---
product_id: 729597365
title: "NF-A4x20 FLX 40mm 3pin Fan 20mm Thick Cooling Fan Case Fan"
brand: "noctua"
price: "$43.31"
currency: USD
in_stock: true
reviews_count: 8
category: "Noctua"
url: https://www.desertcart.us/products/729597365-nf-a4x20-flx-40mm-3pin-fan-20mm-thick-cooling-fan
store_origin: US
region: United States of America
---

# Flow Acceleration Channels boost airflow Compact 40x20mm size Ultra-quiet operation NF-A4x20 FLX 40mm 3pin Fan 20mm Thick Cooling Fan Case Fan

**Brand:** noctua
**Price:** $43.31
**Availability:** ✅ In Stock

## Summary

> ❄️ Small Fan, Big Chill – Stay Cool, Stay Ahead!

## Quick Answers

- **What is this?** NF-A4x20 FLX 40mm 3pin Fan 20mm Thick Cooling Fan Case Fan by noctua
- **How much does it cost?** $43.31 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/729597365-nf-a4x20-flx-40mm-3pin-fan-20mm-thick-cooling-fan)

## Best For

- noctua enthusiasts

## Why This Product

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

## Key Features

- • **Premium Build Quality:** Trusted Noctua reliability with a 1-year warranty
- • **Whisper-Quiet Operation:** Near-silent fan keeps your setup cool without distraction
- • **Adaptive Step Inlet Design:** Optimizes air intake for efficient cooling performance
- • **Aerodynamic Flow Acceleration Channels:** Engineered for maximum airflow with minimal noise
- • **Precision Cooling in a Miniature Package:** Compact 40x20mm size fits tight spaces seamlessly

## Overview

The Noctua NF-A4x20 FLX is a premium 40x20mm 3-pin computer case fan designed for compact spaces. Featuring advanced Flow Acceleration Channels and a Step Inlet Design, it delivers efficient, quiet cooling. Ideal for noise-sensitive setups, it balances airflow and silence with Noctua’s renowned build quality and a 1-year warranty.

## Description

1

Review: Not loud at all. Wonderful. - I used this to replace the fan in my hub. Keeps things cool.
Review: 音の静かさは折り紙つき! 文句無し!! - 10G EthernetハブTL-SX1008のファンがうるさすぎるので、色々調べてこれに交換。付属の回転数を制御する短いハーネスはつけずに、ダイレクトに基盤に繋ぎ１番早い5000スピードで運用。ほぼ無音となった! 体感的にはうるさかったファンの80%くらいの風量は出てると思う。さすがプレムアムの品質です。ちなみに価格もプレムアムですが…(笑)

## Features

- Size 40x20mm
- Flow Acceleration Channels
- AAO frame
- Step inlet design

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B072JK9GX6 |
| Air Flow Capacity | 9.4 Cubic Meters Per Hour |
| Amazon Bestseller | #77,568 in Computers ( See Top 100 in Computers ) #673 in Computer Case Fans |
| Brand | Noctua |
| Brand Name | Noctua |
| Compatible Devices | Desktop |
| Cooling Method | Air |
| Customer Reviews | 4.8 out of 5 stars 2,371 Your Review |
| Included Components | 1 |
| Item Dimensions L x W x H | 40L x 40W x 20H mm |
| Manufacturer | Noctua |
| Material Type | Fiberglass reinforced PBT |
| Maximum Rotational Speed | 5000 RPM |
| Model | NF-A4x20 FLX |
| Noise Level | 14.9 Decibels |
| Part Number | NF-A4x20 FLX |
| Power Connector Type | 3-Pin |
| Product Dimensions | 40L x 40W x 20H mm |
| UPC | 841500110116 |
| Unit Count | 1.0 Count |
| Voltage | 12 Volts |

## Product Details

- **Air Flow Capacity:** 9.4 Cubic Meters Per Hour
- **Brand:** Noctua
- **Compatible Devices:** Desktop
- **Cooling Method:** Air
- **Material:** Fiberglass reinforced PBT
- **Maximum Rotational Speed:** 5000 RPM
- **Noise Level:** 14.9 Decibels
- **Power Connector Type:** 3-Pin
- **Product Dimensions:** 40L x 40W x 20H mm
- **Voltage:** 12 Volts

## Images

![NF-A4x20 FLX 40mm 3pin Fan 20mm Thick Cooling Fan Case Fan - Image 1](https://m.media-amazon.com/images/I/71lyRpVR4OL.jpg)

## Questions & Answers

**Q: Whats the cfm of this fan?**
A: The output, converted from 9.4 m3/h is just 5.5 cfm, very low indeed.

**Q: 14.9dba at what speed?**
A: 5000rpm.

**Q: How many dB is this fan?**
A: 14.9db(a)

**Q: What is the mtbf. How many hours of life can I expect from one of these?**
A: Not sure about the Mtbf, but i purchased 2 of this in Jan 2020, and they have been running 24/7 till now with no problems. Installed them in my 2 poe+ switches

## Customer Reviews

### ⭐⭐⭐⭐⭐ Not loud at all. Wonderful.
*by A***R on November 20, 2025*

I used this to replace the fan in my hub. Keeps things cool.

### ⭐⭐⭐⭐⭐ 音の静かさは折り紙つき! 文句無し!!
*by ふ***ん on September 26, 2025*

10G EthernetハブTL-SX1008のファンがうるさすぎるので、色々調べてこれに交換。付属の回転数を制御する短いハーネスはつけずに、ダイレクトに基盤に繋ぎ１番早い5000スピードで運用。ほぼ無音となった! 体感的にはうるさかったファンの80%くらいの風量は出てると思う。さすがプレムアムの品質です。ちなみに価格もプレムアムですが…(笑)

### ⭐⭐⭐⭐⭐ 静音効果は抜群
*by E***1 on May 4, 2025*

TL-SX1008の純正FANを交換する目的で購入。 期待通りの静音効果が得られ、非常に満足しています。

## Frequently Bought Together

- Noctua NF-A4x20 FLX Computer Case Fan - Cooling Components (Computer Case, Fan, 4 cm, 3700 RPM, 5000 RPM, 4400 RPM)
- Noctua NF-A4x10 FLX, Premium Quiet Fan, 3-Pin (40x10mm, Brown)
- Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-05-20*