AC Infinity CLOUDLINE PRO S6, Quiet 6” Inline Duct Fan with Speed Controller - EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics

I purchased the AC Infinity CLOUDLINE PRO S6, 6” Inline Duct Fan with Speed Controller to help keep my miner room cool, and it has exceeded expectations. The EC motor is both powerful and efficient, and what surprised me most is just how quiet it runs, even at higher speeds. Installation was straightforward, and the included speed controller makes it easy to adjust airflow as needed. Running multiple miners can heat up a room quickly, but this fan has made a huge difference — it keeps temps under control without adding a lot of noise or power draw. The build quality feels premium, and I can tell it’s designed to run continuously without issues. ✅ Pros: Very quiet operation, even at high speeds Strong airflow to keep miner room temperatures down Speed controller included for precise adjustment Efficient EC motor saves power over time Solid build quality, designed for 24/7 use ❌ Cons: Higher upfront cost compared to budget inline fans Speed controller cable could be a little longer 💡 Tips: Use insulated ducting to further reduce noise. Mount the fan with vibration-dampening straps for an even quieter setup. Pair it with a temperature or humidity controller for automatic adjustments. Clean the fan and ducts periodically to maintain peak airflow. Bottom Line: The CLOUDLINE PRO S6 is a top-tier ventilation fan that’s perfect for high-demand environments like mining rooms, hydroponics, or grow tents. It’s quiet, efficient, and powerful — exactly what you need for reliable cooling in a 24/7 setup.

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.

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.

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.

The fan works great and has a wide range of performance that allows you to run this thing at any speed between silent and very loud. I use mine as part of a DIY ventilation system for an old apartment and it provides loads of air movement and static pressure. At full blast, I measured its power draw at 165 watts. The fan is notably very efficient and can still move a surprising amount of air at its lowest speeds with around just 5-10 watts of power usage. (Though you won't be ventilating a whole space at that level.) One thing to seriously note though: This fan can be a real safety hazard if not used correctly. It should really have some feature to kill the power easier since at full blast this fan will happily consume any nearby debris and probably result in injury if you were to get your hand in it. There is no built in grill or safety screen. The controller allows for the selection of 10 speeds, but requires you to loop through to the highest speed before it will shut off. Additionally, when you remove the controller by disconnection, the fan defaults to FULL power. I had an incident where the fan swallowed a bag of small screws and I had to hastily chase down the power plug in order to shut it off. I guess as a testament to its durability though the fan didn't seem to suffer any damage. I have since included a shutoff switch in-line with the power cord.

Initial thoughts, I give this 5 stars, but, the speed controller has these 10 small obnoxiously bright LED lights, so I'm whacking one star. They're the white/blue type. Wow, they're like miniature lasers piercing your eyes. They should have gone with red, not the white/blue. The fan is made of plastic, but it's durable. Blades are sturdy. No flimsy materials used. The fan is pretty quiet. Speeds 6+ are pretty noisy, but then again, when you're shoving 730 cubic feet of air into an 8" tube, it's going to make some noise. I find that acceptable. Lots of air flow, which is what we wanted. Once we start using this more, I may be back to update if needed.

this is a must grab for serious indoor growers! super quiet, light and compact, and keeps the environment dialed in perfectly. absolutely phenomenal product for the price.

Worked great for a grow tent. After a while I started using it to suck the hot air out of our attic in the summers. Pretty quiet for what it is