Use Ceiling Fans With or Without AC
Ceiling fans help cool you when the AC is off, and when it’s on, fans can make it more comfortable to keep the thermostat at a higher temperature. According to Alex Wilson, “All other things being equal, a breeze will keep you a lot cooler. If you’re normally comfortable at, say, 72 degrees, using a ceiling fan or oscillating desk fan may enable you to be just about as comfortable with an air temperature of 75 to 80 degrees -- because the moving air evaporates moisture from your skin. Note that fans don’t actually cool the air (in fact, they increase air temperature slightly from the motor’s waste heat), so turn them off when you leave the room.”
Weiner says that ceiling fans, which use much less energy than AC systems, can make you feel up to 4 degrees cooler.