Used the 6x100 to do two layers against the 2500 gallon water tank, then two layers of 2 4x8 foam board, two more layers of this 6x100 roll foil foam foil, then 3 more layers of 2 x4x8 on. Making the total insulation thickness 11 all with taped joints.
This was done on all 6 sides ( bottom, sides, ends and top.) causing a heat loss of 1 degree in 28 days. A NASA design, done with thermo couples between all layers.
Recorded. This is our MTS (mass thermal storage) of aprox 30,000 lbs for winter
Radiant heat stored. Max temp obtained was 172 degrees. (Radiant runs 110-130 degree. Abode in New Hampshire. All your hot water and heat. Replenished with a
4.5 meter (14) solar Concentrator SolarBeam by solartronenergy.com.