This Old-Fashioned Trick Can Slash Your Summer Cooling Costs

Updated August 5, 2020
posted on 06-07-2019


This past Memorial Day - a scorcher in Chicago - Jim Chilsen and his family returned home to find the second floor of their bungalow, where the bedrooms are located, was suffocatingly hot. So hot, Chilsen recalls, that his son and daughter wouldn’t have been able to sleep.

But then Dad came to the rescue: Within an hour, and without central air-conditioning or even a room air conditioner, Chilsen cooled the upstairs so well that his daughter asked for a blanket.

Chilsen, director of communications for Citizens Utility Board, a nonprofit utility watchdog in Illinois, sees a lot of hot cooling tips cross his desk. The most effective ones, he says, cost little or no money to employ. 

"There's a myth that to save money, your last name has to be Trump," Chilsen says. "But one of the great secrets of energy efficiency is that there's lots you can do to save without spending money." 

Chilsen's low-cost, effective way to cool his oven-like second floor? Two $15 box fans. Here's how he did it:

  • He opened the doors to all of the bedrooms to let air circulate.
  • He opened the back bedroom window, and placed a fan in it, which blew into the room. That pulled cool evening air into the room.
  • He opened the front-bedroom window, and placed a fan in it. However, that fan blew out. That sucked the warm air out the window, while also drawing the cool air through the rest of the second floor.

This secret, he says, was well-known in the days before central air but fell out of favor. 

Indeed, fans are a budget's friend in the hot months.

The best friend? The fan on a central air-conditioning unit. Conditioning the air in a home -- cooling in summer or heating in winter -- can account for as much as 70% of a home's energy costs, says Lou Manfredini, home expert for the Ace Hardware chain. The condenser, though, eats the energy, not the fan. The fan efficiently and quickly distributes cooled air. 

Manfredini suggests setting a comfortable temperature of, say 74 degrees Fahrenheit, then setting the fan on "on" instead of "auto." A continuously running fan will distribute cooled air throughout the house, thus signaling to the thermostat that the house is cool. The condenser will cycle on less often, thus saving money. 

Used properly, ceiling fans have a cooling effect, too. The trick is to set the fan on reverse, so it looks like it's moving counterclockwise as you are standing under it. Ceiling fans move cool air around, which helps make air conditioning more efficient and creates a cool, breezy feeling, Manfredini says. 

The exhaust fan in the kitchen can also help cool a house. Use it when you cook on the cooktop, and at night, run it for a while to pull hot air from the home. 

Here are other inexpensive, effective cooling tips:  

- Easy Does It: Set the thermostat a few degrees higher, say at 75F instead of 72F. For each degree upward, you save 2% to 3% on energy costs, Manfredini says. And, he adds, don't set the thermostat at 65F in hopes of cooling the house more quickly; the unit cools air at the same rate no matter what the setting. A lower setting just makes it run longer and thus use more energy. 

- Stay Shady: It's tempting, especially after a long winter, to open up the blinds and let the sun shine in. Don't. Sunlight turns a room into a greenhouse, as windows and insulation trap heat inside. A dark room will stay cooler longer.

- Turn Off Lights: About 90% of the energy used by incandescent lights creates heat, not light, Manfredini says. Turn off lights when they're not in use. Better yet, replace incandescent lights with compact fluorescent bulbs, which use 75% less energy than incandescent bulbs.  

- Cook Out: Nobody wants an oven-baked casserole in summer.  Grill out, or feast on no- or low-cook salads and sandwiches. 

- Use Appliances Strategically: Run clothes washers, dryers and dishwashers -- all of which produce heat -- during the cooler evening or morning hours. 

- Practice Good Household Hygiene: Wash or replace air-conditioning filters every month, because clean filters works more efficiently than dirty ones. 

The Investing Answer: In summer, think first before touching that AC dial. Cooling costs in the warm months account for nearly half a home's energy bill. 

To chop that by at least 10%, use fans to draw cool evening and morning air into a home and hot air out. 

Make the job easier by keeping the interior of the home as cool as possible; keep hot sunlight out, use heat-producing appliances in cooler hours, cook as little as possible and keep lights off. 

The least expensive tip of all? Take it easy. Dress and eat lightly -- and stay hydrated with plenty of water  -- so your body feels cooler.