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Are AC Infinity fans quiet? Their spec tables say 16 to 70 dBA

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· 12 min read

Flat illustration of a black inline duct fan strapped to a ceiling joist between two lengths of flexible duct, with a small clip fan on a pole beside it

AC Infinity prints a "Total Noise" figure in dBA on the spec table of nearly every fan it sells, from a 40mm USB fan to a 20-inch shutter fan, and names no distance or speed for it.

Within its own range the AIRTAP T4 and most AIRTAP T6 register boosters list the lowest single figure, 16 dBA at 140 CFM.

The CLOUDLINE S4 and T4 lead the inline duct fans at 26 dBA and 226 CFM, and the 6-inch S6 lists 30 dBA at 425 CFM for $99.

The AIRPLATE S1 and S2 cabinet fans list 17 dBA, the CLOUDRAY S4 clip fan 29, and the AIRLIFT S12 is the quietest shutter fan at 62. The CLOUDPLATE rack fans print a range instead, down to 8 dBA on their lowest speed.

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 AC Infinity fans

AC Infinity's lowest single noise figure belongs to the AIRTAP T4 register booster fan, which lists 16 dBA at 140 CFM, and its quietest inline duct fan is the 4-inch CLOUDLINE S4, at 26 dBA and 226 CFM.

AC Infinity prints a "Total Noise" row in the spec table of nearly every fan page on its US site, acinfinity.com. On November 4, 2026 we read 125 of those pages, from 40mm USB fans to 20-inch shutter fans.

Many pages print the figure twice, once in a feature line such as "Airflow: 226 CFM | Noise: 26 dBA" and again in the table, and the two agree on all but a few pages listed below.

None of them names a microphone distance, a fan speed or a test standard for it. So every ranking on this page stays inside one AC Infinity product type and size, and range figures, which run from the slowest speed to the fastest, are kept apart from single figures.

How these fans compare with other brands is in our guides to quiet inline duct fans and quiet PC fans, which say where the bases differ.

How did we gather AC Infinity's figures?

On November 4, 2026 we read the fan categories on acinfinity.com, AC Infinity's US store, and its product sitemap, and opened each fan product page they listed.

From each page we copied the "Total Noise" row, the feature line, airflow, static pressure, power, price and stock status, and searched the text for any distance, speed or standard tied to the figure. We found none.

We also read AC Infinity's article on fan noise and the CLOUDLINE S and T manual, which prints no noise figure.

Figures are ranked only within one product line and size. Single figures and ranges are never ranked against each other, and the six models whose pages print two different figures for the same fan sit outside every ranking.

Prices are those AC Infinity's store displayed that day. No AC Infinity fan was measured by us; each figure is the maker's, copied from its US product pages.

QuietSpecs' picks of the quietest AC Infinity fans

Prices as of Nov 4. Product prices and availability are accurate as of the date/time indicated and are subject to change.

Quietest AC Infinity inline duct fan

AC Infinity CLOUDLINE S4

AC Infinity CLOUDLINE S4
  • Noise: 26 dBA in the spec table
  • Price: $89.99 at Amazon, checked Nov 4
  • Best for: A 2x2 or 2x4 tent, a closet or an AV cupboard on 4-inch duct
  • Skip it if: The space needs 6-inch ducting or more than about 226 CFM

The 4-inch CLOUDLINE S4 lists "Total Noise" "26 dBA" with 226 CFM and 223 Pa, the lowest figure on any CLOUDLINE. It runs an EC motor on a 10-speed corded controller and draws 28 W at most.

The T4 prints the same fan figures for $119.00 with a temperature, humidity and VPD controller, while the IP65 H4 lists 27 dBA at 212 CFM and the budget A4 29 dBA at 165 CFM.

Check price at Amazon

Quietest AC Infinity 6-inch inline fan

AC Infinity CLOUDLINE S6

  • Noise: 30 dBA in the spec table
  • Price: $99.00 maker's list price, checked Sep 26
  • Best for: A 3x3 or 4x4 tent, or a grow room, on 6-inch duct
  • Skip it if: A 4-inch S4 moves enough air for the space

Among 6-inch CLOUDLINE fans the S6 and T6 share the lowest figure, "Total Noise" "30 dBA", with 425 CFM and 503 Pa.

The cheaper A6 lists 34 dBA with 352 CFM for $89.99, so the S6 costs $9.01 more for a lower figure and more air. The T6 adds the smart controller for $149.00. Static pressure is more than twice the S4's.

