RESOURCES
What is biofilm in an air conditioning duct?
Technical article from the resource center.
It is a layer of microorganisms attached to a surface and wrapped in a matrix that they produce themselves. In an air conditioning system it forms where there is constant humidity and dirt.
Where it forms
On surfaces that almost never dry: the condensate pan, the coil and the duct sections close to the air handling unit. In a tropical climate, with a system running without an off-season, those conditions repeat all year.
Why running a machine through is not enough
Biofilm adheres to the surface. Removing it takes mechanical brushing of the inside, filtered vacuum extraction and disinfection with a product suitable for ducts, followed by a camera check that the result is as expected.
What is documented
The prior inspection and the later verification are done at the same points, so that the before and the after can be compared in the report.
To see how this applies to a specific installation: See indoor air quality and ductwork. Back to resources.