Ducting Blower Fan Directly to Furnace

Modern and vintage hand fired coal stove are similar to a wood stove and in some cases can burn either. They need to be regulated and fed by hand usually every 12 to 24 hours depending on your usage. They require no power to operate making them ideal for rural settings with long power outages.
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Duengeon master
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Posts: 1944
Joined: Sun. May. 06, 2007 7:32 am
Hand Fed Coal Stove: Harmon Mark III
Coal Size/Type: Anthracite pea and nut mix. Bituminous lump
Location: Penndel, Pa.

Post Sun. Feb. 10, 2008 9:04 am

Will a blower on a Harman mark III make it more efficient? I use it to heat my basement then it heats my whole house. My oil burner sits right next to it, and is very jelous of the stove. :cry2: Can I duct the back of the stove where the fan mounts to the stove and pipe it directly to the cold air side of the furnace, or do you think the heat may hurt the furnace fan assembly? Then I want to hook up the fan only swich that is on my oil burner's thermostat to make use of the basement heat. :)
I am a free man. Free men and women are not part of a collective, we are individuals.

The question isn’t who is going to let me, it’s who is going to stop me... Ayn Rand

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coaledsweat
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Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea
Location: Guilford, Connecticut

Post Sun. Feb. 10, 2008 9:35 am

Sounds like a plan, how about pics? That should generate a plethora of ideas to chose from.
Nothing is impossible for people who don't have to do it themselves.

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Dallas
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Joined: Mon. Nov. 12, 2007 12:14 pm
Hand Fed Coal Stove: Modified Russo C-35
Other Heating: Oil Hot Air
Stove/Furnace Make: Russo
Stove/Furnace Model: Modified C-35
Location: NE-PA

Post Sun. Feb. 10, 2008 9:46 am

Here are my thoughts on that, after having tried using the furnace system as an air circulator.

While the furnace fan will circulate the air, it also passes the "hot stove air" over the furnace heat exchanger. When the air passes over the furnace heat exchanger, it loses a lot of it's heat to the furnace, probably going out the furnace flue. The end result being, any air coming out of the furnace system is too cool to assist warming the house. "Very inefficient"!

If you were to use a separate fan and plumb the stove heat into the hot air plenum of the furnace, it would probably do a better job.

Edit: It should probably have a return to the stove, as well.

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LsFarm
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Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland
Location: Michigan

Post Sun. Feb. 10, 2008 10:38 am

Dallas has it right. the heat exchanger in the furnace will work in reverse, and it will heat the air in the furnace's burn chamber and flue, so it's not a good way to do it.

Put a fan on the MarkIII, this will make it MUCH more efficient, make a duct top like Dallas did for his coal stove, and duct the heat into the upper part of the house.. Put a cold air return duct to the inlet of the distribution fan on the MarkIII, and you will have a little coal burning furnace setup, and working right..

You will still get plenty of radiant heat off the stove's body to heat the basement.

Maybe you can talk Dallas into making you one of his custom stove top heat ducts?? :D :D :lol: :lol: :? :) ??

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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LsFarm
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Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland
Location: Michigan

Post Sun. Feb. 10, 2008 10:40 am

Here is Dallas's custom stove top heat reclaimer: Really temperamental stove/draft !!

Nice metal-bending !!

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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butchs37
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Hot Air Coal Stoker Furnace: Alaska 140 dual feed
Location: Kenvil, NJ

Post Sun. Feb. 10, 2008 3:34 pm

I have mine set up with the furnace blower on a thermostat with relays. When thermostat calls for heat stove will come off of idle and blower will not come on until the fan limiter on stove switches on. I have 1 cold air return in the center of the house piped directly to the stove. All cold air returns on the furnace are shut off via a piece of sheet metal over the air filter. Temps blowing out of the vents are lower than directly off stove about 105 deg. but the house is evenly heated.

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Dallas
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Joined: Mon. Nov. 12, 2007 12:14 pm
Hand Fed Coal Stove: Modified Russo C-35
Other Heating: Oil Hot Air
Stove/Furnace Make: Russo
Stove/Furnace Model: Modified C-35
Location: NE-PA

Post Sun. Feb. 10, 2008 4:51 pm

Butch, where do you have the stove heat entering the furnace system?

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butchs37
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Posts: 60
Joined: Wed. Dec. 19, 2007 5:34 pm
Hot Air Coal Stoker Furnace: Alaska 140 dual feed
Location: Kenvil, NJ

Post Sun. Feb. 10, 2008 5:42 pm

through the access cover for the blower. The blower draws the air through the stove then blows it through the furnace and into ducts.

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Duengeon master
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Posts: 1944
Joined: Sun. May. 06, 2007 7:32 am
Hand Fed Coal Stove: Harmon Mark III
Coal Size/Type: Anthracite pea and nut mix. Bituminous lump
Location: Penndel, Pa.

Post Mon. Feb. 11, 2008 7:33 pm

LsFarm wrote:Here is Dallas's custom stove top heat reclaimer: Really Temperamental Stove/Draft !!

Nice metal-bending !!

Greg L
Dallas's heat reclaimer is awesome. 8-) :up: It's more than I can make. I will go out to buy the blower for a mark III.
I am a free man. Free men and women are not part of a collective, we are individuals.

The question isn’t who is going to let me, it’s who is going to stop me... Ayn Rand

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CoalHeat
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Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Baseburners & Antiques: Sears Signal Oak 15 & Andes Kitchen Range
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert
Location: Stillwater, New Jersey

Post Mon. Feb. 11, 2008 9:41 pm

Sounds like something similar to what I plan to do with the Alaska. I'm going to duct the hot air into the hot air plenum after the oil furnace's heat exchanger. I'm sure it won't produce the same effect as the actual oil burner running, but it will supplement the heat from the Harman.
Heating a circa 1832 farmhouse with a Harman Magnafire Mark I & a 1959 EFM 350 (heating DHW).
100% Oil Free!
"It's what we learn after we think we know it all that counts."

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