To clean restaurant hood filters, pull the metal baffle filters out and soak them in a large sink or tub of hot water mixed with a commercial degreaser. Give them two to three hours for a normal week, or overnight for heavy grease. Then scrub each one with a brush, rinse it with hot water, let it air dry fully, and slide it back in. Your own staff can do that part.
What they can’t do is the other half. The word “hood cleaning” hides two completely different jobs, and mixing them up is how a kitchen ends up failing an inspection or watching an insurance claim get denied after a fire.
How to clean restaurant hood filters, step by step
The soak does the work. Scrubbing a dry, grease caked filter is slow and frustrating, but a filter that’s sat in hot degreaser for a few hours practically wipes clean.
- Turn off the exhaust fan and let the filters cool. Pull each baffle filter straight up and out of its slot. They’re designed to lift out without tools.
- Mix the soak. Fill a large sink or a dedicated soak tub with hot water and a commercial kitchen degreaser at the ratio on the label. Hotter water works faster.
- Submerge and wait. Lay the filters flat in the solution so they’re fully covered. Two to three hours handles a normal week. For heavy, hardened grease, let them soak overnight.
- Scrub and rinse. Lift each filter out, scrub both faces with a stiff brush to lift the softened grease, then rinse thoroughly with hot water until the water runs clear.
- Air dry, then reinstall. Stand the filters up and let them dry completely before sliding them back. A wet filter drips grease tinted water onto the cook line below.
One caution on the method. Aluminum baffle filters don’t love a hot caustic dish machine run over and over, because the harsh detergent pits and dulls the metal, so a degreaser soak is gentler and lasts longer.
Stainless steel baffles are tougher and handle a three compartment sink or dish machine fine. Either way, the soak chemistry is the same degreasing you’d use anywhere in the kitchen, and it works for the same reason it does on your walls and cook line.
How often to clean your hood filters
Your cooking volume sets the schedule, not the calendar. The more grease you put into the air, the faster your filters load up.
- High grease kitchens running fryers, a charbroiler, or heavy saute usually need filters cleaned weekly. Fast food and fried food volume can push that to every few days.
- Lower volume kitchens with lighter cooking can often stretch to monthly.
The trick that keeps this from becoming a dreaded chore is rotation. Instead of pulling and soaking the whole bank at once, clean one or two filters a night on a rolling basis, or drop the full set into an overnight soak on your slowest night. Either way the job never piles up into an overwhelming Sunday project.
How to tell a filter is overdue
Filters give you clear warnings before they become a hazard. Watch for any of these:
- Grease actually dripping off the filter or pooling on the ledge below it
- A filter that no longer sits flush in its track because grease has gummed the slot
- Smoke and cooking haze lingering in the kitchen instead of being pulled up and out
- A visibly dull, tacky coating across the baffles instead of clean metal
A filter this loaded isn’t just dirty. It’s a wick of concentrated grease sitting directly over open flame, which is exactly the condition that turns a flare up into a fire, and it feeds grease straight into the part of the system you can’t reach.
Where your job ends and the exhaust trade begins
Behind those filters sits the part of the system that is not yours to clean: the hood plenum, the ductwork running up through the building, the exhaust fan, and the rooftop unit. That whole path is covered by NFPA 96, the national fire code standard for commercial cooking exhaust, and it has to be cleaned to bare metal by trained, qualified technicians who leave a dated record of the work.
How often depends on how hard you cook. NFPA 96 sets four tiers:
- Monthly for solid fuel cooking (wood or charcoal)
- Quarterly for high volume, 24 hour, charbroiling, or wok cooking
- Semiannually for moderate volume kitchens
- Annually for low volume or seasonal operations
This isn’t optional housekeeping. Most Pennsylvania fire and building codes adopt NFPA 96, your inspector can require more frequent cleaning if they find buildup, and many insurance policies make certified exhaust cleaning a condition of coverage. Washing your filters is the routine you own. The certified exhaust cleaning is the specialty trade you hire, and the two are not interchangeable.
