Gary's solar thermal tank for Thermal storage

[Mike in Maine]

Have decided on using this link for "Gary's" simplified Thermal storage design. Something even I can build. Just want to float the matter out there to see if anyone has any suggestions or caveats. before setting down to the supply list...
I will use copper coils to indirectly draw from the stored heat energy for Domestic Hot water and Baseboard Heating here in cold cold Maine. Will probably try to make it the full 4X8 size for the bit of additional capacity ~700gal (1500sq ft home). Would it be more practical/beneficial to use a copper coil to indirectly transfer the heat energy into the tank... or just to circulate the higher temp water right from the boiler into the actual water in the EPDM lined storage tank? My younger Furnace guy who is an experienced oil furnace installer is new to this storage tank thing but is willing to do the plumbing and has a relation who has a similar thing goin'. (any experienced ideas on coil suspension or connections through into the tank would also welcome)

God Bless/Thanks
Mike in Maine


http://www.builditsolar.com/Projects/SpaceHeating/SolarShed/Tank/Tank.htm

 

[WoodNotOil]

Most boilers have a closed system which would run through a coil or plate hx to transfer heat to an open tank like that design. If your boiler is a closed system, you cannot put the water into an open tank directly. Here are two threads where we are currently hashing out the costs and effectiveness of plate hx vs. building/buying coils:

https://www.hearth.com/talk/threads/18452/
https://www.hearth.com/talk/threads/14559/

I think sparke made a plywood tank similar to that one. Good luck.

 

[diyer]

I am thinking about a vented ferrocement tank. The best structure for a tank is a sphere, or at least a cylinder. The least amount of surface area (heat lost) is a bubble. Anything long and rectangular has more surface area and higher losses.

Has anyone tried hot storage in a ferrocement tank? It seems like a quick/cheap solution.

thanks,

Carl