A temperature door for an air handling system of a heating, ventilating, and air conditioning system includes a first surface defining a sealing perimeter and a pivoting structure coupled to the first surface and defining an axis. The first surface is configured to pivot about the axis in the housing of the air handling system. A sealing lip is disposed about the sealing perimeter of the first surface and is adapted to engage a corresponding sealing surface of the housing of the air handling system. A pivoting of the first surface about the axis from a sealed position causes a progressive disengagement of the sealing lip from the sealing surface beginning in a location proximate the axis while at least a portion of the sealing lip remains engaged with the sealing surface at a location spaced from the axis.