Troubleshooting IAQ Complaints
Typical Problems and Potential Solutions BY D. JEFF BURTON
Indoor air quality problems are often driven by occupants’ complaints. NIOSH studies suggest that the heating, ventilating, air conditioning system itself is the source of about half of all IAQ complaints.

Below are 10 common complaints, their associated HVAC-­related problems, and potential solutions. Many problems are obvious and simple to correct. Others may require expert assistance. For most IAQ complaints, the old adage applies: “When you hear hoofbeats, think of horses, not zebras.” Investigate the simplest explanations first, then expand your study until you (or your expert) find the problem and its solutions.
In this article, “OA” stands for outdoor (fresh) air and “SA” stands for supply air, which consists of RA (return air) and OA. See Figure 1 for a diagram of a typical HVAC system.
D. JEFF BURTON is an IH engineer with broad experience in ventilation used for emission and exposure control. He is the author of many books and training courses, and is current chair of the ANSI Z9.2 and Z9.10 subcommittees. His full biography can be found online. He can be contacted via email.