Kitchen ventilation is one decision with two technologies. Ducted hoods exhaust cooking air to the outdoors through a duct system. Recirculating hoods filter the air through grease and charcoal filters and return it to the kitchen. Both look similar at the hood itself. The performance, install cost, and air quality outcome differ significantly. This guide breaks down what each technology actually accomplishes, who should choose which, and how to evaluate the trade-offs honestly.
What ducted hoods remove
A ducted hood captures the rising thermal plume from the cooktop and exhausts it outside through a duct. With proper installation (correct duct size, short run, sweep elbows, make-up air), a ducted hood removes essentially everything in the captured airflow:
Grease aerosol from sauteing, frying, and high-heat cooking. The plume carries microscopic oil droplets that would otherwise deposit on cabinets, walls, and ceiling over years of cooking.
Water vapor from boiling, steaming, and braising. Cooking releases significant humidity into the kitchen air; ducted hoods send it outside.
Combustion gases from gas cooktops. Natural gas combustion produces water vapor, carbon dioxide, nitrogen dioxide, and small amounts of carbon monoxide. NO2 and CO are health concerns at indoor concentrations. A ducted hood removes them.
Particulate matter from any high-heat cooking. Searing meat, charring vegetables, or burning anything releases fine particulates (PM2.5) that contribute to indoor air pollution. Ducted exhaust removes them.
Cooking odors. Strong-smelling dishes (curries, fish, fried foods) that linger in the kitchen for hours after cooking get exhausted within minutes of the hood being turned off.
The capture rate depends on the hood capability, the ducting, and the cook’s habits (using the hood from the start of cooking, not just at the end). A well-installed ducted hood used correctly removes 70 to 95 percent of the cooking emissions.
What recirculating hoods remove
A recirculating hood pulls air through a grease filter (which captures oil droplets), then through a charcoal filter (which adsorbs some organic compounds), and returns the air to the kitchen. The technology can only remove what its filters capture:
Grease aerosol: captured by the mesh or baffle grease filter. Good capture rate, typically 80 to 95 percent for a well-maintained filter.
Some cooking odors: adsorbed by the activated charcoal filter. The charcoal works for the first 3 to 6 months and then saturates. Saturated charcoal does nothing.
Some VOCs (volatile organic compounds): captured by activated charcoal alongside the odors. Same saturation timeline.
Water vapor: not captured. Returns to the kitchen humidified.
Combustion gases from gas cooking (NO2, CO): not captured. Return to the kitchen.
Fine particulates: largely not captured by standard charcoal filters. Return to the kitchen.
Heat: not removed. Returns to the kitchen.
A recirculating hood meaningfully addresses grease and (when the charcoal is fresh) some odors. It does not address the air quality problems from gas combustion, the humidity from boiling, or the particulates from searing.
Install cost comparison
Ducted install in new construction or open renovation: $300 to $900 for the duct work plus the hood. The work includes running rigid metal duct from the hood through the wall or roof, installing a termination cap, and sealing the joints. Most kitchens have a path that does not require structural modification.
Ducted retrofit into a kitchen with no existing duct: $400 to $1,500 if the path is straightforward (exterior wall close, no structural conflicts), $1,500 to $3,500 if the path involves significant framing modifications.
Recirculating install: $0 to $200 above the hood cost. Most recirculating hoods plug into a standard 120V outlet and require no exterior penetration, no ducting, no permit. The simplest installation by far.
For apartment kitchens, condo kitchens, and interior kitchens without exterior wall access, recirculating is often the only feasible option.
Filter maintenance comparison
Ducted hoods use only a grease filter, which is typically a stainless steel mesh or aluminum baffle. The filter goes in the dishwasher every 2 to 4 weeks. Lifespan: indefinite if not damaged. Cost: $20 to $60 to replace if damaged, but most last the life of the hood.
Recirculating hoods use the same grease filter plus an activated charcoal filter. The charcoal filter is not washable. It must be replaced every 4 to 12 months depending on use. Cost: $15 to $40 per replacement. Annual cost for a regularly-cooked-in kitchen: $30 to $80 per year.
Many owners of recirculating hoods skip the charcoal filter replacement, which means the hood is running with a saturated filter that does almost nothing for odors. The hood works as a fan that recirculates air, with grease capture but no meaningful air cleaning.
Energy and conditioned air
Ducted hoods exhaust conditioned indoor air. In winter, that air is heated; in summer, that air is cooled. The hood pulls outside air in (either through the make-up air system or through infiltration) to replace it, and the new air has to be conditioned again.
For a typical household using the hood 1 to 2 hours per day, the energy penalty is small but real. In cold climates with electric heat, the annual cost is $30 to $80. In moderate climates, $10 to $30. In hot climates with high cooling loads, $20 to $50.
Recirculating hoods have no conditioned-air penalty because no air leaves the house. This is one of the few genuine advantages of recirculating over ducted.
