AC Infinity Inline Duct Fan Silencer, 4" Noise Reduction Muffler Blower Silencer for Indoor Hydroponics Grow Tent Ventilation Systems

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.

Made it very quit. Must have.

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. Oh yeah, and don’t use duct tape. It defeats the purpose a little since sound will get through the joints. AC Infinity sells 8 inch silencer clamps which is a tube of thick rubber and a clamp at each end. Not only is this more secure and cuts down on sound, but they make your setup look really clean. Another clamp was needed for my filter, just fyi. Note: if you really want this in silver, you may need to request it. Mine came in black, but still looks great.

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.

Easy to install and instantly quieter.

Install motorized zone dampers in ductwork. Noise much lower to the point I don’t hear them opening and closing anymore out my registers.

Really does drop the noise by A LOT. your mileage may vary, but I had it installed on the intake before the fan as an exhaust and full speed doesn't feel like I'm next to a wind tunnel, it sounds about the same as a small desk fan. No one posted a video of the difference, so I'll include one. Sound also appears to be very quiet on the downstream near the exhaust.

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 installed it in my basement to reduce noice between basement room and the kitchen. Works great, I noticed significant reduction

Definitely makes it a bit quieter

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 👍

Macht was es soll Abluft in Verbindung mit Phonetec Abluftschlauch kaum zu hören