Professional duct cleaning is one of those home maintenance tasks that many Ontario homeowners overlook — until they notice allergy symptoms, dusty vents, or strange smells from their HVAC system. Here’s what you need to know about duct cleaning frequency and when it’s time to book a service.

The General Rule: Every 3–5 Years

The National Air Duct Cleaners Association (NADCA) recommends professional duct cleaning every 3–5 years for most homes. However, several factors can mean you need it more frequently.

Clean More Often If You Have:

• Pets: Pet dander and fur accumulates rapidly in ductwork. Pet owners should clean every 2–3 years
• Allergy or asthma sufferers: Cleaner ducts mean fewer airborne triggers
• Young children or elderly residents: More sensitive to air quality issues
• Recent renovation: Construction generates massive amounts of drywall dust and debris that enters your duct system
• Mould or pest issues: Clean immediately if you notice musty smells or evidence of rodents/insects in ducts
• New home purchase: You don’t know when (or if) the previous owners ever cleaned the ducts

Signs Your Ducts Need Cleaning Now

• Visible dust or debris blowing from vents when system starts
• Dusty buildup around vent covers
• Musty or stale odour when HVAC runs
• Allergy symptoms that worsen indoors
• Uneven airflow between rooms
• It’s been more than 5 years since last cleaning

What Professional Duct Cleaning Includes

A proper NADCA-method duct cleaning covers: all supply and return ducts, registers and grilles, the air handler and blower, furnace heat exchanger surfaces, and the evaporator coil. It’s a whole-system cleaning — not just a brush through the vents.