Mold Growth on Univent Classroom heating and cooling units, called univents, always located at the exterior wall of a classroom, are rarely cleaned. During the hot and humid summer, when the classroom is closed up, mold often grows in the dust. When the blower operates in the winter, mold spores are blown into the classroom.

The Sick School © 2008 Jeffrey C. May, M.A. John had been a teacher in the same classroom for four years. He loved teaching but this was to be his last day, because he felt that he had become allergic to his classroom. The school was about 30 years old, and the classroom heating equipment had never been cleaned. (Comment: The heating equipment contained large clumps of dust that had been there for decades. Much of the dust contained growing mold. John sealed all the openings and vents for the heating unit, and he was able to complete the year.)

Jeffrey C. May is a building consultant, Certified Indoor Air Quality Professional (CIAQP), and author of My House is Killing Me! The Home Guide for Families with Allergies and Asthma (2001) and My Office is Killing Me! The Sick Building Survival Guide (2006), as well as co-author of The Mold Survival Guide: For Your Home and for Your Health (2004) and Jeff May's Healthy Home Tips (2008), all published by Johns Hopkins University Press. A former educator and organic chemist (M.A. Harvard University), Jeff is principal scientist of May Indoor Air Investigations LLC in Tyngsborough, Massachusetts.