VIVOSUN 4 Inch Inline Duct Fan 100 CFM, HVAC Exhaust Ventilation Fan with Low Noise for Basements, Bathrooms, Kitchens and Attics, Silver

Works well. Tight fit on 6” pipe but does fit. Simple to use. Good price.

Works perfectly, super quiet.

Installed over a register in a 2nd floor bedroom with poor airflow. I have it plugged into a temperature control switch. It's noisy but a little less than the last one without a speed control. The speed control is not real effective on this fan as I would like to slow it down a little more. With that said,I might return and try another one!

The VIVOSUN 4 Inch Inline Duct Fan with 100 CFM is an absolute must-have if you own a Keystone RV, especially models like the Avalanche 390DS. The lack of proper airflow in the HVAC system of these RVs, particularly in the rear bedroom, can make it unbearably hot. Keystone's quality control issues only add to the frustration. Installing this ventilation fan was straightforward, and the difference in airflow is night and day. The rear bedroom now receives proper air circulation, making it comfortable even on hot days. The fan operates quietly, which is a bonus, ensuring that it doesn't disturb your peace. For anyone dealing with similar HVAC issues in their Keystone RV, I highly recommend the VIVOSUN Inline Duct Fan. It's a reliable solution to prevent overheating and improve overall comfort. 🌬️🚐❄️

At only 100 CFM, this fan isn't too bad. If 100 CFM is what you need. I was expecting more from the design, I guess. With adding an 8 gig video card to my recent computer build, the temps on my chip cooler sky rocket to around 104°F or 40°C on many games, from an average of around 82.4°F (28°C). Which isn't too bad really, but I want to add some filters for dust, & having 104°F pumping into the back room, makes it very hot on a summer day. So I searched around & found this, that I thought would be a solution. I figured it was better than a large Molex powered fan. What I wanted, was to remove the heat that the computer was pouring into the room, with a powerful fan & vent system. All of the air flow goes in the direction of the top vent, & out already. Now I want to pull it out of the room, to the window to the outside. The video card is loud enough on it's own (see review elsewhere), so adding filters to soften the sound, as well as a vent to pull the sound, should reduce it, along with the heat. I looked over Amazon & the net, & found this had the most "quiet sound". Quiet, being relative to the user, of course. Some reviews said it was loud (it is). As you can hear in the video, it is louder than the filtered & non filtered computer. Just to give you an idea. The computer has a twin active fan on the video card, A T-1 thermal tower for the CPU, a 120" side panel fan, & some case fans; on it's own it can be a little loud. Mostly it's the video card, as a simular tower build w/o the 8 gig video card can't be heard (see Black Ice Monster review). So, noise isn't winning any awards. The video is via my phone, not great, not bad. Gaming headset doesn't pick it up, as an FYI. The second & most important thing this Vivosun booster fan needs to do, is evacuate the heat from the computer, so that it doesn't enter the room. The third thing it needs to do (on this checklist), is keep the computer cool. Preferably below current temps, but with in an acceptable range, as long as it's evacuating the room. So far, it's doing #2 alright. Bottom line: With the computer filtered & shut; it will drop the temp about 1-2°C in about 2 minutes. With the side panel off, it will drop it 5°C in 1 minute. The mean running temp in spring: is 35°C (95°F) Under load 43°C (109°F) With the fan off the computer has reached 52°C (125°F) under load on a simple game (Little Nightmares), & the VivoSun brought it down to about 42°C in about 10 minutes. Outside it was around 82°F, the room about 75°F with a pole fan running. So it does alright, just not great. It runs helps at about 5°C on average, but it does evacuate the heat to the outdoors for the most part. I can't say if the 240 CFM fan will do any better as I'm afraid it will be much louder. It's not horrible, just not quiet It sounds like an A/C unit. Oh yeah, it has a tick now after intermittent use in three months. I don't run the vivo fan when just doing text or surfing, only when gaming or doing 3D stuff. Also, the power cord is plenty long great job !! I have it on a wireless remote so I just click & on.

Great product

Junk! Lasted 8 days. I was trying it out before I sliced my ductwork, so I just had it taped to a box sitting in front of a space heater to circulate the heat around the room and it worked fantastic. Then it stopped working fantastic and now I'm pissed off

It is used as a booster fan for a dryer exhaust. It works. A minor issue is that the diameter is actually quite a bit smaller than 4" even though it is listed as 4".

Funciona muy bien

The fan encasement is made from a duct-like material, but it is much stronger and more rigid. The fan has plenty of room inside the ducting should the encasing ever be dented or deform from mishandling or falling. When I received it, it would rumble loudly throughout the ducting; the issue had something to do with the seating of the fan blade, because I took it off and ran it and the motor itself was silent. I removed the fan blade, applied some oil, and pressed in the blade while tightening the nut which holds it on -- the rumble was reduced significantly. Overall, an excellent fan exhaust fan at a solid price. Any workshop, growery, or perhaps a smoking room could benefit from this addition greatly., especially with the addition of a carbon filter.

Purchased to exhaust air from a small indoor grow space. 100cfh is not much. It works for my 8' square room, but it took about 2-3 days to get my humidity down to a manageable level. Now it keeps up nicely. Would not recommend for a space much bigger than this. There are 200cfh fans for $10 more on here and they'd be worth it. This unit is VERY quiet as it is low cfh.

No lo compren, viene bien deforme, es ovalado en lugar de circular, no entran los ductos

Desde que lo instale, m problema de ventilación quedó resuelto, muy buen servicio hasta la fecha.