iPower 4 Inch 130 CFM Inline Duct Fan with Variable Speed Controller Ventilation, Quiet HVAC Exhaust Blower

I've ran ipowers six inch, and four inch metal version as well as vivosuns cheaper plastic model and ac infinity cloudlines 4 inch models. This would have gotten a better rating but unless you're looking specifically to wall mount or shelf mount this it's a little unhandy to hang. Otherwise it's noise is less than the metal versions and more so than ac infinity cloudline series. I hope this helps clear up anyone trying to decide, this was a good purchase overall and excited to use this product.

We have used several and recommended to our customers. Quiet, great speed control and easy to install. I have not had them in service for more than a year and cannot comment on durability.

My application for this fan is to deliver clean, warm or cool air from the house to a walled-off laboratory area in the garage, the fan housed in a cupboard in the garage. I'd begun with a very inexpensive fan, which proved no only inadequate but failed with seized bearings after less than a year of continuous use. (This substandard fan is pictured along with the new iPower one in the photo.) The iPower fan runs remarkably smoothly and makes very little noise for the amount of air it moves. I have it fitted with sound-absorbing ducting as well as pre-and-post filtration to deliver dust-free air. As expected, the provided speed controller does corrupt the sinusoidal AC mains waveform so that the slower speeds are not proportionally quieter as one would expect, so I run the iPower at about 80 volts from a transformer to deliver a lower airflow very quietly. The iPower is well built and very efficient, serving the purpose ideally.

So weak. But soft and easy to instal