FOTILE's Pixie Air UQG3002 is certified at 1.2 sones on speed 1 and 4 sones on high. Sones are linear, so top speed comes across as more than three times louder than speed 1, from the same hood in the same kitchen.
Speed is the first lever, then. The others are the filters, the damper, the screws holding everything together and, above all, the duct that carries the air outside, and on that last one ten makers' manuals, installation instructions and help pages have a surprising amount to say. Broan, Zephyr, Vent-A-Hood, Hauslane, Cosmo, GE, Bosch, Faber, Best and Whirlpool supply every step below. To put a name to a particular roar, rattle or whistle first, range hood noises sorts them by sound.
Seven checks, from habits to installer jobs
- Start the fan early and keep it on a low speed.
- Wash the grease filters, or replace charcoal ones.
- Check that the damper flap swings freely.
- Tighten the hood, motor and trim screws.
- Compare the duct size, material and route with the manual.
- Check the hood's height above the cooktop.
- For a new installation, ask about a hood built for a remote blower.
Run the lowest speed that clears the smoke
Bosch, Hauslane and Best all steer owners toward the slower settings for everyday cooking and keep the top speeds for heavy smoke. "Use the lower speed levels for normal use and the higher speed levels for strong odors or fumes," reads Bosch's use and care manual for its DUH and DUHP under-cabinet hoods. It also asks you to switch the blower on about 5 minutes before cooking, so air is already moving up through the hood when the smoke arrives.
The Pixie Air, the top pick in the quietest range hoods guide, moves 240 CFM at its 1.2 sones and 470 CFM at its 4. That is the trade on every hood: more air, more noise.
Hauslane rates most of its hoods at around 60 dB on the highest setting, and its FAQ points to the dial: "You can control the noise of the model through our various speed settings." Best pushes the idea further on its performance page, arguing that a larger blower on a low step can sound up to 50% quieter than a small one flat out.
Saving a lower starting speed
A hood that remembers a speed can start on a low one. Bosch's DUH and DUHP hoods start on the last saved speed, and a press and hold shown in the manual saves it.
Two features push the speed back up. Automatic mode adjusts the fan to the heat it detects. The heat sensor thermostat turns the blower to high when it senses excessive heat above the cooktop, then drops back to the original setting once the temperature falls.
The button beep can go too. With the fan and lights off, a 5 second press and hold toggles it.
Do dirty filters make a range hood louder?
Yes. Dirty, saturated filters obstruct the airflow, and filter care "affects the effectiveness, safety and noise levels of the hood," according to Faber's FAQ. Washable grease filters go through the sink or dishwasher "on average every 2 months"; charcoal filters, which cannot be washed, are replaced every 3 to 4 months. The Valina manual sets the same 2 month minimum for Zephyr's mesh filters and allows the dishwasher "at the lowest setting."
Bosch keeps count for you. A timer tracks hours of use, and when the filters are due the fan button light flashes slowly for 30 seconds as you switch the hood off.
Vent-A-Hood's Magic Lung hoods have no conventional filter at all. Grease collects in the blower housing and the E-Z Clean shield instead, its maintenance page explains, and "High fat content foods and heavy cooking may require cleaning after each use."
Ductless hoods are louder, by Faber's account
Ducting outside is less noisy because "the air passes without obstacles," Faber's FAQ says, whereas "The extra filtration step of charcoal filters creates more resistance for the air and thus creates noise."
None of the spec sheets checked for the under-cabinet range hood guide gives a separate noise figure for recirculating mode. The certified sone ratings in our guides all describe ducted hoods, and a hood running on a charcoal kit may not match them.
What duct size makes a range hood quietest?
The size printed in its installation instructions, kept at that size all the way to the wall or roof cap. Broan, Faber, Hauslane, Best and GE all tie undersized duct to extra noise.
Broan's answer to a loud hood is one check: does the ducting match your model, since the size "varies between models." Its duct FAQ puts most hoods at a minimum of 3 1/4 by 10 inches, the same as 6-inch round, and more powerful ones at up to 10-inch round.
The other makers explain why. "Smaller ducts have a negative effect on suction rates and make the hood noisier," Faber writes, and it wants one size from hood to wall cap. Stepping a 6-inch duct down to 4 inches "cuts performance and increases noise," warns Hauslane's troubleshooting page, and 6 inches is the smallest its FAQ recommends. Best puts it in terms of pressure: "Smaller ducts increase static pressure, reduce airflow, and typically make the hood louder." GE's JVX manual bars its ENERGY STAR versions from duct under 7 inches across and adds that "Fans installed with existing ducts may not achieve their rated air flow."
Too big is possible too
Bosch's DUH and DUHP manual lists "Ductwork is too large / oversized" right beside undersized duct as a noise cause. Best and Vent-A-Hood lean the other way on long runs: "Larger ductwork generally delivers better performance," says Best, and Vent-A-Hood tells installers to "Enlarge the duct for longer duct runs." With makers pulling in different directions, the size printed for your own model decides it.
