The number of fungal species colonizing thermal and acoustic fiberglass insulations used in heating, ventilation, and air conditioning (HVAC) systems was fewer than that obtained from initial direct culture of these insulations. The colonization. determined by the microscopic observation of conidiophores with conidia, was primarily of acrylic-latex-facing material, but eventually the fungi permeated the fiberglass matrix. Isolates of Aspergillus versicolor were most often obtained from non-challenged insulation, whereas Acremonium obclavatum appeared to be the primary colonizing fungus in high-humidity (>90%) challenge chambers. At a lower humidity (about 70%) Aspergillus flavus was one of the more prominent fungi, Not all duct liner samples were equally susceptible to colonization and duct board appeared relatively resistant to colonization.

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Fungal production of volatiles during growth on fiberglass.

I M Ezeonu, D L Price, R B Simmons, S A Crow, and D G Ahearn

Biology Department, Georgia State University, Atlanta 30303-4010.

Acoustic and thermal fiberglass insulation materials used in heating, ventilation, and air-conditioning systems were colonized with fungi in laboratory chambers. The mixed fungal population, principally Aspergillus versicolor, Acremonium obclavatum, and Cladosporium herbarum, produced odoriferous volatiles, including 2-ethyl hexanol, cyclohexane, and benzene. These volatiles may be related to poor indoor air quality and the sick building syndrome. Full text

• fungi and molds in buildings and their envelopes
• insulation : fiberglass insulation in HVAC
• ventilation - Air Infiltration and Ventilation in Buildings