--- product_id: 82236934 title: "Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)" brand: "noctua" price: "$37.62" currency: USD in_stock: true reviews_count: 13 category: "Noctua" url: https://www.desertcart.us/products/82236934-noctua-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm store_origin: US region: United States of America --- # >150,000 h MTTF reliability 5000 RPM max speed Ultra-quiet 14.9 dB(A) Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) **Brand:** noctua **Price:** $37.62 **Availability:** ✅ In Stock ## Summary > 🛠️ Quietly conquering noise, one tiny fan at a time. ## Quick Answers - **What is this?** Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) by noctua - **How much does it cost?** $37.62 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/82236934-noctua-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm) ## 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 - • **Built to Last:** Engineered with premium bearings and reinforced materials, backed by a 6-year warranty for long-term peace of mind. - • **Compact Yet Mighty:** Ultra-compact 40x40x20mm size fits tight spaces like 1U servers and network equipment without compromising airflow. - • **Whisper-Quiet Power:** Experience near-silent airflow at just 14.9 dB(A), turning noisy gear into a peaceful workspace essential. - • **Precision PWM Control:** Seamlessly adjust fan speed with 4-pin PWM for optimal cooling and energy efficiency tailored to your device’s needs. - • **Complete Installation Kit:** Includes anti-vibration mounts, extension cables, and OmniJoin adaptors for effortless, professional-grade setup. ## Overview The Noctua NF-A4x20 PWM is a premium 40x40x20mm quiet fan designed for professional-grade cooling in compact devices like 1U servers, routers, and NAS units. Featuring a max speed of 5000 RPM with smooth 4-pin PWM control, it delivers efficient airflow at an ultra-low noise level of 14.9 dB(A). Built with high-quality bearings and reinforced materials, it offers exceptional durability with a mean time to failure exceeding 150,000 hours. The fan comes complete with anti-vibration mounts and versatile adapters, making it the go-to upgrade for professionals seeking to transform noisy network gear into a calm, productive environment. ## Description Product description Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctua’s AAO frame, the NF-A4x20 is a highly optimised, premium-quality quiet fan in size 40x20mm. The PWM version sports Noctua’s custom-designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers and comes with a Low-Noise Adaptor as well as an OmniJoin Adaptor Set for easy connection to proprietary fan headers. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands. 40x20mm size Compared to Noctua’s award-winning NF-A4x10, the NF-A4x20 is twice as thick, which allows for increased static pressure performance and makes the NF-A4x20 ideal for demanding applications with high flow resistance. Flow Acceleration Channels The NF-A4x20 impeller features suction side Flow Acceleration Channels. By speeding up the airflow at the crucial outer blade regions, this measure reduces suction side flow separation and thus leads to better efficiency and lower vortex noise. SSO2 Bearing The NF-A4x20 features the further optimised second generation of Noctua's renowned, time-tested SSO bearing. With SSO2, the rear magnet is placed closer to the axis to provide even better stabilisation, precision and durability. Integrated Anti-Vibration Pads Integrated Anti-Vibration Pads made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard mounting systems and fan clips used on heatsinks. Scope of delivery NA-RC7 Low-Noise Adaptor (L.N.A) NA-YC1 4-pin PWM y-cable NA-EC1 30cm extension cable OmniJoin adaptor set 4x NA-AV3 anti-vibration mounts Fan screws AAO frame Noctua's AAO (Advanced Acoustic Optimisation) frames feature integrated anti-vibration pads as well as Noctua's proprietary Stepped Inlet Design and Inner Surface Microstructures, both of which further refine the fan's performance/noise efficiency. 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 Review: Quiet, great accessory pack, affordable option... - 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. ## 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 | 40 Cubic Centimeters Per Second | | Best Sellers Rank | #26 in Computer Case Fans | | Brand | Noctua | | Brand Name | Noctua | | Compatible Devices | Desktop | | Cooling Method | Air | | Customer Reviews | 4.8 out of 5 stars 2,033 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 Decibels | | 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 | 1.0 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 ![Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) - Image 1](https://m.media-amazon.com/images/I/71lyRpVR4OL.jpg) ![Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) - Image 2](https://m.media-amazon.com/images/I/81abh0+LmWL.jpg) ![Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) - Image 3](https://m.media-amazon.com/images/I/71ZYfijIyBL.jpg) ![Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) - Image 4](https://m.media-amazon.com/images/I/71dP+BWXMRL.jpg) ![Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown) - Image 5](https://m.media-amazon.com/images/I/61xqdXxj1uL.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 ### ⭐⭐⭐⭐⭐ 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. ### ⭐⭐⭐⭐⭐ Unrivaled Performance in a Compact Package! *by J***. on January 21, 2024* I recently added the Noctua NF-A4x20 PWM to my server setup, and the performance of this 40x20mm fan has left me thoroughly impressed. Noctua's reputation for premium quality is well-deserved, and this fan is no exception. Firstly, the build quality is exceptional. The brown color may be unconventional, but it's a symbol of Noctua's commitment to quality. The construction feels robust, and the attention to detail is evident. This fan exudes durability, assuring me that it can handle continuous operation in a server environment. Now, let's talk about the noise level—or rather, the lack of it. This fan is remarkably quiet, especially considering its size. Noctua's focus on providing a quiet solution without sacrificing performance is evident here. Whether my server is working at full capacity or idling, the NF-A4x20 PWM operates silently, contributing to a peaceful and distraction-free environment. The PWM functionality is a standout feature. The fan's speed is dynamically controlled based on the system's temperature needs, ensuring optimal cooling without unnecessary noise. This adaptability is a game-changer for maintaining the right balance between temperature control and acoustics. Installation was a breeze, thanks to the included accessories and clear instructions. The fan integrates seamlessly into my server setup, and the 4-pin connector allows for precise control over its operation. The performance, reliability, and quiet operation make it a top-tier choice for anyone seeking a compact, high-quality fan for their server. In my book, it's a solid 5-star product, and I wouldn't hesitate to recommend it to anyone looking to add performance and lower the noise level of their server or PC. ## 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) --- ## 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.us/products/82236934-noctua-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm](https://www.desertcart.us/products/82236934-noctua-nf-a4x20-pwm-premium-quiet-fan-4-pin-40x20mm) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-05-22*