Round against rectangular duct
Shape can change the certified figure, though not always in the same direction. HVI rates the Pixie Air at 4 sones on 7-inch round duct and 5.5 on rectangular. Broan's Glacier goes the other way, at 6.5 sones (420 CFM) on rectangular against 7.0 sones (380 CFM) on 7-inch round, as the under-cabinet guide records. Best's WCP1 wall hood, in the wall-mount guide, carries 9.5 sones on high for both. Look up the certified figure for the duct shape your wall or ceiling actually has.
Is flexible duct louder than rigid duct on a range hood?
Most makers think so, and four forbid it. "DO NOT USE FLEXIBLE DUCT; it creates back pressure/air turbulence and reduces performance," say Bosch's installation instructions for the DUH hoods. GE's JVX list reads "Do not use any type of flexible ducting", the Valina manual calls for "single wall rigid Metal ductwork only", and Vent-A-Hood says corrugated or flex duct "must not be used as it restricts airflow."
Broan stops short of a ban. Pick smooth metal over flexible metal, it advises, because "The ridges found in flexible metal duct create turbulence and will diminish airflow."
Two makers allow it with conditions. Hauslane says to "Fully extend flexible ducts" wherever rigid or semi-rigid duct is not used, and prefers semi-rigid or rigid for island hoods. Cosmo's COS-QS75 page quotes "as low as 40 dB on lowest fan speed with rigid ducting (sold separately)", then adds that the hood "comes with flexible ducting for convenient installation."
How long can a range hood duct be before it gets loud?
Makers count a duct run in equivalent feet, where every elbow, reducer and cap adds length. Zephyr caps the total at 150 equivalent feet, and the Valina manual's ducting calculation sheet shows what each piece costs:
| Duct piece | Counts as |
|---|---|
| 1 foot of straight round duct | 1 foot |
| 45° round elbow | 9 feet |
| 90° round elbow | 15 feet |
| 6, 7 or 8 inch round in-line damper | 15 feet |
| 7 to 6 inch or 8 to 7 inch tapered reducer | 25 feet |
| Round wall cap with damper | 30 feet |
For rectangular duct, the same sheet counts a flat 90° elbow as 24 feet, against 15 for the ordinary rectangular elbow. One tapered reducer costs more than a 90° turn.
Bosch shortens its maximum with every elbow. For 8-inch round duct "to achieve 80% exhaust efficiency", the DUH instructions allow 92 feet with a cap and no elbows, 78 feet with one elbow and 62 feet with two, and they warn that "Back to back elbows and 'S' turns give very poor delivery and are not recommended."
Best's checklist aims for under 50 linear feet of duct, ideally four or fewer elbows and transitions, a 2 foot straight stretch between any two 90-degree elbows, and transitions at least a foot from the hood outlet. Vent-A-Hood wants 4 to 5 feet between turns, each one "smooth and gradual, not sharp and angled."
Tape the joints at the hood
Screws are the problem on a Vent-A-Hood, whose dampers sit right under the duct. Only duct tape should attach transitions or duct to the top of the hood, because screws "extend inside the duct work and may obstruct the damper from opening." Further along the run, Zephyr wants both: "Fasten all connections with sheet metal screws and tape all joints." Bosch specifies 2-inch metal foil duct tape, and Hauslane asks you to check that every joint is sealed against leaks.
A stuck damper adds airflow noise
GE lists a damper blade that has not opened among the causes of loud airflow noise. Its blades "may flip over and will not fully open", the JVX manual warns, and the fix is to set the blade back where it started.
On a Vent-A-Hood, screws pushed through the ductwork are the commonest culprit. Take off the blower housing, find the flap and make sure it opens and closes freely. A damper pushed down into the blower housing during installation can be lifted gently "until it clicks past and above the housing." Outside, roof and wall openings must "open freely (i.e., NOT spring-loaded)."
Wind rattling a closed damper is a different sound, covered in range hood noises.
One damper or two
It depends on the maker. Hauslane says removing the hood's internal damper blades helps when the outside cap already has a damper. Bosch goes the other way for cold climates, adding a second backdraft damper on the cold side of a nonmetallic thermal break, as close as possible to where the duct enters the heated part of the house. Zephyr's sheet prices each one: 15 equivalent feet for an in-line damper, 30 for a wall cap with damper. Your hood's instructions decide which ones stay.
Mounting height matters indirectly
No maker ties height to noise directly. What Zephyr, Vent-A-Hood and Best do say is that a hood hung too high catches less smoke, so you end up on a louder speed.
