Hon&Guan 4 Inch Inline Booster Duct Fan with Speed Controller - 130 CFM Airflow with 6W Ultra-Low Power and Low Noise

I bought both this 3"and the 4" version to test out for my camper van. One I will use for my composting toilet. The other I will use for air movement in the main living space until the AC cools down the van. The 3" is a little louder than the 4" but the 3" cranks out way more air than the 4". You can always dial back the 3" to a very quiet hum and even with the lowest speed setting, you get plenty of air flow for the composting toilet. Since the toilet is also in the sealed shower room with a large ceiling, I will need more air vents from outside the room so that when the ceiling fan is on, I can crank up the 3" to avoid back flow air through the composting toilet. The 4" fan is nice but I almost want to use the 3" fan for airflow in the main living space since it makes a better breeze. Even though it is a little louder. The noise is not really bad. Slightly more than the AC noise. only due to the higher frequency which you can turn down as needed. the 3" needs 2.75" pipe adapter to MSTR with a 2” pipe. ~$10 each.https://www.amazon.com/gp/aw/d/B0BQW8W49Q/ref=ox_sc_act_image_1?smid=A34RJ9S07AUY15&psc=1

Pros: Fairly quiet at half speed from the outside of the vent pipe. Pushes a lot of air.Motor runs smoothly throughout the speed range.fairly small footprint.No idea of longevity. I'm running half speed continuously for two days now.Cons: You can hear some noise when it is running much like a bathroom or vent hood. At high speed it would make a lot of noise like a vent hood on high.It is about 1/8" less than 6 inches in diameter. Metal A/C tape is required.

A Reliable and Efficient Ventilation SolutionThe Hon&Guan 3 Inch Inline Marine Bilge Blower Fan with Speed Controller has proven to be a valuable addition to my marine setup. Its compact design and powerful performance make it a versatile choice for various ventilation needs.Key Features and Benefits:Impressive Airflow: The fan delivers a substantial 130 CFM of airflow, effectively removing moisture, odors, and stale air from enclosed spaces.Speed Control: The adjustable speed controller allows me to customize the airflow intensity to suit different situations, ensuring optimal ventilation without excessive noise.Durable Construction: The fan's sturdy plastic housing and corrosion-resistant components make it well-suited for marine environments, where exposure to moisture and salt is a constant.Easy Installation: The built-in mounting feet and straightforward design simplify the installation process, making it accessible to both DIY enthusiasts and professionals.Quiet Operation: The fan operates at a relatively low noise level, minimizing disturbances and providing a comfortable environment.Overall Satisfaction:I've been highly satisfied with the Hon&Guan 3 Inch Inline Marine Bilge Blower Fan. Its reliable performance, ease of use, and durability have exceeded my expectations.

I bought this as a vent for spray paint booth, and it worked great. I have an air monitor in my apartment that is very sensitive, and every time I cook it sets it off, even with the windows and stove fan on. I put this in one of my windows and the P.M 2.5 barely moved (in addition to barely seeing a change in the HCHO and TVOCs). I loved the fact you could also adjust the fan speed as needed.For the price, this is a great product! Very powerful! Great Value for the money!

This little guy is great. I needed an inline exhaust fan for my resin printer and this works perfectly. It’s got more than enough power and I don’t even use it higher than 2/3 of the way. It seems durable and is made of metal. It’s very easy to use and it also works perfectly with a smart plug. The weight isn’t too heavy either and can be mounted if needed without it having too much strain from the weight of it. I didn’t have any issues fitting it to my 3” tubing either. I recommend this if you’re looking for a small inline exhaust fan.

I have purchased about 8 of these fans over the last 18 months or so, I use them for a variety of applications around the house, especially for circulating air relating to our woodstove, which is our primary heat source.Overall, they are awesome. They are easy to use, reasonably quiet, and very light weight considering how much air they can move. My issue is, of the 8 I've bought 2 of them (25%, 1/4) have had the bearing(s) go bad within a few weeks of use. For both, I noticed they had a slightly different tone/pitch when running when first installed. Over time, this pitch became noticeable and eventually obvious and irritating. Operation of the fans never failed as I removed them fairly soon after the pitch became obvious and irritating. Given the application I use them for, I both didn't want to have to listen to them and couldn't risk a potential fire should the motor lock up while I'm out of the house.The other 6 fans have been phenomenal, and I plan to give them another shot and buy a few more. I do hope quality control deals with the bearing issue. If not, am going to need to find a different manufacturer (which would be a shame, because these really do have a lot that is desirable about them).I only left a one start rating so it would get more attention. In reality I would have left a 3 star review, but nobody, including myself, usually reads those ratings.

Briefly used out of the box. Excellent flow, control knob works fantastic. Slightly loud on full blast but honestly not bad at all. 10/10 if you need a 4" fan I would recommend this. I have bought other 4" fans and there is a good chance I will replace them with this for the money.

This products easy burn and not working when you run so long time. I bought this few months ago but it stop working last months. I used it for my small Solvent printer machine. When at new runing smoothly and quietly. Easy install and good price. Just use this not for heavy used, i used it all day (heavy used) because my printer working all day.