AC Infinity RAXIAL S6, Inline Booster Duct Fan 6” with Speed Controller - Low Noise Inline HVAC Blower Can Fan for Basements, Bathrooms, Kitchens, Workshops

I was experiencing very little air flow at the end of my living area at the farthest point from my furnace. I installed two of these fans in two 6inch round HVAC ducts. I used relays, triggered by my furnace convection blower motor circuit to power receptacles where I plugged in the fans. Note the fans are approximately 1/10 inch smaller in diameter then the 6 inch duct work. However, this slight difference facilitated reconnecting the duct work.

I have a 2 story house. Upstairs is hot in summer. Brand new furnace and a/c. I installed 2 boosters. One for each bedroom upstairs. It works great. These replaced other ones I had installed 5 years ago that did not have an adjustable speed. Those worked but were so loud and blasted almost too much air. These are perfect as you can adjust for smaller rooms and dial it down. The highest setting is too loud and annoying, medium is just a shade louder than a normal furnace when it’s blowing at a high speed. I set mine just below medium and it blends In with the furnace so you can’t really notice it. I scoured reviews before buying this, I hope this is useful to someone.

I bought this S6 fan to create some circulation in my basement The fan works well and seems to be well-made.My basement is about 2000 sq feet and is chopped into these three main areas:Space A. Unfinished area (about 350 sq feet)Space B. Main living area (about 1200 sq feet)Space C. Exercise/rec room. (450 sq feet)Space A connects to Space B via a door. Space B connects to Space C through another door. Space C does not connect to Space A directly.We have a humidity/mold problem throughout the basement, so I installed a dehumidifier in Space A. I wanted to pull air from Space C over the wall into Space A then push it out to Space B and back to Space C to complete the cycle. I am hoping that by circulating some air through space A the dehumidifier will dry out the whole basement over time.My dehumidifier is rated to process 160/190 cfm on its two speed settings. So I bought this 265 cfm AC Infinity S6 fan and 8' of 6" flex duct from AC Infinity as a circulation fan. My configuration is as follows:I cut a a 6" round opening in the Space C ceiling. I put a 90" hard elbow there and attached the 8' of 6" duct that terminates in Space A.In Space A at the other end of the duct I mounted this fan onto a 12x4x6 90-degree register box and a 12x4 diffuser. I hope to pull over some air from Space C past the dehumidifier.Issue: After completing the install, the noise level in Space C at all fan speeds (where the intake vent is) is higher than I would have liked. I measured some dB readings with my iphone app and here are the results.[NOTE: For reference, in this next part I am looking at the speed control's dial like a clock face, where you have the "off" position at the 6:00 (bottom) position. Then "Low" is at 8:00. "Medium" is at 12:00 (top). And "High" at 4:00 position.]While the controller seems infinite, there are really only three or four distinct areas of power/noise:At the 8:00 and 9:00 position, the noise level in space C is about 40 dB.At 10:00 position it jumps to 49 dB (nearly ten times louder).At 11:00 - 12:00 it is about 52 dB.Then at the 1:00 position it jumps to 54 dB and doesn't really get much louder from there.Recall that the dB scale is logarithmic, not linear. If there is a relationship between noise and cfm, then between the 1:00 position and 4:00 position, it seems there is very little air volume increase.I am not an HVAC engineer nor a sound expert, but it seems you have a low 40-ish dB setting, a low 50-ish dB setting and then a 54 dB setting, all as measured on the inlet-side vent, which for me is 8' from the fan. I would like to make it quieter in Space C because my wife spends a lot of time down there, and she doesn't tolerate noise well.I don't really care about the noise level in space A, as it is not occupied and the dehumidifier (generating 52 - 54 dB) is in there too. But for reference, with the fan attached right to the register outlet box, the noise levels in Space A (without the dehumidifier running) are 2 - 4 dB higher than the above readings from under the inlet vent in Space C.Note: I have 9' basement ceilings, and I took all measurements directly beneath the vents at 5' up from the floor. Not a scientific result, but I hoped to give you all some idea of the noise levels.

This 6 inch fan is probably more value for my money than any other purchase in the past few years. It's powerful, compact, and quiet for it's power. Some fans that I’ve tried can sound a little wobbly at lower speeds, but this one is steady throughout. My only wish is that the fan could spin even slower, but I’m not sure that should be expected with a 6 inch attic fan.

The Inline Booster Duct Fan 6” was well package. I like that the body has no seams. It's all one piece. Fan seems higher quality than the cheapo replaced that was 1/2 the CFM. Used it on my HVAC duct work coming from the furnace. Short run with 3 elbows. Was a little surprised the existing fluted 6" furnace pipe would not slide into the wider side of the fan housing. Ended up working out great as the fan can fit into a pipe that is cut in 1/2. That way you can expand the pipe outward from the fan body as needed and you can get it into really tight spaces. Make sure you have some aluminum tape to seal.Fan on max I'm guessing tripled output. Noise not much different than existing sound from vents at least for me as furnace in the basement was not too far from 1st floor room. If you have loose duct work, that volume of air pushed might make more noise. I don't.

Thank you

Well made and highly durable. Use in 95-100 humidity environment, holds up great. I run it 24/7 for 8 months, no issues.

Too noisy on high speed