How To Clean Kitchen Grease Exhaust | Fire-Safe Method

If your range hood pulls poorly, smells off, or leaves a film on cabinets, the exhaust path is overdue for a deep clean. This guide gives you a clear, step-by-step process that home cooks and small food operators can follow to restore airflow, cut smoke, and reduce fire risk. You’ll learn what to use, where to start, and when to call a pro.

Best Way To Clean A Kitchen Exhaust System Safely

Grease removal works best when you move in one direction—top to bottom and clean to dirty. Power off the hood, lay down protection for the cooktop, and stage your supplies. Use a food-safe degreaser, warm water, and non-scratch tools so you don’t scar metal or lift coatings.

Tools And Materials You’ll Need

Gather everything first so you don’t track drips through the room. Choose a safer degreaser that still cuts heavy residue and pair it with heat (warm water) and dwell time.

Item	What It Does	Notes
Degreaser (Safer Choice)	Breaks down baked-on fats	EPA Safer Choice listings help you pick products with safer ingredients.
Dish Soap + Baking Soda	Lift film; mild abrasion	Mix into hot water for soaking filters and wiping the hood skin.
Microfiber Cloths	Trap grease without streaks	Reserve darker cloths for heavy soil; keep a dry stack for final buff.
Nylon Brush / Old Toothbrush	Scrub seams and corners	Stiff bristles speed up work on baffles and mesh edges.
Plastic Scraper	Lift thick deposits	Use gentle pressure to avoid gouging painted metal.
Screwdriver	Remove filters & panels	Some hoods use clips; others use small screws for light covers.
Gloves & Eye Protection	Keep hands and eyes safe	Grease and alkaline cleaners can irritate skin and eyes.
Drop Cloth / Paper	Protect cooktop & counters	Catch drips from the fan housing and duct collar.

Step-By-Step Cleaning: Hood, Filters, Fan, And First-Reach Duct

1. Shut Off Power. Switch off the breaker or unplug the hood. Remove any bulbs if your model exposes them during cleaning.
2. Remove Filters. Slide out baffles or mesh screens. If there’s a charcoal insert for a recirculating setup, set it aside; it gets replaced, not washed.
3. Soak Filters. Fill a sink with hot water, a squeeze of grease-cutting dish soap, and a spoon or two of baking soda. Submerge metal filters for 15–20 minutes. Agitate, brush along the grain, rinse hot, and air-dry upright.
4. Pre-Wipe The Hood Skin. With a damp, soapy cloth, wipe exterior and interior panels to remove loose film. Refresh water when it cools or looks milky.
5. Degrease The Interior. Spray degreaser onto a cloth (not directly into the fan cavity). Work the underside first, then side panels, then the plenum around the fan.
6. Detail The Fan Area. Pop the blower cover if your model allows. Wipe the impeller blades by pinching each blade with a damp cloth and rotating by hand. Don’t bend fins.
7. Reach The Duct Collar. With the fan covered, wipe just inside the round or rectangular collar where residue pools. Don’t shove lint deep into the duct.
8. Rinse And Dry. Wipe with clean water, then buff dry. Metal left wet can streak or spot, especially stainless.
9. Reassemble And Test. Once filters are dry, reinstall them. Restore power and run the fan on high for a minute to confirm smooth airflow.

Filter Types: What You Can And Can’t Wash

Residential hoods use one of three filter styles. Treat each the right way to avoid damage and airflow loss.

Aluminum Mesh

Great at catching vaporized fat but easy to clog. Hand-wash in hot, soapy water with light brushing. Some models allow dishwashing; always check your manual. Many makers advise non-phosphate detergents for machine cycles to limit discoloration. See the maker’s guidance for details on cycle choice and detergent type (e.g., Broan-NuTone’s filter cleaning note).

Reference: manufacturer guidance such as Broan-NuTone filter care.

Stainless Baffle

Common on pro-style hoods. The internal channels force grease to drop into the tray. These can usually handle a dishwasher cycle if the manual allows it. Space them apart and use a standard, non-abrasive program. If hand-washing, let them soak, then brush along the channels.

Charcoal Pads (Recirculating)

These absorb odor but don’t trap grease well. They are not washable. Replace on the schedule in your manual (often every 1–3 months depending on cooking volume).

Surface Care Without Streaks

Stainless looks best when you wipe along the grain. Start damp, finish dry. Skip scouring pads and steel wool. For fingerprints, a small amount of dedicated stainless cleaner on a cloth finishes the job. On painted or powder-coated skins, stick to mild soap and water; strong solvents can dull the sheen.

