I have a question regarding sizing of wholehouse fans. PG&E and DOE calculations show that the volume of the house should be divided by 2 or 3 to get to the CFM needed. So for a 2500 sqft house, with standard ceiling height of 8ft, we need ~10000 CFM fan. Some other commercial web sites recommend much lower than that, maybe 10 or even 15. Which one makes more sense? I think the higher is better, but they're bigger, need more attic ventilation area, ...

Also any recommendations for latest types/models?

I live in San Francisco bay area. Any referrals for whole house fan installers? Can people who have it installed share their experience?