---
product_id: 6470798
title: "AC Infinity, MULTIFAN S4 Quiet USB Cooling Fan"
brand: "ac infinity"
price: "€ 44.88"
currency: EUR
in_stock: null
reviews_count: 8
category: "Ac Infinity"
url: https://www.desertcart.fi/products/6470798-ac-infinity-multifan-s4-quiet-usb-cooling-fan
store_origin: FI
region: Finland
---

# 67,000 hrs dual-ball bearing lifespan 57 CFM airflow - powerful breeze 18 dBA noise - whisper quiet AC Infinity, MULTIFAN S4 Quiet USB Cooling Fan

**Brand:** ac infinity
**Price:** € 44.88
**Availability:** ❌ Out of Stock

## Summary

> 🆒 Stay cool, stay silent, stay ahead.

## Quick Answers

- **What is this?** AC Infinity, MULTIFAN S4 Quiet USB Cooling Fan by ac infinity
- **How much does it cost?** € 44.88 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.fi](https://www.desertcart.fi/products/6470798-ac-infinity-multifan-s4-quiet-usb-cooling-fan)

## Best For

- ac infinity enthusiasts

## Why This Product

- Trusted ac infinity brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Plug & Play USB Power:** Powered directly from USB ports on your devices—no extra adapters needed.
- • **Whisper-Quiet Cooling:** Ultra-quiet 18 dBA operation keeps your workspace serene without sacrificing airflow.
- • **Precision Speed Control:** Multi-speed controller lets you dial in the perfect balance of cooling and silence.
- • **Durable Dual-Ball Bearings:** Engineered for longevity with 67,000 hours of reliable, vibration-free performance.
- • **Versatile Mounting Options:** Lay flat or stand upright to fit seamlessly into any AV or gaming setup.

## Overview

The AC Infinity MULTIFAN S4 is a UL-certified, ultra-quiet 140mm USB cooling fan delivering 57 CFM airflow at just 18 dBA noise. Featuring a multi-speed controller and durable dual-ball bearings rated for 67,000 hours, it offers versatile mounting and USB-powered convenience—perfect for extending the life of your AV gear, gaming consoles, and electronics with whisper-quiet, customizable cooling.

## Description

desertcart.com: AC Infinity MULTIFAN S4, Quiet 140mm USB Fan, UL-Certified for Receiver DVR PlayStation Xbox Computer Cabinet Cooling : Electronics

