A strong fan is not a new cooling system. It's a "blower door" that helps find hidden air leaks during a home energy audit.
"We'll suck on the house and depressure it so air when all the doors and windows are closed comes in through all the places that you wouldn't suspect it would like through recessed lighting, certain areas of the walls, fixtures, things like that," said Corbett Lunsford, Green Dream Group.
And places like basements. One device shows cold air seeping into the living areas. Technicians from the green dream group also use an infrared camera to take pictures of deficient insulation behind walls and other areas of heat loss.
It's problems like that that are revealed in a home energy audit. Homeowner Carol Clennon decided to have one before making renovations.
"If you're going to use energy to heat your home, you should be doing it as efficiently as you can because otherwise you're wasting it," said Clennon.
The energy audit also tests major appliances, including the furnace and water heater.
"We'll test the combustion appliances for temperature, efficiency, carbon monoxide content," said Corbett Lunsford, Green Dream Group.
They also do what's called "zonal pressure testing" to make recommendations for areas that can be tough to heat -- like basements and attics. In this attic, so much heat is escaping, they recommend insulating the floor rather than the roof.
"To know that your house is insulated, to know that there's none of this sort of cold air seepage, to have the idea in your head that you're not heating the outside like your mom used to say, 'close the door, you're heating the outside,' that means a lot," said Clennon.
A home energy audit like that one can range in price from about 500 to a thousand dollars. Make sure the company you chose is nationally certified and possibly a member of the Illinois Association of Energy Raters.www.ilenergyraters.org