Fire Safety While You Degrease

Hot oil and residue can ignite, and cleaning can stir up hidden gunk. Keep a lid, sheet pan, or Class B/K extinguisher nearby, and know basic actions if a flare-up happens.

• Keep a metal lid within reach when frying. If a small pan fire starts, slide on the lid and switch off the burner. Don’t move the pan.
• Never splash water on burning oil. Water makes the flames surge and spread.
• Smother tiny flames with baking soda or salt if a lid isn’t handy. If the fire grows, get out and call emergency services.

For official guidance on safe cooking practices and small grease fires, see the U.S. Fire Administration cooking fire safety page.

Troubleshooting Common Grease Exhaust Problems

Fan Runs But Airflow Is Weak

Clogged filters, a blocked damper, or a collapsing flexible duct can starve the fan. Clean or replace filters first. Check the damper at the wall or roof cap for sticking. If the duct is accordion-style, consider replacing it with smooth metal for better flow.

Rattling Or Hum

Grease on an impeller can unbalance the rotor. A careful, thorough wipe of the blades restores smooth spin. Check that filters seat square; loose baffles can buzz.

Drips From The Hood Front

Trapped grease in the plenum or filter channels can slump forward when the fan starts. Pull the filters, tip them to drain, and scrub the channel edges. Empty and wash the drip tray if your unit has one.

Deep Cleaning The First Section Of Duct

You can safely clean the reachable collar and the first few inches of duct where sludge collects. Wrap a microfiber around a flexible plastic spatula, dampen with degreaser, and swab the lip. Don’t push lint into the run. If residue extends deep, book a qualified service that cleans ducts from the terminal cap back to the hood.

Food businesses follow a formal standard that sets cleaning and inspection duties for hoods, ducts, and suppression gear. While home kitchens aren’t under that code, the same logic applies: more frying means more frequent cleaning.

Suggested Cleaning Intervals By Use

Cooking Pattern	Hood & Filters	Duct & Fan
Light (1–2 hot meals/week)	Wipe monthly; wash filters every 2–3 months	Inspect yearly; clean if residue is visible at collar
Medium (daily sauté/boil; rare deep-fry)	Wipe monthly; wash filters monthly	Inspect 6–12 months; clean as needed
Heavy (frequent frying, wok, griddle)	Wipe biweekly; wash filters every 2–4 weeks	Inspect 3–6 months; schedule professional duct cleaning if buildup persists

Grease Disposal And Shop Rag Safety

Never pour oily waste down a drain. Let skimmed fat cool and harden, then trash it in a sealed container. Soaked cloths can heat up on their own while oil oxidizes. Store them in a metal can with a self-closing lid and take them out with solid waste pickup guidelines for your area. If your local program accepts household hazardous items, ask about solvent-soaked rags.

Eco-Safer Choices That Still Cut Through Gunk

Look for labels that tell you the formulation meets safer-ingredient criteria. The EPA Safer Choice program explains how products earn the mark. For day-to-day upkeep, hot water and dish soap plus a microfiber do most of the work. Reserve strong chemistries for heavy sections and rinse well.

Quick Maintenance Habits That Keep Grease Down

• Run The Fan Early. Switch it on before the pan heats so the system captures vapor from the start.
• Use Lids And Splatter Screens. You’ll collect less film on the hood skin and cabinets.
• Wipe While Warm. After cooking, a damp cloth and a drop of soap lift residue before it hardens.
• Change Odor Pads On Time. If you use a recirculating setup, fresh charcoal keeps the kitchen fresher.
• Mind The Roof Or Wall Cap. Clear lint, leaves, and stuck dampers each season to maintain flow.

When To Call A Professional

Book help if any of these apply: the duct run is long or hidden; grease oozes from seams; the fan rattles after cleaning; or airflow stays weak even with spotless filters. Commercial operators should follow their local fire marshal and insurer requirements tied to recognized standards for cooking ventilation. Routine documentation and visible duct cleanliness reduce risk and downtime.

Printable Mini-Checklist

Use this as your end-of-article deliverable—copy to your notes app or print, and you’ll breeze through the next cleaning.

• Power off, protect cooktop, stage tools.
• Pull filters, soak in hot soapy water; brush, rinse, dry.
• Pre-wipe hood skin; apply degreaser to cloth, not into fan.
• Wipe underside, sidewalls, plenum; detail impeller blades.
• Swab duct collar; don’t push lint into the run.
• Rinse surfaces, dry, reinstall filters, test on high.
• Dispose of waste properly; store oily rags in a metal can.
• Set a reminder for your next filter wash based on your cooking pattern.