Inline Duct Fan, 150 mm, 748 m³h with Variable Speed Control for Grow Tent, Ventilation, Plant Tent, Indoor, Garden, Ventilation Fan, Z6 Pipe Fan, Black

Very quiet and reliable! The speed control is icing on the cake because even more-expensive fans seldom have that option. This fan was actually cheaper than a similar Chinese-made blower that I bought months ago, but this one is MUCH better made. This one it is replacing was too loud, and after just a week started rattling and making out-of-balance noises that only improved slightly when I tightened things up. Not the Vivosun fan! This thing has now been in service just as long as the old one, and it still sounds and moves air like it was brand new. I very much feel comfortable comparing its performance to that of a Hurricane fan (one of which I also own). These things are perfect for building stand-alone air filter/charcoal filter boxes. My whole family has allergies, and teamed with the right filters this thing is keeping my family sniffle-free without all the noise of a HEPA filter.

Mad flow of air. Used this to pull in air for my mining rigs that I had setup in a grow tent. Bu it is noisy when winding up to full rpm. Overall great value, and great product

I have owned a few inline fans over the years the wattage is right for this size. I fired it up it was powerful. But the cord is to short and it turns down but not right to off. But it still turns down which helps with getting the air exchange just right. Make sure it is installed on a straight Piece of strong wood use a level for that is for intake or place right over the filter that is for exhaust. It will last a long time. They are so quiet my better half told me to turn it on I said it is on she was shocked. That was my 8 inch model. These are so we'll built. I just bought another that makes 6 inline fans I have purchased. Amazon is the only way to shop. Lower you carbon footprint.

We had a 2nd floor room in our century-old house that had only a faint breeze coming from its vent via 6" flexible duct tube that was routed down through an old chimney to the basement where there was only a short distance between the main duct from the furnace/HVAC and the hole in the chimney. Consequently, longer inline fans were not an option. After installing the Vivosun 6" fan, that previously hot-in-the-summer and cold-in-the-winter room now has the best airflow in the house-- even airflow overkill for just one room. The variable speed controller on the fan allows you to adjust from super fast all the way down to very fast. Yeah, it won't blow slowly. This fan is no wimp! The fan is well balanced and lubricated and runs very quietly. About the only noise is from the wind that the fan creates, which is to be expected and is unavoidable. The motor itself is just about silent. UPDATE: January 15, 2020. After using it for a year and a half, it started to squeak and then make a rubbing sound. I contacted Vivosun and asked if there were any lubricants that they recommended or would advise against. They refunded my purchase price (!) and said that purchasing a new one from Amazon would be faster than servicing it. This is well past any warranty time and WAY ABOVE AND BEYOND any expected customer service! Excellent service!

UPDATE: Fan began to become very loud within a few months. Vivosun refunded me and let me keep the fan. 4/5 From the moment you unbox this product, you can tell it means business. Everything seems incredibly sturdy and well put together. Packaging was done well too. My eyes widened when I turned on the unit, it was incredibly powerful and I knew it was going to do the job I needed. The unit itself is actually quite heavy, so I opted to hang it in my grow tent instead of mounting it on a wall. I had a VIVOSUN 100CFM 4" fan exhausting from my tent, but it did not help whatsoever once hooked up to a carbon filter (Tent size: 2x4x5). Do not mess around with exhaust, I nearly killed my plant. Get something powerful. Can't go wrong. I installed this product at the top of my tent, venting it to the attic and it reduced my temperatures from 33 degrees to 23 degrees and completely stabilized everything. There is now little temperature difference between having my light on and off. I was told my CFM should be calculated based on the size of my tent, which is why I went with the 100CFM fan, but it was virtually useless in circulating the air, even though I went above and beyond the imagined CFM needs.. I even had all vents open and a 100CFM intake too. This new fan negated my use of an intake fan since it is powerful enough to draw its own intake. All in all I think you'll save money by just going with a powerful exhaust and leaving your vents open. I heard that the unit gets quite loud after a few weeks, but I have mine on the lowest setting and its not very noticeable behind some wood doors. Will update my review if necessary. Also, others are right. You cannot completely control the speed of the fan with the controller, but I'd say it goes 2x as fast going from its lowest to highest setting, perhaps more. Either way, it packs a punch.