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Quietest wall exhaust fan: BV's 70 CFM BV-WF-01-LV rates 4.0 sones

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· 7 min read

Illustration of a square exhaust fan grille set into a painted wall above a laundry shelf

BV's BV-WF-01-LV carries the lowest rating among current through-the-wall exhaust fans we could check: 4.0 sones at 70 CFM, which HVI's directory lists at 0.03 inch of static pressure.

Broan's 512M moves the same 70 CFM at 6.0 sones on Broan's sheet, Air King's EWF180 is 6.5 sones at 180 CFM, and Broan's 509 and 509S are 8.5 sones at 200 CFM, all at 0.03 inch.

Broan's 503, a ducted fan for a wall or ceiling, is 5.0 sones at 160 CFM at 0.1 inch and is ranked on its own.

On this page
  1. How we chose
  2. Our picks
  3. How to choose
  4. Comparison
  5. FAQs
  6. Bottom line
  7. Review history

A quick look at the quietest wall exhaust fans

A through-the-wall exhaust fan is a single box that sits in an outside wall, with a grille on the room side and a cap with a damper on the other, so it needs no duct run through a ceiling or attic. Kitchens, laundry rooms, garages and workshops are where makers aim them.

Every current model below carries a sone rating its maker prints. Four of them share one test point, 0.03 inch of static pressure, which lets us rank them across brands. A fifth, Broan's ducted 503, is rated at 0.1 inch and stands alone.

How did we pick these wall exhaust fans?

Every fan in this guide has a sone figure from the company that builds it, for the US model number, and a fan is ranked only beside fans tested at its own static pressure.

We started from HVI's certified products directory, data generated October 21, 2026, and read every entry in its other room exhaust fan category, then checked each candidate on its maker's site. We also looked for through-the-wall models from Air King, Fantech, Continental Fan, Panasonic and Delta Breez; Delta's wall-capable fans are ceiling or wall bath fans, outside this guide.

Broan-NuTone's site blocks automated readers, so every Broan page and spec sheet here is an Internet Archive copy of Broan's own document, dated in the sources. BV's and Air King's pages were read directly on November 5, 2026.

Prices are the makers' own, from BV's store on November 5, 2026 and from the archived Broan pages on the dates shown; Air King and the archived 503 page show none. We did not measure any of these fans ourselves.

QuietSpecs' picks of the quietest wall exhaust fans

Lowest rating, 4.0 sones at 70 CFM

BV Through-The-Wall Utility Fan, 70 CFM, 4.0 Sones, 6 Inch (BV-WF-01-LV)

  • Noise: 4.0 sones at 70 CFM (BV page); 0.03 in. w.g. in HVI's directory
  • Price: $69.99 maker's list price, checked Nov 5
  • Best for: A laundry room, mudroom or small workshop with an outside wall
  • Skip it if: The fan is going into a bathroom, which BV rules out

BV's page says the BV-WF-01-LV "Runs at 70 CFM and has a 4.0 sone rating", and HVI's certified directory lists the same pair at 0.03 inch of static pressure, the test point Broan and Air King print for their wall fans.

That is the lowest figure among the current wall fans here. The housing adjusts for walls 6 to 10 inches thick, and BV puts it at rooms up to 85 square feet.

BV lists it at $69.99, though its store showed it as unavailable on November 5, 2026.

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Broan's 70 CFM wall fan, 6.0 sones on its sheet

Broan-NuTone 512M 70 CFM Through-Wall Ventilation Fan

  • Noise: 6.0 sones at 70 CFM, 0.03 in. (Broan sheet and page); HVI lists 4
  • Price: $82.00 maker's list price, checked Jul 15
  • Best for: A one car garage or laundry room that needs about 70 CFM
  • Skip it if: You want the lowest maker figure at 70 CFM, where BV's 4.0 leads

Broan's spec sheet for the 512M lists 6.0 sones at 70 CFM, rated at .03 inch of static pressure, and the archived product page repeats "6.0 Audible Sones". HVI's directory, generated October 21, 2026, lists the same fan at 4 sones and 16.3 watts.

We rank Broan's own figure. The galvanized steel housing fits walls from 5-1/4 to 10 inches thick, with a 6-inch flexible duct and a wall cap with bird screen in the box. Broan showed $82.00.