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Quietest 6-inch AC Infinity clip fan

AC Infinity CLOUDRAY S6 Grow Tent Clip Fan 6 inch

  • Noise: 31 dBA in the spec table
  • Price: $49.99 maker's list price, checked Nov 4
  • Best for: Air movement under the canopy in a 3x3 or 4x4 tent
  • Skip it if: You do not need oscillation, since the A6 prints the same 31 dBA

The CLOUDRAY S6 lists "Total Noise" "31 dBA" with 325 CFM, and the A6 prints the same pair without automatic oscillation. Only the 4-inch CLOUDRAY S4, at 29 dBA and 204 CFM, is lower in the clip fan line.

The S6 adds 10 speeds, 10 "dynamic wind modes" and 10 oscillation ranges on an EC motor rated IP-54, and draws 11 W.

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Lowest single figure AC Infinity prints

AC Infinity AIRTAP T4 Smart Register Booster Fan 4 x 10 inch, White

  • Noise: 16 dBA in the spec table
  • Price: $69.99 maker's list price, checked Nov 4
  • Best for: A room at the end of a duct run that stays warmer or colder than the rest
  • Skip it if: Your registers are another size, or the room needs a through-wall fan

The AIRTAP T4 register booster lists "Total Noise" "16 dBA" with 140 CFM, the lowest single figure on any AC Infinity fan page we read.

All four T4 versions, white or bronze in 4 x 10 or 4 x 12 inches, print that pair at $69.99. It sits in a floor or wall register, and AC Infinity says its "Electronic vents automatically open when your HVAC system activates".

It has an LCD, a remote and app control.

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Quietest AIRPLATE cabinet fan, tied with the S2

AC Infinity AIRPLATE S1 Quiet Cabinet Cooling Fan 4 inch

  • Noise: 17 dBA in the spec table
  • Price: $26.99 maker's list price, checked Nov 4
  • Best for: A small closed cabinet with one receiver or streaming box
  • Skip it if: The cabinet holds an amplifier or console that needs more than 26 CFM

The 4-inch AIRPLATE S1 lists "Total Noise" "17 dBA" with 26 CFM, the lowest figure of any AIRPLATE, shared with the 35 CFM S2. It uses AC Infinity's ACX-FD8025 fan in an aluminum frame, runs from USB or a wall outlet, and draws 1.1 W.

Its spec row matches the MULTIFAN S1, which is $12 cheaper without the frame. For more air, the twin-fan S7 lists 19 dBA at 104 CFM.

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Most airflow of the USB-powered MULTIFANs

AC Infinity MULTIFAN S7 Quiet USB Cooling Fan Dual 120mm

  • Noise: 19 dBA in the spec table
  • Price: $22.99 maker's list price, checked Nov 4
  • Best for: Cooling a receiver or game console on an open shelf
  • Skip it if: There is no free USB port and you would rather plug into the wall

The MULTIFAN S7 is two 120mm fans on one controller, listed at "Total Noise: 19 dBA" with 104 CFM and 1300 RPM. Among USB-powered MULTIFANs nothing moves more air, and the 17 to 18 dBA models move 12 to 57 CFM.

AC Infinity says the USB plug works from ports "behind popular AV electronics and game consoles". The AC-powered S7-P lists 130 CFM at the same 19 dBA.

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Lowest low-speed figure in AC Infinity's range

AC Infinity CLOUDPLATE T1 Quiet Rack Cooling Fan System 1U Exhaust

  • Noise: 8 to 28 dBA (range by speed)
  • Price: $139.00 maker's list price, checked Nov 4
  • Best for: A network rack in a living space
  • Skip it if: The rack runs hot enough to need the 300 CFM of a T9

The 1U CLOUDPLATE T1 prints its noise as a range, "8 to 28 dBA", beside "20 to 60 CFM", and its page says it "can reach 8 dBA".

That 8 dBA is the lowest number on any AC Infinity fan page, but it belongs to the slowest speed, so we rank it only against the other CLOUDPLATE ranges. The intake T1-N prints the same range.

