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EFM 520 Heat Storage Advantage/Disadvantage

Posted: Fri. Aug. 06, 2010 6:36 pm
by eskimo
if one had a super insulated house R40/wall, R/80 ceiling, what would be the advantage/disadvantage to a super insulated 2000 gallon storage tank be?
if the boiler was off for 2-3 days and you ran off the tank temp untill it got too low, would you wipe out your coal savings by the boiler running flat out to heat the large tank volume back up before you could shut it off again? in wood gasification boilers it is done alot, I just wondered what the pros or cons would be for coal instead of the boiler running normal with out a storage tank?

thanks

eskimo

Re: EFM 520 Heat Storage Advantage/Disadvantage

Posted: Fri. Aug. 06, 2010 7:31 pm
by whistlenut
With coal, slow and steady wins the race. You absolutely do not want or need to have a super insulated water storage tankage and let the boiler fire die out. You COULD do that, but you would be using the boiler like a gassification unit, and that never was or is the design intent.

I have seen dozens of Tarm style installations with one, two, or three additional storage tanks of a couple thousand gallons of heated water. If you were in Iceland, go for it. When in America; burning a very stable fuel like anthracite coal, forget about the storage tanks. Save the money.....go on a cruise.....help out a friend who has been sucked into the "heated storage" dilemma. Think of the space you will save not having all the tankage, controls, circs, aquastats.......and how about the humidity of the storage tank area. I know it's covered, but it isn't air tight. My $.02......can't wait to hear from the 'greenie set' who actually do invest 50K into these systems....... :? :shock: :cry: :idea:

Re: EFM 520 Heat Storage Advantage/Disadvantage

Posted: Fri. Aug. 06, 2010 7:52 pm
by tsb
I agree with whistlenut. With the insulation you have,
you don't need 2000 gallons of hot water hanging around.
My new system has about 35 gallons of water total. You want
to heat the water as you need it. With coal, the flywheel effect
is in the boiler itself. What do you do with 2000 gallons of HOT water
if the outside temperature goes up for a few days ? Windowstats ?

Tom

Re: EFM 520 Heat Storage Advantage/Disadvantage

Posted: Sat. Aug. 07, 2010 12:28 pm
by AA130FIREMAN
2000 gallons would need alot of space and one heck of an expansion tank :shock: . My axeman doesn't have an insulated jacket nor did they ever make many (handfull) with the insulation. If you are makeing heat their needs to be a place to release the heat when their is no demand. Seems their is some thought behind not insulating the boiler :idea:

Re: EFM 520 Heat Storage Advantage/Disadvantage

Posted: Sat. Aug. 07, 2010 5:32 pm
by coaledsweat
eskimo wrote:in wood gasification boilers it is done alot, I just wondered what the pros or cons would be for coal instead of the boiler running normal with out a storage tank?
Wood gasification almost requires it, with hand fired boilers it can be handy. With a coal stoker, it is a waste of time, money and space.