You could create a mood reminiscent of “Casablanca” with a ceiling fan whose blades move so slowly that they barely break up the clouds of smoke in the room.

But when it’s warm or sweltering outside, who cares about evoking nostalgia? You want to stay cool, and a ceiling fan can serve as an ideal companion to your central air conditioner because the fan can help you save money on your electric bill at the same time. Just be sure that you turn up the speed to “medium” or “high.” It may be a decidedly un-Bogie-like look, but it’s an efficient one.

Charlie’s Tropic Heating & Air Conditioning has been sharing practical tips like this one with homeowners in northeastern Florida since we opened our doors in 1998. Since then, we’ve noticed that people either tend to gravitate to the look and aura of ceiling fans or they don’t. But people in the latter group often reconsider their decision once they understand how ceiling fans function.

Fans cool people, not rooms

Ceiling fans provide ventilation, similar to when you open windows on opposite sides of your home to circulate air. While table-top and floor fans also push air around, they can’t compete with the cooling power of ceiling fans.

Ceiling fans produce something that meteorologists talk about: a wind-chill effect. (http://energy.gov/energysaver/articles/fans-cooling)This effect explains why you might shudder or even reach for a sweater while you’re sitting directly below a fast-moving fan. To create a wind chill, the blades on a ceiling fan must turn in a counterclockwise direction. (In the winter, the blades should be reset to turn in a clockwise direction so that they push warm air down from the ceiling.)

The wind chill quotient leads many people to assume that a ceiling fan reduces a room’s temperature. But this is a misconception. The wind chill from a ceiling fan absorbs moisture from your skin, which makes you feel cooler. But a fan will not reduce a room’s temperature, not even by 1 degree.

This “cold, hard fact” has practical repercussions: It doesn’t pay to keep a ceiling fan running while no one is in a room or even at home because there is no tangible benefit besides the calming, appealing look of rotating blades. Ceiling fans cool people, not rooms.

Charlie’s Tropic Heating & Air Conditioning can help you choose and install an Energy Star ceiling fan, which will generally move about 20 percent more air than other models. It’s a choice that will compound your energy savings – and possibly inspire a Humphrey Bogart-like double-take from everybody in the room.