg L

Burning Pea/Buckwheat through an antique stoker [semi retired SSboiler],
Running an Axeman-Anderson 260M boiler burning Pea, About 150-250#per day
Farming, Fixing, Fabricating and Flying: 'spare time' what's that?

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Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
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Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon
Location: Cuba, NY

Post Fri. Aug. 08, 2008 7:48 am

Depends on how hard you are running it, my hyfire I running full bore and AFTER the baro damper usually averages 200-250+ Deg. F before going up the chimney. I have a digital temp. probe in the pipe. I don;t think I have ever seen it over 300.

The baro damper usually opens and helps cool the exhaust when it starts really drawing up the chimney, to keep a constant draw on the stove.
- Dave
Hyfire I & Keystoker 90K heating an 1890 Victorian
- Amsoil Authorized T1 Certified Dealer

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Post Fri. Aug. 08, 2008 7:53 am

WNY wrote:Depends on how hard you are running it
There is no such thing as an "average" stack temp. (kinda like saying what is your average driving speed?........While you can figure it out mathematically after a road trip, it is totally variable & under your control)
Your oil furnace runs at a constant temp & provides heat to your house based on the amount of time it is on. A coal appliance is burning all the time & you regulate you home's heat by varying the heat output of the appliance. (I've only run coal stoves so I am no expert on running coal furnaces, but I think the principle is the same......Higher stove/furnace temps create more heat for your home, not just time on. If I am wrong about this, I'm sure one of our resident furnace experts will correct me. :D
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Post Sat. Aug. 09, 2008 10:49 pm

The last time I cleaned my 39 year old oil fired boiler, Sept '07, the stack temp was 585 degrees before cleaning.
540 after cleaning. :shock: :mad:

Don't know about coal yet. As soon as the oil tank is empty, a few days I expect, I will be installing my Keystoker boiler.

I think newer boiler manufacturers advertise their stack temps much lower.

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Post Sun. Aug. 10, 2008 12:27 am

My KA-6 was hitting 165+/- during the stoke cycle last weekend.
Almost no load (140/160) and 45 sec. idle burn every 15 min.

I was surprised at how low the temps have been.
I need a new 9 volt for the meter. I'll give you more data, as I collect it.

It was just my imagination
running away with me...

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