How Often Should You Clean Kitchen Exhaust?
Kitchen exhaust cleaning frequency is the interval at which a commercial kitchen's hood, filters, plenum, duct, and exhaust fan must be cleaned back to bare metal, and under NFPA 96 that interval is set by cooking volume and fuel type rather than by the calendar. The four intervals are monthly for solid fuel, quarterly for high-volume kitchens, semi-annually for moderate volume, and annually for low volume. Filters need attention much more often than that, and a home range hood follows no code interval at all. This guide separates all three answers so the right one is easy to lift.
How often should a commercial kitchen exhaust system be cleaned?
A commercial kitchen exhaust system is cleaned monthly, quarterly, semi-annually, or annually depending on what the line cooks and how much of it, with the whole path from canopy to rooftop fan included in that visit.
The word "system" is doing real work in that sentence. The interval applies to the complete exhaust path, not to whichever part of it is easiest to reach: the canopy over the cook line, the baffle filters, the plenum cavity sitting behind them, the grease duct running up through the roof deck, and the exhaust fan on top. A visit that stops at the filters has not met the interval, however clean the kitchen looks from the pass.
NFPA 96 also fixes the point at which a system is out of compliance, and it is a thickness rather than an opinion: 0.078 inches of grease deposit on any surface in that path. That number is why frequency is set by production rather than by preference. A wok line laying down grease-laden vapour every service crosses the limit in weeks. A legion hall that fires up for a Friday dinner and a Remembrance Day lunch takes a year to get near it. Same standard, very different calendars.
Barrie Fire and Emergency Service enforces the Ontario Fire Code, and the Ontario Fire Code adopts NFPA 96 by reference. An inspector is therefore not asking whether the kitchen feels clean. The question is whether there is dated evidence that the whole path was cleaned at the correct interval, which is a documentation question as much as a cleaning one. The NFPA 96 compliance guide covers what that evidence has to contain.
What are the four NFPA 96 intervals in 2026?
The four intervals map onto four kinds of cooking, and the table below puts each one beside the type of Barrie and Simcoe County kitchen it usually describes.
| Cooking type | System interval | Typical local example | What usually moves it |
|---|---|---|---|
| Solid fuel | Monthly | Wood-fired oven, charcoal grill line | Nothing. Solid fuel sits at monthly regardless of cover count, because the deposit is creosote-laden as well as greasy. |
| High volume | Quarterly | Busy quick service, wok line, 24-hour Highway 400 stop | Dropping a fryer or a wok burner from the line. Cutting late-night service. A menu change away from fried items. |
| Moderate volume | Semi-annual | Full-service restaurant, golf club dining room, long-term care servery | A banquet or tournament season that doubles output for a stretch. Adding a second daily service. |
| Low volume | Annual | Legion and community hall, church kitchen, event-only space | Renting the hall out for regular catered service, which quietly turns an annual kitchen into a moderate one. |
| Filters, high volume | Wipe nightly, soak weekly | Fryer and wok lines | Baffles that stop draining and start holding liquid grease. That symptom overrides the schedule. |
| Filters, moderate volume | Soak weekly | Dining room and servery lines | A heavy function week. Visible drip marks on the canopy lip below the filter bank. |
| Filters, low volume | Soak after each event run | Hall and event kitchens | Filters left dirty between bookings, which is how a low-volume kitchen ends up with a badly loaded plenum. |
Barrie Hood Cleaning confirms which row a kitchen belongs in during the free walk-through, then books the next visit before leaving the building. Full-system work is covered on the kitchen exhaust cleaning page.
How often do commercial kitchen hoods need to be cleaned?
A commercial hood is cleaned on the same interval as the system it belongs to, because NFPA 96 sets frequency for the exhaust system as a whole rather than for the canopy on its own.
That answer surprises people who expected the hood to have its own number. It does not, and the reason is worth understanding: grease that gets past the filters does not stop at the canopy. It collects in the plenum cavity behind the filter bank and then travels into the duct. Cleaning the visible stainless while the plenum stays loaded produces a kitchen that photographs well and fails an inspection.
What does vary is how often a hood is cleaned more often than the interval. A quarterly kitchen frequently books an interim canopy and filter visit at the six-week mark, purely as housekeeping, because grease running down the canopy lip onto the cook line is a food-safety and staff-morale problem long before it is a code problem. That interim visit is useful, but it is not a substitute. The system interval still has to be met with a full-path clean, and the certificate has to say so.
The other case is a hood that has been neglected long enough that the first visit is a restoration rather than a maintenance clean. That happens most often when a kitchen changes hands and nobody can produce a record. In that situation the honest sequence is a full-system clean first, an assessment of what the deposit thickness actually was, and only then a sensible ongoing interval. Detail on the canopy and plenum work itself is on the commercial hood cleaning page.
How often should commercial kitchen hood filters be cleaned?
Baffle filters need attention weekly at minimum and nightly in a high-volume kitchen, which is far more often than the exhaust system behind them.
Filters are the only part of the system that kitchen staff handle routinely, and they are the part where a schedule matters least and a symptom matters most. A baffle filter works by making grease-laden vapour change direction sharply so the grease drops out and drains. Once the baffles are coated thickly enough that liquid grease sits in them instead of running out, the filter has stopped filtering and started storing. Everything downstream gets worse from that moment.
