I'm not complaining about my attic fan working as well as it does. I
just don't know a lot about home construction and I don't know why the
fan is so effective.

We have a ranch-style home with an unfinished attic. There are gable
vents at each end of the attic. The fan is in one of the vents, the
other one is open.

The attic floor is covered with deep insulation, fiberglass, I think.

I understand that the purpose of the attic fan is to exhaust the air
that's been heated by the sun shining on the roof, and replacing it
with the relatively cooler air from outside.

With the central air conditioning running, turning on the attic fan
can cause the house temperature to drop two degrees (maybe more; we've
never tried it because the two degree drop is fine).

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