---
product_id: 89275796
title: "CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics"
brand: "ac infinity"
price: "£107.99"
currency: GBP
in_stock: true
reviews_count: 13
category: "Ac Infinity"
url: https://www.desertcart.co.uk/products/89275796-cloudline-pro-s4-quiet-4-inline-duct-fan-with-speed
store_origin: GB
region: United Kingdom
---

# 205 CFM airflow 28 dBA ultra-quiet 10-speed EC motor control CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics

**Brand:** ac infinity
**Price:** £107.99
**Availability:** ✅ In Stock

## Summary

> 💨 Elevate your air game with silent, smart airflow mastery!

## Quick Answers

- **What is this?** CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics by ac infinity
- **How much does it cost?** £107.99 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/89275796-cloudline-pro-s4-quiet-4-inline-duct-fan-with-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

- • **Built to Last:** Durable dual ball bearings and premium polycarbonate housing ensure long-term reliability.
- • **Whisper-Quiet Power:** Ultra-low 28 dBA noise keeps your space peaceful and productive.
- • **Energy-Smart EC Motor:** PWM-controlled motor delivers max airflow with minimal energy use.
- • **Versatile Installation:** Compact 4” duct size fits grow tents, AV racks, and home HVAC boosters.
- • **Precision Airflow Control:** 10-speed wired controller plus app compatibility for tailored ventilation.

## Overview

The CLOUDLINE PRO S4 is a premium 4-inch inline duct fan featuring a powerful 205 CFM airflow and whisper-quiet 28 dBA noise level. Equipped with a PWM-controlled EC motor and a 10-speed wired controller compatible with smart UIS systems, it offers precise, energy-efficient ventilation ideal for grow tents, hydroponics, AV racks, and HVAC boosting. Its robust build with dual ball bearings and mixed flow blade design ensures reliable, long-lasting performance in high-resistance duct setups.

## Description

AC Infinity is a technology company that specializes in environmental controls for agricultural and HVAC applications. Our smart controllers and integrated grow equipment are designed to work together to create the perfect climate for your plants. Grow Tent Systems Visit the Store Grow Tent Systems Visit the Store Grow Ventilation & Circulation Visit the Store Grow Ventilation & Circulation LED Grow Lights Visit the Store LED Grow Lights Environmental Controllers Visit the Store Environmental Controllers

Review: My Greenhouse - Sorry I didn't take pictures of the unboxing because this thing is packaged so well in terms of padding and just an overall esthetic that you get when the packaging wows you. Phones are a great example of this esthetic and this purchase was the same - just like "Oh wow...". I probably did not need this nice of a fan, but after reading the reviews, I thought it might not be a bad idea to step up to something that was so highly praised. And the reviews are not wrong, this is very high quality at a reasonable price. It is powerful and very quiet, although noise is not something that is going to bother me in the greenhouse. As others have noted, the installation felt weird because you need to take out the middle bit to screw down the base, but it makes sense it would work like that. The clamps are quite sturdy and fancy looking. They work well to snug up so that there won't be any vibration. Using it in my teeny little greenhouse, just one day's worth of experience. It didn't bring down the temperature right away, not as much as I hoped anyway. The little greenhouse that could goes well past 100 degrees some days, when it's not even hot outside. I don't have an inlet (yet), but I do have a gizmo that raises the roof vent when it gets hot. Oh well, TMI, here's a pic. Nice fan, buy it!
Review: The Rolls-Royce of exhaust fans - This is my third, and likely last, exhaust fan I've bought for a project. I wanted an exhaust system for our cat's litter box cabinet so that it would create a small amount of negative pressure and pull the bad odors outside. This fan is absolutely perfect in every possible way and has far exceeded my expectations. I arrived at this fan, after purchasing two others that were just too loud, as the noise seemed to bother the cat. I installed 2" PVC in the wall behind where the cabinet is, because I needed something small enough to fit. I then had a 90 degree elbow coming out of the wall, through a cover plate and then going into the back of the cabinet. In the attic, I installed a 2" to 4" duct adapter onto the 2" pipe, ran 25' of flex duct to this fan, and then another 16' run of duct to the roof vent. While the first two fans where very noisy, even at the lowest speeds, this one is virtually silent. I'm running it on level 2 and cannot hear anything inside the cabinet or in the house. Since I'm restricting the intake to only 2", anything above level 2 would likely just be a waste of power. This setup is working perfectly and creates more than enough exhaust to do the job and it does it in silence. The prior fans moved the air ok but had a really annoying hum that could be heard through the ductwork and also inside the house through the insulated ceiling. I hear nothing with this one. In addition to the above, the fan is rock solid and came with EVERYTHING one could possibly need to install it, including hose clamps. It's almost overkill but shows attention to detail. It also came with a very nice instruction book (yes, it's a substantial book) with detailed instructions on every aspect of installation and operation. The speed controller is very nice and easy to use. I just set it to my desired level and forget it. It will remember its current setting and resume after a power outage. This fan cost a bit more but is absolutely worth every penny paid. The difference in quality and quietness cannot be matched. I could not be happier, cat is happy, and we have an odor-free home.

