I have a brick ranch 3 bedroom home built in 74. When we moved in we blew in insulation in the attic and last year put in brand new windows in the whole house. When I close the doors to those two rooms they get warmer in the summer and cooler in the winter. There is alot of air that comes from the registers. There is also 31 inch air returns on the walls in both rooms. Is it possible that these are too big for the rooms causing this problem or could it be something else?