That is the assessment of Marc Blauvelt of Bluefield Supply, Grand Rapids. Blauvelt recently addressed the Grand Rapids Chapter of the American Indoor Air Quality Council. His topic was "Utilizing Ventilation and Monitoring for Proper Indoor Air Quality."
"Ventilation systems make up about 40 percent of pollution emission sources," said Blauvelt. "Circulation of air can eventually wear down coated surfaces of ductwork, creating porous surfaces which can capture and hold moisture."

In addition, poor IAQ results in increased levels of allergies and asthma.
"The number of cases of asthma has increased 75 percent between 1980 and 1999," Blauvelt said. "More than 17 million Americans suffer from asthma. Annually, 5,300 Americans die from asthma."
He quoted a report from the Johns Hopkins School of Public Health, which concluded, "America is in the middle of an asthma epidemic - an epidemic that is getting worse, not better."
Blauvelt pulled an inhaler out of his pocket, adding, "More and more people are carrying these around."
"Typically, the rooftop units on these older buildings don't get the attention they need," he said.
Blauvelt noted that leaky ductwork and poorly maintained mechanical systems lead to negative pressure inside buildings, reducing the airflow and increasing the number of unhealthy airborne particles, which remain "undiluted." By bringing in more outdoor air and creating positive pressure, "You can decrease the occupant dissatisfaction rate," Blauvelt said.
He jokingly suggested that the government should "issue every building occupant a biohazard suit," but said there are some basic solutions to poor IAQ, including providing adequate airflow to each occupied zone to dilute harmful contaminants and providing proper building pressure control.
"You also have to look at factors that affect dilution and airflow, even the wind factors on rooftop units," he said.
Publication date: 12/22/2003