Mount at the lowest height the maker recommends, Best's sizing page advises, and above that add about 100 CFM "for every additional 3 inches." In Vent-A-Hood's words, "The higher the hood is mounted, the less effective it will be." Zephyr calls going past 32 inches on the Valina "the installers' choice", one that "may compromise performance."
| Maker and hood | Height above the cooktop |
|---|---|
| Zephyr Valina | 24 to 32 inches |
| GE JVX under-cabinet hoods | 24 inches minimum, 30 maximum recommended |
| Bosch DUH and DUHP hoods | 24 inch minimum over electric, 30 over gas |
| Hauslane | 24 to 30 inches over electric, 28 to 30 over gas |
| Vent-A-Hood under-cabinet, 9 inches tall | 24 to 27 inches |
| Vent-A-Hood wall mount and island | 30 inches |
Going below the minimum is out. A hood installed lower than its manual's height loses the warranty, Faber's FAQ warns, and Best says that installing below the maker's minimum "is not recommended."
A loose hood rattles
Vibration, rattling and scraping trace back to the installation first, in Hauslane, Bosch, Faber and Vent-A-Hood documents alike: a hood not fixed firmly, a loose motor, screws left untightened, a blower wheel touching its housing.
Hauslane wants the hood firmly attached to the cabinet or wall, with extra screws if needed, and the motor secure. Bosch's list of causes for excessive noise includes wood screws "not fully tightened", loose screws in trim parts and a transition that "is too small or is loose".
One fix runs backwards. For an unbearable whistle from its under-cabinet hoods, Hauslane suggests loosening the mounting screws slightly: "they may be too tight!"
A hood that is loud straight after installation may have something inside it. Hauslane's FAQ has you cut the power, take the duct off and look for anything that fell in during fitting.
Scraping is a wheel problem on a Vent-A-Hood. The blower wheel can touch the front edge of the housing or the motor mount screws, and the fix is to reseat the housing on the motor housing or move the wheel along the motor shaft. Faber asks owners to check the installation against its manual, or have the installer do it, before calling customer service.
Are remote and inline blowers quieter?
At the hood, yes, by Vent-A-Hood's and Best's accounts, but neither prints a sone figure for one. The remote blower on the PRH18 "Moves the blower motor to a roof, attic or exterior wall location to reduce noise." In Vent-A-Hood's own Full Product Catalog, though, the CEO writes that he chose the in-hood Magic Lung for his kitchen "because it is the quietest" option.
Best's EB6 and EB9 sheet gives the layout: "To achieve reduced sound levels at the range hood, the exterior blower should be installed at least 10 feet away from the hood location and include one 90° elbow in the duct run between the hood and blower." That elbow "can help reduce noise transmission into the kitchen," the performance page adds.
Adding a fan to an existing hood is a different matter. Broan rules out in-line or external fans on a hood "that has its own power unit", since the boost "will not be effective" and voids the warranty. Hoods built to take a remote blower are in the island and wall-mount guides.
No maker sells a quieter replacement motor
Broan matches hood switches to the original motor's amp rating, and Whirlpool and Vent-A-Hood describe motor and blower work only as like for like.
Whirlpool's vent hood noise page has owners switch off the power and wiggle the motor shaft. If it moves at all, the bearings are worn and the whole motor has to be replaced. Vent-A-Hood pairs white blower wheels with white motor mounts and black with black, and a wheel on the wrong motor "will not function properly."
When the noise needs a technician
If it survives a check of speed, filters, damper, screws and duct, or the motor itself is worn, the makers want a professional. Whirlpool forbids lubricating or repairing a motor that is not working properly, because it "must be replaced." Faber asks owners to call customer service with the model and serial number from the label behind the grease filters. Vent-A-Hood, which sells through distributors, sends owners back to theirs.
Duct faults belong to the installer. When loud airflow comes from the wrong duct size, "GE Appliances service technicians cannot correct this issue if installed improperly," the JVX manual warns, and Zephyr's warranty requires installation by "a qualified professional installer." Grinding and whining, which several makers send straight to service, are covered in range hood noises.
How quiet can a range hood get?
Not silent at full power. On high, the quietest hood we could verify carries a certified 4 sones while moving 470 CFM, and hoods sold as quiet carry certified high-speed ratings of 5 to 13 sones.
Those figures come from the Home Ventilating Institute listings behind the quietest range hoods guide, which ranks only certified high-speed ratings. Low numbers on a box usually describe the slowest speed. Best's HBN5 insert, sold on "less than 0.3 sones at low speed", is certified at 11.5 sones on high.
Decibel claims such as Hauslane's 60 dB or Cosmo's 40 dB cannot be set against sones; sones vs decibels explains why. Both quote a low or top speed and neither says how far from the hood the reading was taken.
When a quieter hood is the better fix
Clean filters, a free damper, tight screws, the duct its manual asks for, and the rated sones at the speed you need are still too much? Then the hood is the problem.
The quietest range hoods guide ranks hoods on certified high-speed sones, with separate guides for under-cabinet range hoods, wall-mount range hoods, island range hoods, range hood inserts and downdraft range hoods. Brand pages set each maker's own figures beside HVI's for Broan, Zephyr, Vent-A-Hood and Hauslane. For a hood over an open-plan room, read planning a quiet open-plan kitchen, and a vent fan built into a microwave is covered in how to make a microwave quieter.
