attic air enters the space below or cold air goes up into the attic?
cold air leaks out your front door or humid air is sucked in through the door frame?
Is this a single story or two story house?
Are the supply and return grilles in the ceiling?
Is there a central return grille off of a hallway near the attic access?
The house is under negative pressure, so hot attic air and outside air are being sucked into the house from the attic access and underneath the door. It is a single story house. The supplies are in the ceiling. It has a free return with a return transfer system (flex run from one room to the next). The attic access is in a far corner of the house, and the air handler is in the middle of the house. The are probably 30 feet apart.