AC InfinityCLOUDLINE S8 PRO, Quiet 8” Inline Duct Fan with 10-Speed Controller, EC-Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics

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.

The AC Infinity CLOUDLINE S8 PRO has been a total game changer for venting my miner room. The 8” inline duct fan moves a huge amount of air while still being surprisingly quiet thanks to the EC motor. The 10-speed controller makes it easy to fine-tune airflow depending on the temperature load, and I’ve noticed a big difference in keeping my miners cool and stable.Build quality is excellent — sturdy housing, smooth fan operation, and the controller feels responsive and reliable. Installation was straightforward with the included hardware, and once running, it just works flawlessly.✅ Pros:Moves a lot of air with quiet operation10-speed controller allows for precise airflow controlSolid build quality, built to lastEC motor is energy-efficient and quietPerfect for grow tents, server rooms, or mining setups❌ Cons:Higher price point than basic fans (but worth it for performance and reliability)Ducting not included, so you’ll need to purchase separately💡 Tips:Pair it with insulated ducting to reduce noise further.Position exhaust outside or into a larger ventilated area to prevent recirculating hot air.Use a temperature/humidity controller with it for fully automated cooling.Mount with rubber isolators if possible to cut down on vibration.Bottom Line:This fan is a must-have for serious ventilation needs. If you’re running miners, servers, or even grow tents, the S8 PRO is a reliable, efficient, and quiet way to keep heat under control. Well worth the investment.

I have been amazed with this product. And I have been wanting to write a detailed review to highlight the quality of this product, but also to highlight that HVAC booster fans can work despite the negativity found online from the HVAC industry.First of all the quality of these fans is amazing. Very high quality construction and for their size they are remarkably quiet. I am not sure how the manufacturer rates the sounds levels, but at their highest fans speeds they are quit noisy, but for an HVAC booster application you will only need the lower fan speeds which are very quiet. Since my fans are mounted in the attic, the only added noise I hear in the house is the additional air flow coming through the ceiling registry/vent. As for airflow rates, this fan has some ridiculous flow capacity. Literally the first time I fired up the fan with it sitting on my wood flooring, at speed 8 the fan started traveling across the floor like a swamp boat. Now I will mention that if used in an HVAC application, you will need to properly insulate the fan housing to prevent condensation from forming on the exterior of the fan housing. I also questioned what the current load was for these fans and the manufacturer was not able to provide that information, so I took my own current readings. Below are the current loads at each fan speed for the 8" model:1 - 0.08 amps2 - 0.10 amps3 - 0.18 amps4 - 0.30 amps5 - 0.48 amps6 - 0.75 amps7 - 1.12 amps8 - 1.52 ampsThe reason I needed to know the current load for these fans is that in my application I wanted the booster fans to run only when the central HVAC blower was on. To accomplish this I installed a dedicated outlet that is switches on by a Vortex Power Fans AC Current Switch (or current operated solid state relay). The problem is this current switch is limited to handling 2.5 amps. My original plan was to run a relay for each fan, but since I was operating the fans at speeds 1-3 only, I was able to combine the fans on a single current switch.So at the end of the day why did I need these fans? Well my HVAC is poorly laid out with the unit located at one end of the house, so our master bedroom at the other end of the house has a 50-ft duct run, where most of the house is on duct runs less than 20-ft. The air flow loss due to the long duct run caused an average temperate difference of 2.5 degrees, with spikes of 5-6 degrees during the late afternoon sun, as documented by my Ecobee themostat and additional temperature sensors. Since installing the 2 booster fans that route air to our master bedroom, we have completely reversed the temperature difference, so that now our master bedroom averages about 0.5 degrees cooler than the main thermostat. So a full 3 degree temperature swing and that is with both fans running on the lowest speed (1). The reality is, I could have easily gotten away with installing only 1 fan, as I ran a single fan for several days at speed 3, and that was enough to balance our bedroom alone.