Adding Return Air Ducts
Question…I have 2 air return ducts in my home, one in the upstairs hallway, and the other in the family room next to the mechanical room. The upstairs hall air return is nothing more than the stud cavity. Could I add a vent in this same stud cavity opposite the existing vent in the adjacent room? Would this reduce the efficiency of the return system? The room I want to add the return always seems to be a little warmer than the others. The down side of this is that if the vents were both at the same level you would be able to almost see through into the room. The upstairs hall return is toward the top of the wall, and I was thinking to do the same on the opposite side.
Are you in California?
That's a trick the HVAC guys do in California to cut their costs.
Had one like this at floor level in a previous house, btwn BRs .. hated it, not so much the line of sight thing, the louver's will block that .. but noise also travels ..
Yes, you can add a retrun grille to the stud cavity plenum and no it will not adversely affect the overall operation of the system.
Line of sight can be addressed easliy enough, make sure the blades or louvers on both are going different directions, one up, one down. What is almost impossible to address in a situation like this is sound transfer from room to room. No good way to prevent it. Two return grilles in the same stud space will act like a microphone and a speaker to transmit sound from space to space.
You could suspend a piece of tile held in place with heavy rubber bands. The tile would not block the free flow of air up, but would block the free passage of sound and light.
Using heavy rubber bands is a trick used to silence Hard drives in computers.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Cutting another return in will not adversely affect the system, may actually help it. But noise transfer may be a problem. Line of sight is an easy fix, if its near the ceiling there shouldn't be a problem.