---
product_id: 82236934
title: "NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)"
brand: "noctua"
price: "€ 39.34"
currency: EUR
in_stock: true
reviews_count: 13
category: "Noctua"
url: https://www.desertcart.hr/products/82236934-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm-brown
store_origin: HR
region: Croatia
---

# >150,000 h MTTF reliability 5000 RPM max speed Ultra-quiet 14.9 dB(A) noise level NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)

**Brand:** noctua
**Price:** € 39.34
**Availability:** ✅ In Stock

## Summary

> 🛠️ The tiny fan that tames roaring servers — upgrade your workspace serenity now!

## Quick Answers

- **What is this?** NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) by noctua
- **How much does it cost?** € 39.34 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/82236934-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm-brown)

## 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

- • **Compact Yet Mighty:** 40x40x20 mm size fits tight 1U servers and network gear while delivering efficient airflow.
- • **Whisper-Quiet Power:** Experience near-silent airflow at just 14.9 dB(A), perfect for noise-sensitive workspaces.
- • **Precision PWM Control:** Automatic speed adjustment via 4-pin PWM ensures optimal cooling without wasting energy.
- • **Plug & Play Versatility:** Comes with extension cables, y-cable, and OmniJoin adaptors for seamless integration with proprietary headers.
- • **Vibration-Free Operation:** Includes anti-vibration mounts to keep your setup stable and noise-free.

## Overview

The Noctua NF-A4x20 PWM is a premium 40x40x20 mm quiet fan designed for 1U servers, routers, and network devices. Operating at up to 5000 RPM with a noise level as low as 14.9 dB(A), it features advanced acoustic optimization and Flow Acceleration Channels for superior airflow. Its 4-pin PWM connector enables smart speed control, while anti-vibration mounts and included adaptors ensure easy, stable installation. Built for longevity with over 150,000 hours MTTF, this fan transforms noisy enterprise gear into a peaceful office companion.

## Description

Buy Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown): Case Fans - desertcart.com ✓ FREE DELIVERY possible on eligible purchases

Review: Very quiet yet still move enough air. Good for 1U switches that come with loud fans - Got these to install in a MikroTik switch that is inside my office area. Worked great! They fit pefectly and the fan header connectors were compatable with the switch. They would probably also work in a 1U server but they may not push enough air for really demanding cooling. Switch and router and lower power 1U devices they are perfect. Also include the standard Noctua goodies in the box. Very nicely made and high quality.
Review: Noctua NF-A4x20 PWM: The Tiny Fan That Turns Screaming Network Gear Into a Polite Roommate - The Noctua NF-A4x20 PWM is one of those tiny components that punches hilariously above its weight. At 40mm, it looks like it should be decorative, yet it’s capable of transforming loud, grumpy network gear into something that no longer sounds like it’s preparing for takeoff. Drop one of these into a firewall or switch that shipped with a fan clearly designed by someone who hates silence, and suddenly the room feels calmer, cooler, and more civilized. It’s small, precise engineering doing a big favor for your ears. In real-world use, this fan is a peace offering to anyone who’s had to live near enterprise hardware. It moves air efficiently for its size, ramps smoothly under PWM control, and avoids that high-pitched whine that cheaper 40mm fans love to produce. Thermals stay under control, airflow is steady, and the fan itself behaves like it understands its job description. It doesn’t try to impress; it just quietly fixes a problem you’ve been ignoring because you assumed loud was unavoidable. Where the NF-A4x20 really shines is in reclaiming sanity from gear that was never designed for human proximity. Firewalls, routers, compact servers—anything that technically fits under a desk but audibly objects to the arrangement—benefits immediately. It’s the kind of upgrade that makes you wonder why manufacturers insist on shipping jet-engine fans in devices meant to live in offices. The improvement isn’t subtle; it’s the difference between “background noise” and “oh, I forgot that thing was on.” Noctua’s usual attention to detail is all here: solid bearings, predictable PWM behavior, and build quality that inspires confidence. It’s not flashy, it’s not exciting, and it doesn’t need to be. It simply does what good engineering is supposed to do—solve a problem cleanly, quietly, and without introducing new ones. Pros • Dramatically quieter than stock 40mm fans • Smooth, predictable PWM control • Excellent airflow for its size • High-quality bearings and long service life • Instantly improves livability of noisy network gear Cons • 40mm size still limits absolute airflow • Requires compatible PWM control • Physical fit can vary by device • Once installed, you’ll notice how bad the original fan really was

## Features

- Premium quiet fan, 40x40x20 mm, 12V, 4-pin PWM, max. 5000 RPM, max. 14.9 dB(A), >150,000 h MTTF
- Award-winning A-series design with Flow Acceleration Channels and Advanced Acoustic Optimisation frame for superior quiet cooling performance
- 40x20mm size ideal for 1U servers or replacing fans in network and storage equipment (routers, switches, NAS etc.) or other devices such as DVRs
- 4-pin PWM version for automatic speed control via 4-pin PWM fan headers, 5000rpm maximum speed (4400rpm with supplied Low-Noise Adaptor)
- Includes anti-vibration mounts, fan screws, extension cable, y-cable and OmniJoin adaptor set for connecting the fan to proprietary fan headers

