--- product_id: 6470798 title: "AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller" brand: "ac infinity" price: "¥6460" currency: JPY in_stock: true reviews_count: 13 category: "Ac Infinity" url: https://www.desertcart.jp/products/6470798-ac-infinity-multifan-s4-ultra-quiet-140mm-usb-fan-speed store_origin: JP region: Japan --- # 57 CFM airflow power Ultra-quiet 18 dBA noise 67,000 hrs dual-ball bearing life AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller **Brand:** ac infinity **Price:** ¥6460 **Availability:** ✅ In Stock ## Summary > 🌀 Stay cool, stay ahead—silence never looked this powerful! ## Quick Answers - **What is this?** AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller by ac infinity - **How much does it cost?** ¥6460 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/6470798-ac-infinity-multifan-s4-ultra-quiet-140mm-usb-fan-speed) ## 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 - • **Compact Yet Mighty:** Slim 5.5-inch frame delivers powerful 57 CFM airflow, cooling your electronics efficiently without bulk. - • **Plug & Play USB Power:** Seamlessly power your fan via any USB port on your AV gear or gaming consoles—no extra adapters needed. - • **Whisper-Quiet Cooling:** Experience near-silent airflow at just 18 dBA—perfect for focused work or gaming marathons. - • **Durability Meets Design:** Dual-ball bearings ensure a remarkable 67,000-hour lifespan, with versatile flat or upright placement. - • **Precision Speed Control:** Customize your cooling with a multi-speed controller for the ideal balance of airflow and noise. ## Overview The AC Infinity MULTIFAN S4 is a UL-certified, ultra-quiet 140mm USB fan engineered for professional-grade electronics cooling. Featuring a multi-speed controller, dual-ball bearings rated for 67,000 hours, and a compact 5.5-inch design, it delivers 57 CFM airflow at a whisper-quiet 18 dBA noise level. Powered directly via USB, it’s ideal for AV receivers, gaming consoles, and home lab setups seeking reliable, customizable cooling without the noise. ## Description desertcart.com: AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller | UL-Certified, Dual-Ball Bearings, Noise-Absorption Pads for Receiver DVR, PlayStation, Xbox, Computer, Cabinet Cooling : Electronics Review: Almost Invisible/Stealth Quiet - Im writing this review during a very HOT unusual few June weeks in Minnesota, its been over 90 for almost 2 weeks now, I have a full size 42U server rack for my home lab, it has a big hole on top that nobody's exhaust fans fit, 21 x 5.5, but the 140mm measurements of this fan is just big enough that I can sit about 4 of them on top of the racks hole. I work in Tech Recycling, so I see what happens to most tech equipment when its removed from service, its rare to see AC Infinity products, I rescued a old AC Infinity Controller they don't appear to sell anymore, but its similar to the one they sell now, and rescued a 2U Rackmount 4 fan with controller unit, I was amazed how quiet the rack mount fan unit was even after many years of use, the LCD controller is a bit hard to read, but other then that it works fine. So I needed some USB fans to plug into the other controller I rescued, I was concerned there was only 2 USB ports, which is the same as new model they currently sell, but when these fans arrived, I saw a lovely daisy chain USB connector, apparently you can have up to 4 of these on 1 of the USB controller ports so those 2 ports give you maybe 8 fans , I don't need that much, but its a nice feature, I plugged these in to the old controller set it on AUTO and away they go. The controller appears to have Low/Med/High setting but these fans also have a 4 way switch on the cord which seems to be 1 notch higher then whats available on the controller, I have them maxed, very light hum, not much more then my laptop fans on a hot day. Compared to others, I have rescued hardwired plug and run fans with no thermostat, that sound like a bunch of servers running, so these are by far the quietest ive heard (almost can't tell they are running), Now that I know they daisy chain, I bought 2 more, with 4 of these at about $15 each vs $300-400 exhaust fans that are usually 120mm, they sell for most racks this is a great deal and larger. Perfect product, not sure how strong they are? they are not as FAT/DEEP as some Ive seen at work, its very hot, my rack runs about 3-4 degrees hotter then the room its in, so even with the fans they are having a hard time cooling it down, but air circulation is always good. its hard to get cool when the room itself is hot upper 80s, and rack is maintaining lower 90s. Only thing I would add to this product, RGB colors would be nice for those of us that like adding colors to our loved computers, but probably wastes electricity and reduces power so maybe its better they don't have color lights. (only if it don't sacrifice cooling power) CLIPS, since Im buying 4 of these to fill that big 5.5 x21 inch hole in my rack that normally a bunch of wires would go through, but in my home lab all wires go down, Im using that hole as a exhaust for the heat to exit up to the ceiling, these cool rubber feet are nice, but it would be nice to clip these together with some kind of clip so instead of 4 loose fans its 1 big fan. The feet are good, but since I have 3 cats that can jump on top of the rack it would be nice to link these fans together with some kind of bracket or clip just in case, not too worried about it, but it would be a nice modular feature. Lucky for me its only hot in Minnesota 3 months a year, so most the year these fans won't have to work hard, but they are running 24/7 now in a near 90 degree