Norm took a big Refrigarator, one with metal insides. Stripped all the electrics out of the bottom, and replaced them with a small propane burner, and a fire box. He puts the chips and wood clippings in the fire box, then lights the burner. Once it gets hot and going good he turns off the burner, no longer needed as long as he keeps an eye on it and keeps it fed with fresh wood and chips. He mostly uses dried Alder that we cut along the banks of rivers, and bring home for this purpose.
He also took out the freezer, and placed more metal racks. He has racks every six inches from the bottom to the top. He put a 3" smoke stack on the top, but the pipe runs flat to keep it from drawing too fast. He also added a damper to the stack. He added temp gages on the outside with the senses on the inside. One near the bottom, one in the middle, and one near the top. Norm loves smoking, and once he get this thing fired up he will keep it going for several days. He smokes Salmon, Cod, Moose, Caribou, Bear, Rabbits, Grouse, Ptarmigan, Turkey, and even pigs, brought in by friends that have raised them over the summer. I and another neighbor often go over and relieve him so he can get some sleep, or just sit and talk, and learn from a master smoker.