Fans are one of the oldest and most reliable mechanical means of cooling a home, and they use far less energy than an air conditioner. In fact, you conceivably could run several fans and still consume a smaller amount of energy than you would by running a single room air conditioner.
However, fans don’t cool rooms the same way an air conditioner does; instead, fans create a cooling effect by moving air across your skin. So, opening the windows and using one or more fans during very hot and humid weather won’t be an effective cooling strategy– especially if you’re accustomed to using an air conditioner most of the time. Your cooling costs might go up, because opening the windows will increase the humidity your airconditioning unit needs to remove, forcing the system to run longer than normal.
Window fans and whole-house fans are the best choices for accomplishing power ventilation in your home. Smaller oor, table and ceiling fans are best used to create a single-room “wind-chill” effect and are much less e ective as whole-house ventilators.
No matter what type of fan you need, when you go shopping look for a one that’s ENERGY STAR® qualifed. Ceiling fan/ light combination units that have earned the ENERGY STAR are about 50 percent more efficient than conventional models. Also be sure to look for a model with a high-quality motor and a long-term warranty, to choose a fan with a low noise rating and to consider a fan with “airfoil-style” blades that are designed to maximize air flow.
- A ceiling fan will allow you to be comfortable at a higher temperature in occupied rooms and let you raise the thermostat in those areas. A good ceiling fan should create enough air movement that you will be comfortable at 82 degrees and 80 percent relative humidity. If you’re using the fan to supplement or circulate air-conditioning, you should be able to raise the thermostat a full four degrees and still be comfortable. For every degree you raise your air conditioner’s thermostat, you’ll save about three to five percent on your cooling costs.
- Choose the correct ceiling fan for damp or wet areas. For a bathroom, buy a fan that has been U.L. listed with a damp rating. For a location where a fan might come into direct contact with water – such as a porch – select a fan with a wet rating.
- Use the appropriate ceiling fan mount and downrod length for the slope and height of your ceiling. Mount the fan as closely as possible to the middle of the room – at least seven feet above the oor. If the ceiling allows, a height of eight or nine feet is better for optimal air ow. A “hugger” fan, which mounts ush to the ceiling, will not move as much air because its blades will be just a few inches from the ceiling.
- Set the direction of ceiling fans for proper air circulation. Run ceiling fans in a counterclockwise direction – as viewed from below – during warm weather months.
- Use window fans to create crossventilation on warm, still days. Open windows on the shady side of your house and position the fans so they blow air out of windows on the hot side of the house. Be sure to tie back curtains so they don’t get into the fan.
- On a cool, low-humidity night, a whole-house fan can cut the temperature in your home by up to 20 degrees in a relatively short time. A whole-house fan pulls the cool outside air from open windows on the lowest living level of your home into the attic, where warm air is vented to the outside. This type of fan usually is installed in a hallway ceiling on the top floor of your house.
- A small fan is not adequate for cooling large areas. An oscillating fan, box fan or table fan are good choices for one-person cooling, circulating the air in a small room or extending the cooling range of a window- or wall-mounted air conditioner.
- Remove heat, humidity and odors from the kitchen and bathroom with a properly sized exhaust fan. Don’t leave an exhaust fan on longer – or at a higher speed – than necessary. In one hour, an exhaust fan can blow a houseful of cooled air outside.