Technical directory · Ducts
Flex duct cleaning limits
Flexible duct has a ribbed liner that can be damaged by aggressive tools or crushed by poor access.
What to observe
Locate flex segments, inspect for tears, kinks, wet insulation and loose connections before cleaning.
A field example
A crushed flexible run can starve one room despite being clean inside. A tear in its liner or wet insulation changes the repair decision; aggressive brushing can make the defect worse.
What the written work should say
Ask what tool and pressure are appropriate for the actual duct material and whether damaged runs need repair or replacement.
Where this task stops
Do not treat fragile or wet insulated flex as if it were bare sheet metal.