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Most airflow per sone, 6.5 at 180 CFM

Air King EWF180 Through the Wall Exhaust Fan, 180 CFM

  • Noise: 6.5 sones (180 CFM, 0.03 in., Air King sheet)
  • Price: No maker list price
  • Best for: A garage or workshop that needs 160 to 225 square feet of ventilation
  • Skip it if: The fan is for a kitchen, which Air King's manual forbids

Air King's sheet heads the EWF180 with "180 CFM/6.5 Sones @ 0.03" SP", so it moves more than twice the BV fan's air for 2.5 sones more.

Its sones column is labeled ".1 SP", but 180 CFM is the airflow its own table gives at 0.03, so we read the pair as 0.03. The manual says "DO NOT USE IN KITCHENS" and bars solid-state speed controls.

HVI's directory has no Air King wall fan, and Air King's page shows no price.

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Most airflow, 8.5 sones at 200 CFM

Broan 509 200 CFM Through-the-Wall Exhaust Fan

  • Noise: 8.5 sones (200 CFM, 0.03 in., Broan sheet and HVI)
  • Price: $104.00 maker's list price, checked Apr 18
  • Best for: A kitchen or large garage where airflow matters more than noise
  • Skip it if: The room is under about 100 square feet, where a 70 CFM fan is enough

Broan rates the 509 at 8.5 sones and 200 CFM at 0.03 inch on the sheet it shares with the 509S, and HVI lists the same figures.

It is the loudest current fan here and the one that moves the most air, which Broan pitches at garages, kitchens, laundry and rec rooms. The steel housing fits walls 4-1/2 to 9-1/2 inches thick with a built-in wall cap and backdraft damper.

Broan showed $104.00; the 509S adds a switch dial on the grille for $134.00.

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Ducted wall or ceiling fan, 5.0 sones at 0.1 in.

Broan-NuTone 503 160 CFM Side Discharge Wall or Ceiling Fan

  • Noise: 5.0 sones at 160 CFM, 0.1 in. (Broan sheet, HVI)
  • Price: No maker list price
  • Best for: A kitchen or rec room where a short duct can run to the outside wall
  • Skip it if: You want a single box that passes straight through the wall

The 503 is a side discharge fan that Broan says "can be mounted on either the ceiling or the wall", with its air carried outdoors through a rectangular duct, 3-1/4 by 10 inches.

Its sheet lists 5.0 sones at 160 CFM with a 0.1 inch test point, matching HVI's directory, which adds 52.9 watts. Because the test point differs from the 0.03 inch through-the-wall fans, it sits in a group of one.

Broan pitches it at rec rooms, workshops and kitchen odors. No archived Broan page we read shows a price.

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How to choose

New to the units? Read dBA explained or sones vs decibels.

Which through-the-wall exhaust fan is the quietest?

BV's BV-WF-01-LV is the quietest through-the-wall exhaust fan with a current maker rating, 4.0 sones at 70 CFM, which HVI's certified directory lists at 0.03 inch of static pressure.

Ranked on that shared test point:

  • BV BV-WF-01-LV: 4.0 sones at 70 CFM
  • Broan-NuTone 512M: 6.0 sones at 70 CFM
  • Air King EWF180: 6.5 sones at 180 CFM
  • Broan 509 and 509S: 8.5 sones at 200 CFM

Sones rise in step with loudness as people hear it, so the 509 at 8.5 sounds roughly twice as loud as the BV fan at 4.0. Our sones and decibels explainer covers how the unit is built.

Airflow changes the picture. The two 70 CFM fans suit a small room, while Air King's 180 CFM for 6.5 sones is the most air per sone in the list, and the 509 moves 200 CFM at the top of the noise range.

Why does HVI list the Broan 512M at 4 sones?

The Broan 512M appears in HVI's directory at 4 sones and 16.3 watts at 70 CFM and 0.03 inch, while Broan's spec sheet and product page both say 6.0 sones, and neither explains the gap.

Broan's sheet carries the usual "HVI-2100 CERTIFIED RATINGS" paragraph and the line "Air delivery shall be no less than 70 CFM and sound level no greater than 6.0 Sones." The archived page from July 15, 2026 repeats "6.0 Audible Sones".

We rank the maker's figure, so the 512M sits second at 6.0. If HVI's 4 is the newer test, it would tie BV's fan at the same airflow.

What static pressure are wall fan sones rated at?

Broan and Air King rate their through-the-wall fans at 0.03 inch, and BV's fan appears in HVI's directory at that point too. Broan's ducted 503 is rated at 0.1 inch.

Static pressure measures how hard the air pushes back on the blade. A fan that blows straight out through its own wall cap has almost none, which fits the low 0.03 test point. A ducted fan is tested at 0.1 inch, so its sones come from a harder test and cannot be set beside the wall fans.