The workable rhythm is a nightly wipe of the filter faces as part of close-down in any kitchen running fryers or woks, a proper soak weekly, and an exchange or deep clean at every full-system visit. Lower-volume kitchens can drop the nightly step, but should still soak weekly rather than waiting for a visible problem. Two failure modes are worth naming: filters put back the wrong way around, which stops them draining into the trough entirely, and filters run in a dishwasher on a cycle that strips an aluminium frame. Both are common and both are avoidable.
Where a kitchen does not have the sink space or the staff time for a weekly soak, an exchange schedule solves it: clean filters arrive, dirty ones leave, and the cook line never runs a shift on clogged baffles. That service is described on the hood filter cleaning page.
How does Barrie seasonality change the interval?
Barrie Hood Cleaning sets seasonal kitchens on their peak-season volume and times the visit to land at the end of the peak, rather than averaging a year that was never average.
Simcoe County runs two opposite tourist seasons and one long-weekend season, and each of them bends the interval. Wasaga Beach and the Georgian Bay kitchens do the bulk of their year between June and Labour Day. The ski hill kitchens around Horseshoe Valley, Snow Valley, and Mount St. Louis Moonstone do theirs between December and March. The Highway 400 stops spike on long weekends in both directions. A kitchen doing four times its shoulder-season output for a quarter of the year does not stay compliant on an interval calculated from its quiet months.
There is a second local factor that has nothing to do with volume. Barrie sits at the south end of the Georgian Bay squall track, and a rooftop exhaust fan can spend December through March under packed snow and ice. A fan without a hinge kit is close to unserviceable in a January wind off Kempenfelt Bay. So rooftop work gets pulled forward of freeze-up rather than scheduled into it, which sometimes means a visit lands a few weeks early on the calendar in exchange for actually being able to open the fan. Anything genuinely unreachable is written down as not accessible rather than quietly certified.
How often should a range hood be cleaned at home?
A home range hood has no code interval, so the useful measure is cooking habit: filters monthly for most households, every two or three weeks for anyone who fries or woks regularly.
This section exists because a large share of people asking "how often should you clean kitchen exhaust" are standing in a home kitchen, and it would be misleading to hand them a commercial answer. NFPA 96 governs commercial cooking operations. A range hood over a domestic stove sits outside its scope, there is no inspector coming, and no certificate is involved. Nothing on this page about intervals, deposit limits, or commercial pricing applies to a home kitchen.
What does transfer is the physics. Grease still condenses on the filter, still drips if the filter is saturated, and still coats the fan housing over time. A reasonable home rhythm is metal mesh filters washed monthly, the canopy underside wiped at the same time, and the fan housing opened up once or twice a year. Households that cook with a lot of oil should shorten the filter interval rather than scrubbing harder later. If the fan is already loaded and dripping, the recovery method is set out in the guide on cleaning an oily exhaust fan.
Kitchen exhaust cleaning frequency: frequently asked questions
The five follow-up questions operators ask once they know their interval.
How often do commercial kitchen hoods need to be cleaned?
A commercial kitchen hood is cleaned on the same NFPA 96 interval as the system it belongs to, because the standard sets frequency for the exhaust system as a whole rather than for the canopy on its own. That means monthly under solid fuel, quarterly at high volume, semi-annually at moderate volume, and annually at low volume. The practical difference is that a hood can be cleaned more often than the interval without the duct being touched, which is why a busy kitchen sometimes books an interim canopy and filter visit between full-system cleanings.
How often should commercial kitchen hood filters be cleaned?
Baffle filters need attention far more often than the exhaust system does, because they are the first surface the grease-laden vapour hits. In a high-volume kitchen that means a wipe-down nightly and a proper soak weekly. In a moderate-volume kitchen a weekly soak is usually enough. Filters are also cleaned or exchanged as part of every full system visit. The test is whether a filter still drains freely: once the baffles hold liquid grease instead of shedding it, it is overdue no matter what the calendar says.
What decides which NFPA 96 interval applies?
Cooking volume and fuel type decide it, not the size of the building or the age of the equipment. Solid fuel cooking such as a wood-fired oven or a charcoal line sits at monthly regardless of how few covers it does. Above that, the tiers run on how much grease-laden vapour the line actually produces: quarterly for high volume, semi-annual for moderate, annual for low. A kitchen that changes what it cooks changes tier, which is why the interval is confirmed on site rather than assumed from the address.
Does a seasonal Simcoe County kitchen follow the same schedule?
Seasonal kitchens are the local exception worth planning around. A Wasaga Beach patio kitchen or a Georgian Bay resort servery can run four times its shoulder-season volume for three months, and a ski hill kitchen at Horseshoe Valley or Snow Valley does the same in reverse. The honest approach is to set the interval from the peak and time the visit to land at the end of it, rather than averaging the year and arriving with the system already loaded.
How often should a range hood be cleaned at home?
A home range hood sits outside NFPA 96 entirely, so there is no code interval to meet and no certificate involved. As a practical rhythm, a household that cooks most nights gets good results from washing the metal filters monthly and wiping the canopy underside at the same time, with the fan housing opened up once or twice a year. A household that fries or woks often should move the filters to every two or three weeks.
More in the guide library, including how long a visit takes and what it costs.