Noise comparison
Ducted hoods are generally quieter for the same CFM because the air moves through duct work rather than fighting through dense charcoal filters. Typical noise at high speed: 6 to 8 sones for a quality ducted hood at 600 CFM.
Recirculating hoods push air through both grease and charcoal filters, increasing the static pressure the fan has to overcome and the noise generated. Typical noise at high speed: 7 to 10 sones for the same nominal CFM.
The difference is noticeable. A ducted 600 CFM hood at full speed is annoying but tolerable in conversation. A recirculating 600 CFM hood at full speed is loud enough to interrupt conversation.
Health and air quality outcomes
For gas cooking, the air quality difference between ducted and recirculating is significant. Gas combustion releases NO2 and CO; only ducted hoods remove them. The 2022 RMI study found that ducted hoods used during gas cooking reduce indoor NO2 concentrations by 50 to 75 percent. Recirculating hoods do not reduce NO2 at all.
For households with children, asthma, or respiratory sensitivity, this matters. Indoor NO2 from gas cooking correlates with worse asthma outcomes and reduced lung function in children. The CDC and EPA recommend ducted hoods for any kitchen with a gas cooktop where occupants have respiratory concerns.
For electric or induction cooking, the air quality argument is weaker because there is no combustion. The remaining concerns (grease, humidity, particulates from high-heat cooking) still favor ducted but at lower stakes.
Who should choose which
Choose ducted if: the kitchen has reasonable exterior wall access, the cooktop is gas, the household has children or respiratory concerns, the cooking involves regular high-heat searing or wok work, and the budget supports the install cost.
Choose recirculating if: the kitchen is in an apartment or condo with no ducting path, the cooktop is electric or induction (lower combustion air quality stakes), the cooking is light (basic weeknight meals without high-heat work), and the household is willing to maintain charcoal filters on the right schedule.
For a kitchen that currently has recirculating and wants to upgrade: assess the duct path first. If a reasonable retrofit is possible, the air quality improvement justifies the $400 to $1,500 cost. If the path is not feasible, focus on the controllable factors: replace the charcoal filter on schedule, choose induction over gas, and open a window during heavy cooking. For more on ventilation choices, see our methodology page.
Frequently asked questions
Can I really not duct my apartment range hood to outside?+
In most apartments and condos, correct, you cannot duct to outside without significant construction approval that the building will refuse. Apartment hoods are nearly always recirculating because the building envelope, fire ratings, and shared walls do not allow penetration for a kitchen duct. Some newer condo construction includes pre-built duct chases that ducted hoods can use; check the building specs. For renovations, getting approval to duct through an exterior wall in a condo requires HOA approval and is rarely granted. Recirculating is the practical default for apartment kitchens.
Are charcoal filters in recirculating hoods worth replacing or are they a scam?+
They work but only for the first 3 to 6 months of normal use. Activated charcoal filters adsorb organic compounds (cooking odors, some VOCs) onto the carbon surface. Once the surface saturates, the filter passes everything through. Most filters need replacement every 4 to 6 months in a household that cooks daily, every 6 to 12 months for lighter use. Replacement cost: $15 to $40 per filter. Owners who never replace the filter get the noise of the hood with very little air cleaning benefit. The filters are not a scam, but they only work when maintained.
Does a ducted hood reduce indoor humidity from cooking?+
Yes, significantly. A pot of boiling water releases 0.5 to 1 pound of water vapor per hour into the kitchen. A ducted hood pulls that humid air outside before it can spread through the house. A recirculating hood pulls the air through filters that do not capture water vapor and returns the humid air to the kitchen, where it spreads to adjacent rooms through normal air circulation. In a tight house with heavy cooking, the humidity difference between ducted and recirculating is visible: ducted kitchens stay around 40 to 50 percent RH during cooking, recirculating kitchens can spike to 65 to 80 percent RH and cause window condensation and longer drying times.
Will a ducted hood really lower my heating and cooling bills compared to recirculating?+
No, the opposite. Ducted hoods exhaust conditioned (heated or cooled) indoor air, which then has to be replaced with outside air that has to be conditioned again. In winter, exhausting 600 CFM of 70F air and bringing in 30F air costs real money. The energy penalty is small for typical 1 to 2 hour daily hood use but real. Recirculating hoods do not have this penalty because no conditioned air leaves the house. The energy trade-off is one of the few real advantages of recirculating, and it matters most in extreme climates.
How do I retrofit a ducted hood into a kitchen that currently has recirculating?+
If the kitchen has access to an exterior wall or attic above, the retrofit costs $400 to $1,500 for the duct work plus the new hood. The duct runs from the hood through cabinets or soffit to the exterior, with a wall cap or roof cap at the termination. If the path crosses a structural element (header, joist), add $200 to $600 for framing work. If the kitchen is in the interior of the house with no exterior wall access, the retrofit may not be feasible at any reasonable cost; some homes simply cannot be converted to ducted without major construction.