Air King's sheet shows what that pressure does to airflow. The EWF180 moves 193 CFM with no resistance, 180 at 0.03 inch, 157 at 0.1 and 131 at 0.3. Air King prints sones only once, 6.5.

Are through-the-wall fans louder than ceiling bath fans?

Yes: the quietest current through-the-wall fan we found is rated 4.0 sones at the easy 0.03 inch test point, while the ducted ceiling fans in our bathroom guides carry far lower ratings at the harder 0.1 inch point.

A ceiling fan pushes its noise up a duct and into the attic. A wall fan has only a short sleeve through the wall and a grille, so the motor sits close to the room.

If a ceiling or attic is within reach, our bathroom exhaust fan guide ranks ducted fans, while fans mounted out of the room, in the duct itself, are ranked in our inline duct fan guide. For whole-house fresh air through a wall, see the ERV and HRV guide.

Can a through-the-wall exhaust fan go in a bathroom or kitchen?

It depends on the model: BV rules out bathrooms, Air King rules out kitchens and shower areas, and Broan's wall fans are not UL listed for use over a tub or shower.

Bathrooms

BV's page says plainly "Do not use in the bathroom". Air King's manual says "Do not install wall mounted fans inside the shower area." Broan's spec tables for the 512M, 509 and 503 all answer No to "UL Listed for use over bathtubs or showers when connected to a GFCI circuit".

Kitchens

Air King's manual for the EWF180 says "WARNING: DO NOT USE IN KITCHENS." Broan's 512M guide says "Do not mount the ventilator above a cooking surface." Broan's 509 guide, by contrast, includes advice on range-top grease fires, and its page names the kitchen among the rooms it suits. None of these is a range hood; for that, see our range hood guide.

How much airflow does a wall exhaust fan need?

Each maker states the room size its wall fan suits: 65 square feet for Broan's 512M, 85 for BV's 70 CFM fan, 160 to 225 for Air King's EWF180 and up to 195 for Broan's 509.

Broan's 509 page gives two numbers, 195 square feet in its feature list and 170 in its spec table. Broan also says the 512M can ventilate a one car garage, attached or detached.

A bigger fan than the room needs only buys more noise here. Broan sells the 512M for use with its SC100W variable speed control; Air King's manual forbids solid-state speed controls on the EWF180.

Which wall exhaust fans did we leave out?

We left out fans that are discontinued, fans that mount in ceilings, single-room ERVs and wall fans with no published sone figure. Each group is set out below.

Discontinued wall fans

Broan's archived pages mark the 504, 506, 507, 508, 510, 511, 512 and 512N as discontinued, most pointing buyers to the 509 or the 511, though the 511 has since been discontinued as well. Panasonic's WhisperWall FV-08WQ1 has dropped out of HVI's directory, and we found no page for it on Panasonic's US ventilation site. BV's 90 CFM BV-WF-01 is still in HVI's directory at 4 sones, but BV's own store lists only the 70 CFM BV-WF-01-LV.

Ceiling fans in HVI's other room category

HVI files Reversomatic's QCF-200, CF-170ES and QCF-500 as other room exhaust fans, which is how they look like wall fans in a search. Reversomatic describes the QCF series as quiet ceiling exhaust fans, so they are out. Broan's L100E to L300E sit in the same HVI category and are ceiling fans covered on our Broan bathroom fan page.

Wall fans with no sone figure

Fantech's PBW exterior-mount bath fans sit outside on the wall and are fed by a short duct, and Fantech's literature publishes no sone figure for them. Continental Fan's wall fans are direct drive axial units that its brochure aims at factories and warehouses. Vents TwinFresh and Blauberg VENTO wall units are single-room ventilators that supply air as well as exhaust it, and belong with ERVs.

How the quietest wall exhaust fans compare

ProductNoiseAirflowPrice
BV-WF-01-LV4.0 sones at 70 CFM (BV page); 0.03 in. w.g. in HVI's directory70 CFM, rooms up to 85 sq ft$69.99 maker's list price
Broan-NuTone 512M6.0 sones at 70 CFM, 0.03 in. (Broan sheet and page); HVI lists 470 CFM, rooms up to 65 sq ft$82.00 maker's list price
Air King EWF180 (EWF-180)6.5 sones (180 CFM, 0.03 in., Air King sheet)180 CFM at 0.03 in., 157 CFM at 0.1 in.Not verified yet
Broan-NuTone 5098.5 sones (200 CFM, 0.03 in., Broan sheet and HVI)200 CFM, up to 195 sq ft (page features)$104.00 maker's list price
Broan-NuTone 5035.0 sones at 160 CFM, 0.1 in. (Broan sheet, HVI)160 CFMNot verified yet

Frequently asked questions

Which through-the-wall exhaust fan has the lowest sone rating?

