Unlike air conditioners, ceiling fans don’t change the temperature of the air in a room. Instead, they simply cause it to circulate. In summer, the movement of the air causes perspiration on the skin to evaporate more quickly, aiding the body’s natural cooling mechanism. Ceiling fans can be useful in winter too, by helping to distribute hot air from heating systems around the room more evenly; hot air will naturally rise and hang in a layer at the top of the room, meaning the central heating needs to be set even higher to heat the lower levels of the room, where humans spend their time.
The most basic ceiling fans only offer on and off settings, but many have built-in lighting, variable speed settings, or remote controls. Some brands even adjust their speed in response to temperature changes in the room.
When buying, check that the fan comes with all the necessary mountings – and of course that your ceiling is strong enough to support the weight. If in doubt, consult a professional.
One major advantage of ceiling fans is that they make the air feel cooler than it actually is. Since you can therefore run your AC at a slightly higher temperature, you’ll save on power bills. Similarly, in winter you can turn the thermostat down a few notches because the hot air is recirculated down from the ceiling, instead of leaving all the cold air hanging at floor level. But spare a thought for the ceiling fan’s power consumption: Look out for the Energy Star logo, which guarantees energy efficiency and can save you up to 25 USD per year.