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.

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.

I'm questioning whether there is something wrong with this fan. It works but it is very loud. I found that a wire from the motor was looped up and touching the fan blade. I pushed it down with hemostats. The fan runs quiet as expected now.

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.

The first fan ordered did not work as it should - when turning the controller knob, there is a humming noise like a voltage transformer and the blades hardly move. Then suddenly in some position the fan turns on at full power and makes quite a lot of noise, about 28 decibels - it's nothing. Turning the regulator knob to maximum turns the fan off. I thought I had gotten a defective fan and decided to replace it with another one of the same kind, so to speak, to give the company a chance. However, the second one has exactly the same problem. Too bad, the window insert for the 4” vent from this company is quality, no complaints.

I bought this to improve airflow between my basement and main floor, but I found that it was too noisy, even on the lowest setting. I know it gave the decibel rating, but it's hard to know just how noisy that is in real life. I couldn't talk over the noise this fan put off. If you're using it in a duct that is far away from living areas, it might be just fine.

Great little fan