BV's BV-WF-01-LV, rated 4.0 sones at 70 CFM on BV's page and in HVI's directory at 0.03 inch. Broan's 512M is 6.0 on its own sheet, Air King's EWF180 is 6.5 and Broan's 509 is 8.5, all at the same test point.

How many sones is a through-the-wall exhaust fan?

The current models we checked run from 4.0 to 8.5 sones at 0.03 inch of static pressure: 4.0 for BV's 70 CFM fan, 6.0 for Broan's 512M, 6.5 for Air King's EWF180 and 8.5 for Broan's 509 and 509S.

Why does HVI list the Broan 512M at 4 sones when Broan says 6.0?

Neither source explains it. Broan's sheet and its archived product page both give 6.0 sones at 70 CFM at .03 inch, and HVI's directory, generated October 21, 2026, lists 4 sones and 16.3 watts at the same airflow and pressure. We rank Broan's 6.0 because it is the maker's figure.

Is the Panasonic WhisperWall still sold?

Not as a current model that we could find. The FV-08WQ1 is no longer in HVI's certified directory, and Panasonic's US ventilation site has no page for it, so we do not rank it, even though some retailers still list it.

Can a through-the-wall exhaust fan go in a bathroom?

Read the label first. BV's page says "Do not use in the bathroom", Broan's 512M and 509 are not UL listed for use over a tub or shower, and Air King's manual says "Do not install wall mounted fans inside the shower area."

Are Reversomatic's QCF fans wall fans?

No. HVI files the QCF-200 and CF-170ES under other room exhaust fans, but Reversomatic calls the QCF series "quiet ceiling exhaust fans" and says the CF 170ES mounts on concrete ceilings or wooden joists, so neither is a through-the-wall model.

The bottom line

Through-the-wall fans are the loud cousins of the bathroom fan. The quietest one I could pin to a current maker figure is 4.0 sones, several times the rating of a good ducted ceiling fan, and the plain reason is that little more than a grille stands between the blade and the room. You buy one because there is no attic or ceiling space to run a duct, not because it is quiet.

Within that, I would take a 70 CFM fan for a laundry room or small workshop and only step up to 180 or 200 CFM for a garage. If you can reach a ceiling, I would put a ducted fan there instead. One quirk worth knowing: HVI's directory lists Broan's 512M at 4 sones while Broan's own sheet says 6.0, and I rank Broan's number.

Stanley Alu, founder and editor

What we also considered

These are worth knowing about, and why they didn't make the list.

  • Broan 509S 200 CFM Through-the-Wall Exhaust Fan with On/Off Switch

    The 509 with an on/off dial on the grille, so no wall switch has to be wired. Broan rates it identically, 8.5 sones at 200 CFM at 0.03 inch, and showed it at $134.00.

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How we reviewed this article

Every statement here comes from the 18 maker documents, standards and agency pages listed under Sources, quoted where the wording matters. We did not measure, inspect or repair anything ourselves. Each substantive revision is dated below. How we work

  1. Current version

    First published, written by Stanley Alu.

Sources

Every figure on this page was read on one of the pages below. We did not measure anything ourselves.

All 18 sources
Manufacturer pages and manuals for every product

Related guides

The quietest bathroom exhaust fans, by real sones

The sone rating on the box is measured under ideal conditions. We ranked bathroom fans on how loud they are once installed, and on the duct you have.

Broan bathroom fan sones at 0.1 inch, and the few rated at 0.25

The EVOLVE PTE511RK and its lighted twin are Broan's quietest fans: under 0.3 sone at 50 and 80 CFM and 0.3 at 110 CFM at 0.1 inch on a 6-inch duct, and 0.9 sone at 110 CFM at 0.25 inch, still at full airflow. Most of Broan's 89 current sheets give a sone figure at 0.1 inch only.

The quietest inline duct fans

Inline duct fan figures run from 26 dBA for a 4 inch EC fan to 45 dBA at 8 inches. Eighteen fans with maker figures, how AC Infinity, VIVOSUN, TerraBloom and VENTS rate theirs, and which brands publish nothing at all.