Question:
you never have a differential of temperatures by heating an
>outdoor pool of 5¡ãC per day, haven¡¯t you ?
Answer:
A 6' deep pool with 384 Btu/F-ft^2 of thermal capacitance and
a solar cover that transmits 2500x0.5 = 1250 Btu/ft^2 of sun (a clear
May day where I live) gains at most 1250/384 = 3.3 F on the first day,
if it's perfectly insulated, less on the 2nd day, and so on.
(I measured a sample of the Deluxe Solar-Cell Sunblanket (TM) from
"The Pool Cover Experts," Century Products at 171 Medford Street/
Malden, MA/02148 (800) 225-3472. "Saves Energy! Raises water temp
10 degrees or more in season, without running your heater.")