room. These would be great for quiet rooms, chances are your normal household fan is louder. Love the product, both the old ones I rescued that were not quite ready to be recycled yet, and these new fans. Review: Scientific results show a massive cooling affect. I am VERY glad that this product exists. - My Onkyo model is known to die early, so I wanted to make sure that it doesn't get too hot in my new TV stand. I was very impressed with the quality of this fan, so I had to put it to some scientific test. I've been building my own PCs since a kid as a hobby, and this fan is much better quality than any computer fans I've come across (including the massive 200mm fan on top of Antec 900). It's also literally silent even on high setting when it's inside the cabinet. At first I thought the USB port on the receiver wouldn't power the fan and was debating whether to use an AC adapter to run it 24/7, but it turns out the receiver's USB port has a 10 second delay before it sends power after you turn it on. Make sure you are patient when you plug it in. Test setup: Onkyo HT-RC360 7.2 channel Receiver (5.1 setup) All Ch Stereo (5 channels) at 80% volume 4.8" clearance above the receiver (see photo) ivation wireless thermometer with 2 sensors placed directly on top of receiver ambient temperature - 75F After doing several tests with different variables, I realized playing songs made the temps fluctuate too much. Then I realized that without a source, turning up the volume on the receiver created high stable heat since the power wasn't being transferred to the speakers and it only relied on dissipation. Listed below are highest stable temps(F) for both sensors. Door open, no fan - 118/115 Door closed, no fan - 122/117 (protection circuit tripped at this temp and it shut down for a moment) Door closed, fan on low - 100/93 Door closed, fan on medium - 99/93 Door closed, fan on high - 99/93 As you can see, the temps get very hot without circulation, almost getting uncomfortable to touch by hand. With the cabinet door closed, I would not be able to watch movies at all since it's running dangerously close to overheat protection threshold even with the door open. The speed setting on the fan had almost no impact in my cabinet because of the limited holes that hot air can escape. The benefit will vary depending on each setup, but going from no circulation to even limited amount of circulation makes a large difference (just like the 386 that had heatsink with no fan running hotter than 486DX with a fan). This fan is exactly what I needed/wanted, and I would highly recommend it. Was this review 2 hours well spent? Was it worth risking my receiver frying? You betcha! ## 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 cfm | | Best Sellers Rank | #3 in Computer Case Fans | | Brand | AC Infinity | | Brand Name | AC Infinity | | Compatible Devices | Amplifier | | Cooling Method | Air | | Customer Reviews | 4.7 out of 5 stars 3,209 Reviews | | Global Trade Identification Number | 00854759004365 | | Item Dimensions L x W x H | 1"L x 5.5"W x 5.5"H | | Item Weight | 9.07 g | | Manufacturer | AC Infinity | | Material Type | Rubber | | Maximum Rotational Speed | 2000 rpm | | Model | AI-MPF140A | | Noise Level | 18 db | | Number of Items | 1 | | Number of Packs | 1 | | Part Number | FBA_AI-MPF140A | | Power Connector Type | 4-Pin | | Product Dimensions | 1"L x 5.5"W x 5.5"H | | UPC | 854759004365 | | Unit Count | 1 Count | | 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 db - **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, Ultra-Quiet 140mm USB Fan with Speed Controller - Image 1](https://m.media-amazon.com/images/I/713+w3dU6UL.jpg) ![AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller - Image 2](https://m.media-amazon.com/images/I/715TZNiNZAL.jpg) ![AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller - Image 3](https://m.media-amazon.com/images/I/61937PlfmYL.jpg) ![AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller - Image 4](https://m.media-amazon.com/images/I/71Wzh47qmHL.jpg) ![AC Infinity MULTIFAN S4, Ultra-Quiet 140mm USB Fan with Speed Controller - Image 5](https://m.media-amazon.com/images/I/61-6CgQl2iL.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 ### ⭐⭐⭐⭐⭐ Almost Invisible/Stealth Quiet *by D***3 on June 9, 2021* Im writing this review during a very HOT unusual few June weeks in Minnesota, its been over 90 for almost 2 weeks now, I have a full size 42U server rack for my home lab, it has a big hole on top that nobody's exhaust fans fit, 21 x 5.5, but the 140mm measurements of this fan is just big enough that I can sit about 4 of them on top of the racks hole. I work in Tech Recycling, so I see what happens to most tech equipment when its removed from service, its rare to see AC Infinity products, I rescued a old AC Infinity Controller they don't appear to sell anymore, but its similar to the one they sell now, and rescued a 2U Rackmount 4 fan with controller unit, I was amazed how quiet the rack mount fan unit was even after many years of use, the LCD controller is a bit hard to read, but other then that it works fine. So I needed some USB fans to plug into the other controller I rescued, I was concerned there was only 2 USB ports, which is the same as new model they currently sell, but when these fans arrived, I saw a lovely daisy chain USB connector, apparently you can have up to 4 of these on 1 of the USB controller ports so those 2 ports give you maybe 8 fans , I don't need that much, but its a nice feature, I plugged these in to the old controller set it on AUTO and away they go. The controller appears to have Low/Med/High setting but these fans also have a 4 way switch