Loud A/C return intake?

[C&EC]

My A/C's air intake vent in the living room is really loud, so much so that it drowns out the TV with the volume way up. A tech came over today and lowered the fan speed but it didn't affect the noise. I also removed the grille which also did not lower the noise.

I'm looking for any ideas out there...I do not have the money or know how to re-route the ducts. The dimensions of the intake area are 18"Wx14"Hx15"Deep (the fan is right on the other side of the filter). Maybe I could try and build some dampeners on the inside?

Thanks
Chris

 

[mtrycrafts]

My A/C's air intake vent in the living room is really loud, so much so that it drowns out the TV with the volume way up. A tech came over today and lowered the fan speed but it didn't affect the noise. I also removed the grille which also did not lower the noise.

I'm looking for any ideas out there...I do not have the money or know how to re-route the ducts. The dimensions of the intake area are 18"Wx14"Hx15"Deep (the fan is right on the other side of the filter). Maybe I could try and build some dampeners on the inside?

Thanks
Chris

No expert by any means; how far is that fan, at that 15" depth? What is the duct, sheet metal?

I think you will have a difficult time without major modifications.

 

[MDS]

I have the exact same problem and posted a thread on it awhile back.

I used sound dampening sheets I bought from Parts Express to line the enclosure and the metal walls of the unit. I also filled the cavity with absorption panels. It only helps minimally and now my ears have adjusted to the sound and I swear it's even louder than before (although it is actually 10 dB lower now - about 58 dB right by the intake). It's highly annoying when watching movies and sometimes I just shut it off.

The only real solution is to tear down the wall and rebuild it with sound isolation in mind, like using double drywall and rock wool or some other insulator between the layers.

 

[Alex2507]

The dimensions of the intake area are 18"Wx14"Hx15"Deep
Thanks
Chris

Call up an HVAC company and get youself 2 pieces of 2'x4' 1" thick black duct liner. Line the air return duct in between the grill and filter (that portion quoted above).

Use 3M 77 spray adhesive to stick it to the duct and spray the cut edges to trap the glass fibers.

To quote the HVAC guy who gave me a bag of that stuff, "That's going to be your biggest bang for the buck noise drop." My retun is only 7" long. He was right. I put a lot of effort into other measures to control fan noise but the real magic happened with lining that 7 inches.

 

[Alex2507]

(although it is actually 10 dB lower now - about 58 dB right by the intake)

10 dB lower is fantastic. I was under the impression that you had no success with that. The OP at least has a duct to line.

I just checked mine about 4' away from the return on a table and it's 66 dB. I have an end table that I rigged with some sound proof carpet and weather stripping (it doesn't look as bad as it sounds ) that re-routes the incomming air and makes the sound from the fan take a corner. I only use that durring movies as it does cause a restriction and it takes another 3dB off for a grand total of 63 dB. I would kill for 58dB.

 

[C&EC]

Thanks, I'll look into that liner. Any good online places to buy it?

 

[Alex2507]

Thanks, I'll look into that liner. Any good online places to buy it?

Go local.