Airborne mould & IAQ · 1 min read
Airborne mould and indoor air quality in commercial buildings
What airborne mould actually is, how it moves through HVAC systems, why surface cleaning alone cannot address it, and how continuous management differs from one-off treatment.
The mould people see is a small fraction of the mould in a building. The rest is airborne — microscopic spores and fragments carried by air movement, distributed by mechanical ventilation, and breathed in by everyone in the space.
How it moves
Air-conditioning systems draw air from occupied rooms, pass it through plant that is often damp, and return it to every room they serve. A single source in a ceiling void or an AHU becomes a building-wide exposure. Doors, lifts and stairwells do the rest.
Why cleaning doesn’t reach it
Surface cleaning removes what is on the surface that was cleaned. It does nothing for the air, for surfaces that were not cleaned, or for the cavities and ductwork where the source often sits. This is why buildings that are cleaned regularly can still have persistent complaints.
Reduction versus one-off treatment
A single airborne treatment reduces the population in the building on the day. For buildings whose conditions produce mould continuously — climate, occupancy, use — a program keeps the population low indefinitely, and produces the trend data that lets a facilities manager demonstrate it.