## Features

- Designed to ventilate grow tents, transfer heating/cooling to rooms, circulate air, exhaust odors, and cool AV racks.
- Features a wired 10-speed fan controller; also compatible with all UIS controllers with intelligent programming.
- PWM-controlled EC motor provides quiet and energy-efficient performance with minimal heat and noise.
- Mixed flow design with stator blade and hydrodynamic wind circles enables airflow delivery in high resistance areas.
- Duct Size: 4” | Dimensions: 6.9 x 11.9 x 7.4 in. | Airflow: 205 CFM | Noise: 28 dBA | Bearings: Dual Ball

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07JB292JC |
| Air Flow Capacity | 205 Cubic Feet Per Minute |
| Best Sellers Rank | #1,941 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #1 in Hydroponic Ventilation Equipment |
| Blade Length | 7.4 Inches |
| Blade Material | Plastic |
| Brand | AC Infinity |
| Brand Name | AC Infinity |
| Cable Length | 144 Inches |
| Collection Name | Channel Fans |
| Color | Pro Speed Controller for S4 |
| Control Method | App |
| Controller Type | Button Control,Remote Control,App Control |
| Customer Reviews | 4.7 out of 5 stars 4,108 Reviews |
| Electric Fan Design | Exhaust Fan |
| Electric fan design | Exhaust Fan |
| Finish Type | Matte |
| Global Trade Identification Number | 00819137020290 |
| Included Components | Cord, Remote |
| Indoor Outdoor Usage | Indoor |
| Installation Type | Versatile Mounting (Horizontal or Vertical) |
| Is Product Cordless | No |
| Item Dimensions D x W x H | 6.9"D x 11.9"W x 7.4"H |
| Material | Polycarbonate |
| Model Name | CLOUDLINE S4 |
| Model Number | AI-CLS4 |
| Motor Type | EC motor |
| Mounting Type | Downrod Mount |
| Noise Level | 28 Decibels |
| Number of Blades | 10 |
| Number of Power Levels | 10 |
| Number of Speeds | 8 |
| Part Number | AI-CLS4 |
| Power Source | AC |
| Product Dimensions | 6.9"D x 11.9"W x 7.4"H |
| Recommended Uses For Product | Inline Duct Fan |
| Room Type | Indoor |
| Size | 4-Inch |
| Smart Home Compatibility | Smart Home Compatible |
| Special Features | Programmable |
| Speed | 2800 RPM |
| Standby Power Shutoff | High |
| Style | Cloudline S4 |
| UPC | 819137020290 |
| Unit Count | 1.0 Count |
| Voltage | 240 Volts (AC) |
| Wattage | 21 watts |

