Should I clean my ductwork after a Toronto home renovation or remodel?

Yes, you should absolutely have your ductwork professionally cleaned after any significant renovation in your Toronto home. Renovations generate enormous amounts of fine dust — drywall compound, sawdust, concrete dust, insulation fibres, and paint overspray — and much of it ends up inside your duct system, even when contractors try to protect supply and return openings during the work.

During a renovation, your HVAC system acts like a vacuum, pulling airborne particles through return air grilles and depositing them throughout the duct network. Drywall dust is especially problematic because it is extremely fine, travels deep into ductwork, coats the interior surface of ducts and the evaporator coil, and recirculates every time the system runs. If your furnace was running during the renovation — which is common during GTA winter renovations when shutting off the heat is not an option — the contamination is even worse. Many GTA homeowners finish a basement renovation or kitchen remodel and wonder why the entire house feels dusty for months afterward. The answer is almost always renovation debris circulating through the duct system.

The timing matters. Wait until all renovation work is completely finished, including final sanding, painting, and cleanup, before scheduling duct cleaning. Having ducts cleaned while work is still ongoing wastes money because new dust will immediately re-contaminate the system. Once the renovation is done, schedule a professional duct cleaning within a week or two before the debris has a chance to compact and harden inside the ducts.

A proper post-renovation duct cleaning in the GTA costs $300 to $700 for a typical home, depending on the size of the system and the extent of contamination. Some companies charge a premium for post-renovation cleaning because the debris is heavier and requires more aggressive agitation. Make sure the company uses truck-mounted equipment with source removal technique — this means they insert agitation tools into each duct run while the truck-mounted vacuum pulls debris out through the trunk line under strong negative pressure. Companies that just stick a hose into a few registers are not performing legitimate cleaning.

Beyond the ducts themselves, ask the cleaning crew to inspect and clean the evaporator coil (the A-coil above or inside your furnace). Renovation dust that passes through the filter accumulates on the coil fins, reducing airflow and cooling efficiency. A clogged coil can reduce HVAC efficiency by 20 to 30 percent and cause the system to freeze up during summer cooling. Also replace your furnace filter immediately after cleaning — install a fresh MERV 11 or MERV 13 filter to capture any residual fine particles.

For major renovations in older Toronto homes — particularly pre-1975 homes in neighbourhoods like East York, Scarborough, or Etobicoke — have the renovation contractor test for asbestos in existing duct tape, insulation, or vermiculite before any demolition begins. Disturbing asbestos during renovation and then running the HVAC system can spread fibres throughout the entire home. If asbestos is found, professional abatement is required before any duct cleaning. Post-renovation duct cleaning is one of the most worthwhile investments you can make to protect indoor air quality and get your HVAC system running efficiently after construction wraps up.