Whole House Attic Fans ??

[vincewarde]

Evaporative coolers do that far more, and they're everywhere out here. My attic is not connected to the living area by any vents. In Lake Havasu I had a Mastercool evap cooler with up duct discharge. (Without up ducts you have to have windows open to allow air to exit the home or you will pressurize the interior). With up ducts it discharges the cooled air into your attic and out the attic vents, cooling it to near the inside temp.

The problem with evaporative coolers is you can't run them if the dew point is over 55%, or you will muck up the house with too much humidity. That's why I just have A/C in this home. But all this attic fan will do is exchange cooler outside air into the attic, replacing hot air trapped in the attic. I'm not seeing how dust would be a factor inside the house?

+1 on all of the above.

I would add that the effectiveness of coolers is directly linked to the humidity.  When I lived in CA I installed one to save on air conditioning costs.  Our humidity typically was about 15% and the cooler worked well up to about 92-93 degrees - then we would have to resort to the A/C.  In desert areas, with very low humidity you can get as much as a 35 degree reduction in temperature, which means you can use them all the way into the low 100s.  All in all, they are a good way to save on energy.

Last of all, the biggest mistake people make with coolers is not opening enough windows.  You need to allow the cooler to push the hot air out and replace it with cooler air.