Thermal mass heat storage

[bluefin650]

I am looking to store more water for my IWB. I am having a hard time finding a tank that can be pressurized, preferably insulated without spending over $1000. I would like to hold 200 gallons. Thought about having one built out of SS, but I am not sure how to stop the tank from bulging. 3x3x3 square or a cylinder with a radius of 1.5' and 4' tall would give 200+ gallons.
Any thoughts or suggestions on manufactured tanks or on making one?

 

[jackel440]

Locate an used propane tank and use it.I plan to add 4 500 gallon propane tanks stood on end to my system in a year or two for mass storage.lots of good info on the Hearth website on mass storage.

 

[loganj01]

A lot of the solar hot water plans I've looked at use a wooden tank with an EPDM liner. I don't know what the temperature limitations of this type of tank might be...or the temp limitations of the liner. The tank would be easy to insulate and, if housed out of the weather, last a long time. Check out Solar space heating -- active and passive solar projects for space heating for some possible ideas.

 

[Steveguy]

Instead of using a pressurized tank you could use a plate exchanger and a circulator pump to transfer the heat from your pressurized boiler to an unpressurized storage tank, and back again. As long as the water is circulated through the plate exchanger, it will try to equalize with the boiler loop. A large pressurized vessel is expensive and possibly more dangerous if overheated.
Just my thoughts.

 

[ICindrich]

Instead of using a pressurized tank you could use a plate exchanger and a circulator pump to transfer the heat from your pressurized boiler to an unpressurized storage tank, and back again. As long as the water is circulated through the plate exchanger, it will try to equalize with the boiler loop. A large pressurized vessel is expensive and possibly more dangerous if overheated.
Just my thoughts.

A superstore tank keeps the domestic hot water at street or well pump pressure and keeps the water hot with a heating loop running on its own zone from the boiler. This could be accomplished with a propane tank and a domestic loop from an scrap oil or propane burner. I would then stash the whole thing in a wood box and stuff it with pink insulation.

 

[loganj01]

I missed the "pressurized" part...obviously an EPDM lined tank wouldn't work for that.