AC Infinity MULTIFAN S3 USB Cooling Fan

An effective add-on for hot hifi equipment

A very cost-effective solution to cooling an invented hifi amplifier (an NAD M10V3).

K. Steinhoff

June 16, 2026

I works

Works great. I added it to the rear top of my Dell Alienware R13. Really helps to pull the heat out.

quiet as a ghost

This fan is a game-changer for Xfinity gamers. I've been experiencing frequent disconnects while playing Marvel Rivals. My Xfinity modem tends to overheat, especially during intense games. This fan not only keeps it cool, but half the time I don't even notice it's on. It's so quiet. The attached video shows it on its Max setting with nothing else running.

0:10

Funciona

Es lo que compre, lo pobre conectandolo a un usb y funciona correctamente. Es para un router que aún no llega pero si me acuerdo dejare alguna actualización.

Okami

August 29, 2024

Nice fan!

Bought this to cool my usb wifi adapter for my PC since it gets pretty hot. Been using it for 3 years. Make sure you clean it from time to time.

Perfect for Plants

Perfect little fans! I really like these, they fit well on my succulent shelves and they run forever.

Kevin G.

May 6, 2024

Perfect!

My Cox panoramic Wi-Fi always ran hot even in the winter. This changed it overnight and I keep it on high and you can’t hear it at all unless you were standing next to it with no other sound in the house. The unit is not even warm to the touch anymore, seems to work great.

Silent and Effective

Used this to cool down my fanless OPNsense firewall. Effective in maintaining the temp between 85 to 90. Fan is very silent.

Doug B

August 25, 2023

Great quiet fan for cooling audio/video equipment

After spending almost $500 for a good quality audio/video receiver for my home theater system, I was kind of disappointed at how hot it runs. It sits in a semi-ventilated A/V table and gets almost scorching hot to the touch and you can almost smell the electronics burning. I thought I would try a fan to put on top to help cool it and selected this product and I could not be happier. I plugged it into a USB port on the TV that is only powered when all of the A/V equipment is on. It is whisper quiet and it is amazing how much of a difference in surface temperature this fan makes on the receiver even though I only have it set on the medium speed. It has been a few years and it is still running strong, so it is a high quality product.

A must have to keep your WiFi modem cool.

My previous WiFi modem always seemed to get hot and I know electronics don't like to get too hot. So I have them in a room that is generally cooler and leave the ceiling fan on. Since I got the new upgraded one from Xfinity I wanted to ensure that it doesn't overheat with everything being connected. I seen this and decided to give it a try. Within the 24 hours I noticed a big difference. Especially since it helps keep it at a better temperature. I have it on the lowest speed. It's super quiet, you won't know that it's even there. This is a must have!

Just Awesome! Exactly what I needed

I have one of those Aliexpress mini PC's that I use as a pfsense router. However I upgraded to a Protectli one with a little better specs so I repurposed the old one into a proxmox machine for VM's and containers. Without the fan the CPU would stay with acceptable levels but the m.2 nvme inside was getting almost near its thermal limit of 82c. It was constantly hitting 78c-79c. This little fan immediately dropped the nvme down to 50c-55c and the CPU stays under 60c even under heavy loads. I am sitting about 3 feet away from it and even on its max setting I can BARELY hear it. Couldn't be happier, I will be buying more of these.

Great product!

Bought this cooler for my Xfinity router, and I’m so excited. This is really good stuff for any equipment which should be cool down while working at all times. On this video you can see working process with medium speed and it’s quiet, even I turn high speed, will be quiet as well! It doesn’t take too much space on your desk or any surface you’re going to use. Definitely recommend to buy this Great product! High quality for Good price!

0:18

Solved my Roku overheating problem

For months now my Roku stick has been over heating and causing all kinds of problems. Error messages, restarting over and over again. Then I read about using a cooling fan to stop it from overheating. Well I have to say, I decided to purchase this AC Infinity MULTIFAN S3, Quiet 120mm USB Fan, and it has done the trick. It's small, quiet and easy to install as you can see by the attached photo. I have not had the problem since. So if you have this same issue with the Roku or other electronic devised and want to find a solution, be sure to check the fan out and you will be glad you did. It more than met my expectations!

I'm a fan!! .... of this company!

Very nicely built and designed, these little fans were just what I was looking for. The packaging had a professional feel to it and added to the "neatness" of the presentation.

Easy daisy chain setup on my little "space compromised desk" lowered my temps BIG TIME in all 3 crowded units.