Review: Excellent cooling solution — fixed my overheating router instantly - Bought these during the summer when my internet started cutting out. Turned out my router and modem were overheating. Added these AC Infinity USB fans and the problem was immediately fixed. They’re quiet, move plenty of air, and I really like that they can be daisy-chained so multiple fans can run off one USB port (I daisy chained the 120 and 140 together and plugged them directly into my router). Setup was simple and clean. They’ve been running continuously for months with no issues. Solid, reliable, and absolutely worth it.
Review: UPDATE: Just Repurchased! Works great, very quiet, no vibration - 2/11/2021 UPDATE! Just reordered another S7 pair of fans! Andy, I have never met you, but I sure like these quiet fans and continue to recommend these! I have three of these fans in a media closet that is about the size of a tall refrigerator. Inside on shelves I have a high-powered AV receiver, a BluRay player, a Cable TV DVR, and other stuff that is producing an amazing amount of heat. When we built the house the wife wanted all AV equipment hidden, and as an Audiophile I wanted to be able to see what I want to see and hear what I want to hear in the Home theater seating area, but without any extraneous noise. Solution: I bought this item, and set two fans on top of the AV Receiver and a third identical fan on top of the cable box/DVR. Closed the door and waited an hour. Heat load dropped in half. I did not want to just move a hot air around in this large closet, so there is a passive vent installed in the sealing of the closet .... just a simple louvered floor vent like people have in their homes for floor heat. I just waited until the wife unit was out of the house and used one of her good steak knives to saw a hole in the drywall ceiling a drop this Lower cheap floor vent in:) Vacuum the mess up and done. These fans have been running flawlessly for two years now - and my wife, who could hear a mouse fart, has never noticed them. Quality/overall impression: Frankly, I thought these were two cheap to be really durable, but I bought them because at the time they were one of the few USB fan setups with a speed controller, no fan-boi disco light show LEDs, and with a CEC rating. The fans are very quiet, well-made, and have nice rubber anti-vibration feet. I was nervous about leaving cheap fans on 24-7 because the last thing I want to do is have a house fire because the units were wired up by orphaned slave labor recruited from a deplorable third world slum. But those fears were immediately put out of mind when I opened the box upon receipt. Beautiful packing, high quality wiring and fan construction. I am back on their site today reordering a second set to place on my desktop next to my computer workstation. I have a couple of good friends who work designing high end consumer electronics - the really pricy stuff. Both techs told me that placing a good quality cooling fan on an AV receiver can add several years working lifetime to such units. Therefore, I highly recommend these AC Infinity products. Just buy the dual fan setup, set the speed controller wherever you are comfortable and forget about them! (slower is a little quieter, but even on high these were very acceptable for my application) And like I said, I am back today repurchasing another set, which I should have done long ago:) Heat kills electronics. And if you are checking out cooling fans, you already know that stereos, AV equipment and computer gear can generate enough heat to slowly nuke your gear... Next possible project for these.... We have a couple of large walk in closets, which we keep the doors closed on because our ever-curious weenie dogs like to curl up in when we are not home. Anyway, I put the old computer fans, which were too noisy, in the closets to keep the air circulating and not smelling musty when we have been gone for awhile. One of these small fans would be much quieter, and would be strong enough to push all the air it needs to under the closet door to keep things smelling fresh in there - even after we have returned from a couple weeks vacation.

## Features

- Ultra-quiet UL-certified USB fan designed to cool various electronics and components.
- Features a multi-speed controller to set the fan’s speed to optimal noise and airflow levels.
- Dual-ball bearings have a lifespan of 67,000 hours and allows the fans to be laid flat or stand upright.
- USB plug can power the fan through USB ports found behind popular AV electronics and game consoles.
- Fan Size: 5.5 x 5.5 x 1 in. | Airflow: 57 CFM | Noise: 18 dBA | Bearings: Dual Ball

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00MWH4FL4 |
| Air Flow Capacity | 57 Cubic Feet Per Minute |
| Best Sellers Rank | #4 in Computer Case Fans |
| Brand | AC Infinity |
| Compatible Devices | Amplifier |
| Cooling Method | Air |
| Customer Reviews | 4.6 4.6 out of 5 stars (36,538) |
| Date First Available | October 18, 2013 |
| Global Trade Identification Number | 00854759004365 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 0.32 ounces |
| Item model number | AI-MPF140A |
| Manufacturer | AC Infinity |
| Material | Rubber |
| Maximum Rotational Speed | 2000 RPM |
| Noise Level | 18 Decibels |
| Power Connector Type | 4-Pin |
| Product Dimensions | 1"L x 5.5"W x 5.5"H |
| UPC | 854759004365 |
| Voltage | 5 Volts |
| Wattage | 1.5 watts |

## Product Details

- **Brand:** AC Infinity
- **Compatible Devices:** Amplifier
- **Cooling Method:** Air
- **Material:** Rubber
- **Maximum Rotational Speed:** 2000 RPM
- **Noise Level:** 18 Decibels
- **Power Connector Type:** 4-Pin
- **Product Dimensions:** 1"L x 5.5"W x 5.5"H
- **Voltage:** 5 Volts
- **Wattage:** 1.5 watts

## Images

![AC Infinity, MULTIFAN S4 Quiet USB Cooling Fan - Image 1](https://m.media-amazon.com/images/I/61prBJ2QyFL.jpg)

## Available Options

This product comes in different **Size** options.

## Questions & Answers

**Q: What is the rpm on these?**
A: I am not sure of the exact rpm.  I can tell you that I have 7 of these. 1 80mm, 4 120mm, 2 140 mm.  I use them on top of my receiver, under my laptop, router and on my nas. Very quiet while still pushing or pulling a good cfm number.  Sorry I do not know the exact rpm speed but if your looking at a home theatre application I think these will work great.  If you want cfm and some noise is OK you can probably do better.

