My house is a stick built that is shaped like a double wide... It is 1000 sq. ft. heated and a 100 sq. ft. garage built to the end of the house, all under one roof... The end has vents at the peak of the roof line... Would adding a single fan to one end of the house, exhaust the hot air that builds up in the attic area cut cooling cost in the summer? The attic is fully covered with 10" fiber insulation (blown in style) on the ceiling/floor...
What about blocking the vents off in the winter, would that help on heating? There is only a 18" x 18" crawl space to enter the attic, no other openings to that space...

I would only add one fan to one end of the roof and leave the other end a free flow... The attic actually gets around 120 degrees in the extreme summer, if not hotter... Would I notice a difference in the actual living space below as far as cooling? My heat pump struggles to keep 79F in the extreme summer temps, and I have had it checked out...