VIVOSUN Inline Booster Duct Fan 4” 106 CFM with Speed Controller, HVAC Exhaust Ventilation Fan with Low Noise for Basements, Bathrooms, Kitchens, Attics, Grow Tents

I was extremely happy with this product I did expect it to be the size that it was and it was which is sometimes surprising. The power that this thing has the fan to suck the air from one part of the house to the other is absolutely wonderful I use it for my attic space to keep the hot air out in the summertime.

Vivosun is a great company to deal with. Awesome customer support. I installed this in my dryer exhaust line and it has sped up my dry time. Fan runs quiet and every efficient. Can’t go wrong with this product.

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.

Worked like a charm. Needed to improve airflow in my drying tent - this made that happen

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.

This fan didn't move any air at all. I tested it with fog so I could see how well it would pull air through conduit and nothing. Yes, nothing would get pulled through. It actually blocked more air than if I had just left the test hole open.

This does not produce any air movement with any length of duct attached whatsoever. It's a shame! The construction and quality seem reasonable (all metal), noise is low, but fan design is absolutely terrible... You can't feel any air out of this thing, let alone the advertised "106 CFM". You'll be lucky to get 100 CF per hour! I have tried all three levels, and it's not pushing any air.

This exhaust fan works great. I have had it and tested it for over a month now. It is very quiet, I wish bathroom motors were this quiet, next the power dial also controls the speed of the fan. the fan speed is completely adjustable this is a HUGE bonus. Most air duct exhaust fans are either on or off, this one has fan speed control. It hooks up pretty easy the length of the cord is about 6 feet which is good. The on off switch is the dial, so the only negative is the switch position. I wish the switch was closer to the outlet and further away from the actual inline booster module.