upgrading the combustion blower?

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leoman584
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Post by leoman584 » Mon. Dec. 02, 2019 12:07 pm

I was speaking to a gentleman at a shop locally that sells coal stokers.

He told me that it might be a good idea to hook up the combustion blower to a hose or pipe to pull in air from the outside. (similar to a pellet stove set up)

He also mentioned installing a larger blower to get more cfm into the coal grate.

It was interesting conversation, but I'm wondering if it is worth it to do.
It wouldn't be super pricey to do what he said. (PVC pipe is cheap, and I have an extra blower motor that would fit)

Has anyone tried this? Is it worth doing? Any noticeable gains in efficiency or heat output?

 
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captcaper
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Post by captcaper » Tue. Dec. 03, 2019 5:18 am

I have my stove in the basement so no outside source is necessary. Plenty of leaked cool air coming in. I wouldn't go more then the recommened blower for the stove. Issues would develope I'm sure. If you don't have enough BTU's out of it I would upgrade to a stove that will.

 
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titleist1
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Location: Cecil County, MD
Hot Air Coal Stoker Stove: Harman Mag Stoker - 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

Post by titleist1 » Tue. Dec. 03, 2019 7:20 am

I have a pipe running from outside to the intake of the combustion motor and I believe it has helped with the draftiness of our basement where the stoker is located

What stoker are you running? I would not put in a combustion fan with more cfm. Generally the combustion fans have a plate to limit intake air flow so it does not pressurize the fire box and force exhaust out places other than the flue pipe. My 75cfm fan on a flat bed stoker is a little more than 50% closed. You have to adjust the combustion fan airflow to balance the firebox draft with the draft out the flue pipe to avoid pressurizing the firebox.

 
leoman584
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Post by leoman584 » Tue. Dec. 03, 2019 9:34 am

It's a Reading Juniata.

It works well until it gets really cold, then it struggles a little.

I have no issues with combustion.
It was just conversation.

Pulling in outside air would be easy to do and inexpensive, so I may try it.
Doesn't seem like it would harm anything.
My stove is in the basement and is fairly air tight, so pulling in fresh outdoor air could help

I'm currently searching for something larger with more BTU, but am trying to get everything that I can out of this stove until I have some more cash saved up.

I've been having trouble getting a straight answer to this question:
If I upgrade to a stove that puts out more BTU, will I burn more coal?
Seems like an obvious "yes", but I've got some conflicting answers.
Some say that a larger unit will burn more efficiently, so it won't burn much more than I do currently.
Others have said if I jump up to a larger unit, then I would absolutely see an increase in consumption.
What say you?

I'm rated at 85K BTU
I've been sniffing around for something over 100K.

Visit Alternate Heating Sytems

 
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titleist1
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Location: Cecil County, MD
Hot Air Coal Stoker Stove: Harman Mag Stoker - 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

Post by titleist1 » Tue. Dec. 03, 2019 9:49 am

Generally speaking with similar free standing "stoves" you will burn more coal going from 85k BTUs to over 100k btu's.

If you get a "furnace" and efficiently tie it into your ductwork then the better heat exchanger and ductwork set up will work much better distributing heat and I would guess you'd burn less. I base this on a friend of mine that has the same mag stoker I do, but has his tied into the ductwork of his two story home (ours is freestanding in the basement of our spread out rancher). He burns less than we do.

If you get a boiler with a heat exchanger in your ductwork then I think you'd definitely burn less.

 
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McGiever
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Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: RICE,PEA,NUT,STOVE /ANTHRACITE and EGG / BIT
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Tue. Dec. 03, 2019 10:08 am

His Reading stove's combustion fan blower wheel is on same motor shaft as carpet feed. Not a independent motor...no air gate adjustment either. Always follows feeder cycle and runs only at full motor speed and is off during idle. For this reason even a Coal-trol can not be used as is.
Only upgrade is to add another second fan and this could allow some independent air control.
There are discussions here for both adding the 2nd independent blower motor as well as adding then a Coal-trol to these one motor Reading carpet stokers...
Reading did sell a controller to use for a 'hold fire timer' with ability to also allow control by a room wall thermostat...this allows a 'set it and forget it' aproach and eliminates constant fiddling with the red feeder stroke nut.

 
Pacowy
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Post by Pacowy » Wed. Dec. 04, 2019 8:40 am

If the basement is tight I would focus on providing adequate make-up air to the room containing the stove, not piping it to the intake. In a tight house, the draw of air by things like clothes dryers, bathroom vents and range hoods can interfere with chimney draft if adequate make-up air is not provided, sucking CO into the house. AFAIK that's why make-up air is now covered by code. Beyond that, I'd be concerned that the extremes of temperature and humidity that occur in outdoor air might not be great for the stoker.

On the coal use issue, if you would use a bigger stove to produce more heat (larger area and/or higher temp), then sure you likely will use more coal, but not because of the size of the stove. If heating the same area to the same temp, there are several efficiency issues that may arise, including relative heat exchange efficiency of the stove, and reliance on optimal fuel/air mix. My $0.02 would be to run your stove at the optimal fuel/air mix (producing 1" band of dead ash at end of grate), and if that doesn't produce enough heat over a big enough area then try a bigger stove.

Mike

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