Another possible solution to room pressure imbalances

Green Building Advisor had an interesting post about a new ventilation strategy for homes with central returns or other HVAC system problems.

The product is an interior door that has free area built into the door itself, while engineering to reduce the amount of sound transmission.  The door has an equivalent open area of 100 square inches.  So it will be able to handle imbalances that are too big for a simple door undercutting.  

The door will cost more than a tradition interior door.  But we've all come across that rare room that has no real wall space facing the main body of the house.  This door might help reduce pressure imbalances to more acceptable levels.

The door will be going into production soon.