I live in S. Florida and want install transfer grills above the doors of our bedrooms to increase the return air flow back to the main return grill in the livingroom. Currently the doors are slightly cut on the bottom but I don't believe it provides the proper amount of return air.
I would like to know how these are typically installed. I will be cutting a how in the sheetrock on each side of the wall above the door and will place about a 6"X12" grill on each side.
I need to know a few things:
If there is a stud which obstructs air flow; is it cut and braced horizontally or just left in place and ignored.
To keep air from flowing from the insides of the wall, should I frame it out with wood or just try to seal it off with pieces of duct board and foil tape?
Will I need a baffle between the grills to reduce noise and retain privacy between rooms? If so, can I buy these pre-made or is the an easy way to make them myself.
I have not seen a home yet with a return duct system in South florida; is this common practice?
Do you think adding the transfer grills is overkill and I should just undercut the doors more? I hasd a quote from an AC Duct company and they said that the new code requires these transfer grills.
Thanks for all opinions and advice, Doug