Bridget Bowan, left, and Laura Lutz, both of Topeka, talk with fair-goers about compact florescent light bulbs Sunday, Oct. 19, 2008 at the Energy Conservation Fair at Free State High School.

Ryan Lewis, front left, and Sarah Hemme participate in the Sustainable Homes Tour in west Lawrence. The tour on Sunday, Oct. 19, 2008 was held in conjunction with the Energy Conservation Fair at Free State High School.

When those first high heating bills arrive this winter, Russ Rudy knows some places homeowners can point fingers.

Try the sliding glass door.

“It’s essentially 72 square feet of very little R value,” Rudy said, referring to the window’s thermal resistance. “The fact is most of us don’t really use the full 72 feet to see the view anyway, so it’s a huge energy waster that in my view doesn’t give us enough aesthetic value to justify the heat loss.”

Don’t have a sliding glass door? Then try pointing a finger at that recessed lighting. It, too, could be the site of heat loss, Rudy said, because in many cases, air leaks through and around the can lights.

“Warm air is finding its way up and leaking out through (the light), making the birds and the squirrels in the attic very happy and causing the snow to melt off the roof of the house,” Rudy said.

Rudy, training programs manager for the Metropolitan Energy Center in Kansas City, Mo., covered both home energy efficiency and inefficiency Sunday in a presentation at the Lawrence Energy Conservation Fair.

The daylong event drew more than 300 people to Free State High School, where nearly 40 exhibitors set up booths and half a dozen speakers covered a variety of topics, from climate change to solar energy.

The lineup included Kansas University law professor Robert Glicksman, who discussed scientific information on the causes and effects of climate change, and Kansas Health and Environment Secretary Roderick Bremby, who discussed Kansas energy policy.

The event also included a tour of sustainable homes, featuring energy-saving appliances and renewable energy building designs, materials, and construction methods.

Karen Flanders, a Lawrence resident who is a 4-H home and environment project leader, listened to Rudy’s talk with some young people involved in 4-H.

“There’s a lot of ways I think we’re losing energy that I didn’t realize,” she said. “I know I’ll go home and make some definite changes.”

Rudy displayed a slideshow featuring the both the good and the bad of home construction. He pointed to pictures of homes where there were gaps between the pieces of insulation and other problems.

“You add up all these little mistakes and you end up with a home that’s not efficient,” he said.

Rudy offered some energy tips. For example, can lights can be made more efficient by buying an airtight light, usually for about 5 percent more money, he said. Track lighting also is an efficient alternative.

When looking for ways to improve a home’s efficiency, Rudy said that upgrading the windows should be a low priority.

“If you’re looking for real performance, real energy performance, you can use that same $500 you’d use for 10 square feet of window to insulate 100 square feet of wall at a higher R value,” he said.

And he offered some inexpensive tips. Temporary plastic window insulators help, he said.

“When the sun is shining on a beautiful day like this, make sure you open your blinds on the south side, so that the heat of the sun comes in and helps warm your house,” he said. “Get heavy drapes and close them at night to keep the heat in. That’s very simple.”