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Quietest AC Infinity duct booster

AC Infinity RAXIAL S4 Inline Booster Duct Fan 4 inch

  • Noise: 28 dBA in the spec table
  • Price: $34.99 maker's list price, checked Nov 4
  • Best for: Boosting a short, open 4-inch duct run
  • Skip it if: The fan will pull through a carbon filter, where a CLOUDLINE fits

The RAXIAL S4 lists "Total Noise" "28 dBA" with 106 CFM, and its page ties both to the high end of its knob, "producing up to 106 CFM and 28 dBA in noise". The S6 lists 35 dBA and the S8 43.

It costs $34.99, against $89.99 for a CLOUDLINE S4 that lists 26 dBA at 226 CFM, but AC Infinity calls the RAXIAL "not suitable for restricted airflow applications".

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Quietest AC Infinity shutter fan

AC Infinity AIRLIFT S12 Shutter Exhaust Fan 12 inch with Speed Controller

  • Noise: 62 dBA in the spec table
  • Price: $169.00 maker's list price, checked Nov 4
  • Best for: Exhausting a greenhouse, garage or shed
  • Skip it if: You want it to run on temperature, which the $199.00 T12 does

Among AIRLIFT shutter fans the 12-inch S12 and T12 list the lowest figure, "Total Noise" "62 dBA", with 830 CFM. The 10-inch S10 is louder at 67 dBA with less air, and the 20-inch S20 lists 65 dBA at 3425 CFM.

The S12 has a 10-level PWM controller and steel shutters, and is $30 cheaper than the T12, which adds temperature and humidity control.

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How to choose

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

What does the Total Noise figure on an AC Infinity page mean?

The Total Noise figure on an AC Infinity page is one A-weighted decibel number per model, and AC Infinity gives no distance, speed or test standard for it. Its own article says the sheet carries the loudest noise the fan makes.

That article, "Fan Speed, Bearings, and Noise", says "The loudest of these noises is stated on the fans specification sheet in decibel units", and adds that the rating "should only be used as a reference". We read each single figure as the fan's top speed on that basis.

The RAXIAL boosters say it outright, "producing up to 106 CFM and 28 dBA in noise", and the CLOUDWAY T10 runs "quietly at a maximum of 48 dBA".

The CLOUDLINE S and T manual linked from the S4 page prints no noise figure at all. A few lines, the CLOUDPLATE rack fans and the controller-equipped AXIAL S fans, print a range such as "8 to 28 dBA" beside an airflow range, which we read as slowest to fastest speed.

Which AC Infinity inline duct fan is quietest?

The CLOUDLINE S4 and T4 are the quietest AC Infinity inline duct fans, at 26 dBA and 226 CFM. At every duct size the S and T models share the lowest figure, and the cheaper A model is rated louder with less air.

By duct size, lowest figure first:

  • 4-inch: S4 and T4 26 dBA at 226 CFM; H4 27 at 212; A4 29 at 165.
  • 6-inch: S6 and T6 30 dBA at 425 CFM; A6 34 at 352.
  • 8-inch: S8 and T8 38 dBA at 857 CFM; A8 42 at 724.
  • 10-inch: S10 and T10 48 dBA at 1201 CFM.
  • 12-inch: S12 and T12 62 dBA at 1604 CFM.

Prices on November 4 ran from $79.99 for the A4 to $399.00 for the T12. The T model costs $20 to $50 more than the S model of the same size for the temperature, humidity and VPD controller; the fan figures do not change.

The figure climbs with size, and the 14 dBA step from the 10-inch to the 12-inch is the largest in the line. AC Infinity against VIVOSUN, TerraBloom and VENTS is in our inline duct fan guide.

How loud are AC Infinity's booster and whole-house fans?

AC Infinity's duct boosters list 28 to 60 dBA and its CLOUDWAY whole-house fans 48 to 62 dBA. The RAXIAL S4, at 28 dBA and 106 CFM, is the quietest booster.

  • RAXIAL S4, 4-inch: 28 dBA at 106 CFM, $34.99.
  • RAXIAL S6, 6-inch: 35 dBA at 265 CFM, $36.99.
  • RAXIAL S8, 8-inch: 43 dBA at 428 CFM, $49.99.
  • Automatic Duct Fan 4-inch (AC-BFP4): 60 dBA at 230 CFM, $99.00.
  • CLOUDWAY S10 and T10: 48 dBA at 791 CFM.
  • CLOUDWAY S12 and T12: 62 dBA at 1250 CFM.

