Chances are, your home’s air conditioner is getting a workout this time of year—and driving your home’s energy use.
It pays to cool your home efficiently, whether you enjoy the money-saving benefit of rooftop solar, or rely solely on a traditional utility. So, avoid falling prey to these myths.
MYTH 1: Cranking the thermostat way down cools the house faster
FACT: Your thermostat doesn’t work that way. All it does is set a “target” temperature for your air conditioner to cool to.
Take this example. Say two of your neighbors have identical homes with identical, well-maintained central air conditioning systems. Both homes are at 88 degrees Fahrenheit one afternoon. One of the homeowners sets her thermostat to 78. The other sets his to 65, thinking it’ll reach 78 faster.
Which house cools faster? Neither. Fact is, both homes should reach 78 at the same time. The second homeowner, however, has a problem if he forgets to reset his thermostat when his home becomes comfortable. His air conditioner will continue to work—and use electricity—until it’s a chilly 65 degrees.
RECOMMENDATION: Set your thermostat to a comfortable temperature (Energy.gov recommends 78 degrees) and let your air conditioner do its job.
MYTH 2: Using a fan helps cool a room
FACT: A fan won’t actually cool a room. However, it will cool you, through the wind chill effect. According to Energy.gov, running a fan can let you raise the thermostat about 4 degrees—saving electricity otherwise used by your air conditioner—with no change in comfort.
RECOMMENDATION: Keep the fan off when you’re not in a room, then switch it on when you enter. And, make sure ceiling fans run counterclockwise in the summer to direct air downward.
MYTH 3: Leaving the air conditioner running all day is more efficient that making it “catch up” when you get home
FACT: Running the air conditioner all day long … while the price of electricity peaks … to cool an empty house? The math simply isn’t in your favor.
RECOMMENDATION: Adjust the thermostat to keep the house 10 degrees warmer during the day, then set it to a comfortable temperature when you get home.
Even better, install a programmable thermostat. Set it to adjust the temperature a half hour before you return, so you walk into a comfortable house. Energy.gov estimates a programmable thermostat can save you up to 10 percent on your energy costs.
MYTH 4: Closing vents in unused rooms boosts efficiency
FACT: Modern central air conditioning systems are designed to operate most efficiently with all the vents open. In fact, keeping vents closed can cause additional wear and tear to your system.
RECOMMENDATION: Keep vents open throughout the house. If you do need to cool a single room, or a set of rooms, consider a zoned mini-split system.
MYTH 5: Keeping windows and doors closed is all you need to do to keep cool air in
FACT: Keeping windows and doors closed is a good place to start. But your home could be losing air in a variety of other ways.
RECOMMENDATION: Energy.gov advises two tactics: Insulate and seal your ducts, as air loss can account for up to 30 percent of your cooling system’s energy consumption. And, insulate your attic and seal cracks in your walls.
So, play it smart this summer. Know how home cooling works—and doesn’t work—to keep you comfortable and use energy efficiently.