While consumers fret this summer about rising gasoline prices, they may be missing the fact that their homes are also guzzling fuel.

The average family spends about $1,400 a year to power their house, about half of it for heating and cooling, the Department of Energy estimates.

There are many steps families can take -- some at no cost -- to keep home energy spending in check, said Rozanne Weissman of the nonprofit organization Alliance to Save Energy in the District.

"The average consumer can cut home energy use without losing comfort -- and help the environment at the same time," she said.

And the savings can be substantial. Set an air conditioner to 78 degrees, and it will cost one-fifth less to operate than maintaining a setting of 72 degrees, utility companies say. Also:

* Turn off lights, computers and other electronic devices when they're not in use.

* Use fans instead of air conditioners.

* Keep air conditioner filters clean.

* Close blinds or shades on south- and west-facing windows -- or plant trees outside -- to reduce the impact of afternoon sun.

* Take quick showers instead of baths.

Weissman said consumers also can save by taking advantage of new technologies that put energy efficiency on autopilot. "I have sensors in my office," she said. "When I walk in, the light goes on. When I leave, after a few minutes, the light goes off."

Similar motion or light sensors can be used in homes and outdoors to keep lights off when they're not needed, she said.

Weissman is also a fan of programmable thermostats, which can be set to turn air conditioners on when they're needed and off when they're not.

The Center for a New American Dream in Takoma Park urges families to replace standard light bulbs with compact fluorescent lights, not only to cut energy costs but also to reduce the release of carbon dioxide. The center also recommends some energy savers such as drying clothes on a line outside, grilling outdoors, and walking or biking to run errands.

When it is time to buy appliances, one way to determine their energy efficiency is by looking for the government's Energy Star designation.

Wendy Reed, a spokeswoman for the Environmental Protection Agency, which runs the Energy Star program with the Energy Department, said hundreds of products in 40 different categories carry Energy Star designations certifying that they exceed federal guidelines for energy efficiency. Even ceiling fans get Energy Star ratings if their motors are efficient and blades aerodynamic, she said.