"LenS" wrote in message

My question is how does the fan make this much difference with all
that insulation between the attic floor and the house ceiling? Is the
fan somehow removing warm air from the living quarters? Is there a
stack or vent or something that leads from the house into the attic
through which the fan might be exhausting warm air from the house?

Any comment will be appreciated.

-Len

Not actually taking heat from the house, but preventing it from entering.

First, there is "heat". There is no such thing as "cold", but merely the
absence of heat. If the attic is very hot, the heat energy is going to go
to any place that is cooler. That is your air-conditioned living space.
In spite of all the insulation, heat will still seek cooler places. (with
less insulation it would be worse) Removing the heat from the attic, it
goes and heats the outside air and thus, the AC has less work to do.

Look at how a solar panel works. Your attic is just a big solar panel, not
as efficient as one designed for that use though, but still the same
principal applies.
--
Ed
http://pages.cthome.net/edhome/