**Q: How many watts does it consume?**
A: With the a/c adapter used, 1.8 watts. Used without the a/c adapter (as usb powered) .80 of a watt.

**Q: 14 months ago I purchased 3 140mm units for 24x7 usage; all 3 now fail to spin and just jiggle when plugged in.  Anyone else have high failure rate?**
A: Out of three 140mm and four 120mm units, that I own and have been running for approximately 24 months...  One failure.  Sent it back and got a replacement with no issues; blade broke.

**Q: I see the power cord has a usb connector on one side.  is the cord hard wired to the fan or is there a  connector? if a connector what type?**
A: It is a full powered USB port? Or does the fan speed switch also affect the power coming out of the USB female attached to the fan?

## Customer Reviews

### ⭐⭐⭐⭐⭐ Excellent cooling solution — fixed my overheating router instantly
*by S***Y on December 31, 2025*

Bought these during the summer when my internet started cutting out. Turned out my router and modem were overheating. Added these AC Infinity USB fans and the problem was immediately fixed. They’re quiet, move plenty of air, and I really like that they can be daisy-chained so multiple fans can run off one USB port (I daisy chained the 120 and 140 together and plugged them directly into my router). Setup was simple and clean. They’ve been running continuously for months with no issues. Solid, reliable, and absolutely worth it.

### ⭐⭐⭐⭐⭐ UPDATE: Just Repurchased! Works great, very quiet, no vibration
*by J***E on February 6, 2021*

2/11/2021 UPDATE! Just reordered another S7 pair of fans! Andy, I have never met you, but I sure like these quiet fans and continue to recommend these! I have three of these fans in a media closet that is about the size of a tall refrigerator. Inside on shelves I have a high-powered AV receiver, a BluRay player, a Cable TV DVR, and other stuff that is producing an amazing amount of heat. When we built the house the wife wanted all AV equipment hidden, and as an Audiophile I wanted to be able to see what I want to see and hear what I want to hear in the Home theater seating area, but without any extraneous noise. Solution: I bought this item, and set two fans on top of the AV Receiver and a third identical fan on top of the cable box/DVR. Closed the door and waited an hour. Heat load dropped in half. I did not want to just move a hot air around in this large closet, so there is a passive vent installed in the sealing of the closet .... just a simple louvered floor vent like people have in their homes for floor heat. I just waited until the wife unit was out of the house and used one of her good steak knives to saw a hole in the drywall ceiling a drop this Lower cheap floor vent in:) Vacuum the mess up and done. These fans have been running flawlessly for two years now - and my wife, who could hear a mouse fart, has never noticed them. Quality/overall impression: Frankly, I thought these were two cheap to be really durable, but I bought them because at the time they were one of the few USB fan setups with a speed controller, no fan-boi disco light show LEDs, and with a CEC rating. The fans are very quiet, well-made, and have nice rubber anti-vibration feet. I was nervous about leaving cheap fans on 24-7 because the last thing I want to do is have a house fire because the units were wired up by orphaned slave labor recruited from a deplorable third world slum. But those fears were immediately put out of mind when I opened the box upon receipt. Beautiful packing, high quality wiring and fan construction. I am back on their site today reordering a second set to place on my desktop next to my computer workstation. I have a couple of good friends who work designing high end consumer electronics - the really pricy stuff. Both techs told me that placing a good quality cooling fan on an AV receiver can add several years working lifetime to such units. Therefore, I highly recommend these AC Infinity products. Just buy the dual fan setup, set the speed controller wherever you are comfortable and forget about them! (slower is a little quieter, but even on high these were very acceptable for my application) And like I said, I am back today repurchasing another set, which I should have done long ago:) Heat kills electronics. And if you are checking out cooling fans, you already know that stereos, AV equipment and computer gear can generate enough heat to slowly nuke your gear... Next possible project for these.... We have a couple of large walk in closets, which we keep the doors closed on because our ever-curious weenie dogs like to curl up in when we are not home. Anyway, I put the old computer fans, which were too noisy, in the closets to keep the air circulating and not smelling musty when we have been gone for awhile. One of these small fans would be much quieter, and would be strong enough to push all the air it needs to under the closet door to keep things smelling fresh in there - even after we have returned from a couple weeks vacation.

