VIVOSUN Exhaust Air Kit, 150 mm, 663 m³/h, EC Motor with Carbon Filter and Pipe, Silent Fan R6 for Indoor Rooms, Grow Tent and Greenhouse, Hydroponics

So, I'm using this fan as part of my custom built ventilation system in my basement room converted to a cigar room. I use it to suck the cigar smoke out through the window via the 6 inch hose and some ducting that goes out. I use it in conjunction with a duct fan that's hooked onto the HVAC ducting that acts as an intake fan for the same room. What I like. 1. The speed controller comes attached. No need to purchase one separately. 2. Durable. I had a mishap where I accidentally dropped it from 7 feet to a concrete floor. No problems, turned it on and fired right up. It's plastic on the outside, but the fan itself has some good heft to it. 3. Powerful. This thing cleans out a room fast. You can watch the smoke going from the cigar a good distance away in the room as it goes right to the area of the fan. What I don't like: 1. This thing is loud. But, that's the compromise. If you want a proper fan that will do the job, noise will be on the table. That all said, it's not loud enough to drown out conversation or music on a small speaker in the room. Further, it's powerful enough to run on low and still keep the room clear with one or two cigar smokers. In all, this being part of my ventilation system saved me hundreds of dollars by not buying a rabbit, or any other overpriced smoke eater. Good price, quality fan.

Bin sehr zufrieden mit dem Ventilator. Macht was er soll, ist sehr leise und die Drehzahlregelung ist auch in Ordnung alles bestens. Wie immer schnelle Lieferung und gut verpackt.

I’m thoroughly impressed with the VIVOSUN Variable Speed Inline Duct Fan! From the moment I set it up, it was clear that this fan is built for performance. The brushless motor and durable plastic blades make it not only efficient but also incredibly quiet—at 34 dB, it’s nearly silent while running. Whether you're using it in an industrial, household, or horticultural setting, it delivers optimal airflow, reaching up to 390 CFM. One feature I love is the stepless speed controller on the power cord. It gives me full control to adjust the airflow and noise level, so I can tailor it to my needs. The compact design (measuring only 8.7 x 11.8 x 8.7 inches) fits perfectly into tight spaces, and installation was a breeze thanks to the included bracket and removable duct ends. This fan is incredibly versatile and does the job exceptionally well. If you're looking for a reliable, efficient, and quiet ventilation solution, I highly recommend this product. It’s the perfect addition to any ventilation system!

I was so impressed with the 4" I also bought the 6". Unfortunately the 6" is much louder! The 4" is advertised as < 31 db (i.e. quiet room), on it's lowest setting that's almost accurate, on it's highest setting it more like 70 db, that's about 15 times louder than the advertised 31 db (decimal scale is exponential). The 6" on it's lowest/quietest setting is about 75 db (i.e. vacuum cleaner), on it's highest setting about 90 db (i.e. table saw), that's 32 times louder than advertised. On it's lowest setting you can hear the fan an all surrounding rooms. Very disappointed with how little you can adjust the fan, on the 4" you can bring it way down, not so much with the 6". I have no way of measuring how much air it moves but it seems to be quite a lot, so no complaints there. I just wish I knew about the actual noise levels beforehand. So choose wisely! EDIT: These comments are with the fan mounted to the ceiling using the bracket, I've since hung the fan inside the tent instead, and am in the process of adding insulated flex ducting which should reduce the noise even more. It's now at an acceptable level of noise (still no where near the "<37 dB" though) Also Vivosun customer service reached out to me based on my review to see how they could help which was unexpected but appreciated. If i have to choose between two products I'll pick Vivosun every time based on my experience with their customer service

Der Rohrventilator ist gut verarbeitet. Die Angegebene Leistung von 663m3/h erreiche ich nicht. Gemessen habe ich knapp unter 600m3/h. Ist aber für das Geld immer noch ein sehr guter Ventilator.