Router, modem and receiver all getting a cool breeze. They used to feel warm to the touch. Now? They're cool as a cucumber.

As far as sound? My computer fans are louder. Not a factor for me. They're quiet. Non issue.

Overall my initial impression is I'm digging it. Let's see how long they last. (within reason of course)

If heat really is electronics biggest enemy against longevity, any stability I can bring along the way seems productive in the long run. Especially for the price.

Like I said, I'm a fan!.. of these fans! 👍

Exactly as advertised. Quiet and easy to use.

Used to exhaust an entertainment center for a PS5. Runs perfectly off the PS5 USB port.

One thing worth noting: if you do intend to screw this into something, the rubber stopper things will have to be removed. That's what I intended to do, but decided to just let it stand on the edges since it's quiet and stable on those rubber things.

Works in small, portable, DIY air cleaner

I built a small, portable air cleaner using this fan and two 10x10x1 MERV 13 air filters. It can filter allergens, particles carrying Covid 19, dust, smoke, etc. out of the air in small spaces like bedrooms, work cubicles, and small motel rooms. It is quiet and runs off a phone charger or the USB port in a car. It can be carried in a shopping bag, backpack, etc. This fan is ideal for this purpose.

Online Shopper

January 15, 2022

Good quality quiet fan, but doesn’t move much air

I’m using this fan to cool down my T-Mobile router. I have a 3D printed shroud over the router, so the fan is pulling hot air out instead of pushing cold air in. On LOW, the fan is able to bring enough air circulation to keep the router cool to touch, and is almost inaudible. On HIGH, the noise is a lot more noticeable.

The main con is that if you need this fan to perform in high static/resistance situations, it will pull/push very little air. In those cases, the dual fan model or a high static pressure fan would be better. But for the price, this is a good deal - you get a high quality fan, speed controller, and USB plug.

iwantgizm0s

July 7, 2021

Cooling Fan for Tmobile Home Internet Gateway

using this with our Tmobile Home Internet Gateway. really too easy to install because only need to sit the gateway on top of the fan, and then plug the fan usb cable into a power source (get a usb-c adapter to plug into the usb-c port on the gateway). very secure because of the rubber feet on both top and bottom of the fan. have the fan temperature control set to the middle setting to not make the fan too loud. noise level is very minimal -- really don't notice the fan sound. and the gateway is apparently staying cool.

in comparison, i also have a Cox Panoramic Wifi Gateway which already has a built-in fan at our other house. so i agree with other users that it makes sense to use a fan like this one with the Tmobile Home Internet Gateway.

also have been using cookie tin cans (which are all sitting on top of an upside paint bucket) to add height to the gateway (to get better reception) where the fan sits snuggly on top of the cookie tin can lid and then the gateway sits on top of the fan. very nice.

this cooling fan is suppose to last 67,000 hours which continuously would be 7.6 years. my guess is in 7.6 years from now, tmobile will probably have a better gateway on 6G (or 7G) with a built-in fan.

Exceeded Expectations

I honestly wasn't expecting to write up a review for a fan. It looked like a standard computer case fan with feet - nothing really exciting about that. However, what I got was an extremely high quality fan with silicone feet and a switched controller with multiple speeds. At the lowest speed, it is virtually silent. It fits perfectly under my USB-C docking station, which runs really hot. Once summer hits, I'll probably be ordering more as needed.

I purchased this with my own money.

These fans are perfect!

These fans are Super easy to set up. Simply plug in the usb and set the fan speed from O to L M or H. The noise level is low and the fan is sturdy made of high quality materials. It’s not plastic! Nice! The 4 corner cushions are great and allow the fan to be lain flat to keep my giant charger cool without laying directly on the fan itself. Those cushions also keep the fans from rattling on the table/desk whether it’s standing or laying flat. It’s a thumbs up for this AC Infinity Multifan S3 in the 2 pack 120mm size & the single S4 also by Infinity in the 140mm size. These fans are perfect!

0:47

Device is now running at room temperature, and quiet

My home network devices are in the closet, the room is not well ventilated. I used to use a spare notebook cooling pad to cool the WIFI router, but if you touch the top of the router, you can still feel that it's quite warm. And the cooling pad fans are loud because of old age.

Now with this fan simply sitting on top of the router, the device is running at room temperature, can't feel even slightly warmth when touching the top of the device. I set the fan speed on low, it is incredibly quiet.

