PREVENTION of duct contamination is KEY to avoiding problems. Follow these recommendations to avoid the need for costly duct cleaning:
New ductwork frequently contains oil and debris. Before new ductwork is connected to the air handling system, it should be inspected for cleanliness and cleaned if necessary.
Perform routine preventive maintenance on HVAC systems, by complying with manufacturer schedules
for changing HVAC filters, cleaning coils, and other components.
During building renovation, seal ductwork to prevent construction dust and debris from entering the HVAC system.
Maintain good housekeeping in occupied spaces.
Ensure that air intakes are located away from contaminant sources.
Consider routine inspections of ductwork. The National Air Duct Cleaning Association (NADCA)’s standard, “Assessment, Cleaning and Restoration of HVAC Systems-ACR 2013,” recommends that HVAC systems be visually inspected for cleanliness at regular intervals, depending on building use. For healthcare facilities, the standard recommends annual inspections of air handling units and supply/return ductwork.
How to prevent building occupants during duct cleaning
Hire a duct cleaning contractor who is a member in good standing of the NADCA. Duct cleaning companies must meet certain requirements to become NADCA members. All NADCA members must have certified Air System Cleaning Specialists (ASCS) on staff who have taken and passed the NADCA Certification Examination.
PROTECT building occupants during and after duct cleaning: • Place a filter over supply and return grills to capture dust
when HVAC system is placed back into service after cleaning.
• Perform duct cleaning during hours when the building is unoccupied, such as nights and weekends.
• Use containment barriers and proper ventilation equipment, such as “negative‐air” machines equipped with high‐efficiency filters.
• Avoid the use of biocides and sealants. Even EPA‐registered biocides may pose health risks, including eye, nose, and skin irritation.
• No biocides are currently EPA‐registered for use on fiberglass duct board or fiberglass‐lined ducts. Both the EPA and NADCA
recommend replacing wet or moldy fiberglass duct material.
• Consult with occupants with medical conditions (e.g. immunosuppressed individuals).