In thinking about building a water storage tank for my radiant floor, I was wondering which design would be more efficient:
1. insulated wood tank, such as this one:
$2K Solar Space + Water: Storage Tank Design
2. tank that's built into the ground, but lined with the same insulation as used in the above design.
I would think that #2 would end up being more efficient, since the outside surrounding temps would be closer to 60 degrees, rather than lower temps during the winter, as in above-ground design.
suggestions?