Rodabaugh said the HVAC system is often at fault for poor IAQ because of improper design, lack of maintenance, or improper remodeling. He mentioned that homes are often remodeled many times without any consideration to modifying the HVAC system to adapt to the changes. He said, "One of the first things you should look for is any unauthorized modification of a building."

Contractors should ensure that building systems maintain 15-20 cubic feet per minute (cfm) per occupant, with higher levels in areas like bathrooms and elevators, according to Rodabaugh. He also suggested adding high efficiency particulate arrestance (HEPA) filters to equipment and air-to-air heat exchangers with fresh air entrainment.

That being said, Rodabaugh told MIACCA members they should test the air in their customers' homes. The problem is that most of the time contractors don't have the expertise or equipment to do so. "In that case, call in an IAQ consultant," he said.

But there are things that contractors can do on their own, such as testing for proper levels of carbon dioxide, which indicate adequate fresh air in a building. "Normal inside readings should be in the 370-450 parts per million (ppm) range," Rodabaugh said. "Anything above 1,000 ppm indicates a problem.

"Showing customers that they have a problem and convincing them to fix it is still the hard part," concluded Rodabaugh.

Publication date: 09/04/2006