Windows in Freezers if specified Efficient Defrost Systems on Walk-Ins with Glass Doors American Panel meets, and in most cases, exceeds all of the above requirements. LEED... and energy consumption. These requirements, signed by the President of the United States, took effect January 1, 2009 and are as follows. Automatic Door Closing Device Strip Curtains... or Air Curtains on Hinged Doors R-25 Insulation in Cooler Walls, Doors, & Ceilings R-32 Insulation in Freezer Walls, Doors, & Ceilings R-28 Insulation in Freezer Floors High Efficiency...