Betty Bost used to work in air conditioning. But she has never lived in it. Nor does she intend to. "We just don't want it," she said.

She'd miss bird songs in the morning, the crickets at night.

"The first thing I notice when I go into someone else's house," Bost said, "is the silence."

Betty Bost, 62, and her husband, Jim, 65, live on 20 acres in Kannapolis, N.C. They have lots of shade trees. They use an attic fan to pull in night air from the woods. Their house is airy, with a cool front porch.

Brian Hardy of Gastonia, N.C., also prefers fresh air, as opposed to "living in a closed-in box with recirculated air." He calls air conditioning "an unnecessary evil" and designed his house to stay cool naturally.

Most people wouldn't even think of living in a home without air conditioning. But some insist summer is better with the windows open - even if you have to alter your home and lifestyle.

Forty years ago, only 10 percent of U.S. homes were air-conditioned. Now, at least in the South, only 10 percent of homes don't have air conditioning.

The history of air conditioning goes