














🌿 Elevate your airflow game—quiet, powerful, and built for pros who demand the best.
The AC Infinity CLOUDLINE S4 is a 4-inch inline duct fan engineered for efficient, whisper-quiet ventilation. Featuring an 8-speed PWM controller and energy-saving EC motor, it delivers up to 205 CFM airflow at just 28 dBA noise. Perfect for grow tents, hydroponics, AV cooling, and HVAC boosting, it comes with all necessary hardware and a UK-compatible Type-G plug for seamless installation.








| ASIN | B07JB292JC |
| Best Sellers Rank | 11,020 in Garden ( See Top 100 in Garden ) 8 in Hydroponic Ventilation Equipment |
| Brand | AC Infinity |
| Colour | Pro Speed Controller |
| Customer Reviews | 4.7 4.7 out of 5 stars (11,455) |
| Date First Available | 21 Nov. 2018 |
| Energy Efficiency Class | A+ to G |
| Item Weight | 2.56 kg |
| Model Number | AI-CLS4 |
| Noise Level | 28 Decibels |
| Power / Wattage | 21 watts |
| Product Dimensions | 9 x 19 x 30 cm; 2.56 kg |
| Special Features | High Velocity, Waterproof |
| Voltage | 240 Volts |
C**G
Quality product.
Quality product. Does the job it's meant to very nicely
A**R
Quite and the remote control is really excellent.
I replaced a built in fan in my kitchen extractor unit (failed motor) by mounting this unit in-line in the extract duct. The remote lead was long enough for me to mount the remote in my old unit and yet have the fan mounted well away. I mounted the fan on wires thus reducing any transmitted running noise (I would not expect much anyway as such a smooth running motor). The level of extraction is variable and perfect for the application. Excellent product 10/10. Fully recommend.
C**R
Brilliant
For me the ac infinity fans were a game changer, got my environment dialled in just how I need it and with ease to, I purchased an s6 and a t4 reasonably priced I might add, they work perfectly together! These fans are great quality and I was even more pleased when they already came with a connector attached to a U.K. plug! Overall 10 out of 10 for these fans, hats off to AC infinity, they’re so quiet and just a quality product, I will never use another make again, if you’re thinking about buying one just do it, you will not be disappointed
W**D
Ac
Works well
D**M
For best performance keep bends away from the fan
I really like this unit, it's powerful, it's quiet and the noisiest bit is the airflow. I am using it to blow air into a portable generator enclosure and the first thing I learnt was to make sure it has a good plenum to draw. I also found it works better if the outlet is not too close to a bend or obstruction or the back pressure affects it. But all of that is good HVAC design practice and for the money its very powerful if you wind it up.
E**D
Best fan money can buy!
This thing is just stupid, you really don't understand how good it is until you get it. It's gonna BLOW YOUR MIND if you are using a general brand extractor... the power is totally unmatched, it's fairly quiet and it's got a wee controller to set the speed of the fan which works VERY well. All in all, i don't know why I didn't buy this years ago - do it, do it, do it!! You will NEVER regret it!
S**N
Good fan
Best I've seen for less than a ton.
A**N
Go overkill for true silence.
Overall it is a great bit of technology, the smart features are invaluable. It is definitely NOT silent though. Past the 4th setting it begins being very noticeably "there" the higher you go (5-6-7-8-9-10) the louder it gets, until it just sounds like a jet engine. Make sure you don't have things laying around while you're testing it as it literally acts like a vacuum cleaner, will suck in your kid and your cat. Only buy this if it wont ever be running past 5th setting if you want quiet. Will work for small 4x4-5x5 spaces excellently. Another complaint is that on the pictures it is advertised with the controller 69, whereas I received the controller 67. The pictures are missleading.
D**N
パワー感は、どうかな? と、いった感じです。
A**Z
The brand is one of the better manufacturers selling to the general public and the vendor was very supportive and provided prompt service. I would buy from them again and recommend the inline fan without hesitation. It’s quiet at lower settings and works without issue.
S**O
AC Infinity has changed the game of home growing for everyone. This fan is priced very well for the level of quality and features it packs. I plugged it into my AC Infinity AI controller and it detected it without hardly any intervention. Since I am not growing plants, but gourmet mushrooms I needed to disable the AI (broke my heart because its truly amazing) and set it manually at the precise numbers I needed. High humidity and low CO2 for fruiting. I had trouble getting it to accept the numbers I wanted since I was not growing standard plants. Called support and had Judy on the line with zero wait time. Judy was a controller ninja and walked me through the clicks to get exactly what I needed set up. Perfection! She didn't ask a million questions, didn't have to go through a painful data collection pre call, just picked up the phone and asked how she could help me. I explained my issue and she had a solution in minutes. Made sure it worked for me and was a pleasure to work with. I don't call support for anything, even at work, unless I am totally dead in the water with no options. AC Infinity made me rethink this stance. The fan itself works great. 10 different settings. Perfect for a mushroom grow tent thanks to the true waterproof rating. Humidity won't even touch this thing. The fan looks sleek and runs silent. I see there is a sound damper available but can't imagine why one would need it unless they sleep next to the tent because its so quiet. The setup was quick and easy. It moves a ton of air and keeps the FAE spot on in my tent. I love the AC Infinity products. I already had a fan and filter and 2 humidifiers that I swapped out just so I could use them with the controller and have more matching gear. I want to set up a garden inside now since this system is so easy to use and works so well.
C**D
Good quality. Very quiet.
C**O
Do not cheap out on fans. Buy one of these. I've got a handful of cheap ebay fans in a pile in the garage and none come even remotely close to the cloudlines. You get what you pay for and these are an absolute testament to that. I've purchased 4 of the AC Infinity products now in varying sizes and every single product is a 10/10 including all the adapters/fittings they sell.