Q:

Can I reduce static pressure in one room by adding a vent to an adjoining room?

Our return vent for our hvac is right outside the master bedroom. The master bedroom gets very little airflow with the door shut.
It was recommended that we add secondary return duct in the master bedroom to combat the high static pressure that the house is under. 
I have a question though, would it be beneficial to put a vent in the wall between the master bedroom and living room to help ventilate air in and out of the room so there is not as much pressure in the master bedroom?

A:

Yes, adding a transfer grille or jump duct will be the easiest and most effective solution. It can be done in a way to minimize transfer of sound between rooms (see links below). Adding a return to the master bedroom doesn't guarantee that the supply/return to the master bedroom will become balanced—the resulting pressure may still be positive or even negative with respect to the rest of the house.

http://www.buildingscience.com/documents/information-sheets/information-sheet-transfer-grilles-and-ducts/
https://basc.pnnl.gov/resource-guides/transfer-grilles

