A ceiling fan has been standard equipment for hot weather since the 1800s. By circulating air downward in a room, they make rooms feel about four degrees cooler on summer days. However, the great majority of ceiling fans have a switch that reverses rotation of the fan, making them useful in winter, too. Instead of circulating air downwards, clockwise rotation in winter draws air up from below, blending it into warm air that naturally collects at the ceiling. The warmed air is driven out to the walls and then pushed back down into the room. This distributes heat more evenly around the room and reduces heat loss through the ceiling. A ceiling fan uses about as much electricity as a 100-watt light bulb but can cut energy consumption in a room 10 percent by allowing the furnace to run less often or at a lower level of operation. Fans can also be placed on the ceiling above stairwells to prevent heat migration from lower floors to upper floors in winter.
Ceiling fans are designed to move large amounts of air at low velocity. Blade length and pitch are more important than motor speed. Here’s how to size one for any room in your home:
- A ceiling at least eight feet high is required for a fan installation. Center the fan in the ceiling with at least 18 inches of space between the fan and the wall.
- Size the fan by blade length. Blades up to 44 inches are appropriate for rooms up to 225 square feet. For rooms larger than this, blades up to 60 inches are suitable.
- Blade pitch, the angle at which the fan blade meets the air, is also important for adequate circulation. A slow-speed fan with a blade pitch of 14 degrees creates the most circulation without blowing papers or disrupting activities in the room.
- Use the lowest speed setting with the directional switch at the clockwise setting for winter.
Donald P. Dick Air Conditioning has served Fresno area homeowners with heating and cooling expertise for more than 40 years. Contact us for more information on installing a ceiling fan to increase home comfort all winter.
Our goal is to help educate our customers in the greater Fresno, California area about energy and home comfort issues (specific to HVAC systems). For more information about ceiling fans and other HVAC topics, download our free Home Comfort Resource guide.
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