I have done this method a few times and it has always turned out perfect. However, I have a new house that has a wall oven and there is an auto fan that runs until the oven cools down after cooking. My question is does the fan actually cause the inside of the oven to cool down faster than a normal oven or is the fan simply cooling the outside part of the oven for safety, etc? I would think it would make a major difference in the cooking of the prime rib if it isn't letting the oven cool down on its own. Anyone know?