Gideon300

December 29, 2020

Performs well beyond expectations

If function means beauty to you, this takes the crown. I needed a temporary solution to my lack of exhaust in my new desktop pc while I wait for the actual fan. This one blew away my expectations. Some may think she ain't pretty, but I find beauty in my pc on how it works first. Function before beauty. It works so well I might just keep it permanent. Real strong air coming out of my case. No more cpu fan spinning like a turbo in a boy racer Honda Civic. And best part, its powered separately no parasitic effect on motherboard. 120mm is a perfect fit like any 120mm desktop pc blower fan. Quiet buy powerful, transferable, and multi-purpose. And at a very reasonable price.

QUIET *shhh*

When I first plugged it in, it was on medium, I didn't hear anything, so I looked & felt to make sure it was on -yup, it was on. If I turn it to high, I can hear it from 3 feet away where I sit if I think about it (but there are so many other sounds in my office that are much louder & more noticeable).

I plugged into one of the USB ports of the external monitor because I really only want to use the USB-C connection on the laptop because, that's the whole point, right?

Does it move air? Sure, there's a noticeable breeze in there now.

How much of a difference will it make in this situation? I'm not sure yet, I'm not expecting any boost in processor speed or anything. My main hope is to increase the longevity of the computer and there will be no way to measure that incremental improvement.

But, it makes me feel geeky and cool ;)

I can see where this would make a big difference in more enclosed spaces with components that don't have their own cooling fans and where airflow is minimal.

Longevity? No idea yet. If it fails or becomes loud, I will write.

GREAT FAN! VERY QUIET, ADJUSTABLE. WHAT MORE COULD YOU ASK FOR.

What an awesome fan!!! Comes with two black fan guards but the think what I like the best is the 4 rubber feet. My Linksys router has a large passive heat sink that gets REALLY warm. With this fan sitting on top it now feels like room temperature. As a bonus I have my cable modem sitting on top of the fan to cool it too! The 3 speed fan switch is great. Fan is Inaudible on low at 1 foot and barely audible on high (at one foot). This was the answer to everything I was looking for at a good price. Will run 24/7 and should last for many years.

Tom Hightower

June 9, 2018

The fan fit nicely under those pads with no additional height

Edit: 8-10-2018

I have purchased 3 more of these, They run great and keep my devices much cooler. I am very pleased with them.

Original:

Works really well at cooling down the internals of my router. True the device probably didn't need a lot of cooling but the inner geek in me said why not. So I did. You know what I am talking about, the kinda where your itching for a cheap project to complete and need something to scratch the itch.

All in all its working really well, I can certainly feel the heat exhausting from my ASUS router. I placed it under my router blowing into the bottom cooling vents and the exhaust air coming out the top. I had previously elevated the router on rubber pads to aid in heat dispersal. The fan fit nicely under those pads with no additional height. You can see a temperature drop during the first 15 minutes from the internal graph. I have not noticed any vibration at all, even running the fan on high all the time. No noise either. I am pleased with my purchase.

I am considering 4 more fo these to retro fit a couple of recessed wall box for switches and alarm panels. Again maybe over kill, but its a super easy thing to do. I plan on using on at the bottom of the cabinet and one at the top, for intake and exit airflow. I will also be buying the grill covers for the fans for this next project.

Jeremy Chadwick

May 30, 2018

Functional and extremely quiet, but may experience ball bearing problems after prolonged use

In June 2017 I purchased the MULTIFAN S3. I wanted an external fan that was extremely quiet, had an RPM adjustment switch, had vibration dampening feet or pads, and was USB-powered. The intended use was for cooling a vertical/upright Asus RT-AC56U/RT-AC56R router. The average temperature of those routers, with both 2.4GHz and 5GHz radios enabled, tends to be quite high (90C is common, especially during summertime). I also didn't want to void my router warranty modding it to support a fan (not to mention, small fans tend to be high RPM to make up for their size, thus loud -- no thanks!).

The MULTIFAN S3 did exactly what I wanted. On medium speed, it's basically inaudible ~4 feet away. At medium speed, it lowered temperatures by about 10C, simply blowing air across the router from the side. The screenshot I've attached shows before-and-after; before, temperatures peaked at ~75C. With the MULTIFAN S3 in place, peaks hit 65C. Excellent for low-RPM, purely external cooling!

