Oil Boiler Running

 
Salemcoal
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Post by Salemcoal » Mon. Jan. 12, 2009 6:51 pm

I have disconnected the wire to the burner. At about 15 degrees the Harman is having trouble holding water temps running at full bore.

 
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coalkirk
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Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Tue. Jan. 13, 2009 9:02 am

The question is is your home warm? When sizing a boiler, my opinion is you don't size for the worst case senario but for the average conditions. During very extreme conditions, it may not be able to "hold" a termperature like an oil boiler could but as long as the water temp is staying in a decent range and your house is comfortable, your doing fine. Having a boiler sized too large isn't efficient.
What is your aquastat setting and what temp is it maintaining under a heavy load?

EDIT: I just went back and read you have it set to 185*. As long as you arn't dropping below 140, I'd say your are doing fine. With some more sophisticated controls, like Highlander has, you could probably do better. By the time the Harman controls react, you temp has already dropped quite a bit. You might also need to fiddle with feed rates during very cold weather.

 
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Coalbrokdale
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Post by Coalbrokdale » Tue. Jan. 13, 2009 11:13 am

I'm burning about 80lbs a day in my VF3000K. I run my boiler hot 185-190 so I never run out of hot water. An we use alot of hot water.... House is 3500 Square Feet, with another 1000 in the basement which is finished off: insulated, sheet rock, drop ceiling, carpeting. So 4500 square feet Total.

Gas Boiler never fires it's a 135 BTU NG,
Gas Hot Water heater is shut off and the well water enters it and exits before running through the VF3000 DHW coil.

I figure if I burn 80lbs in 24/hrs, thats 3.3lbs/hr or 43000 BTU's and hour.

The VF3000 is rated at what, 85000+ btu's..?

Also FYI for recovery rates:
To heat the boilers 50 gal of water 40 degrees it must burn 1 lb of coal.

 
Salemcoal
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Post by Salemcoal » Tue. Jan. 13, 2009 8:21 pm

I have the feed rate turned down a little bit now 3 inches of unburned coal on grate. 33 F out and the boiler is running at a little over 140 Aquastat set at 180. Maybe I'm asking this boiler to do things it wasn't designed to do being outside in an uninsulated (planning on sealing it up good.) 12 by 12 garage away from the house but it seems a campfire in the ashpan would heat up the 50 gallons of water faster . 3000 square foot house About 125 years old and not too well insulated but a Gibraltar handfed is roaring at one end heating about half the house so I'm only trying to heat about 1600 square feet with it.


 
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coalkirk
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Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Tue. Jan. 13, 2009 8:27 pm

What exactly do you mean by 3" of unburnt coal on the grate?

 
Salemcoal
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Post by Salemcoal » Tue. Jan. 13, 2009 8:49 pm

I made a mistake , I mean about 3 inches of burned coal that hasn't fallen off yet.

 
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coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Tue. Jan. 13, 2009 9:10 pm

Ok so you are burning it at a fairly low rate. I've got about half that amount of coal ash on the end of my grate. I'm pushing almost 4 dots.

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