### ⭐⭐⭐⭐⭐ Cooling my modem and router
*by F***S on October 31, 2022*

My last cable modem up and died after just one year, I'm pretty sure because it got so hot all the time. It was a modem+router so extra hotty-hot-hotness from all the circuitry packed into one case. My son thinks this is sort of normal lifespan for routers and modems - he expects only 3 to 4 years. Well I got 8 years out of one of my last modems and 10 out of the other (same modem, WTGS54 whatever that was, it was a very good modem for its time and I got more than enough throughput from it for my needs, including streaming video, I was still running one up until 2 years ago). So *I* was shocked at its short lifespan (especially given the cost, over $200) even if he wasn't. There is just more electronics involved in these tasks, packed into less space, than the older modems. They are GOING to get hot. So in order to keep that from happening again I bought this USB fan kit, comes with 2 fans hooked together, to replace the floor fan I had aimed at the new modem and separate router. I was getting some of these anyway to put on my LED grow lights to cool them (they will ALSO last longer if you keep them cool) so I took one of those and shoved it under the router (because its a flat design, give me vertical any day) and stood the other one up next to the cable modem (which is vertical). I've got them on low and they are cooling both devices very well. On low the router gets barely slightly warm, and the better design of the vertical case for the modem leaves it totally cooled down with this little fan. If I had it to do over I'd look harder for a vertical router as well, its easier to keep them cool. AND they take up a lot less space! I've got a bunch of old computer cases with fans going to waste, I will likely make some USB fans from all those old bits and pieces, but they are likely to be a lot louder. This fan is extremely quiet even on high. I can't hear it at all on low. Also these fans in particular are optimized for humid environments so I wouldn't use anything else in my grow room. A lot of people use the other dual fan kit with the larger fans but they are using them to move air over microgreens to cut down on mold and fungi, I don't have that problem, I just need to cool the lights to improve their longevity, so I'm trying these smaller fans (take up less headroom over the lights, giving me more space under the lights because I can move them further up). I highly recommend cooling your router/modem/game console whatever electronic devices you have sitting around generating heat with some kind of fan, and these are very quiet, easy to assemble (as in plug them in), and very effective. I've seen some people insist that you shouldn't do this because it might "blow dust into the case" - where do these guys live, in the middle of death valley? LOL! Just do it. I've had a floor fan blowing across my very very ancient laptop to keep it from overheating for about 5 years now (even laptop coolers can't cool it enough) and its still going strong. I can even play (very very old) games on it still. Heat will kill your devices WAY faster than whatever tiny specks of dust these fans probably won't blow into the cases anyway. Also, if you have one of those stupid refrigerator closet things where they've built an enclosure all the way around the fridge, that is trapping heat and shortening the life of your expensive stainless steel fridge - you can use these fans to draw hot air out of that too (though I'd go with the larger version for that). Personally I'd tear that crap out but failing that, install these in a side or back wall and pull that heat out of there. Your fridge will thank you. Your bank balance will be the better for it over the long haul.

## Frequently Bought Together

- AC Infinity MULTIFAN S4, Quiet 140mm USB Fan, UL-Certified for Receiver DVR PlayStation Xbox Computer Cabinet Cooling
- AC Infinity Turbo Fan Power Adapter, for MULTIFAN Series USB Fans
- AC Infinity MULTIFAN S3, Quiet 120mm USB Fan, UL-Certified for Receiver DVR PlayStation Xbox Computer Cabinet Cooling

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.fi/products/6470798-ac-infinity-multifan-s4-quiet-usb-cooling-fan](https://www.desertcart.fi/products/6470798-ac-infinity-multifan-s4-quiet-usb-cooling-fan)

---

*Product available on Desertcart Finland*
*Store origin: FI*
*Last updated: 2026-03-08*