Hood Filters in Markham
Hood filter service is the cleaning, sizing and replacement of the baffle filters that form the first stage of a commercial kitchen exhaust system. Markham Hood Cleaning takes filters out of the kitchen for a heated soak rather than rinsing them in place, checks that each one fits its opening with no gap for air to bypass, and replaces any filter whose baffles have warped or split past draining. Filters are the cheapest part of the system and they decide how much grease everything downstream receives.
How a baffle filter works, and how it stops working
A baffle filter is a stainless steel frame holding a set of angled vanes. Grease-laden air entering it is forced to change direction several times in a short distance. The droplets, being heavier than air, cannot make the turns. They hit a vane, coalesce into liquid, and run down the baffle into a trough. Nothing is being strained out. The filter works by inertia, which is why it has no mesh to block and why it works in a fire.
Three things stop that happening. Loading: once the vanes carry a thick coating, the channels narrow, airflow drops, and droplets that would have been caught blow straight through. Warping: repeated heating and cooling, plus the occasional dishwasher cycle, bends the vanes out of alignment so the drainage path no longer runs downhill. Wrong size: a filter narrower than its opening leaves a gap, and air takes the free route around the filter rather than the resisted route through it. A single missing or undersized filter in a bank can carry a surprising share of the total airflow.
All three are found the same way, by taking the filters out and looking at the frame and the opening together. That is the first step of any visit, and it is also when the plenum behind them becomes reachable. The plenum is covered on the exhaust hood cleaning page.
Baffle vs mesh filters in a commercial kitchen
Mesh filters still turn up in Markham kitchens. They should not be there.
| Property | Baffle filter | Mesh filter |
|---|---|---|
| How it separates grease | Inertia. Air turns, droplets cannot, and they drain away. | Interception. Grease is held in the mesh rather than drained out of it. |
| Behaviour in a fire | Designed to resist flame passing through into the duct. | Holds saturated grease directly in the flame path. |
| Airflow as it loads | Falls gradually and predictably. | Falls sharply once the mesh clogs. |
| Cleaning | Soaks clean and returns to service repeatedly. | Rarely comes fully clean once saturated. |
| Where it belongs | Every grease-producing commercial cook line. | Residential range hoods, not commercial kitchens. |
If a hood in a Markham commercial kitchen still has mesh filters, that gets flagged at the walk-through with a replacement quote attached.
When a filter should be replaced rather than cleaned
Four conditions, each of them visible once the filter is out of the hood and held up to the light.
Warped baffles. Sight along the vanes. If they no longer sit parallel, the drainage channels have lost their fall and liquid grease sits in the filter instead of running to the trough. Straightening them is not a repair, because the metal has already fatigued.
Split or separated seams. A frame that has come apart at a corner creates a direct path through the filter with no baffles in it at all. That path takes the easiest airflow, so a filter with one open seam performs worse than no filter would suggest.
Corrosion through the frame. Common where a filter has been run through a dishwasher repeatedly, or where a caustic cleaner has been used on aluminium. Once the frame is pitted through, the filter cannot be certified as sound.
Wrong dimensions. Filters get replaced piecemeal over the years and the sizes drift. Anything narrower than its opening leaves a bypass gap and needs swapping for the correct size, not shimming. Markham Hood Cleaning measures the opening rather than copying the size off the old filter, because the old filter may be the reason the hood is underperforming.
Replacements are quoted per unit at the walk-through with the sizes listed, so the kitchen can approve them before anything is ordered. Nothing gets swapped without approval.
How much does hood filter cleaning cost in Markham in 2026?
Markham Hood Cleaning includes filter cleaning in a scheduled hood cleaning visit, which starts at $385 per visit for a single-hood kitchen up to ten feet, with replacement filters quoted per unit after the openings are measured.
Filters are almost never worth booking as a standalone job. The setup cost of getting a crew into the kitchen and covering the line dominates the price, so a filter-only visit is poor value compared with doing them alongside the hood. The exception is a heavy wok or fry line running long hours, where an interim filter swap between full visits keeps airflow up. That is arranged as a filter exchange rather than a service call.
Replacement filters are a genuine saving over time. A correctly sized baffle filter drains for years, keeps grease out of the plenum and duct, and lets the exhaust fan run at the airflow it was specified for. A warped one quietly loads the whole system downstream of it. The cost of the system it protects is set out on the kitchen exhaust cleaning page.
Next step: call 289-806-9117 or request a written quote. Count the filters in the bank and note anything obviously bent, and the quote can include replacements from the start.
Hood filters in Markham: frequently asked questions
Can hood filters go in the dishwasher?
It is a common practice and it does more harm than good. Commercial dishwasher chemistry is caustic, and on aluminium frames it corrodes and pits the metal over repeated cycles. The heat also warps the baffles out of alignment so they stop draining. A heated soak using a degreaser matched to the filter material cleans further and does not consume the filter.
How often should filters be cleaned?
More often than the rest of the system. Filters are the first stage, so they take the load first. A wok or fry line typically needs them attended to between full service visits, while a low-volume line can run to the scheduled interval. Kitchen staff can help by pulling and rinsing them weekly, which does not replace a soak but slows the loading between visits.
Is it acceptable to run a hood with one filter missing?
No. An empty slot is an open channel straight into the plenum, and air takes it in preference to the resisted route through the neighbouring filters. One missing filter can carry a large share of the total airflow, which means grease arriving in the plenum and duct completely unfiltered. A blank should never be left in place.
What are the small hooks and clips on a baffle filter for?
They hold the filter at the correct angle in its track so the drainage channels run downhill into the trough. A filter installed upside down or the wrong way round still fits and still looks right from the floor, but it drains backwards and sheds collected grease into the airstream. Orientation is checked on refitting after every soak.
Do filters have to be stainless steel?
Stainless is preferred and is what most commercial hoods use, because it tolerates repeated heated soaking without corroding and holds its shape. Aluminium filters exist and work, but they warp sooner and are far less forgiving of caustic cleaners. When a filter is being replaced anyway, stainless is the sensible choice.