ATLANTA — Microbial growth in a residential HVAC system is both a common and expected occurrence. A frequent misunderstanding is the position that the identification of any mold inside an HVAC air handler poses a threat to air quality. This presentation on the proliferation, succession, and nutrient requirements of mold offers a valuable perspective on the occurrence of microbial growth inside an HVAC system.

Excessive mold growth, as demonstrated in case histories, often indicates irregular HVAC system operation and maintenance. Normal HVAC operations are recognized as dust accumulation, local condensation, and mold growth on papered surfaces. The complexities involved with HVAC operation that influence mold growth on integral mechanical parts and their influence on indoor air quality will be presented.