## Product Details

- **Brand:** AC Infinity
- **Color:** Pro Speed Controller
- **Electric fan design:** Exhaust Fan
- **Mounting Type:** Wall Mount/Ceiling Mount
- **Power Source:** Corded Electric
- **Product Dimensions:** 6.9"D x 7.4"W x 11.9"H
- **Recommended Uses For Product:** Air Circulation, Cooling
- **Room Type:** Bathroom, Kitchen
- **Special Feature:** Bladeless
- **Style:** Modern

## Images

![CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics - Image 1](https://m.media-amazon.com/images/I/6117XGasixL.jpg)
![CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics - Image 2](https://m.media-amazon.com/images/I/61qh0zlE6ML.jpg)
![CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics - Image 3](https://m.media-amazon.com/images/I/61B4-3IcMGL.jpg)
![CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics - Image 4](https://m.media-amazon.com/images/I/61B8EwuR7nL.jpg)
![CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics - Image 5](https://m.media-amazon.com/images/I/71CDBlYtPJL.jpg)

## Available Options

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

## Questions & Answers

**Q: What is the max temp of use for this fan? i see you said 240f, but all other manufacturers with plastic impellers say max temp 140f. are you certain?**
A: Always stay a minimum of 25% below specified temp. At minimum they can warp and and motor performance would be affected

**Q: If powered from a switched outlet, will it remember the last speed setting or does that require constant power?**
A: Morning RS, the S4 will not remember your fan speed. It’s a manual setting only. I also have a T4 with a smart controller and it does remember and can be set to auto for heat and humidity. The T4 is for auto exhaust and S4 is intake. If it is your only fan go with the T4. Also, if you have more than 200sf to ventilate go directly to the T6. The are very quiet which is important as my room is under a bedroom. Hope this helps.

**Q: How well does this work with a carbon filter?**
A: I have a 350 Cfm Coco/Carbon Fiber filter that I place on the Exit side of my application. I have tested the filter on both the intake and the exit. I found these units Push much better than they Pull. I do have to increase the power by 10% when I install the exit filter, but it's not really an issue in my application.

**Q: What is the best way to connect this to 12 or 24 volt system?**
A: AC infinity, also looking for DC system compatibility off grid use with solar and lithium battery banks.  Want to avoid DC->AC->DC to save wattage.  I like that your fan design is efficient, but not in my case as the conversion costs wattage/heat.  Ended up buying Atwood unit which does 12/24v which is no where near as nice a fan as this...

## Customer Reviews

### ⭐⭐⭐⭐⭐ My Greenhouse
*by S***E on April 20, 2026*

Sorry I didn't take pictures of the unboxing because this thing is packaged so well in terms of padding and just an overall esthetic that you get when the packaging wows you. Phones are a great example of this esthetic and this purchase was the same - just like "Oh wow...". I probably did not need this nice of a fan, but after reading the reviews, I thought it might not be a bad idea to step up to something that was so highly praised. And the reviews are not wrong, this is very high quality at a reasonable price. It is powerful and very quiet, although noise is not something that is going to bother me in the greenhouse. As others have noted, the installation felt weird because you need to take out the middle bit to screw down the base, but it makes sense it would work like that. The clamps are quite sturdy and fancy looking. They work well to snug up so that there won't be any vibration. Using it in my teeny little greenhouse, just one day's worth of experience. It didn't bring down the temperature right away, not as much as I hoped anyway. The little greenhouse that could goes well past 100 degrees some days, when it's not even hot outside. I don't have an inlet (yet), but I do have a gizmo that raises the roof vent when it gets hot. Oh well, TMI, here's a pic. Nice fan, buy it!

