Ducted vs Ductless Range Hood: Full Comparison and Which to Buy

A ducted range hood is the better performer in almost every kitchen because it sends smoke, grease, heat, moisture and combustion gases outside. A ductless hood is the fallback for kitchens where you cannot run a duct outdoors: it traps grease and some odor, then returns the air to the room. If a duct run is possible, go ducted; if it is not, a good ductless hood is far better than no hood.

Ducted vs ductless at a glance

Performance: what each type actually removes

A ducted hood pulls air through washable metal grease filters and pushes it out of the house. Everything in that air leaves: grease aerosols, smoke, cooking odors, steam, heat and the combustion byproducts from gas burners.

A ductless hood pulls air through the same kind of grease filter, then through a charcoal (activated carbon) filter that absorbs some odor molecules. The cleaned air comes back out of vents on the top or front of the hood. Heat and moisture pass straight through, and so do nitrogen dioxide and carbon monoxide from gas flames. Charcoal also loses its ability to absorb odor as it fills up, so performance drops between filter changes.

That difference matters most in three situations:

• Gas cooking. Burners produce NO2, CO and fine particles every time they run. Only a ducted hood removes them.
• Searing, frying and wok cooking. High heat produces a lot of smoke and grease. Ductless filters load up quickly and the smoke that gets past them stays in the house.
• Humid climates and small kitchens. Steam from boiling and simmering stays in the room with a ductless hood and can condense on cabinets and windows.

Airflow ratings also differ in practice. The extra resistance of a charcoal filter means a ductless hood moves less air than its motor could move through open duct. Compare hoods by their HVI-certified CFM if the manufacturer lists it, and use the range hood CFM calculator to see how much airflow your cooktop needs.

Installation: the real deciding factor

For most people, the choice comes down to whether a duct can reach the outside.

What a ducted install involves

• A path from the hood to an exterior wall or the roof, through cabinets, a soffit, the ceiling or a chase.
• Rigid smooth metal duct sized to the hood collar: 6” round is typical up to about 400 CFM, 7–8” for 600 CFM and 8–10” above that. Some low-CFM under-cabinet hoods use 3¼” × 10” rectangular duct.
• A wall cap or roof cap with a backdraft damper so outside air and pests stay out.
• Foil-tape sealed joints and no screws protruding into the duct, since they catch grease.

The easiest ducted installs run straight through the wall behind the range to the outside, often less than 3 feet of duct. Harder installs cross joists, run through an upstairs floor or need a roof penetration. Every 90° elbow adds resistance roughly equal to 10–15 feet of straight duct, so aim for a total run under about 30 equivalent feet.

What a ductless install involves

A ductless hood mounts in the same spot and connects to power the same way, but there is no exterior hole, no flashing and no damper. Many homeowners can install one in an afternoon if the wiring is already in place. Turn off power at the breaker, not only at the hood’s switch, before connecting any wiring.

When ducting is not possible

Common blockers are condo or HOA rules, a range on an interior wall with a finished floor above, a steel or concrete structure, or no permission to cut an exterior wall in a rental. In those cases ductless is the realistic answer. If ducting may become possible later, buy a hood sold as convertible; see our guide to converting a range hood from ductless to ducted.

Cost: upfront vs over time

Typical US ranges, before any cabinet or drywall repair:

A ductless hood wins on the first day. Over five to ten years, the charcoal filter cost narrows the gap, and a ducted hood keeps working at full strength without replacements. If your ducted setup would need makeup air, that can be the largest single cost, which is one reason many homeowners stay at or below 400 CFM.

Noise

Noise is measured in sones. About 1 sone is a quiet refrigerator and 3–4 sones is normal conversation. Hoods of 600 CFM or more commonly reach 6–9 sones on high.

At the same fan speed, a ducted hood is usually quieter for the amount of air it moves, because air leaves the kitchen instead of blowing back at you through the front grille. Ductless hoods push the fan harder against the charcoal filter, and the return air exits near head height. Poor duct design can make a ducted hood loud too: undersized duct, many elbows and long runs all add roar. Look for HVI-certified sone ratings at both low and high speed.

Maintenance

Both types have washable metal grease filters. Clean them every month with heavy or frying use and every 1–3 months otherwise; our grease filter cleaning guide covers the soak method.

Ductless hoods add charcoal filters. These are not washable unless labelled regenerable and are typically replaced every 3–6 months. A hood that smells stale or stops clearing odors usually needs new charcoal; see charcoal filter replacement.

Ducted hoods add the duct itself. Check that the exterior damper opens freely once or twice a year, and have heavily used ducts inspected for grease buildup every few years.

Looks and layout

Both types come in the same styles: under-cabinet, wall-mount chimney, island and insert. From the front, most look identical. A ductless chimney or island hood has visible recirculation vents near the top of the chimney cover, and a ducted install may need a soffit or chase to hide the duct if it cannot run straight out the back.

Code and safety

The International Residential Code (IRC) 2021, Section M1503, sets the baseline in many US jurisdictions:

• Ducts must be galvanized steel, stainless steel or copper (M1503.4). No plastic or flexible foil duct.
• Exhaust must discharge outdoors, never into an attic, crawl space or inside the building (M1503.3).
• Systems able to exhaust more than 400 CFM need makeup air (M1503.6).
• Kitchens need at least 100 CFM intermittent exhaust or 5 air changes per hour continuous (M1505.4.4). Some jurisdictions treat a ductless hood as not meeting the exhaust requirement.

Local codes vary and are adopted with amendments, so check with your local building department before you cut holes or buy a large hood.

Which should you choose?

Choose a ducted range hood if:

• You cook on gas or plan to switch to gas.
• You sear, fry, stir-fry or cook with high heat several times a week.
• The range is on an exterior wall, or there is a practical path to the roof.
• You want the lowest running cost and the most consistent performance over time.
• You live in a humid climate or have a small, closed kitchen.

Choose a ductless range hood if:

• Building rules, structure or a lease prevent an exterior vent.
• You cook on electric or induction and mostly simmer, boil and bake.
• You need a quick, low-cost install and accept replacing charcoal filters.
• You want a hood now and may add a duct later (buy a convertible model).

If you are torn, the tie-breaker is usually gas. Over a gas cooktop, ducted is worth significant extra effort; our gas vs electric stove ventilation guide explains why.

What to look for when buying

• Confirm whether you can vent outdoors before choosing a hood, and measure the likely duct path.
• Hood width at least equal to your cooktop; 3” wider on each side is better for gas.
• CFM sized to your cooktop using the rules of thumb or the CFM calculator, not the biggest number on the shelf.
• HVI-certified CFM and sone ratings, listed at low and high speeds.
• Duct collar size that matches your planned duct (6” round is the common default).
• Convertible design if you are buying ductless but might vent later.
• For ductless: price and availability of replacement charcoal filters.
• Washable stainless baffle or aluminum mesh grease filters.
• A backdraft damper included at the collar or a wall/roof cap with one.
• Makeup air plan if the hood can exhaust more than 400 CFM.
• Mounting height range in the manual that fits your space (typically 24–30” over electric, 30–36” over gas).

The bottom line

Ducted hoods do the whole job and ductless hoods do part of it. Vent outdoors whenever the house allows it, especially over gas, and treat ductless as a solid option for kitchens that truly cannot be ducted. Whichever you choose, size it with the CFM calculator and keep the grease filters clean.