The Automatic Duct Fan moves about the same air as a CLOUDLINE S4 at a figure 34 dBA higher. The CLOUDWAY fans share their 48 and 62 dBA with the CLOUDLINE S10 and S12 of the same duct size. Other makers' whole-house fans are in our whole house fan guide.

How loud are CLOUDRAY clip fans and CLOUDLIFT floor fans?

CLOUDRAY clip fans list 29 to 35 dBA and the CLOUDLIFT floor and wall fans 62 to 70 dBA. The 4-inch CLOUDRAY S4, at 29 dBA and 204 CFM, is the quietest of the clip fans.

  • CLOUDRAY S4: 29 dBA at 204 CFM, $49.99.
  • CLOUDRAY S6 and A6: 31 dBA at 325 CFM, $49.99 and $44.99.
  • CLOUDRAY S9: 35 dBA at 601 CFM, $69.99.
  • CLOUDRAY A9: 35 dBA at 405 CFM, $59.99.
  • CLOUDLIFT S12: 62 dBA at 1807 CFM, $189.00.
  • CLOUDLIFT S14: 70 dBA at 2130 CFM, $219.00, the highest figure in any AC Infinity spec table.

The 2-Packs list the single-fan figures. The A models give up automatic oscillation, and the A9 also gives up about a third of the S9's airflow at the same 35 dBA, so in that size the S9 is the better buy on AC Infinity's own numbers.

Which AC Infinity fan is quietest for a cabinet or AV shelf?

The AIRPLATE S1 and S2 are the quietest AC Infinity cabinet fans at 17 dBA, and the AIRCOM S7 the quietest receiver fan at 19 dBA. Most AIRPLATE models sit between 17 and 21 dBA.

AIRPLATE cabinet fans, lowest figure first:

  • S1, 4-inch: 17 dBA at 26 CFM, $26.99.
  • S2, 6-inch: 17 dBA at 35 CFM, $36.99.
  • S3 and T3: 18 dBA at 52 CFM, $29.99 and $69.99.
  • S5: 18 dBA at 52 CFM, $36.99.
  • S7 and T7: 19 dBA at 104 CFM, $49.99 and $89.99.
  • T8 and T8 White: 19 dBA, $119.00, with no airflow row.
  • S9 and T9: 21 dBA at 156 CFM, $59.99 and $119.00.
  • P7, with outlets and USB ports: 51 dBA at 98 CFM, $79.99.

AIRCOM receiver fans: S7 19 dBA at 140 CFM; S6 20 at 100; S9 and T9 21 at 210; S8, T8, S10 and T10 24 at 160. The AIRFRAME T7 closet fans and the Rack Roof Fan Kit list 26 dBA at 200 CFM.

The P7 stands far above the rest of the AIRPLATE line at 51 dBA. The network gear that often shares these cabinets is ranked in our quiet router guide.

How loud are CLOUDPLATE rack fans?

CLOUDPLATE rack fans print a range rather than one figure, from 8 dBA at the slowest speed to 38 dBA at the fastest. The T1 starts lowest and also tops out lowest, at 28 dBA.

  • T1 and T1-N: 8 to 28 dBA at 20 to 60 CFM, $139.00.
  • T5 and T6: 9 to 32 dBA at 40 to 180 CFM, $189.00.
  • T7 and T7-N: 10 to 36 dBA at 50 to 220 CFM, $139.00.
  • T2, T9 and T9-N: 12 to 38 dBA at 60 to 300 CFM, $149.00.

Each fan's two ends belong to different speeds, so the low end of a CLOUDPLATE range is never set against a single figure elsewhere on this page. A rack that runs warm will push the thermal controller toward the top of the range.

How loud are MULTIFAN USB fans and AXIAL muffin fans?

MULTIFAN USB fans list 17 to 19 dBA, and AXIAL 120V muffin fans 28 to 65 dBA with a single figure. The MULTIFAN S1 and S2 are the quietest USB fans; the AXIAL 8038 is the quietest single-figure muffin fan.

MULTIFAN: S1 80mm 17 dBA at 26 CFM; S2 centrifugal 17 at 35; Mini 40mm 18 at 12; S3 and S3-P 120mm 18 at 52; S4 140mm 18 at 57; S5 dual 80mm 18 at 26; S7 dual 120mm 19 at 104; S7-P 19 at 130. Prices run $14.99 to $26.99.

