does anyone use a hole house fan, the kind that installs in a hallway & works on a thermostate to pull air out of the house & thru the attic? gordon reid

You know, I wish I had one.  We have warm days, and cool nights most of the summer, usually with low humidity.  We use 3 box ($20 each) fans running all night and it works very well.   You could try this as a test to see how a whole house fan might work for you. 

I grew up in a house that had a whole house fan.  That was in the northwest corner of Ga where the heat and humidity is not ideal for such a unit, but it was still great. I now live in a dryer climate in the Panhandle of TX, and If i ever build a house, I am going to try to incorporate such a unit somehow.  It is certainly ideal in dryer climates to quickly cool a house, and the fresh outside air is fabulous....if you are not horribly plagued by allergy problems.