Kitchens' Exhaust System Cleaning Process

A grease-saturated filter pulled from a working exhaust hood. Filters are the first thing a professional crew removes and deep cleans.

By Florida Kitchen Pros  ·  Updated October 2026

What Counts as the Kitchen Exhaust System

Many people picture someone wiping the stainless hood over the cook line. That hood is only the visible front door. The exhaust system is the full path carrying heat, smoke, and grease-laden vapor from the cooking surface to the outside of the building. It has five parts, and a proper cleaning touches all of them:

• The exhaust hood. The canopy over the cooking line that captures rising heat and grease vapor.
• Grease filters. Baffle or mesh filters seated in the hood that trap airborne grease before it enters the duct. They saturate fast in a working kitchen.
• The plenum. The cavity behind the filters where grease collects out of sight.
• The ductwork. The horizontal and vertical runs carrying vapor from the hood to the roof or exterior wall. Grease coats the inside of these ducts, and this is where the serious fire risk lives.
• The exhaust fan. Usually on the roof, pulling the whole system. Grease buildup on the fan wheel and housing strains the motor and unbalances the airflow.

Any company that quotes "hood cleaning" but leaves the ducts and fan untouched has not cleaned your exhaust system. It has polished the part you can see. Exhaust hood cleaning should always mean the complete system, cooking surface to building exterior.

The Professional Cleaning Process, Step by Step

Here is what a thorough professional visit looks like, in order.

1. Shutdown and kitchen protection

The crew shuts down the cooking equipment and the exhaust fan, locking out power so nothing starts mid-clean. Every surface under and around the hood gets covered: the cooking line, prep tables, and nearby equipment are draped with protective sheeting so grease and cleaning solution never reach food-contact areas. A sloppy crew leaves your kitchen dirtier than it found it.

2. Filter removal and deep cleaning

The grease filters come out of the hood. Each filter is degreased in a hot soak with a commercial degreasing agent, then scrubbed and rinsed until the baffles run clean. Filters are the one part of the system your own staff should also handle regularly (more below), but on a professional visit they get the full deep treatment, not just a rinse.

Mesh and baffle filters trap airborne grease before it reaches the duct. Saturated filters restrict airflow and let grease pass through.

3. Hood and plenum scraping

With the filters out, the crew scrapes the hood interior, the grease trough, and the plenum cavity behind the filters, where thick, baked-on grease accumulates. The hood exterior gets degreased and polished too.

4. Ductwork cleaning, the full run

This is the core of the job and the part a general cleaner cannot do. The crew opens the duct access panels and cleans the duct interiors along the entire run, horizontal and vertical, with brushes and equipment sized for ductwork. Grease inside ductwork is the fuel for exhaust fires, and it is invisible from the kitchen floor. A crew that never opens your access panels never cleaned your ducts.

5. Exhaust fan service

Up on the roof or the exterior wall, the exhaust fan gets cleaned: the wheel, the housing, and the surrounding surfaces. Grease on the fan unbalances it and strains the motor. Belts and general wear get a visual check while the crew is up there.

6. Rinse, polish, and reassemble

Everything comes back together: filters reinstalled, surfaces wiped and polished, sheeting removed, and the kitchen left as it was found. The crew powers the system back up and confirms it runs correctly before leaving.

That sequence is what "exhaust system cleaning" means. Anything less is a hood wipe-down with a fancier name.

What Your Staff Can Handle vs What Needs a Professional

Your kitchen crew has a real role in exhaust maintenance, and doing it well stretches the time between professional visits. But the line between staff work and professional work is a safety line, not a suggestion.

Your staff can and should:

• Pull grease filters on a regular rotation, degrease them, and reinstall them. In a busy kitchen this is a weekly or even more frequent task.
• Wipe down the visible hood exterior and empty the grease collection cups or troughs.
• Watch for the warning signs listed below and report them instead of ignoring them.

Leave to a professional crew:

• Anything inside the ductwork. Duct interiors need proper access, specialized tools, and someone who knows how far the grease has traveled.
• The exhaust fan. Roof work plus electrical plus grease is not a line-cook job.
• Deep degreasing of the hood interior and plenum with commercial-strength chemistry.