I used this setup for about 9 months, until one day I began to hear a very quick and occasional "rattling" noise coming from somewhere near my networking equipment (all of which is fanless, excluding the MULTIFAN S3). This noise became more regular over the course of a few days, allowing me to track down the source: sure enough it was the MULTIFAN S3. Most likely the dual ball bearings were gradually loosening (shifting too much inside of their tract/sleeve), or possibly had developed "clotting" of bearing lubricant, both of which can happen with prolonged use.

I disconnected the MULTIFAN S3 until earlier this week where summer temperatures were beginning to kick in again. Within an hour of hooking the fan back up, the "rattling" and "clicking" returned, no matter what speed the fan was set to. Bummer. I don't think I got a lemon, as it worked fine for many months. This problem with ball-bearing fans is common even with high-end PC case fans. It's one of the reasons I prefer Noctua oil pressure bearing (SSO/SSO2) fans, but Noctua doesn't make a product like the MULTIFAN S3 without use of third-party adapters.

On the subject of fan bearings and lubricant: like most consumer fan products, the MULTIFAN S3 *does not* offer a convenient way to repair, replace, or re-oil the bearings, as there's a very firm plastic or aluminium company logo over the centre spindle on both sides of the fan. And even if there wasn't, many of these types of fans on the market have sealed plastic enclosures so you can't access them anyway, forcing you to buy a replacement.

Overall I give this product 4/5 stars because it definitely does everything advertised and AC Infinity should be commended on their product. Just keep an ear out for any bearing problems.

Worked great! For less than year... then not so much

At first this was a great product and really really quiet, but not even a year later it became a constantly rattling noise on top of my receiver annoying my whole family every time we turn on the receiver for any reason. Very disappointed in that. I'd love to give this product a great review and would have if i decided to do the review at the beginning, but I decided to wait to see if the lack noise would hold up, and it did not sadly :(

0:34

Great fan to keep a modem/router cool

I had problems with my modem/router due to overheating. I looked at cheap laptop coolers but couldn't find anything that would fit on the narrow shelf the modem sits on in my garage.

First thoughts were that it would vibrate off the top of the modem but the price and shipping were reasonable enough for me to give it a go.

We've been having very hot weather with temperatures in excess of 40 degrees C so it's been a good test for the fan. I bought the 120mm version and first impressions were how quiet it was and the lack of any vibration.

I sat it on top of my modem and plugged it into one of the USB ports. I set it on the highest speed on a fairly warm day and was pleasantly surprised to find the modem cool to touch when I checked it a couple of hours later. Since then I have tried medium and low but high seems to be the best for the current wave of hot weather and it hasn't moved at all in the two weeks I've been using it.

So first impressions have been good and it's certainly doing the job required of it, I just hope the fan is of a high quality and it will keep running for many years to come.

Perfect for PS4

I'm very happy with this. Already noticing a big difference. Even games that always made my PS4 scream like a jet engine lately haven't been doing so at all. In general it's running so much quieter which means the fan is really helping keep it cool.

Having a control switch with 3 speeds and off, is great and so is the fact that it also has an inline female USB port also really helps so you don't lose the port you used. It works out especially good for me because I have a USB hub, which I never liked plugging into the front of my PS4, well now I don't have to. Keep in mind though that the inline USB port is only good for charging, you can't plug in a headset or steering wheel into it.

Also, the cable is plenty long, and the fan itself is ultra quiet and mostly made of metal it seems. It's just powerful enough for its purpose too. Definitely not a personal fan, but is fine for clearing air away from hot components.

As you can see in my photo, I have it directly behind the back of the PS4 on the left side (that's where the most hot air comes out). I recommend putting it there. Also, I have the PS4 on a laptop cooling pad as well but mainly just to let air get under it and slant the back of the PS4 upward towards the fan. Plus heat rises so it should flow easily towards the fan as well. Should be a good cooling solution for the PS4 and much better than the cheap intercooler's that exist for it.

Also, you can see the case of my favorite PS4 game, the Last Guardian. Highly recommend it.

MrClean

December 3, 2016

Keeps my electronics cool

My media cabinet was loaded with heat from various electronics the worst offender being the xbox one x. The xbox fan was working overtime sounded like a blow drier so i knew it was running hot. I installed the 120mm fan directly behind the xbox to suck all the heat out from the exhuast and out of the cabinet, i also installed an 80mm version of this fan at the top of the cabinet to help remove the rest of the heat.

the xbox is now quiet and the cabinet is much cooler.

Only issue if you can call it that is that if you daisy chain these fans they operate slower than plugged in individually.