AXIAL fans by frame size, lowest figure first:

  • 80mm: 8038 28 dBA at 23 CFM; 8025 32 at 22.
  • 92mm: 9225 37 dBA at 37 CFM; 9238 40 at 47.
  • 120 x 25 mm: 1225 30 dBA at 51 CFM.
  • 120 x 38 mm: LS1238 32 dBA at 62 CFM; 1238 and 1238W 47 at 110.
  • Larger: 2589 10-inch 50 dBA at 550 CFM; 1751 52 at 211; 2060 65 at 425.

With speed controllers, the S1225 and S1225D print 16 to 38 dBA and the S1238 and S1238D 21 to 47 dBA. How AC Infinity's small fans sit beside Noctua's appears in our Noctua fan decibels page.

How loud are AIRTAP register boosters and room-to-room fans?

AIRTAP register boosters list 16 dBA on seven of their eight pages, and AC Infinity's room-to-room fans 23 dBA. The AIRBLAZE fireplace blowers, the other fans sold for living rooms, list 26 to 30 dBA.

  • AIRTAP T4, 4 x 10 and 4 x 12, white and bronze: 16 dBA at 140 CFM, $69.99.
  • AIRTAP T6, 6 x 10 white and both 6 x 12: 16 dBA at 140 CFM, $69.99 to $79.99.
  • AIRTAP T6, 6 x 10 bronze: 18 dBA at 120 CFM, $69.99.
  • Room to Room Fan 6-inch: 23 dBA at 207 CFM, $99.00.
  • Through-wall Room to Room Fan 8-inch: 23 dBA at 350 CFM, $129.00.
  • AIRBLAZE S10 and T10: 26 dBA at 120 CFM; S12 and T12 28 at 160; S14 and T14 30 at 200.

A register booster sits a few feet from where people sit or sleep, which is why its low figure matters more than a duct fan's in the attic.

How loud are AIRLIFT shutter fans and AIRTITAN crawlspace fans?

AIRLIFT shutter fans list 62 to 68 dBA, and with the CLOUDLIFT floor fans they are AC Infinity's loudest lines; AIRTITAN crawlspace fans list 30 to 32 dBA. The 12-inch AIRLIFT S12 and T12 are the quietest shutter fans.

  • AIRLIFT S12 and T12, 12-inch: 62 dBA at 830 CFM.
  • AIRLIFT S20 and T20, 20-inch: 65 dBA at 3425 CFM.
  • AIRLIFT S10 and T10, 10-inch: 67 dBA at 631 CFM.
  • AIRLIFT S16 and T16, 16-inch: 67 dBA in the table, 70 in the feature line, at 2560 CFM.
  • AIRLIFT S14 and T14, 14-inch: 68 dBA at 1513 CFM.
  • AIRTITAN S3 and T3: 30 dBA at 120 CFM.
  • AIRTITAN S7, T7, T8 and T8-N: 32 dBA at 240 CFM.

Unlike the duct fans, the AIRLIFT figure does not rise with size. Attic and gable fans from other makers are in our attic fan guide.

Where do AC Infinity's pages disagree with themselves?

AC Infinity's pages disagree in four places we found, and we quote each figure as printed.

The AIRLIFT S16 and T16 pages list "Total Noise" "67 dBA" in the spec table and "Noise: 70 dBA" in the feature line above it.

The four Smart Home Fan and Smart Home Pedestal Fan pages list "Total Noise" "20 dBA", while their feature text says the motor "operates quietly at 23dB". With airflow given only as "up to 1000 CFM", we cannot tell which speed either number belongs to, so these fans and the two 16-inch AIRLIFTs sit outside every ranking.

The bronze AIRTAP T6 in 6 x 10 inches lists 18 dBA and 120 CFM; the white 6 x 10 and both 6 x 12 versions list 16 dBA and 140 CFM. We list the bronze page as printed.

And the CLOUDPLATE T2 page says "With a noise level that can reach 8 dBA", while its own table gives "12 to 38 dBA". The 8 dBA matches the T1, so we follow the table.

Which AC Infinity fans print no figure, and which are discontinued?

Every AC Infinity fan we found on its US site prints a noise figure. The products without one are not fans: speed controllers, thermal triggers, passive grilles, filters and duct kits.

We found no fan page marked discontinued. The AXIAL 1751 was marked out of stock on November 4, and we list it with its 52 dBA figure. The CLOUDLINE names LITE, PRO and EVO do not appear among AC Infinity's US fan products or its sitemap, so a fan sold under one of those names is not a current AC Infinity US model.

