VIVOSUND4 4 Inch 195 CFM Inline Duct Ventilation Fan HVAC Vent Blower for Hydroponics Grow Tent

Affordable and works great! Rather than buying a more expensive fan I opted for this fan because I don’t need all the bells and whistles. Increased air flow and I’m overall happy with my purchase. Several years later and it’s still in use and working great!

They work pretty well. The suction isn't super intense, so we used two for a medium-sized room. They aren't very quiet, but also not very loud. Using them in a smoke room.

I really debated on four or five stars. I can't give it two stars since I'm using it as a bathroom fan (not it's intended purpose). I noticed the fan really chokes down if you restrict the inlet at all. But chokes less if you restrict the outlet, so I put my back draft door on the outlet. It is certainly quiet and has a much more pleasing tone than the $150 garbage bath fans you get from the depot.' This fan seems to be well constructed with good bearings, well balanced and the wired plug is a nice thing to have...... fits 4" duct reasonably well.... a great mounting bracket.In all, for MY purpose it's meh, but again, it's intended to be an HVAC fan so I can't give it too hard a time. The price is less than the depot fan and I still think it moves double the air of a depot fan, just not 200cfm in my application.

The media could not be loaded. In making this next generation gaming computer, with an 8 gig Radeon video card among other things, the blowing or ambient heat from the computer is enough to heat a small room. I can & have used it in the winter to do that. Well, I was running something, & it was on over night.In the summer, I want to expel this heat so I can stand to be in there, gaming. Trying to get the right CFM to noise ratio can be difficult in a computer environment, in a small room. Mainly home based. This extractor from VivoSun is a great one.It's not quiet, & sometimes I can't wait to turn it off, but it pulls out the heat like I want it to, well, enough to keep the temps nice. Generally, the CPU's radiator will get up to about 107°F-113°F (42-45°C ) with this 195 CFM fan bringing it to (32°C-37°C) 89.6°F-98.6°F & it's pulling most of that heat out the window.I included a snap of some general video editing temps with out the VivoSun, & the bottom one is after it got going. The temps dropped in about a minute, which is super fast! When I "forget" to turn it on, & the computer gets up to about 45°C, it takes the exhaust about eight odd minutes to bring it down to 35°C & about a full 10 minutes to level off at 33°F.So that's not bad really. I have tried a small CFM unit (106 CFM), but the pull just wasn't there. I have included a video so you can hear how it sounds. Of course, it's muffled a bit, being I captured it from my phone, & recordings always sound different than your ear. If I can, I'll try to include a video of the room's cooling turbo fan so you can hear them both.Not bad, but not whisper quiet. They don't claim to be, either, so nothing on them. If I bring the tower down to the floor, or move it away, that will change things a whole bunch.If you're thinking about adding an external cooler to your gaming/video unit, I strongly suggest VivoSun. The product works great, & they are on top of any blips you may have. In fact, they helped me upgrade to this unit with a matter of an e-mail. That's AWESOMENESS to the 10th!Now I don't have to "worry" about leaving the computer on for a bit while I'm in the middle of a game, or when I step away for a moment. I know that this exhaust fan is going to keep the system cool.Bottom line, this exhaust fan works very well sealed to my tower's top fan port. So much that I will be adding a smaller one to my 3D printer to better help regulate the temps in that case.I did need to purchase dryer duct (hose), & a 4" inlet pipe. The aluminum tape & clamps came with the dryer ducting. I used some sticky sound dampening on the I/O exit panel to better direct the air flow being pulled up & out.Also, it has holes in the "feet" for more secure mounting. I just hot glued it.

I built a custom enclosure for my laser engraver and this exhaust fan is just what I needed. It is plenty powerful at 195CFM to properly ventilate the entire enclosure. I wish it came with an inline switch, but I installed one easily enough.

It's cheap, it has exceptional airflow, but there is no speed control and it's very loud (I measured 55db from 3 feet away). Since I'm using it to ventilate a 3D printer in a home office, this is way too loud. If noise isn't a concern for you, this is an excellent bargain option, but if you are placing it somewhere like a home office where you will be spending time, I'd recommend spending a little more on a more quiet (and speed-controlled) option.

The media could not be loaded. No problem with seller. I bought a both the Viviosun D4 and M4 fans and compared them side by side. The single speed fan was 6 db quieter. The variable speed fan sounds like its out of balance. I am using the D4 fan as a Radon pump. It pulled the radon level down from 11.2 pCi/L to 1.5 pCi/l. No point spending $350 for an official radon pump when this will do the same thing. A little air leaks out between the two halves of the plastic shell. I had to put RTV silicone on the crack to seal it up because some sub-slab radon air was leaking out into the basement. Also (if you do this) you need 3 inch duct collection cuffs to connect it to PVC pipe. The 3 inch rubber cuffs you get from the "home center" store are too small to fit the fan.

This fan is great! It is exactly what I was looking for. I only have a small 2x2x3 tent. Traditional 4" inline fans are very large, but this unit is about half the size of the standard inline fan design; a happy surprise for me. It's like they built the housing just big enough to cover the motor. This also creates the only con that I can think of regarding this product. Because the housing is small, coupled with the fact that it has really good suction, it's pretty loud. It's not like a jet engine or anything...more like a regular box fan on high, but really throaty, like the sound is coming through a tube. It doesn't come with a fan controller, so that is something you will also need, unless noise is not an issue for you. I have a controller so I am GOLDEN! My thanks to Vivosun for making the perfect little fan.I saw complaints about the power of the fan, but if you have a small setup, I would say no bigger than a 3x3x6, and you are using LED's , you should be fine. I hope this helps.