AC Infinity Inline Duct Fan Silencer 4", Noise Reduction Muffler

Purchased for a fairly novel use: ventilation for a Whisper Room isolation booth. I am a professional audiobook narrator and require a very low noise floor. Unfortunately, in the past, I've been relegated to quiet computer fans, which simply do not replace enough air in a small space that I spend hours in at a stretch. This fan has been a game changer. With the old computer fan system, I'd end the work day partially asphyxiated - literally. Overly tired, light-headed and confused. Not good! Changing to this fan, I'm probably replacing the air in the booth several times per hour, meaning everything about my performance has drastically improved. The best thing? I can't hear the fan *at all*, and neither can my audio equipment. My noise floor is -72dB with this fan on the fourth setting. Over all, I couldn't be happier.

I have this added in a 2x4x5 tent. I originally was running a crappy vivosun 4" fan and filter because of Reddit and boy did my girls suffer. Everyone online says one cycle every 1-3 minutes. They're nuts, you want to cycle once a minute or more if you're doing air exchange for cooling. I have my AC at 70 and with the vivosun running full speed the tent was hitting 84-87. With this 6" setup and the controller 67 at 70% during day 30% at night the tent never gets over 72-74 during the day and 65-68 at night. What an amazing improvement overall. For the silencer, I am using it in front of the fan that is working as an exhaust and most people are probably going that's wrong but it's absolutely right for me. I had it configured in the other fashion and it sounded like a jet engine in the tent. In this setup it sounds like swooshing air and I love it. Best decision ever made now I have to dig my 8" out of the ceiling of my closet and attach a 8" silencer to it.

Made a difference in the noise from our HVAC. The unit and a return is right behind our TV room and we could hear the fan running - I put this in the line between the HVAC unit and the return grate in the room and it made a noticeable difference to me. Installation was very easy if you know what you are doing.

I am using this on my radon 4” PVC exhaust pipe to reduce the fan noise and it works great. I had been looking for a muffler that I could use on a 4” PVC pipe and they are hard to find. This one fits nicely and is sealed with silicone caulk to the pipe. I would have rather had a muffler made out of PVC but there are none out there that I could use. This muffler is made of steel so time will tell how well made it is and if it has a zinc coating under the paint. Would buy again.

I’m using this for residential crypto mining with an 8 inch S8 fan. It is crazy loud, but still quieter than the fans on the mining ASIC. Before buying this, it was just too loud to run at night, costing me income. The fan needs to be at least on level 8 during the day to cool the hash boards, and that is really loud in a residential area. For grow tents, you probably won’t need to run it at level 8 unless you need a jet intake in your tent for some reason. This is perfect. It is so effective that I can run the fan at 7, maybe 8, even at night. It also doesn’t restrict the air flow much at all, and temperatures are not affected. I have an 8 inch duct filter on the end, and it’s even more quiet. AC Infinity sells 8 inch silencer clamps which is a tube of thick rubber and a clamp at each end. This cuts down on sound and they make your setup look really clean. Another clamp was needed for my filter, just fyi. They are not the most secure things though, especially because the fan shrouds are plastic and flex a bit. Note: if you really want this in silver, you may need to request it. Mine came in black, but still looks great.

Great quality and it works for sure quiets the sound like after a muffler

This is my second purchase. If I need something from AC infinity, I usually order it from their website if I do not immediately need it so I can build points. However, I needed this ASAP. This silencer helps cut down on noise and it looks cool as hell. Cheers!

The product does what it says, reduces air flow noise from/through ducting. Don't expect it to reduce noise from a fan itself (motor noise). Like others have stated, my product came with dents. That dispute any poster's comments regarding these products being "well packaged." Maybe the others are, but this one isn't. There is foam in the box on the top and bottom of the device, but none on the sides at all. Any impact or pressure on the sides of the box will dent the product. Get on that AC Infinity, should know better by now. And on packaging, this product DOES come with labels on the outside clearly stating what it is. If you live somewhere that discreet packaging is important, this can be a big issue. Get on that AC Infinity, should know better by now. These are simple fixes.

didn't do that much on high speed but for low speed did some worth mentioning the 6 inch came black ( it's a new model ) i think it's much better but easily get scratched

Der Rohrschalldämpfer ist von hoher Qualität und senkt den Geräuschpegel merklich ab - geschätzt 25 % weniger - er macht also was er soll, daher eine klare Kaufempfehlung von mir 👍

As described prompt post well securely packed would buy from again

Tres bien conçu et robuste

My house air filtration system incorporates Merv13 + hepa + carbon cylinder + RAM 150mm fan + 8 meters of ducting. The noise at the outlet was 73db. Installed the silencer about halfway in line. Noise dropped to 63db (almost half audible). Unfortunately, air flow reduced by 10% - in my system went down from 3.0 m/s (85 m³/h) to 2.7 m/s (76 m³/h). Note that my RAM is rated at 517 m³/h, and the real life readings are due to multiple filters restricting. The airflow is just about enough for two people.