Assessment of fungal (penicillium chrysogenum) growth on three HVAC duct materials.

Describes how laboratory experiments were conducted to assess the susceptibility of three types of ventilation duct materials to fungal growth. They were fibrous glass ductboard, galvanized steel, and insulated flexible duct. The results showed that only the flexible duct supported moderate growth of P. chrysogenum. The other duct materials showed no growth. Soiling with dust from residential heating and air conditioning systems increased the susceptibility of all three types, albeit at different levels of soiling, with the galvanized steel the least susceptible.