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

So far this fan works great. Using it to vent out cat litter smell and so far it is working like a charm. I like the variable speed control, works perfect. Has a hum to it but I wouldn't say it is loud. I have this fan in the laundry room venting the cat litter box. Well, it worked a little to good and was venting warm air from the house. Not the whole house but any room connected to the laundry room. So it does have some power to it.

Plugged it in and worked no problem. Quality seems pretty good, no crazy vibrations. Not too loud on lower settings but I like that you can adjust it with the dial. Airflow seems adequate.

Update (1 year later)... One star deduction. The fan power supply died just short of 1 year. The fan started cycling on and off. I replaced the power supply with a 24 volt non-adjustable type and the fan is working great again. In fact, I like the air volume so much I just purchased the same model for my other son's room. The factory power supply runs extremely warm so I'm not expecting it to last. I'll be ready with a 24 volt model when it happens. I have a second floor bedroom used for PC gaming that gets unbelievably hot in the summer. Installing a booster fan in the 6" duct leading to that room mostly solves the problem. I had a 240 cfm all metal duct fan running for about three years that finally died. It was noisy and didn't seem to push as much air as advertised. This Hon&Guan model is a major improvement. Although being 100% plastic, it still easily mounts to the duct using aluminum duct tape. The claimed 345 cfm airflow is no lie. I plugged it in before installation and it rearranged all the papers in my kitchen. Compared to the twice as expensive home center metal duct fan, this one has 100 cfm greater capacity, half the power usage, adjustable speed and lower noise. My son gave me the thumbs up after a day of use. His room stays in the mid-70's (deg F) compared to 87-89 (deg F) without the fan. It is only activated when the furnace blower runs so it is not constantly on. If it lasts a few years I'll be very satisfied.

I bought this to ventilate a small paint booth I had thrown together while working on restoring some old car parts. This fan is very quiet, smooth, and pushes a lot of air. It's compact yet powerful, and the adjustment allows me to raise the speed when spray painting to get rid of overspray, and slow things down to let the paint off-gas/cure quicker. The fan has held up against a lot of spray paint being sucked right into it and has no issues. It works as I intended, and the included clamps are a bonus.

Great product! I bought for a laser vent system. It works amazing! It has great power and adjusts for fine tuning. Very easy to install. Fits 4" vent pipe perfectly.

Using to boost flow upstairs where hot air is stagnant. Works wonderfully. I have it plugged into a smart outlet so it works with Alexa. A little loud on high but works amazingly, very well built and fit perfect .

I've been running this as an exhaust fan for a laser engraver. It does the job admirably. Plenty of airflow with a reasonable noise level. The control fob is convenient with a long enough cord to place it where you need.

Got this to vent resin printer fumes out the window. After messing around with it a bit it seems like it's up to the task. [UPDATED REVIEW 5/5/24] To stress test the fan a little, I left it by the window for 2 days, running non-stop at half power. Not exposed to direct sunlight or rain, on a level surface, etc. Normal working conditions. The fan eventually developed a rattle, like the fan is unbalanced or something. The rattle comes and goes. It's still quiet enough that the hose and enclosure mostly muffle it, but it's definitely concerning, and disappointing considering the good first impression it gave me. Maybe spend the extra 2 bucks on a metal exhaust fan instead, assuming those are sturdier. [CONSTRUCTION] This 4-inch inline fan is made of lightweight plastic, including the blades. Its tough not to be snarky and say this is basically a glorified computer fan, but that's the impression it gives because of all the plastic. The housing is sturdy though, it won't flex unless you're cranking down on the hose clamps at the ends (hose and clamps not included). This is actually one of the nicer products I've bought from Chinese manufacturers, it doesn't have that worrisome "cheap" feeling. If the plastic is a dealbreaker for you though, there are def more options in the same price range that have a metal housing instead, with varying CFM. This unit comes with a stepless dial-like controller to adjust the fan speed. There are no guards over the fan blades so don't stick your fingers in there, and don't leave it out for curious pets to play with. [NOISE] This fan can be quiet and noisy depending on the power level. When set somewhere between 45%-90% power there's an underlying mechanical whine. It doesn't sound like anything is loose or broken, it's more like the sound a jet turbine naturally makes as it ramps up in speed. I actually think it sounds cool, but I can understand why some people don't like it. Without the whine it simply sounds like a strong computer fan. I could sleep with it in the room, but maybe not at full speed. Playing with the speed controller is almost therapeutic. Don't bother with fidget spinners, get one of these fans instead! [IN USE] I used this to ventilate a small resin 3D printer enclosure, and the 130 CFM Hon&Guan claims for this unit is more than enough for the task. I can set it to under the 40% power mark (where the mechanical whine starts to be noticeable) and it's still effective. I have a short hose though, if you're running a hose across the room you may need more power, or even a second inline fan. (There is a 6-inch version of this fan available if you need a lot more CFM.) I left it running at max power for a few minutes and haven't noticed any hot spots on the fan housing or controller, but I will keep checking on that. If you're using this fan to vent fumes, VOCs, etc., be sure the air you blow out the window isn't being blown back in by the air outside, or getting sucked back in through a different window haha. Also maybe consider putting some netting over the exhaust end to keep bugs from getting in when not in use. Another tip, try to install the fan as close to the window as possible. What you want to do is have the fan pulling air out of the hose/enclosure, not pushing it through. Pulling air prevents the polluted air from escaping from any leaks in your ventilation system, while pushing air through the hose will push it out of all those leaks along the way. [RECOMMENDATION] This is one of the cheapest and most streamlined options for resin printer ventilation on Amazon, and thankfully it works great. I will update this review if I find any long-term issues.

Muy fácil de usar, hace ruido, pero para mi uso que es un extractor de humo de soldadura, lo conecte con un tubo de extractor y coloque el extractor en una especie de tela colgante para evitar que la vibración hiciera ruido, añadí en la punta un filtro de carbón, y funciona excelente

Good for its job and price

exhaust powe Good

This does exactly what I need, well! Wanted a forced air duct from my sun room (lots of windows/poor insulation) to the basement, pulling cold winter air or hot summer air down to be conditioned by the furnace/AC. Also to create airflow from the rest of the house in that direction to keep the rest of the home from being affected by that air, offering a preferred path of return air to the furnace/AC. This worked perfectly; initially it was a little noisy (if being VERY picky) but I ran ~12' of flexy hose (the type with the wire coil and flexible plastic) before the fan, and put plenty of twists and bends in it. Works practically silently now even at higher speeds. My home is much more comfortable without having the noisy forced air and AC kick on so much. Been running for months now without any issues. Love the speed control unit too, easy to install somewhere accessible and extend the cable if needed.

It works really well, very efficient love the product.