re: cheap thermal storeage
28 nov 2005
jeff thies wrote:
>>>i am planning to just dig the hole in a basically rectangular shape
>>>with sides that have about a 60 degree tilt.
>> you might make a tank about 3' deep x 4' wide that way, by folding up
>> a single piece of 10'-wide epdm.
>so, for vertical walls and 4' long, 48 cubic feet and a bit less than
with a 10'x16' piece of epdm, which can stretch about 100%. this might
work for 60 degree walls.
> with a 20degree f cycle, nearly 60,000 btu
>one big "tank" or several smaller ones?
gary might make his shed tank 20' long, with a 10'x24' piece of epdm
and 240 ft^3 storing 240x62(170-80) = 1.3 million btu of useful heat.