Post-Construction HVAC Cleaning: A Turnover Checklist

Why new systems fail early

If the HVAC ran during construction — or if ducts sat open on the deck — the system is already loaded with gypsum dust, sawdust and insulation fiber. Gypsum is abrasive and hygroscopic: it scours blower wheels and holds moisture against coils, which is how a brand-new system develops microbial growth in its first cooling season.

The turnover checklist

• Clean all supply and return ductwork by source removal under negative pressure.
• Clean and, where needed, replace flex duct that was left open during framing.
• Wash coils and clean blower wheels and drain pans in every AHU and RTU.
• Replace all construction filters with the specified operating filters.
• Clean grilles, registers and diffusers before ceiling sign-off.
• Verify airflow and balance readings against the design.
• Deliver photo documentation for the closeout binder.

Timing it right

Schedule the clean after final drywall sanding and painting but before ceiling grid close-in wherever possible. Cleaning too early means doing it twice; cleaning after occupancy means doing it around tenants at night rates.