I live in LA and summer can get to the low 100s. In the evenings though the temperature can dip into the 60s.  So I though of venting out the heat and drawing in the cool air, at night and early morning. I installed this in one of the casement windows in my house.  The way I installed it allowed for the window to be closed without taking down this fan.  So at night, I turn this on and vent out the hot indoor air, and it creates a negative pressure in the house so it sucks air through my front door and windows of the other bedrooms. It does create a cool breeze as it is drawing in the cooler fresh air.  I have not turned on my Air Conditioner since I installed this.