CLOUDLINE S4, Quiet 4” Inline Duct Fan with Speed Controller

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.

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!

I needed additional pull from my laser engraver enclosure, and I initially went cheap, buying a $25.00 in-line fan that left me with plenty of odor and escaped fumes. I saw the AC Infinity, but the price made me balk, and I wish I had not, and bought this first. This moves substantial air. It creates positive pressure inside my enclosure, and fumes simply do not rise out or seep through gaps. The smell of what I am engraving no longer lingers in the air. The speed control is very nice, and maybe what some will enjoy, because it quiets the fan, though I keep mine cracked to full all the time. The device is relatively quiet. Indeed, it makes less noise than my earlier cheap, but much weaker, in-line fan. In my case, my enclosure had a 3-inch duct, and the reduction in airflow was significant through and adapter, although this still made a dramatic difference. I have since 3D printed a new 4-inch duct hole and installed in in the enclosure, and even with 16 feet of dryer vent between the enclosure and the outside vent, the exhaust strength is impressive. Get this if you don't want to be disappointed.

For years I used box fans- the $20 fans you can get at any hardware store. During fire season or when there were other air pollutants, I taped a high efficiency furnace filter to the air inlet of the box fan, and it worked great for reducing pollutants inside my house. But my wife complained that the box fans made too much noise, so I got one of these fans, made a box from taped-together furnace filters, taped a piece of plywood to the open side of the filter box, cut a hole in the plywood, and installed this fan through the hole. SO much quieter. A bit less air flow, but no problem, I just leave it on 24/7 and within a few weeks it's collected so much pollution from our indoor air that I can see the filters getting dirty. That crud would have been going into our lungs! The other day, after having used the fan almost 24/7 for a long time, I looked inside of it and found it had a lot of dust in it. I tried to clean it without taking the fan apart, but wasn't able to reach far enough into it from either end, to get most of the dust. Then I found that you can't take this fan apart to clean it. Fortunately I have an air compressor, and was able to blow 135 psi air stream into it from both ends, which removed over 90% of the dust. Also, part of the reason this fan is so reasonably priced is the control: it has many different speeds, and say you have the fan on at the lowest speed and then you want to turn it off: well, the only way to turn it off is to turn it up, through all of the faster speeds, until you reach the top speed, and then one more button press and it turns off. Not really a big deal, it's just poor planning on the part of whoever designed the fan.

Powerful and quiet, using mine on an airbrush spray booth to remove the fumes, working great. Plan to use this on a future laser cutter to remove smoke. I attached it directly the side of a floor joist in the corner of the shop, you have to remove the fan motor to do this, but it goes back together easily. Flexible 4 inch vent tubing fits directly on the ends, secured with the included hose clamps.

i bought this for noise level reduction. to achieve my desired lowered noise level, i cannot use it at 100% speed..i have to keep it on 70% which still controls temp for my cilantro microgreens 2 flats in a 2'x2'x 3' tall tent. keeps temps down to 70-71 F in my cellar where before they were 74-75 with my older fantech fan which sounded like a jet engine. it was also 4". dba was at least 150% that of this fan's dB rating. this is def. an improvement for me and so i am satisfied. but to keep it stealth, it has to be on 70%.. so considering that, and that it still keeps temps to 70 F with a 65W LED & 55" LED lighting 6 sq ft of space with 6 sq ft of foliage also generating heat... thats pretty good. some people might need higher airflow, but you wont get stealth. now consider all i've said knowing i put this fan back in it's original box and cut holes on either end and for the venting and also completely filled the box with bubble wrap and used the styrofoam inserts that came with it - all to dampen noise further - and also suspended it in midair to eliminate vibration in totality... yet i can still hear a faint drone from beneath my living room floorboards. not a big deal. but if ineeded 100% for major temp control then this fan would be impeding on my living room entertainment to the poiint i'd have to turn up the tv twice past my normal viewing experience sound wise. consider all this knowing also that the charcopal filter dampened then sound, too. so if the filter was inside the tent where the fan is not.. it'd be even louder. now, if i had the fan in the ten with filter outside, that would probably be the quietest, even without using the cardboard packaging as an added damper.. but my tent has no room for this... so considering that as well, one may achieve a few less decibles should they go that route. it is the stealthiest fan ive used and has the lowest dB rating in it's class of 4" fans ( i believe). i think their may be only one fan out there that surpasses this and its twice the price. and you can probably achieve that fan's advertised dB rating with a few hacks like ive described above . in the end, it would be the better choice becaquse you can obviously surpass thiss fan's dB with another fan that has a lower base dB rating

This fan is being used to remove smells from my work shop (epoxy vapor, wood working, painting). It is a 13 x 11 work area which translates into just under 1200 cubic feet. This means that at full speed this fan can “turn” the area every 6 minutes. I drilled a 4” hole through the house rim so I can exhaust the smelly air outside. The power cable is about 8 ft long. The control cable is 18 ft which allowed me to place the controller in a good location. I love how it all came together, speed control is effortless. At the first three speeds there is almost no sound, after that the noise level gradually increases. At the 3rd speed I measure 40 db at 3 ft removed from intake Full speed registers at 63 db. The area itself registered at 35 db. For your reference the 40 db is virtually unnoticeable. For me this fan was worth every penny. The included documentation is very clear. As mentioned this fan comes complete with hardware, strapping, 4” band clamps…… Very Nice!

パワー感は、どうかな？ と、いった感じです。

Good things: a) the wired speed control has a long cord and lets you set the speed easily b) plugs into a socket; no direct wiring needed c) the fan can be replaced without having to redo vents, due to the clever mounting bracket. The fan itself is only about 1/3 of the total width you see in the picture; the ends are part of the bracket. d) extremely quiet e) great installation instructions. By "great", I mean GREAT. f) the only packaging I've ever seen that's as good as theirs is when I buy Apple gear. Funny thing: I'm using it as a bathroom fan, but it included a detailed 80-page manual about how to grow hemp... from seed germination to drying the crop LOL. I've had it installed for about a month now, and everything about this item is high quality. Great purchase.

-It comes with the right power plug for EU(for 220v), even if the original images of the product don't show it(i think they are old), it looks like in the past wasn't the case because of others reviews, but now it comes with the right power plug -The cables are long, i mean, looong(power and controller cables), 2,5 meters for uis cable and 2,3 meters for power cable -I took photos of the manual only so you can see: +installation in different scenarios +cleaning +you can see its an actual useful manual +and the warranty part makes me feel like they really care -It comes with every screw, strap and little thing you need to install it in all possible scenarios(see the photos) -If you want to get noise test you can go to amazon.com(eeuu version) and see the videos on the reviews, my phone mic is trash so I wont do a noise test, but I can tell you that at level 1(it has 10 levels) makes 0 noise, at level 5 its the maximum I can deal with(and need) and above looks like its for scenarios where you really need to ventilate and dont care about the noise, so it gives you options, from 3 to 5 in my case is enough(I will never go above most likely) -I like the philosophy of "its yours, you have the control: you can fully open it(normal screws), you have all these intensity levels(from 1-"it barely moves" 2-"quiet and performant" to 3-"hold on to something, this airplane its gonna liftoff", you have a detailed manual, you have long cables, in the box you have all needed screws and little things" -btw the fan is exposed...not a bad thing, its made for people that think a bit

Me llegó a tiempo, excelente extractor de aire, viene con todo lo necesario para su instalación y con folleto, volveré a comprar sin duda, gracias AMZN

Not quiet, 40dB at lowest speed 2 meters away