I made the shelves out of 2x4s, 3/4 AC plywood on top and 1/2 AC Plywood on the bottom and 2" thick insulation. Then 3/4 Oak plywood for the sides and top and 1/2 AC for the back. then I used more 2" insulation on the inside back and sides covered with 1/2" AC plywood. After assembly I lined the insides with white tectured fiberglass/PVC sheeting, onthe doors I used white board so I can right on the doors what's inside and dates... also added 1" insulation to backs of the doors. I had friend who works for Coke found an old 1.5hp cooling unit out of an display unit, after installing he came over and serviced it.