The original version of this article gave do-it-yourself steps for the whole system. We removed them: the parts that matter most for fire safety are exactly the parts no untrained person should open up.

How Often Your Exhaust System Needs Professional Cleaning

There is no single right schedule. NFPA 96, the National Fire Protection Association standard for commercial cooking ventilation and fire protection, sets cleaning frequency by what and how much a kitchen cooks, not by building size. Florida fire officials enforce exhaust cleanliness under the state fire code, which references NFPA 96. The schedule:

• Monthly: kitchens cooking with solid fuel, such as wood, charcoal, or pellet-fired equipment.
• Quarterly: high-volume operations, including 24-hour kitchens, charbroiling, and wok cooking.
• Semi-annually: moderate-volume cooking operations.
• Annually: low-volume operations such as church kitchens, day camps, and seasonal businesses.

When in doubt, take the shorter interval. Your local fire marshal has the final word.

Florida adds its own pressure. Humid air keeps grease tacky instead of drying it out, high tourist-season volume pushes kitchens harder for months, and fire marshals here inspect exhaust systems as a matter of routine. If your kitchen runs heavy volume from winter through spring, plan professional cleanings around that calendar, not a generic annual reminder.

Warning Signs Your Exhaust System Is Overdue

• Grease dripping from the hood or filters. Saturated filters stop trapping grease and start passing it through, or dripping it back onto the line.
• Smoke hangs in the kitchen instead of clearing. Restricted airflow from grease-choked ducts or a struggling fan.
• Cooking odors spread through the dining room. A healthy exhaust system pulls odors out. When they linger, capture is failing.
• The fan sounds different. New noise or vibration from the rooftop unit often means grease buildup has thrown the fan wheel off balance.
• Visible grease inside the duct access panels. Heavy buildup at the first access panel means the rest of the run is worse.
• It has been longer than your NFPA 96 interval. The schedule above is the baseline, not a suggestion.

Any one of these means calling for a visit now, not at the next scheduled date.

Why Neglecting the Exhaust System Gets Expensive

The costs of postponing show up fast:

• Fire risk. Grease coating duct interiors is fuel sitting in a hot air stream. Cooking equipment and exhaust systems are a leading origin point for restaurant fires. A clean duct starves a fire of fuel. A dirty one feeds it.
• Failed inspections. Fire marshals and health inspectors check exhaust cleanliness on routine visits. A grease-laden system draws write-ups, re-inspection visits, and in serious cases orders that disrupt service until it is fixed.
• Equipment strain. A fan fighting through grease buildup works harder, moves less air, and wears out sooner. Restricted airflow also makes the whole kitchen hotter and smokier, which your staff feels every shift.
• Insurance exposure. After a fire, exhaust system condition is one of the first things investigators document. A documented, scheduled professional cleaning is the straightforward way to show the system was maintained.

Choosing an Exhaust Cleaning Company in Florida

Before you book, ask these questions:

• Do you clean the entire system or just the hood? The answer you want names the ducts and the fan explicitly. If the quote only covers the visible hood and filters, keep looking.
• How do you handle the ducts? They should describe opening access panels and cleaning the full run, not spraying what they can reach from the hood.
• What do you protect while you work? A professional crew covers the cooking line and food-contact surfaces before a single drop of degreaser comes out.
• Are you familiar with NFPA 96 scheduling? They should be able to place your kitchen on the right interval and explain why.
• Are you local and insured? Pick a local, insured company over the cheapest quote from a crew you will never see again.

Florida Kitchen Pros is based in Dade City and serves commercial kitchens across the state. If your exhaust system is due, or overdue, call (727) 507-1735 or request a free quote and we will put your kitchen on a proper cleaning schedule.

Frequently Asked Questions

Your exhaust system is the hardest-working safety equipment in your kitchen, and the easiest to ignore because the grease hides inside the ducts. If it has been longer than your cleaning interval, or you are seeing any of the warning signs above, now is the time. Call Florida Kitchen Pros at (727) 507-1735 or get a free quote online. We clean the full system, cooking line to rooftop, for commercial kitchens across Florida.