For optimal cooling during the summer, air should blow straight down rather than up toward the ceiling. Running your ceiling fan in a counterclockwise direction will do the trick. The airflow produced creates a wind-chill effect that makes you feel cooler. Be sure to adjust the fan speed as the weather heats up: the warmer the weather, the higher the speed. And remember that you can set your AC thermostat a little higher when you're running ceiling fans.