So, are AC Infinity fans quiet?

By their own figures, most AC Infinity fans built for homes are low: in the cabinet, AV, USB, register and room-to-room lines, every model except the AIRPLATE P7 prints 24 dBA or less. The inline duct fans run 26 to 62 dBA by size, and the shutter and floor fans 62 to 70.

What AC Infinity's numbers cannot do is cross a brand line. With no distance or standard, a 26 dBA CLOUDLINE and a 26 dBA rival are not known to sound alike. Our decibel chart sets levels like these beside everyday sounds, and comparing decibel ratings covers why test conditions change the number.

How the quietest AC Infinity fans compare

ProductNoiseAirflowPowerPrice
AC Infinity AI-CLS426 dBA in the spec table226 CFM, 223 Pa28 W max, 21 W average$89.99
AC Infinity AI-CLS630 dBA in the spec table425 CFM, 503 Pa70 W max, 38 W average$99.00 maker's list price
AC Infinity AC-CCS631 dBA in the spec table325 CFM11 W$49.99 maker's list price
AC Infinity AC-RBF4-W16 dBA in the spec table140 CFM, 6.5 mm-H2O8 W, 12V DC$69.99 maker's list price
AC Infinity AI-CFS80BA17 dBA in the spec table26 CFM, 1.6 mm-H2O1.1 W, 3 to 7V DC$26.99 maker's list price
AC Infinity AI-MPF120A219 dBA in the spec table104 CFM, 1300 RPM2.9 W, 3 to 7V DC$22.99 maker's list price
AC Infinity AI-CPT18 to 28 dBA (range by speed)20 to 60 CFM8 W$139.00 maker's list price
AC Infinity AC-RXS428 dBA in the spec table106 CFM, 4.90 mm-H2015 W$34.99 maker's list price
AC Infinity AC-ALS1262 dBA in the spec table830 CFM, 73 Pa54 W$169.00 maker's list price

Prices as of Nov 4. Product prices and availability are accurate as of the date/time indicated and are subject to change.

Frequently asked questions

How loud is an AC Infinity inline fan?

By AC Infinity's Total Noise rows, from 26 dBA for the 4-inch CLOUDLINE S4 and T4 to 62 dBA for the 12-inch S12 and T12. The 6-inch S6 and T6 list 30 dBA, the 8-inch S8 and T8 38 dBA and the 10-inch S10 and T10 48 dBA. The cheaper A4, A6 and A8 list 29, 34 and 42 dBA.

Which AC Infinity fan is the quietest?

On single figures, the AIRTAP T4 register booster and three of the four AIRTAP T6 versions, at 16 dBA and 140 CFM. Next come the AIRPLATE S1 and S2 and the MULTIFAN S1 and S2 at 17 dBA. The CLOUDPLATE rack fans print ranges that start lower, 8 dBA on the T1, but only at their slowest speed.

At what distance does AC Infinity measure its dBA figures?

AC Infinity does not say. No product page, manual or article we read names a distance, a fan speed or a test standard for the Total Noise row. Its article on fan noise says only that "The loudest of these noises is stated on the fans specification sheet", so we treat single figures as top-speed ratings and rank them only against each other.

Is the CLOUDLINE A series quieter than the S series?

No. At each size AC Infinity rates the A series louder and with less airflow: the A4 29 dBA at 165 CFM against the S4's 26 at 226, the A6 34 at 352 against 30 at 425, and the A8 42 at 724 against 38 at 857. The A models cost $9 to $20 less.

Can I compare AC Infinity dBA with Vivosun or Noctua figures?

Only loosely. AC Infinity names no distance or test, and other makers use their own conditions, so a 26 dBA AC Infinity fan and a 26 dBA fan from another brand may not sound alike. Our inline duct fan and PC fan guides set the brands side by side and say where the bases differ.

Does the T model of an AC Infinity fan run quieter than the S model?

Not by AC Infinity's figures. Across CLOUDLINE, AIRLIFT, AIRTITAN, AIRBLAZE and CLOUDWAY, the T model prints the same noise figure and airflow as the S model of the same size. The difference is the controller: T models add temperature and humidity triggers, and cost about $19 to $50 more.

The bottom line

AC Infinity is the rare maker that puts a decibel figure on almost everything it sells, and its pages agree with each other far more often than not. What it never says is where the microphone was or which speed the number belongs to. Its own article says the sheet states "the loudest" noise, so I read each single figure as the top speed, and I would not set any of them against another brand's dBA.

