short cycling does add to utility costs.
start up of compressor uses more amps than
running of compressor.
if the unit comes on and stays on for a long period
of time it costs less than one that starts and stops
several times in the same length of time.
short cycling adds to high humidity in that the
unit doesn't run long enough to remove humidity.
not familiar with the polar foam. open cell, closed cell?
new home with foam as only insulation, is how I read the
original post. is this correct?
were any load calcs or correction of rule of thumb sizing
used in a foam sealed house with foam sealed unvented attic?
this seems to be the big disconnect with foam insulation companies
and hvac companies.
best of luck.
The cure of the part should not be attempted without the cure of the whole. ~Plato