The four things that matter most in a range hood

A range hood's job is to pull cooking smoke, steam, and odor out of your kitchen. The ones that do this well share four measurable traits: CFM rating (how much air they move), duct type (where the air goes), noise level, and filter type. Everything else — finish, lighting, controls — matters less than these four because a hood that doesn't move air or fits your kitchen wrong will frustrate you every time you cook.

The most common mistake is buying a hood that looks right but has a CFM too low for your stove size. The second is choosing ducting that doesn't work with your home's layout, forcing you to vent into the attic or a wall cavity instead of outside. The third is ignoring noise — a hood that sounds like a jet engine gets turned off, and then it does nothing.

Key Takeaways

  • CFM (cubic feet per minute) should be at least 100 per linear foot of cooktop width; a 36-inch stove needs roughly 300 to 400 CFM minimum.
  • Ducted hoods that vent outside remove odor and moisture completely; ductless hoods with charcoal filters recirculate air and need filter changes every 3 to 6 months.
  • Noise above 65 decibels becomes noticeable during normal conversation; most quality hoods run between 50 and 65 decibels at high speed.
  • Baffle filters (metal louvers) last longer and clean easier than mesh filters, but cost more upfront and require washing every 1 to 3 months.
  • Mounting height and depth matter: wall-mounted hoods should be 24 to 30 inches above the cooktop, and island hoods need 30 to 36 inches clearance.

CFM: How much air the hood actually moves

CFM stands for cubic feet per minute — the volume of air the hood pulls through per minute. A higher CFM means faster removal of smoke and steam. The rule of thumb is 100 CFM per linear foot of cooktop width, though some builders and contractors use 150 CFM per foot for gas stoves, which produce more heat and smoke than electric.

A 30-inch electric cooktop needs roughly 300 CFM. A 36-inch gas stove needs 400 to 500 CFM. A 48-inch commercial-style range needs 600 CFM or more. If you buy a hood rated at 200 CFM for a 36-inch gas stove, it will not clear smoke fast enough, and you will smell cooking for hours after you finish.

Check the hood's spec sheet for CFM at high speed — that is the number that matters. Some manufacturers list CFM at low or medium speed, which looks better on paper but does not reflect real-world performance. If the spec sheet does not list CFM, the hood is probably underpowered and the manufacturer is hiding it.

Ducted versus ductless: Where the air goes

Ducted hoods push air outside through a duct that runs through your wall, ceiling, or cabinet. They remove odor, moisture, and heat completely. Ductless hoods pull air through a charcoal filter and push it back into the kitchen. Ductless hoods are easier to install but do not work as well.

Ducted is better if your kitchen layout allows it. The duct should be as short and straight as possible — every bend and every foot of length reduces the hood's effective CFM. A duct that runs 20 feet with three elbows will perform worse than the same hood with a 5-foot straight duct. If you have to run duct through an attic or crawlspace, make sure it is insulated so condensation does not drip back into the hood.

Ductless hoods work in apartments and kitchens where exterior venting is not possible. The trade-off is that you must replace the charcoal filter every 3 to 6 months, depending on how much you cook. A clogged charcoal filter stops working and cannot be cleaned — it must be thrown away and replaced. If you forget to replace it, the hood becomes a recirculating fan that does almost nothing.

Noise level: What you will actually hear

Range hoods are loud. A hood running at high speed can produce 65 to 80 decibels — louder than normal conversation. Below 65 decibels, you can talk while the hood runs. Above 70 decibels, you will have to raise your voice. Most people turn off hoods that are too loud, which defeats the purpose.

Check the decibel rating on the spec sheet. A hood rated at 55 decibels is noticeably quieter than one rated at 70 decibels. The difference between 65 and 75 decibels is roughly double the perceived loudness. If the spec sheet does not list decibels, assume the hood is loud.

Noise comes from the motor and the air moving through the duct. A longer, narrower duct makes the hood louder. A duct with sharp bends makes it louder. A hood with a larger motor and slower fan speed is usually quieter than a smaller motor running fast. If you have a choice between a 400 CFM hood at 65 decibels and a 400 CFM hood at 72 decibels, the quieter one is worth the extra cost.

