I'm considering having a couple of powered attic vents installed. Despite a lot of anecdotal evidence, I'm not sure how much difference they'll make to the temperature inside the house. We live in a high desert environment (Carson City, NV); the single-floor house is 11 years old, and is quite well insulated. It has 2x6 exterior walls which are full of fiberglass, and there is about a foot of blown insulation in the attic. What's giving me pause is some measurements I've made with a handheld infrared thermometer. Readings taken at 3 PM and 8 PM show only one-to-two degree difference between interior walls, exterior walls, and the ceiling, even though it does get quite hot in the attic. Will one or more attic fans make a significant difference in the indoor temperature?

Thanks,
Jeff