"SA Development" wrote:

Hi,

Before all the other stuff, could you tell us the fundamental stuff?
Whether you're trying to heat or cool at the time of the problem. And
your local climate.

Sure, I am in Oklahoma, and the biggest issue is cooling during the summer.

Then you want the return vents up high to return warm air to the air
conditioner, assuming that you have central air.

You should be able to get a grill that fits between two studs 16" and
use the air space between them for the vent, on an interior wall.

That is what I did, replace a single double stud wide grill with two
half wide, one low and one high.