Commercial dryer vent cleaning is not a shop vac at the wall cap. Here is what actually happens in a properly executed multifamily vent cleaning, unit by unit, and why each step exists.
Step 1 — Access and Isolation
The dryer is pulled forward and disconnected from the transition duct. This alone reveals a substantial proportion of the deficiencies we find: crushed transitions, foil flex duct, over-length hoses coiled behind the appliance, and lint packed into the connection. The transition duct is inspected and cleaned or flagged for replacement.
Step 2 — Rotary Brush Through the Full Run
A flexible rotary brush on segmented rods is driven through the duct under rotation. The brush agitates and breaks up compacted lint along the entire run — including the elbows and offsets where compaction concentrates. This is the step that distinguishes real cleaning from theatre: a vacuum applied at either end removes loose lint from the ends. Only mechanical agitation through the full length removes what is packed against the duct wall in the middle.
Rod length is matched to the run. High-rise vertical risers require considerably longer rod sets and higher-torque drive than a garden-style wall termination — which is why vendors equipped only for the latter cannot service the former.
Step 3 — Negative Air Extraction
A high-volume negative air machine draws the agitated lint out of the system rather than allowing it to settle back or blow into the unit. Extraction runs concurrently with brushing. Without it, brushing simply relocates the lint.
Step 4 — Termination Cleaning and Inspection
The exterior termination is cleared, the damper flap checked for free movement, and the cap inspected for damage, corrosion or bird nesting. Screened termination caps — which trap lint and should never be used on dryer exhaust — are photographed and flagged. Roof terminations require rooftop access and fall protection.
Step 5 — Airflow Verification
Airflow is measured at the termination with the dryer running. This is the proof step. A unit that still shows restricted airflow after full-run cleaning has a physical duct problem — a crushed section, a disconnected run, a collapsed elbow — not a lint problem. Those units go to the deficiency report.
Step 6 — Reconnection and Documentation
The dryer is reconnected, the area left clean, and before/after photographs of the unit’s vent are captured with the unit number attached. The photograph is taken at the point of work, not reconstructed later.
Time Per Unit
A garden-style wall termination takes roughly 15-20 minutes per unit including access, cleaning, verification and photography. A high-rise riser unit takes considerably longer. Anyone quoting five minutes per unit is not doing all six steps.
What Gets Delivered
Within 48 hours: per-building photo reports, a deficiency log with locations, an airflow verification summary, an access exception list, and a completion certificate referencing NFPA 211.