So I decided to setup a digital thermometer that has dual zone capability. Typically these are used for indoor and outdoor measurements but I set my system up to measure my attic temperature and either the indoor or outdoor temperatures at my home in Temecula.
Even now on a nice Temecula evening while the temperature is a beautiful 71 degrees outside at 7pm my attic is still 90.8!
I ran my Trident 5.5 Pro whole house fan on high for about an hour and the attic temperature dropped from 90.8 to 77.1 degrees.
13.7 degrees cooler might not seem like a huge achievement until you realize that the thermal mass heating effect in your attic will continue to radiate heat down into your living space for hours and hours as it slowly cools down by the passive venting found in most homes.
I ran the fan for another hour and it lowered the attic temperature to 71 degrees which was about the same temperature as the bedrooms upstairs.
Whole house fans can lower not only your attic temperature but your homes interior temperature dramatically in a very short time.