Relocation Of Return Duct B/c Of Noise

72chevy4x4

I'm looking at a small split system unit located in a 3x4 closet which is in a busy hallway setting by a door-placed here to combat the added heating needs of a frequently opening/closing door. The return was installed facing directly into the hall-when opening the vent (as if to change the filter), you see the motor assembly-this of course transmits a lot of noise into the hall.

any ideas on sound control? placing a duct into the ceiling could, but space is at a premium b/c of building/truss configuration-there would barely be enough room to run a 12" flexible duct-and I don't think that would be enough.

Has anyone experiemented with configuring baffles inside a fiberglass board return?

******xx
x x
x x x
x x x
x x x
x x x
x
'inlet' x 'outlet'
x ******x


instead of the current configuration:

*********
x x
'inlet' 'outlet'
x ******x

72chevy4x4

Argh-I did an elaborate drawing with X's, but the post took all of the spaces out of it!