on the cord which seems to be 1 notch higher then whats available on the controller, I have them maxed, very light hum, not much more then my laptop fans on a hot day. Compared to others, I have rescued hardwired plug and run fans with no thermostat, that sound like a bunch of servers running, so these are by far the quietest ive heard (almost can't tell they are running), Now that I know they daisy chain, I bought 2 more, with 4 of these at about $15 each vs $300-400 exhaust fans that are usually 120mm, they sell for most racks this is a great deal and larger. Perfect product, not sure how strong they are? they are not as FAT/DEEP as some Ive seen at work, its very hot, my rack runs about 3-4 degrees hotter then the room its in, so even with the fans they are having a hard time cooling it down, but air circulation is always good. its hard to get cool when the room itself is hot upper 80s, and rack is maintaining lower 90s. Only thing I would add to this product, RGB colors would be nice for those of us that like adding colors to our loved computers, but probably wastes electricity and reduces power so maybe its better they don't have color lights. (only if it don't sacrifice cooling power) CLIPS, since Im buying 4 of these to fill that big 5.5 x21 inch hole in my rack that normally a bunch of wires would go through, but in my home lab all wires go down, Im using that hole as a exhaust for the heat to exit up to the ceiling, these cool rubber feet are nice, but it would be nice to clip these together with some kind of clip so instead of 4 loose fans its 1 big fan. The feet are good, but since I have 3 cats that can jump on top of the rack it would be nice to link these fans together with some kind of bracket or clip just in case, not too worried about it, but it would be a nice modular feature. Lucky for me its only hot in Minnesota 3 months a year, so most the year these fans won't have to work hard, but they are running 24/7 now in a near 90 degree room. These would be great for quiet rooms, chances are your normal household fan is louder. Love the product, both the old ones I rescued that were not quite ready to be recycled yet, and these new fans. ### ⭐⭐⭐⭐⭐ Scientific results show a massive cooling affect. I am VERY glad that this product exists. *by S***N on August 22, 2016* My Onkyo model is known to die early, so I wanted to make sure that it doesn't get too hot in my new TV stand. I was very impressed with the quality of this fan, so I had to put it to some scientific test. I've been building my own PCs since a kid as a hobby, and this fan is much better quality than any computer fans I've come across (including the massive 200mm fan on top of Antec 900). It's also literally silent even on high setting when it's inside the cabinet. At first I thought the USB port on the receiver wouldn't power the fan and was debating whether to use an AC adapter to run it 24/7, but it turns out the receiver's USB port has a 10 second delay before it sends power after you turn it on. Make sure you are patient when you plug it in. Test setup: Onkyo HT-RC360 7.2 channel Receiver (5.1 setup) All Ch Stereo (5 channels) at 80% volume 4.8" clearance above the receiver (see photo) ivation wireless thermometer with 2 sensors placed directly on top of receiver ambient temperature - 75F After doing several tests with different variables, I realized playing songs made the temps fluctuate too much. Then I realized that without a source, turning up the volume on the receiver created high stable heat since the power wasn't being transferred to the speakers and it only relied on dissipation. Listed below are highest stable temps(F) for both sensors. Door open, no fan - 118/115 Door closed, no fan - 122/117 (protection circuit tripped at this temp and it shut down for a moment) Door closed, fan on low - 100/93 Door closed, fan on medium - 99/93 Door closed, fan on high - 99/93 As you can see, the temps get very hot without circulation, almost getting uncomfortable to touch by hand. With the cabinet door closed, I would not be able to watch movies at all since it's running dangerously close to overheat protection threshold even with the door open. The speed setting on the fan had almost no impact in my cabinet because of the limited holes that hot air can escape. The benefit will vary depending on each setup, but going from no circulation to even limited amount of circulation makes a large difference (just like the 386 that had heatsink with no fan running hotter than 486DX with a fan). This fan is exactly what I needed/wanted, and I would highly recommend it. Was this review 2 hours well spent? Was it worth risking my receiver frying? You betcha! ### ⭐⭐⭐⭐⭐ It really works! *by G***E on August 17, 2026* I have an Onkyo TX-NR609 receiver that is always very warm, even on standby. It sits on top of a table, so venting isn't an issue, it is just hot. Since the receiver is getting on in years and I want to extend its life a little, I bought this fan and placed it on the top of the receiver over what is presumably the power supply area (hottest part of the vents) and turned it on. Now the entire top venting area is cool to the touch. This thing really works! It is silent as can be and just runs, doing its thing which is pulling the heat out of the AV so that it doesn't build up. I should have bought this fan 14 years ago (if it existed then)! ## 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.jp/products/6470798-ac-infinity-multifan-s4-ultra-quiet-140mm-usb-fan-speed](https://www.desertcart.jp/products/6470798-ac-infinity-multifan-s4-ultra-quiet-140mm-usb-fan-speed) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-08-23*