VIVOSUN 6 Inch Inline Duct Fan 240 CFM, HVAC Exhaust Ventilation Fan with Low Noise for Basements, Bathrooms, Kitchens and Attics, Silver

I use this to extract heat from a portable A/C unit.I needed a fan with metallic blades due to heat. The heat it is exposed to will warp plastic fan blades. I was worried about the fan motor’s exposure to heat as well.This fan (in my application) is exposed to 145 degree internal duct heat for hours at a time which is right at the end of the motor’s advertised tolerance.It has been working without issues for over two months in Florida weather. I run it for as long as 6 hours straight, as needed.I use this fan to extract exhaust heat from a portable 9000 BTU A/C unit in my garage. This unit may also have use in a hurricane aftermath scenario (as in cooling a tent erected inside the house for sleeping (powered by a gas generator located OUTSIDE), if the power is out for weeks.This fan is hard mounted to a plate which I fabricated which seals the window opening completely. It can be removed from the window in less than 30 seconds. It also locks the window to help avoid entry from outside.I insulated the original flex duct with commercial grade insulation material used for A/C ducts in attics.The portable A/C unit is connected to the insulated duct, and then to this fan assembly at the window plate on the other end. The straight 4 foot duct run has two 45° elbows... this fan creates a vacuum in the duct to draw the heat outside better than the A/C u it could before.These portable A/C units are completely useless unless you facilitate the extraction of the heated air they produce. The uninsulated plastic exhaust ductwork they come with simply transfers all the heat the create right back into the room before it gets outside. It’s so hot in fact, it melts and distorts the window mount that comes with the A/C unit, allowing the heated air to literally blow back into the space you are trying to cool! It would heat and cool the garage simultaneously. Incredibly stupid and costly.To remedy, I insulated the exhaust duct from the A/C unit all the way up the the fan (at the window plate) in order to keep the heat in the duct, and not let it radiate back into the garage airspace. This fan sucks the hot air out.The window/fan mounting plate is made of 3/8 finish grade plywood, and painted with a two part epoxy, as to be waterproof and look nice.The fan is mounted to the plywood with a metal ring I fabricated using rivets, and it seals with a gasket. Control of the fan is manual, via the same power strip that supplies the A/C unit. The sound level is lower than the A/C unit’s noise output.The result: My garage can now reach 78°, with a 50% humidity level on a July day like today. Without the AC, the garage is 85% humidity, and 95°F.

I am using this for a custom project and it has held up well. I have it in a high heat situation and its performing great.

I bought this to duct fan to replace a much more expensive and powerful fan that stopped working. Out of the box, the nut holding the fan blades to the drive bolt and the screws holding the motor to the support were all extremely loose. I had to tighten everything to keep the blades from rubbing on the inside of the housing. Performance wise, this thing is fairly loud and I do not believe it's moving around 200 cfm rather than the claimed 400. Ultimately, it does what it's supposed to do at a very affordable price. That said, I'm going to buy a replacement of the original fan (4x the cost of this one) since it moves much more air with less noise. I will keep this one as a backup though.

I don't care about plastic housings and I'm happy to wire my own switches where relevant, so for me and the applications for which I use fans (in this case, cooling inside my truck/paired with optional swamp cooler water flow), this is awesome bang for my buck. It's a bit loud but I don't care, that's to be expected when going for something with high airflow.I do wish I'd considered getting a couple of different sizes because this is actually more powerful than I need for its current use, but that's fine, sooner or later I'll move it and the attached swamp cooler setup I built to a different larger space and build a new smaller one for my truck. I'd much rather overengineer something than have it be insufficient (like my first pitiful swamp cooler attempt with computer case fans -- fun starter project to learn about wiring in series and wiring a three-prong switch, but totally inadequate for cooling the inside of a Ford Explorer!).So yeah, can't speak to how good this is for actual use in ducts, but as a cheap powerful basic fan for a DIYer doing something fan-related, it's a great buy and I'm thrilled I got it. The only way it could be more perfect would be if it had an on/off switch already integrated into the power cord, but that's not a big deal and of course it's not like it advertised/implied that it would have one. It's exactly what I expected, except more powerful. Everything about it seems solidly made and I anticipate it'll last a very long time. I'll most likely buy from this same manufacturer again in the future when I need fans of other sizes.

I bought two of these, one 6 inch and another 8 inch, both for sub-floor moisture ventilation. I installed this one first and quickly regretted it. It is SUPER LOUD and shakes the wall with vibrations. I had to pack a ton of insulation around it to help minimize just how loud and annoying this thing is. Since I already used it, I did not send it back like some Prime abusers like to do. Instead I sent only the 8 inch back and then bought one at local hardware Depot store that costs a little more, but is whisper quiet compared to this thing.I don't expect this one to last 7+ years like the one from the Depot store did. It's going to vibrate itself to death.

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. 🌬️🚐❄️