How to Clean Grease Buildup from a Range Hood and Ductwork

Grease buildup in your range hood isn't just an eyesore—it's a fire hazard and a performance killer. That dark, sticky film that collects on the hood cover and inside the ducts reduces airflow, makes the fan work harder, and gives your kitchen a perpetually oily smell no amount of air freshener fixes. Range hoods pull in thousands of cubic feet of air per minute, trapping grease and moisture meant for the outdoors, but if you're not cleaning them regularly, that grease gets baked on by repeated heat cycles and becomes cement-hard. A proper cleaning takes a weekend afternoon and a few basic supplies—nothing exotic, nothing that requires a contractor. The payoff is a hood that breathes again, a quieter fan, and a kitchen that actually smells clean.

1. Kill the Power First. Flip the breaker switch that controls the hood or unplug it from the outlet if it's plug-in hardwired. Test the fan to confirm it's dead. Never work on an electrical appliance while it's powered.
2. Document Your Setup. Open the hood and locate the filter or filters—most hoods have one or two metal mesh or baffle filters held in place by latches or tabs. Lift or slide them out according to your hood's design. Hold them up to a light source. If you see through them, they're cleanable; if they're opaque with grease, replacement might be faster than heavy scrubbing.
3. Start the Soak. Use your bathtub, a large utility sink, or a plastic storage tub if you have one. Fill it with hot water as hot as your tap allows—near-boiling is ideal for cutting grease. Add a commercial kitchen degreaser according to the label instructions, or use a 1:1 mix of hot water and white vinegar with a squirt of dish soap. Stir to combine.
4. Strip the Housing. Mix a fresh batch of degreaser solution in a spray bottle or spray a commercial degreaser directly onto the hood surfaces. Start at the top and work downward so gravity helps the cleaner drip over dirty areas. Let it sit for 2–3 minutes to break down the grease, then wipe with a non-scratch sponge or cloth. For stubborn, baked-on buildup, use a plastic scraper to gently lift it before wiping. Pay special attention to the underside of the hood canopy where grease pools.
5. Free the Fan. Most hoods have a removable or accessible fan wheel or blades visible inside the upper housing. If your model allows it, carefully remove the fan cover and inspect the blades. They will be greasy. Spray them with degreaser, let it sit briefly, and wipe with a cloth. If the blades are permanently mounted or access is difficult, you can clean them in place by spraying and wiping from the front, but understand some residual grease will remain. Do not force any covers or blades—if removal isn't obvious, leave it.
6. Clear the Damper. Look at where the hood ductwork exits the unit. There's usually a damper (a one-way flapper) that prevents outside air and pests from entering. This damper accumulates grease buildup on its hinged sides and surface. Spray it with degreaser and wipe it clean. Test that it swings freely. If the ductwork is visible where it connects to the hood, wipe that section as well—this is where grease accumulates fastest.
7. Scrub Deep. After 30 minutes or more of soaking, the grease on the filters should be soft and easier to remove. Use an old soft-bristle brush, a plastic scrub brush, or even an old toothbrush to work the degreaser into the mesh or baffle channels. Hold the filter under running water and brush from both sides. Rinse thoroughly under hot water until no soap residue or grease remains. You should see clean metal beneath.
8. Dry Completely. Hold the clean filters under running water one more time to remove any lingering degreaser. Shake off excess water and stand them upright to air-dry on a clean towel or the edge of your sink. Do not reinstall wet filters—grease and moisture can collect and promote mold growth. Give them at least an hour to dry, or wipe them dry with a clean cloth.
9. Reseat the Filters. Once the filters are completely dry, slide or lift them back into the hood in the same orientation they came out. They should fit snugly and lock or latch into place. Give them a gentle tug to confirm they're seated properly. Do not force them—if they don't fit smoothly, check that you have the correct orientation.
10. Expand the Clean. While you have degreaser out and the hood is clean, spray and wipe the cooktop surround and any cabinet surfaces or backsplash directly behind or around the range. Grease vapors settle on these surfaces too, and a quick cleanup while you're in the zone keeps the whole area fresh. Use the same cloth-and-wipe method as the hood.
11. Test the Airflow. Flip the breaker back on or plug in the hood. Turn on the fan and listen—it should sound quieter and run smoother now that filters are clean and grease isn't restricting the motor. Feel the airflow at the front of the hood; it should be noticeably stronger. If airflow is still weak, the buildup may extend deep into the ductwork and require professional duct cleaning.
12. Stay Ahead. Mark your calendar to clean the hood filters at least monthly, or every two weeks if you cook heavily. A quick soak-and-scrub every 30 days prevents the baked-on buildup that makes this task miserable. A full hood exterior wipe-down quarterly keeps grease from accumulating again. This 30-minute monthly habit prevents needing a 3-hour deep clean every 18 months.