Cistern

[runaround]

I'm new to the forum and a new owner of a Sequoyah e-3400 owb. It's connected to system 2000 oil boiler (low mass) with 250k btu 50-plate hx. I'm heating 9000 sq ft with 10 zone control valves. Part of the house is a 1850's granite cape with an old, approx. 550 gallon cistern in the basement. The cistern has 6'' cement walls, or at least a cement skim coat, with an open top. I'm looking for advice concerning it's suitability for heat storage and the best approach to tying it in to current system. Any help would be greatly appreciated.

 

[bigblue]

I am no expert, but from what I hear most people don't use storage with an OWB. The most common reason for storage is with a gasifier so you can keep it at high efficiency and store the heat not needed at that time.
I bought a used STSS 1000 gallon storage from a guy who had a tarm multiheat boiler and then switched to a large OWB and decided the storage didn't make sense with the OWB.

 

[gorsuchmill]

Sorry to hijack, but bigblue do you still have the used storage and, if so, is it for sale?

Thanks.

Lee

 

[Duetech]

Welcome to the forum....The principal for storage and gassifiers is to allow down time for the boiler which relates to less burned wood and work/time saved too. The problem with using OWB's for storage is where they are at. Would your boiler be ok if left out in the freezing cold for 8-12 hours with out a fire in it? Would it freeze/damage the boiler? Would the time it takes to get your boiler up to temp to start heating your place be economical to your storage considerations, that is, would it take more fuel to reheat the boiler than the gain storage gives you?
In line with the storage you have mentioned you will have considerable thermal leakage with an un-insulated tank whether it is above or below ground level. You would eventually get a massive thermal radiator but the out put would be a 360* sphere and that would take a lot of fuel to heat and the secondary heat gain to you would be minimal. The amount of storage that is in the cistern is far below what your btu requirements would be for a place that large. My boiler is rated at 4000 sq ft and minimum recommended storage for it is approximately 500 gallons. That in mind you should probably have not less than 1125 gallons of storage but probably 2 1/2 to 3 times as much. That would take substantial amounts of wood to heat. Then the question arises would your boiler be able to supply the heat your place needs and recharge storage of that size? I'm no expert but I think you would save money bypassing the storage where the cistern is concerned. If you are adamantly inclined to have sufficient storage you might be able to go solar....Stay warm