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B071W93333 |
| Air Flow Capacity | 9.4 cubic meter per hour |
| Best Sellers Rank | #23 in Computer Case Fans |
| Brand | Noctua |
| Brand Name | Noctua |
| Compatible Devices | Desktop |
| Cooling Method | Air |
| Customer Reviews | 4.8 out of 5 stars 2,068 Reviews |
| Item Dimensions L x W x H | 1.57"L x 1.57"W x 0.79"H |
| Manufacturer | Noctua |
| Material Type | Fibre-glass reinforced PBT |
| Maximum Rotational Speed | 5000 rpm |
| Model | NF-A4x20 PWM |
| Noise Level | 14.9 db |
| Number of Items | 1 |
| Part Number | NF-A4x20 PWM |
| Power Connector Type | 4-Pin |
| Product Dimensions | 1.57"L x 1.57"W x 0.79"H |
| UPC | 841500110109 |
| Unit Count | 1 Count |
| Voltage | 12 volts |
| Warranty Description | 6 year manufacturer’s warranty |

## Product Details

- **Air Flow Capacity:** 9.4 Cubic Meters Per Hour
- **Brand:** Noctua
- **Compatible Devices:** Desktop
- **Cooling Method:** Air
- **Material:** Fibre-glass reinforced PBT
- **Maximum Rotational Speed:** 5000 RPM
- **Noise Level:** 14.9 Decibels
- **Power Connector Type:** 4-Pin
- **Product Dimensions:** 1.57"L x 1.57"W x 0.79"H
- **Voltage:** 12 Volts

## Images

![NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) - Image 1](https://m.media-amazon.com/images/I/71lyRpVR4OL.jpg)

## Available Options

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

## Questions & Answers

**Q: What is the CFM rating of this fan?**
A: 5.5 cfm

**Q: would anyone recommend this fan for a 3d printer hontend/part cooling fan?**
A: Yes, we'd recommend using this fan for your 3d printer. (Please note that this is a 12V DC fan.)

**Q: What is de difference between noctua nf-a4x20 pwm and noctua nf-a4x20 flx?**
A: one fan is pwm controllable (pwm), the other is not (flx).

PWM controlling: https://en.wikipedia.org/wiki/Computer_fan_control

**Q: Is a 4-pin two Fan splitter included?**
A: yes

## Customer Reviews

### ⭐⭐⭐⭐⭐ Very quiet yet still move enough air. Good for 1U switches that come with loud fans
*by M***G on June 25, 2026*

Got these to install in a MikroTik switch that is inside my office area. Worked great! They fit pefectly and the fan header connectors were compatable with the switch. They would probably also work in a 1U server but they may not push enough air for really demanding cooling. Switch and router and lower power 1U devices they are perfect. Also include the standard Noctua goodies in the box. Very nicely made and high quality.

### ⭐⭐⭐⭐⭐ Noctua NF-A4x20 PWM: The Tiny Fan That Turns Screaming Network Gear Into a Polite Roommate
*by D***Q on December 26, 2025*

The Noctua NF-A4x20 PWM is one of those tiny components that punches hilariously above its weight. At 40mm, it looks like it should be decorative, yet it’s capable of transforming loud, grumpy network gear into something that no longer sounds like it’s preparing for takeoff. Drop one of these into a firewall or switch that shipped with a fan clearly designed by someone who hates silence, and suddenly the room feels calmer, cooler, and more civilized. It’s small, precise engineering doing a big favor for your ears. In real-world use, this fan is a peace offering to anyone who’s had to live near enterprise hardware. It moves air efficiently for its size, ramps smoothly under PWM control, and avoids that high-pitched whine that cheaper 40mm fans love to produce. Thermals stay under control, airflow is steady, and the fan itself behaves like it understands its job description. It doesn’t try to impress; it just quietly fixes a problem you’ve been ignoring because you assumed loud was unavoidable. Where the NF-A4x20 really shines is in reclaiming sanity from gear that was never designed for human proximity. Firewalls, routers, compact servers—anything that technically fits under a desk but audibly objects to the arrangement—benefits immediately. It’s the kind of upgrade that makes you wonder why manufacturers insist on shipping jet-engine fans in devices meant to live in offices. The improvement isn’t subtle; it’s the difference between “background noise” and “oh, I forgot that thing was on.” Noctua’s usual attention to detail is all here: solid bearings, predictable PWM behavior, and build quality that inspires confidence. It’s not flashy, it’s not exciting, and it doesn’t need to be. It simply does what good engineering is supposed to do—solve a problem cleanly, quietly, and without introducing new ones. Pros • Dramatically quieter than stock 40mm fans • Smooth, predictable PWM control • Excellent airflow for its size • High-quality bearings and long service life • Instantly improves livability of noisy network gear Cons • 40mm size still limits absolute airflow • Requires compatible PWM control • Physical fit can vary by device • Once installed, you’ll notice how bad the original fan really was

### ⭐⭐⭐⭐⭐ Quiet, great accessory pack, affordable option...
*by T***. on May 8, 2026*

Purchased to replace fans in a Unifi USG Pro 4. The fans are the same size, still move good air and are basically silent. Full adapter, extension, and mounting hardware included was great. I used the rubber mounts and trimmed them, fans held securely. Great option for this fan size - would purchase again if needed moving forward.

## Frequently Bought Together

- Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)
- Noctua NF-A4x10 FLX, Premium Quiet Fan, 3-Pin (40x10mm, Brown)
- Noctua NF-A8 PWM, Premium Quiet Fan, 4-Pin (80mm, Brown)

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**Shop now:** [https://www.desertcart.hr/products/82236934-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm-brown](https://www.desertcart.hr/products/82236934-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm-brown)

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*Product available on Desertcart Croatia*
*Store origin: HR*
*Last updated: 2026-07-28*