### ⭐⭐⭐⭐⭐ The Rolls-Royce of exhaust fans
*by R***T on December 8, 2023*

This is my third, and likely last, exhaust fan I've bought for a project. I wanted an exhaust system for our cat's litter box cabinet so that it would create a small amount of negative pressure and pull the bad odors outside. This fan is absolutely perfect in every possible way and has far exceeded my expectations. I arrived at this fan, after purchasing two others that were just too loud, as the noise seemed to bother the cat. I installed 2" PVC in the wall behind where the cabinet is, because I needed something small enough to fit. I then had a 90 degree elbow coming out of the wall, through a cover plate and then going into the back of the cabinet. In the attic, I installed a 2" to 4" duct adapter onto the 2" pipe, ran 25' of flex duct to this fan, and then another 16' run of duct to the roof vent. While the first two fans where very noisy, even at the lowest speeds, this one is virtually silent. I'm running it on level 2 and cannot hear anything inside the cabinet or in the house. Since I'm restricting the intake to only 2", anything above level 2 would likely just be a waste of power. This setup is working perfectly and creates more than enough exhaust to do the job and it does it in silence. The prior fans moved the air ok but had a really annoying hum that could be heard through the ductwork and also inside the house through the insulated ceiling. I hear nothing with this one. In addition to the above, the fan is rock solid and came with EVERYTHING one could possibly need to install it, including hose clamps. It's almost overkill but shows attention to detail. It also came with a very nice instruction book (yes, it's a substantial book) with detailed instructions on every aspect of installation and operation. The speed controller is very nice and easy to use. I just set it to my desired level and forget it. It will remember its current setting and resume after a power outage. This fan cost a bit more but is absolutely worth every penny paid. The difference in quality and quietness cannot be matched. I could not be happier, cat is happy, and we have an odor-free home.

### ⭐⭐⭐⭐⭐ Used it to Boost the Exhaust of a Falcon A1 Laser Engraver
*by M***C on February 1, 2026*

This review is for the 4" version of the AC Infinity CLOUDLINE PRO, also known as the S4. My son had received a Falcon A1 Laser Engraver from his wife for Christmas and I offered to create a custom exhaust setup for it. They have a young child and what I had read about the possible toxicity of laser engraving fumes (specifically for leather cutting and engraving) motivated me to get the fumes completely out of their house and garage. After a few hours of research, I zeroed in on this CLOUDLINE PRO S4 for the task, as well as some 4" flexible duct and a silicone elbow/reducer (4" to 3", also found on Amazon). I was not disappointed with the results! See my two photos. I'm very methodical and careful, so it took me a few hours to complete the system, but most of that time was spent sawing through the garage drywall and configuring the termination of the duct at the roof's soffit. My observations: The inline fan is fairly big, but lightweight and is very easy to secure to the wall with the included mounting bracket. It's very quiet! The ten-speed variable control will take it from too quiet to hear, up to a whisper, and finally to a slight swooshing sound at full speed. I was impressed with the air volume it moved. I could definitely feel the air coming from the outlet outside. It reminded me of the volume of air a clothes dryer would produce. Sure enough, with a rating of 205 cfm (likely measured without ductwork), this fan compares to the average clothes dryer exhaust of 150 - 200 cfm. A bonus for the setup I installed is that garages are very leaky and exhausting this much air will bring a similar amount of outside air as "makeup air" and will create a cooling effect for the garage when it's hotter inside than outside. Everything I read online indicated that AC Infinity made good quality inline fans and I got the same impression working with it. Even the packaging and "presentation" upon opening it was far nicer than I had expected. I would definitely buy this brand of inline fan again the next time I need this type of ventilation.

## Frequently Bought Together

- AC Infinity CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics
- AC Infinity Flexible 4-Inch Aluminum Ducting, Heavy-Duty Four-Layer Protection, 8-Feet Long for Heating Cooling Ventilation and Exhaust
- AC Infinity Flexible 4-Inch Aluminum Ducting, Heavy-Duty Four-Layer Protection, 25-Feet Long for Heating Cooling Ventilation and Exhaust

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*Product available on Desertcart United Kingdom*
*Store origin: GB*
*Last updated: 2026-05-22*