How often should you replace a range hood charcoal filter?
Updated July 2026
Swap the charcoal (carbon) filter in a recirculating range hood every 6 to 12 months, dropping to every 3 months if you cook heavily or fry often. Unlike the metal grease filter below it, which you wash and reuse, carbon cannot be cleaned; its whole job is to trap smoke and odor molecules as the hood recirculates air back into the kitchen, and once the pores saturate it just passes them through. A ducted hood that vents outdoors has no charcoal filter to change at all.
What changes the interval
| Your situation | Interval | Why |
|---|---|---|
| Light cooking, recirculating hood | Every 12 months | A low grease and odor load stretches the carbon |
| Average cooking, recirculating | Every 6 months | The typical replacement point for most kitchens |
| Heavy frying, wok, or lots of onions and garlic | Every 3 months | Strong odors and oil vapor exhaust the carbon quickly |
| You still smell dinner hours later | Replace now | Odor breakthrough is the signal the carbon is full |
| Metal grease filter (separate part) | Wash monthly | Reusable mesh; that is the washable filter, not the carbon |
| Ducted hood (vents outside) | No carbon filter | Air leaves the house, so nothing needs absorbing |
The cost of skipping it
What skipping it costs: a spent carbon filter does not fail loudly, it just quietly stops working, so grease vapor and smoke drift up and settle as a sticky film on cabinets, walls, and the ceiling above the range. Odors from last night's dinner hang around the next morning. The bigger money problem is the grease filter ignored alongside it: caked grease chokes airflow and is a fire hazard over the burners. A carbon filter runs $15–40 (often sold in pairs), cheap next to a range hood that costs $150–600 and lasts 10–15 years. See what a grease-caked hood filter can cost.
How to do it (5–10 minutes · DIY, no tools)
- Switch the hood off and remove the metal grease filter to reach the carbon filter behind or above it.
- Unclip or unscrew the old charcoal filter (many twist a quarter turn to release; some snap into the fan housing).
- Check the hood model number on the label under the hood and order the matching carbon filter, usually a pair.
- Seat the new filter fully so there are no gaps for air to bypass it, then refit the cleaned metal grease filter.
- While you are in there, degrease the metal filter in hot soapy water or the dishwasher before it goes back.
Knowing the interval is the easy half. OnOtto reminds you at the right interval, and it won't let you snooze it into next year. Tasks persist until they're done, and completing charcoal filter changes schedules the next one automatically.
Put this on autopilot, free for 30 daysFrequently asked questions
How do I know when the charcoal filter is used up?
The clearest sign is odor: if the kitchen smells of dinner long after you have finished and the hood is running, the carbon is saturated. You may also notice the air feels greasier and the film on nearby surfaces returns faster after cleaning. Carbon gives no visible cue the way a clogged grease filter does, which is why a calendar reminder every 6 to 12 months beats waiting for the smell to tell you.
Can I clean and reuse a charcoal filter?
No. Carbon filters are consumable and cannot be washed, baked, or vacuumed back to life; the pores fill with grease and odor molecules and stay full. The washable part is the metal grease filter, a separate component that sits in front of the carbon. Trying to reuse a spent carbon filter just recirculates the smells you wanted gone. Budget one or two replacements a year and keep a spare on the shelf.
Do all range hoods have a charcoal filter?
No, only recirculating (ductless) hoods do. A ducted hood pushes cooking air outside through a duct and needs only the metal grease filter, so it has no carbon to replace. Recirculating hoods are common where running a duct through an exterior wall or roof is not practical, such as interior kitchens and many condos. If yours vents outdoors, skip the carbon entirely and just keep the grease filter clean.
Will a fresh carbon filter fix a hood that is not clearing smoke?
Only partly, and often not at all. A new carbon filter absorbs odor, but a recirculating hood never removes heat and steam the way a ducted one does, and a weak or undersized fan will not clear smoke regardless of the filter. First clean or replace both filters, then check the fan speed and that nothing blocks the outlet grille. If smoke still lingers, the hood may be underpowered for your cooking. See the range hood checklist for the full routine.