Filter type: Mesh, baffle, or charcoal

Mesh filters are thin metal screens that catch grease. They are cheap, straightforward to remove, and can be washed in the dishwasher. They clog quickly and need cleaning every 1 to 2 months if you cook often. Baffle filters are thicker metal louvers that direct air sideways through the filter. They catch more grease, last longer, and need cleaning every 2 to 3 months. They cost more upfront and are harder to remove, but they work better.

Charcoal filters are used only in ductless hoods. They absorb odor but do not catch grease — you still need a mesh or baffle filter in front of the charcoal. Charcoal filters cannot be washed or reused. Once they are full, they go in the trash and you buy a new one.

If you cook frequently or cook with high heat, a baffle filter is worth the extra cost. If you cook occasionally and do not mind cleaning filters often, a mesh filter is fine. Do not buy a ductless hood unless you are certain you will replace the charcoal filter on schedule — most people do not, and the hood stops working.

Mounting height and clearance

A wall-mounted hood should be 24 to 30 inches above the cooktop surface. Too low and you risk steam and heat damaging the hood. Too high and it does not capture smoke effectively. An island hood (mounted to the ceiling above a cooktop in the middle of the kitchen) should be 30 to 36 inches above the cooktop.

Check the hood's depth before you buy. A shallow hood that does not extend past the front of the cooktop will not capture smoke as well as one that overhangs by 3 to 6 inches. If your cooktop is 30 inches wide, the hood should be at least 30 inches wide, ideally 36 inches.

Measure your cabinet space before ordering. A 36-inch hood will not fit in a 35-inch opening. Some hoods come with trim kits that extend the width, but these add cost and complexity. Measure twice and order once.

Power and controls: What actually matters

Most hoods have three or four speed settings. Low speed is for light cooking and odor removal. High speed is for heavy cooking, frying, or when you have burned something. Variable speed controls (a dial or slider instead of buttons) are nicer to use but cost more and have more parts that can break.

Some hoods have a timer that turns them off automatically after 15 or 20 minutes. This is useful if you forget to turn the hood off, but it is not essential. Some have a humidity sensor that turns the hood on automatically when steam is detected. These sensors are convenient but add cost and can be unreliable.

Lighting is nice but secondary. A hood with a 40-watt incandescent bulb or LED lights helps you see the cooktop. LED bulbs last longer and use less power, but the difference in cost is small. Do not buy a hood based on lighting alone.

Frequently Asked Questions

What CFM do I need for a gas stove versus an electric stove?

Gas stoves produce more heat and smoke, so they need higher CFM. For a 36-inch electric cooktop, 300 to 400 CFM is usually enough. For a 36-inch gas stove, 400 to 500 CFM is better. If you have a commercial-style gas range, you may need 600 CFM or more. Check your stove's BTU output — higher BTU means more CFM needed.

Can I install a ductless hood in a kitchen with a ducted hood already?

Yes, but you lose the benefit of venting outside. If your existing duct is damaged or blocked, a ductless hood is a workaround. Keep in mind you will need to replace the charcoal filter regularly, and odor will stay in your kitchen instead of leaving through the duct.

How often do I need to clean or replace filters?

Mesh and baffle filters need washing every 1 to 3 months, depending on how much you cook. Charcoal filters in ductless hoods need replacement every 3 to 6 months and cannot be cleaned. If you cook daily, plan on replacing charcoal filters four times a year.

Is a more expensive hood always better?

Not always. A $300 hood with the right CFM, noise level, and filter type will outperform a $600 hood with low CFM and high noise. Focus on the four measurable traits — CFM, duct type, noise, and filter — rather than brand name or price. A mid-range hood from a reliable manufacturer often offers the best value.

What happens if my duct is too long or has too many bends?

The hood's effective CFM drops. A 400 CFM hood with a 20-foot duct and three elbows might perform like a 250 CFM hood. If your duct run is long or complex, buy a hood with higher CFM than the calculator suggests, or consider a ductless hood instead.