VIVOSUN Inline Booster Duct Fan 4” 100 CFM, HVAC Exhaust Ventilation Fan with Low Noise for Basements, Bathrooms, Kitchens, Attics, Grow Tents, Black

Very happy with this product. I installed it into a green house connected to a thermostat and ran the supply off of a HVAC leg. With the air hepa filtered on the unit and the house temp at a constant 70/71, when it calls for cooling the fan pulls that extra air in with the adjustable speed and power to move cool air in.Easy to install, works great, and Vivosun Quality as always.

Nice quiet, speed adjustable exhaust fan.

Works great, but really loud. I bought a speed controller from Amazon for $20.00 that took care of the noise level. All in all, it does what I want it to do.

Does the job

This thing has no suction power at all the cheep plastic one i replaced it with had 10x as much power. Do not buy.

It does work well and easily installed. The only problem is the noise level. I do not have a way to measure noise level but it can be heard throuout the entire house.

Easy to install

I have an 800 cfm squirrel cage style blower in my brewery above a pilot system to evacuate heat and steam. The motor can't be exposed to the moisture, so I ducted it through a 4" diameter down-pipe ending a foot above the floor to pull cooler air into the motor.That down pipe proved to be too restrictive to provide enough air to keep the motor from thermal-tripping, so I added this small blower to the down-pipe, and it has made all the difference needed. Where I had been experiencing a couple of motor shutdowns due to overheating on most brewing days, I haven't had any since installing this blower.All that related, this little fan moves just enough air to suffice my needs - it isn't going to impress anyone with the volume it moves. But for an application that doesn't need a lot of air movement, this could work.Cheers!