What clean filters do and do not protect you from
Clean filters earn their keep. A well maintained baffle catches a real share of the grease riding the air up toward the duct. That slows how fast the hidden parts of the system load up, and keeps your kitchen drawing smoke and heat the way it should.
What clean filters can’t do is clean the duct. Grease still gets past even a perfect filter, and over months it builds a coating inside the plenum and ductwork that only a certified exhaust cleaning removes.
That hidden layer is the real fire fuel, the same grease buildup that drives kitchen fire risk, and it’s the reason NFPA 96 exists at all. Keeping the dated cleaning records from that work matters too, because they’re exactly the kind of proof an inspector asks for, which we cover in the cleaning records and logs inspectors want to see. Think of clean filters as slowing the clock on the duct, never stopping it.
A simple split to run your kitchen by
One split keeps a kitchen both clean and covered: the filters and surfaces belong to your staff, and the exhaust system belongs to a certified trade.
Your staff own the filters and the surfaces. Soak the baffle filters on a schedule matched to your volume, and degrease the cook line, walls, and equipment on a routine. That work is well within a trained crew or a general cleaning service, and it’s the same degreasing method that runs through how professionals degrease a commercial kitchen.
A certified exhaust cleaner owns the system. Book the hood interior, ducts, fan, and rooftop unit on your NFPA 96 interval, and keep the dated records they leave. Don’t ask a general cleaner to do this, and don’t let a certified exhaust cleaning stand in for your weekly filter soak. They’re two jobs.
If you run a restaurant around Wilkes Barre, Scranton, or Kingston and the grease on your surfaces has gotten ahead of your team, Excellence Janitorial Services handles the kitchen degreasing side. That frees your staff to keep the filters on schedule while your certified exhaust cleaner handles the ductwork. Keep the two jobs straight, and you never get caught short on either one.
Frequently asked questions
How often should I clean my hood filters?
It depends on your cooking volume. High grease kitchens with fryers or a charbroiler usually need them cleaned weekly, and very high volume operations even more often. Lighter, lower volume kitchens can often go monthly. Cleaning one or two filters a night on a rotation keeps the task manageable.
Can I put hood filters in the dishwasher?
Stainless steel baffle filters handle a commercial dish machine or three compartment sink fine. Aluminum filters don’t do well with repeated hot caustic dishwasher cycles, which pit and dull the metal over time, so a degreaser soak is the safer choice for aluminum. Always let filters air dry completely before reinstalling.
What is the difference between cleaning hood filters and hood cleaning?
Cleaning the filters means washing the removable baffle filters your staff can pull out and soak. Hood cleaning, in the code sense, means cleaning the entire exhaust system, the hood interior, ducts, fan, and rooftop unit, down to bare metal. Filters are a routine staff task. The full system is a certified trade covered by NFPA 96.
How do I know when my hood filters need cleaning?
Look for grease dripping off the filter or pooling on the ledge below, a filter that no longer sits flush in its slot, or smoke and haze lingering in the kitchen instead of being drawn up. Any of those means the filter is loaded and overdue.
Is kitchen hood cleaning required by law?
In most places, yes. NFPA 96 is adopted into most state and local fire codes, so certified cleaning of the exhaust system on a set schedule is a legal requirement, not a suggestion. Fire inspectors check for it and insurers often require it. The frequency depends on your cooking type.
Do clean filters mean I do not need professional hood cleaning?
No. Clean filters slow how fast grease reaches the ductwork, but grease still gets past them and builds up inside the system, where only a certified exhaust cleaning removes it. Clean filters reduce the risk between cleanings, but they never replace the NFPA 96 system cleaning.
Who is responsible for cleaning the hood, the restaurant or a cleaning company?
The restaurant is responsible for making sure it happens. Day to day filter cleaning is done by staff. The certified exhaust system cleaning is hired out to a qualified company on the NFPA 96 schedule, and the restaurant keeps the dated records as proof it was done.