Within the range the useful pattern is the cheap A series: the A4, A6 and A8 inline fans are $9 to $20 cheaper than the S models of the same size and are rated louder with less air. If I were buying a 6-inch fan for a tent in a bedroom, I would pay the extra $9.01 for the S6.

Stanley Alu, founder and editor

What we also considered

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

  • AC Infinity CLOUDLINE H4 Humidity-Proof Inline Fan 4 inch

    An IP65 4-inch fan built for mushroom rooms, listed at 27 dBA with 212 CFM and 324 Pa for $99.00, 1 dBA above the S4.

    Search Amazon for this model

  • AC Infinity CLOUDLINE T4

    Same fan as the CLOUDLINE S4 with a temperature, humidity and VPD controller: the same 26 dBA and 226 CFM for $119.00.

    See it at Amazon

  • AC Infinity CLOUDLINE A4 Quiet Inline Fan 4 inch

    The budget 4-inch CLOUDLINE lists 29 dBA with 165 CFM for $79.99: $10 less than the S4, 3 dBA higher and 61 CFM lower.

    Search Amazon for this model

  • AC Infinity CLOUDLINE A6

    At $89.99 the A6 lists 34 dBA and 352 CFM, louder and weaker than the $99.00 S6.

    See it at Amazon

  • AC Infinity CLOUDLINE S8

    The quietest 8-inch CLOUDLINE, tied with the T8, at 38 dBA and 857 CFM for $159.00; the A8 lists 42 dBA at 724 CFM.

    Search Amazon for this model

  • AC Infinity CLOUDLINE S10 Quiet Inline Fan 10 inch

    The 10-inch S10 lists 48 dBA with 1201 CFM for $279.00, the same figures as the T10.

    Search Amazon for this model

  • AC Infinity CLOUDLINE S12 Quiet Inline Fan 12 inch

    The largest CLOUDLINE jumps to 62 dBA with 1604 CFM for $379.00, 14 dBA above the 10-inch.

    Search Amazon for this model

  • AC Infinity CLOUDRAY A9 Grow Tent Clip Fan 9 inch, Manual

    The manual-tilt 9-inch clip fan lists 35 dBA, the same as the S9, but 405 CFM against the S9's 601.

    Search Amazon for this model

  • AC Infinity AIRTAP T6 Smart Register Booster Fan 6 x 10 inch, Bronze

    The one AIRTAP page that breaks the pattern: 18 dBA and 120 CFM, where the other three T6 pages list 16 dBA and 140 CFM.

    Search Amazon for this model

  • AC Infinity AIRCOM S7 AV Receiver Cooling Fan 12 inch, Top Exhaust

    The quietest AIRCOM AV receiver fan at 19 dBA with 140 CFM for $59.99, 1 dBA below the S6, which moves 100 CFM.

    Search Amazon for this model

  • AC Infinity AXIAL 1225 120V AC Muffin Low Speed Cooling Fan 120mm

    The quietest 120 x 25 mm AC-powered AXIAL fan with a single figure, 30 dBA at 51 CFM and 1800 RPM, for $21.99.

    Search Amazon for this model

  • AC Infinity AXIAL S1225 120V AC Muffin Cooling Fan 120mm with Speed Controller

    The same 120mm size with a speed controller prints a range, 16 to 38 dBA, which we keep apart from single figures.

    Search Amazon for this model

  • AC Infinity AIRLIFT T12 Shutter Exhaust Fan, 12 Inch, Temperature Humidity Controller

    The AIRLIFT S12 with a temperature and humidity controller, the same 62 dBA and 830 CFM for $199.00.

    See it at Amazon

  • AC Infinity AIRLIFT S16 Shutter Exhaust Fan 16 inch with Speed Controller

    Its spec table lists 67 dBA and its feature line 70 dBA, for 2560 CFM, so it is quoted twice and left unranked.

    Search Amazon for this model

  • AC Infinity Smart Home Fan with 100 ft MERV-2 Filter

    The table lists 20 dBA and the feature text "23dB" on the same page, with airflow "up to 1000 CFM", so it stays out of the ranking.

    Search Amazon for this model

How we reviewed this article

Every statement here comes from the 19 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 19 sources
Manufacturer pages and manuals for every product

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