AC Infinity
AC Infinity MULTIFAN S4
Bottom line: The AC Infinity MULTIFAN S4 ($18.99 on Amazon as of 2026-10-06): 57 CFM airflow at only 18 dBA, quiet enough for a media cabinet; main trade-off: single 140mm fan may not cool a fully packed AV rack alone.
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*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.
Pros & Cons
Pros
- ✓ 57 CFM airflow at only 18 dBA, quiet enough for a media cabinet
- ✓ Multi-speed controller trades airflow for silence on demand
- ✓ Dual-ball bearings rated 67,000 hours, mountable flat or upright
- ✓ Runs off any USB port, including console and receiver service ports
Cons
- ✗ Single 140mm fan may not cool a fully packed AV rack alone
- ✗ 1-inch depth still needs clearance behind or above the gear
- ✗ No thermostat, so speed is set by hand rather than by temperature
- ✗ USB-only power means a dead console port leaves the fan off
Manufacturer description
The AC Infinity MULTIFAN S4 is a 140mm USB-powered cooling fan built for the cramped, unventilated spaces where AV gear and game consoles overheat. Rated 57 CFM of airflow at just 18 dBA, it moves real air through a receiver shelf, DVR cabinet, or console cubby without adding a whine you can hear over dialogue. The multi-speed controller lets you dial airflow up when a component is working hard and back down when you want silence, so you are not stuck with one noisy setting. Power comes from any standard USB port, including the service ports found behind most AV receivers, PlayStation and…
SpecPicks Verdict
SpecPicks scored AC Infinity MULTIFAN S4 using a rating × review-volume × price-fit model applied to published specs and reviews across the retro cpu coolers & fans category. AC Infinity's retro cpu coolers & fans lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.
Common buyer scenarios for retro cpu coolers & fans of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.
Frequently Asked Questions
Will this fan actually cool my AV receiver inside a closed cabinet?
It pushes 57 CFM, which is enough to keep air moving across a receiver or console in a cabinet cubby. For a fully enclosed rack with several hot components, plan on more than one unit.
How loud is the MULTIFAN S4 on its highest setting?
AC Infinity rates it at 18 dBA. The included multi-speed controller lets you drop it lower if you want it inaudible during quiet dialogue.
Can I power it from my PlayStation or Xbox instead of a wall outlet?
Yes. It uses a standard USB plug and is designed to draw from the USB ports found behind AV receivers and game consoles, so no separate adapter is required.
Can the fan stand upright, or does it have to lie flat?
Both. The dual-ball bearings support flat and upright orientation, so you can lay it on a shelf or stand it against a cabinet wall.
How long will the fan last before the bearings wear out?
The dual-ball bearings are rated for a 67,000-hour lifespan. For warranty coverage, check the current product listing, as terms are set by AC Infinity.
Key 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
Full Specifications
| Brand | AC Infinity |
|---|---|
| Model | AI-MPF140A |
| Voltage | 5 Volts |
| Wattage | 1.5 watts |
| Fan Size | 5.5 x 5.5 x 1 in. | Airflow: 57 CFM | Noise: 18 dBA | Bearings: Dual Ball |
| Material | Rubber |
| Dimensions | 5.5 x 5.5 x 1 in |
| Unit Count | 1 Count |
| Noise Level | 18 Decibels |
| Part Number | FBA_AI-MPF140A |
| Connectivity | USB |
| Compatibility | Xbox |
| Material Type | Rubber |
| Cooling Method | Air |
| Number of Items | 1 |
| Air Flow Capacity | 57 Cubic Feet Per Minute |
| Compatible Devices | Amplifier |
| Power Connector Type | 4-Pin |
| Maximum Rotational Speed | 2000 RPM |
| Item Dimensions L x W x H | 1"L x 5.5"W x 5.5"H |
| Full listing title | AC Infinity MULTIFAN S4, Quiet 140mm USB Fan, UL-Certified for Receiver DVR PlayStation Xbox Computer Cabinet Cooling |
Ready to buy?
AC Infinity MULTIFAN S4, Quiet 140mm USB Fan, UL-Certified for Receiver DVR PlayStation Xbox Computer Cabinet Cooling is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.
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