Can running fans really lower your AC bill? Here's what experts say

Here's when fans can help reduce cooling costs—and when they're just using extra electricity.

With the arrival of summer's warm days come family BBQs, a garden in full bloom, and afternoons spent by the pool. But the heat also increases home energy bills as people run their air conditioners around the clock to keep cool. Turning on ceiling, tower, and pedestal fans can also help people feel cooler—but especially with ceiling fans, can they actually lower your cooling costs?

We consulted HVAC experts and a licensed energy broker to find out.

"Ceiling fans provide additional airflow to help keep you comfortable in your home," says HVAC expert Patrick Gambel. "For example, when your thermostat is set to auto, your AC isn't constantly blowing air through your vents. A ceiling fan helps keep air moving throughout the room so the room doesn't feel as stuffy."

Read on to learn whether running fans can help reduce your AC's energy use, plus additional tips for keeping energy costs down while maintaining a cool and comfortable home all summer long.

Meet Our Expert

• Patrick Gambel, owner of General Heating & Air Conditioning
• Lane Martin, co-founder of Modern PURAIR, an indoor air quality service
• Michael Strickland, licensed energy broker

Related: Should You Turn Off Your AC When You Leave the House? Here's What Experts Say

How Fans Reduce AC Costs

All fans may reduce AC costs by moving air throughout your home, allowing you to feel cool while keeping the thermostat at a higher temperature—but a ceiling fan can really make a difference.

"A ceiling fan will help to move the conditioned air around the room," says co-founder of Modern PURAIR Lane Martin. "And although it doesn't lower the temperature, you will feel a noticeable difference."

But to see these savings on your energy bill, you need to raise your thermostat setting. "Savings come from raising the thermostat when using the fan," explains licensed energy broker Michael Strickland. "For every degree the thermostat is raised, cooling costs drop by 3 to 5 percent."

According to the U.S. Department of Energy, ceiling fans are the most effective type of circulating fan for improving comfort. Using a ceiling fan lets you raise your thermostat by about 4 degrees Fahrenheit without sacrificing comfort. "This translates to 12 to 20 percent off the cooling portion of the bill," Strickland says.

When Leaving Fans On Isn’t Efficient

Running your AC and ceiling fan at the same time won't make the room any colder than the AC can on its own. Instead, the fan circulates the cooled air and creates a wind-chill effect that helps you feel cooler while you're in the room. For this reason, there's no benefit to leaving ceiling fans running in empty rooms. "A big mistake I regularly see homeowners make is leaving fans on constantly in unused rooms," says Martin. "It won't help to cool the room like an AC and will just use electricity unnecessarily."

The Best Way to Use AC and Ceiling Fans Together

Knowing how to use your AC and ceiling fans in tandem correctly is critical in keeping your home cool and your energy bills down.

Adjust Your Thermostat

As stated, you must adjust your thermostat to reap the energy-saving benefits of this technique. Strickland recommends raising the thermostat by two to four degrees when your fans are running. "The extra airflow from your ceiling fans can help you feel cooler, so you might not feel the need to lower your thermostat as much," Gambel adds.

Run Ceiling Fans Counterclockwise

Most ceiling fans have a direction switch, and setting them to counterclockwise during summer will help push warm air up and cool air down. "This creates a breeze that helps you feel cooler, even when the thermostat stays the same," says Gambel. Setting your fans in this direction will help compensate for a higher thermostat setting.

Focus on Frequently Used Rooms

Focus ceiling fan use in the rooms you spend the most time in, says Strickland. "The bedroom tends to matter most," he adds. Remember, ceiling fans don't cool a room. They move air, creating a wind chill effect that makes people feel a few degrees cooler. "This trick only works when someone is in the room," he notes. "Running a fan in an empty room is a waste."

Other Easy Ways to Reduce Energy Costs During Summer

You are not powerless when it comes to your energy bill. "I often see homeowners focusing solely on the thermostat while overlooking everything else," says Martin. "The thermostat is only one piece of the puzzle. Airflow, maintenance, window coverings, and reducing heat gain all play a part in how hard your air conditioner has to work." As you go about your day, these small habits can result in a lower HVAC bill at the end of the month.

• Replace the air filter regularly: "A clogged filter restricts airflow and forces the system to run longer to do the same job," says Strickland. "It is one of the highest-impact maintenance tasks and one of the most commonly skipped."
• Seal gaps around doors and windows: Sealing gaps helps prevent cool air from escaping. "It is unbelievable how much heat can enter the home just from a few gaps," says Martin.
• Ensure vents are open and unobstructed: Keep supply vents open and furniture at least 3 feet away to avoid obstructing them, says Gambel. This allows your AC to cool your home evenly.
• Close blinds and curtains: "Closing blinds or blackout curtains can reduce indoor heat by up to 25 to 60 percent (depending on the window covering and how tightly it fits)," says Martin.
• Use exhaust fans: Take advantage of kitchen and bathroom exhaust fans to remove excess heat and humidity when needed.
• Create a DIY ice bucket fan: Gambel recommends placing a bucket of ice in front of a tower or pedestal fan to create cool air. "It's good for small rooms at creating some extra direct cold air, but definitely doesn't work as well as your AC system," he notes.
• Use box fans strategically: "A box fan positioned to exhaust hot air out of a window rather than just circulate it can lower indoor temperatures meaningfully during cooler transition periods," says Strickland.
• Check that the outdoor condenser unit is stable and level: "A unit that is tilting, sinking, or has shifted off its pad puts stress on refrigerant lines and shortens system life," says Strickland.  
• Schedule annual HVAC maintenance: It is all too common for homeowners to skip maintenance in hopes of saving money. However, Strickland says a dirty filter or uncleaned condenser reduces your system's efficiency, which can raise energy bills.

Read the original article on Martha Stewart