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Commercial · Commercial Duct CleaningCommercial Duct Cleaning
Commercial duct cleaning is worth paying for when there is a reason you can point to: construction or fit-out dust, a tenant turnover, debris blowing out of the diffusers, or evidence of mould or pests. It is not a service to buy on a fixed calendar. We clean the whole air path — supply and return trunks, every branch, and the rooftop unit's plenum, coil and drain pan — with the system held under negative pressure, after hours, and hand over before-and-after photos. A typical house runs $300–$700; a commercial space is quoted per system after a site look.
The method is the one set out in ACR, the NADCA standard for assessing and cleaning HVAC systems. A negative-air machine is connected at the trunk so the ductwork stays under suction the entire time, then each branch is agitated with brushes, air whips or compressed-air tools so the debris travels toward the collector instead of into your space. When the collector has to discharge indoors, it does so through HEPA filtration. Vacuuming the diffusers from a ladder is not duct cleaning, and it is usually what a quote that looks too cheap actually contains.
On a commercial system the ducts are only half the job. Most offices, shops and industrial units in Burlington, Oakville and Hamilton are fed by a packaged rooftop unit, and the dirt that matters most sits in its return plenum, on the upstream face of the cooling coil and in the drain pan. A matted coil cuts airflow more than any amount of dust on a duct wall, and a plugged pan grows the slime that people later report as a musty smell on Monday morning. So the unit is in the scope: plenum vacuumed, coil cleaned, pan and trap cleared, filters replaced and the blower wheel checked.
What justifies the work is evidence, not a date on a sticker. Drywall and concrete dust after construction or a tenant fit-out is the most common reason, followed by a turnover where the last occupant's process left residue, visible debris at the diffusers, rodent or bird evidence in the ductwork, and mould confirmed on a duct or coil surface. If none of those apply, a camera look inside the trunk and a better filter usually do more for the air than a cleaning. Mould that keeps returning is a moisture problem — a wet coil, a blocked drain, uninsulated duct sweating in a ceiling space — and the source gets fixed first or the growth comes back.
One scope boundary and a note on price. Kitchen grease exhaust — the hood, the duct and the fan above a cook line — is cleaned under NFPA 96 by a separate certified trade with its own inspection tags, and we do not do it. Commercial pricing follows the system: how many rooftop units, the length and height of the ductwork, the ceiling type, and how many diffusers have to come down, so the per-vent prices on our residential duct cleaning page do not carry over and you get a written per-system quote after a walk-through. See commercial HVAC for how we run after-hours work, or contact the shop to book the site look.
Equipment we install and service
Main trunks, branch runs, flexible connections and the diffusers and grilles themselves, which come down and get washed. Flexible duct tears if it is brushed like sheet metal, so it is cleaned with air tools and replaced where it has already collapsed or split.
The return plenum, the evaporator coil face, the condensate pan and its trap. This is where a commercial system holds its dirt and its moisture, and leaving it out means the first hour of run time re-soils the ducts that were just cleaned.
Ductwork with internal fibreglass liner cannot be scrubbed hard without shedding fibres into the airstream. It is contact-vacuumed with a HEPA machine instead, and liner that is delaminating, wet or mouldy is quoted for replacement because cleaning will not restore it.
A portable negative-air machine sized to the trunk, HEPA-filtered when it exhausts inside the building, with rotary brushes and air whips matched to the duct material. Access openings cut into the duct are closed with gasketed, screwed panels, not tape.
What goes wrong in these buildings
- The contractor finished the fit-out three weeks ago and there is still white dust on every desk each morning.
- Black streaks are forming on the ceiling tiles around the diffusers.
- The incoming tenant wants proof the ducts were cleaned before they take possession.
- There is a musty smell for the first ten minutes after the unit starts on Monday.
- We found mouse droppings above the ceiling and I do not know how far into the ductwork they got.
- The last company was in and out in an hour and nothing looks any different.
How it works
We walk the roof and the ceiling space, put a camera into the trunk, count diffusers and note any lined duct or hard-to-reach runs. You get a written per-system price, and if the camera shows clean metal we will say the cleaning is not needed.
Desks and stock are covered, diffusers come down, the collector is connected at the trunk and each branch is agitated toward it. The rooftop unit's plenum, coil and pan are cleaned the same night and new filters go in before the system restarts.
Dated before-and-after photos of the trunk, the coil and the drain pan, labelled by unit, with a note of anything found: damaged liner, disconnected runs, a drain that needs re-piping. Landlords and tenants both keep it as the record that the work was done.
Common questions
How often should a commercial building have its ducts cleaned?
There is no fixed interval that fits every building. Have the return plenum, coil and a section of trunk looked at once a year during regular maintenance, and clean when that inspection finds accumulation, after any construction or renovation, or after a pest or water problem. A space with good filtration changed on schedule can go many years between cleanings.
Can the ducts be cleaned while the business is open?
No. The air system is shut down, diffusers are out of the ceiling, the collector is loud and ladders are moving through the space, so the work is booked for evenings or a weekend. Clinics, food businesses and offices with sensitive equipment get extra covering and a wipe-down before staff return. Most single-unit spaces are finished in one night.
Does duct cleaning get rid of mould?
It removes growth from bare sheet metal, coils and drain pans, which are hard surfaces that can be cleaned. Porous materials such as fibreglass liner or duct board cannot be cleaned back to sound condition and are replaced. Either way the moisture source has to be corrected, and where occupants have health concerns a third-party air quality assessor should confirm the result.
Who pays for duct cleaning in a leased unit, the landlord or the tenant?
The lease decides. Under many net leases the tenant pays for cleaning inside its own premises, while landlords often pay at turnover to hand over a clean system. Dust left by a contractor is normally that contractor's responsibility under the construction contract, so raise it before the final payment is released. The photo report gives each party the same facts to work from.
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