Technical directory · Ducts
Visible debris at registers
Particles released from supply outlets are more specific evidence than ordinary dust sitting on a grille.
What to observe
Note which outlets release debris, when the fan runs and whether renovation work recently occurred.
A field example
A room that releases particles immediately after a renovation is a different case from one with a dusty grille after months of normal use. Identify the affected outlet and material before generalizing to all floors.
What the written work should say
A contractor should inspect the path from affected branches through the air handler before quoting a cleaning area.
Where this task stops
Do not assume every room's duct is equally affected from one outlet observation.