Hood Filters for North York Commercial Kitchens
A hood filter is the first barrier between a cooking line and the rest of the exhaust system, and on a Type 1 canopy it must be a listed baffle filter rather than a mesh screen. Elite Hood Cleaning North York removes, washes and assesses every filter on each visit, reports the ones that are damaged, and supplies correctly sized replacements. Filters are the cheapest component in the system and the one that decides how fast everything downstream loads.
How a baffle filter actually works
It is not a strainer. Nothing is being sieved out of the air, and that misunderstanding is behind most of the bad filter decisions in commercial kitchens.
A baffle filter is a set of interlocking metal vanes that force the airstream to change direction sharply, several times, over a short distance. Grease droplets carry far more momentum than the air around them, so when the air turns, the droplets do not. They strike the vane, coalesce into liquid, and run down the baffle into the trough below under gravity.
Two consequences follow. First, a baffle filter works continuously without clogging closed, because grease drains away rather than accumulating in a mat. Second, it only works if it is installed the right way up and the right way round, so the drainage channel points where the designer intended. A filter fitted upside down still looks fine in the rail and does a fraction of the job.
This is also why filters have to sit tight in the rail with no gaps. Air takes the easiest path available. A missing filter, an undersized filter, or a gap at the end of a bank creates a free route straight into the plenum, and a large fraction of the airflow will use it. One missing filter in a bank of six can undo a great deal of the protection the other five provide.
Baffle vs mesh, and why mesh keeps turning up anyway
Mesh filters are cheap, widely sold, and wrong for a grease canopy. They persist because nobody checks what the previous tenant fitted.
| Baffle vs mesh | Listed baffle filter | Mesh or screen filter |
|---|---|---|
| How it separates grease | Momentum change, droplets strike a vane and drain | Impaction into a fibrous mat, which holds the grease in place |
| Behaviour as it loads | Drains continuously, airflow stays roughly stable | Clogs progressively, airflow falls, capture degrades |
| Behaviour in a flare-up | Designed to resist flame passing through into the plenum | Saturated mat of grease sitting directly above a flame |
| Suitability for a Type 1 grease hood | Required | Not acceptable |
| Cleaning | Washes clean repeatedly, long service life | Rarely returns to clean, usually discarded |
| Typical way it appears in a kitchen | Fitted at installation and kept | Bought cheaply as a like-for-like replacement without checking |
When a walk-through finds mesh filters over a grease line, it gets flagged immediately and in writing, because it is one of the few findings that can be corrected the same week for a small amount of money. It also tends to explain a duct that has loaded much faster than the cooking volume suggests it should.
Washing, and why it happens off the line
Filters cleaned in place are not cleaned. They are rinsed, and the grease goes into the plenum or onto the floor.
Every filter comes out of the rail and is washed away from the cookline in contained equipment, using hot water and a degreaser strong enough to break polymerised grease. Soaking does most of the work, because heated cooking fat forms a varnish that is chemically closer to a resin than to a liquid, and it responds to time and temperature rather than to scrubbing pressure.
Kitchens that put baffle filters through a dishwasher nightly are doing something genuinely useful, and it should continue. A commercial dish machine keeps the surface load down and extends the interval at which the bank becomes a restriction. What it does not do is clear the interior of the baffle channels on a heavily loaded filter, or address the trough and plenum behind them, so it complements the scheduled service rather than replacing it.
After washing, each filter is inspected individually before it goes back. Condition is recorded and photographed, and the report tells you filter by filter which are serviceable, which are marginal, and which should be replaced before the next visit.
When a filter should be replaced rather than washed
Filters are consumable. Running them past the point of usefulness is a false economy that shows up in the duct.
Warped or bowed frame
A filter that no longer sits flat in the rail leaves a gap at its edge, and air will use that gap in preference to passing through the baffles.
Split seams or holes
Any hole through the filter body is a direct bypass into the plenum. Corrosion at the lower edge, where liquid grease sits, is the usual origin.
Crushed or bent baffles
Vanes knocked out of alignment stop redirecting the airstream properly. This usually happens when filters are dropped or forced back into the wrong rail.
Wrong size for the rail
An undersized filter that rattles, or a bank that has been made up from mismatched sizes, leaves permanent gaps. This is common in kitchens that changed hands.
Missing handles or damaged ends
A filter that cannot be safely handled will not be removed for cleaning by kitchen staff, which quietly ends the nightly routine that was protecting the system.
Not a baffle filter at all
Mesh, aluminium screen or a domestic-style filter over a grease line gets replaced with a correctly sized listed baffle filter, not washed and put back.
Common questions about hood filters
How often should kitchen staff clean the hood filters?
Daily for a high-volume grease line, and at minimum weekly for anything cooking with fat. Nightly through the dish machine is the practical routine for most North York kitchens and it makes a measurable difference to how fast the duct loads. It supplements scheduled cleaning rather than replacing it.
Can we run the hood with a filter missing while it is being cleaned?
No. A gap in the bank sends grease-laden air straight into the plenum and past the protection the filters exist to provide. If filters are being washed during service, use a spare set so the bank is always complete. A spare set is inexpensive compared with a duct clean brought forward by six months.
How many filters does a hood need?
Enough to fill the rail completely with no gaps, sized so each filter seats firmly. The count comes from the length of the canopy and the filter width, and it is checked at the walk-through. A bank made up of mismatched leftovers from previous tenants is a common and easily corrected finding.
Do stainless steel and aluminium baffle filters perform differently?
Both work when they are listed baffle filters of the correct size. Stainless generally survives repeated hot washing and rough handling far longer, which matters in a kitchen where filters come out nightly. Aluminium is lighter and cheaper and tends to distort sooner. The material matters less than the type and the fit.
Is filter cleaning charged separately?
No. Removing, washing and assessing the filters is part of every exhaust system visit, included in the $385 single-hood and $725 multi-hood pricing. Replacement filters are quoted separately because the price depends on size and count, and you are told what is needed before anything is supplied.
Our filters look clean but the kitchen is still smoky. Why?
Clean filter faces do not mean clear airflow. The restriction is often in the plenum behind them or further along the duct, and it can equally be a fan or make-up air problem that has nothing to do with grease. The exhaust hood cleaning page covers how capture failures are diagnosed.