Abstract: A method and system for controlling a temperature of products in a rotating drum employs nozzles to deliver a heat transfer fluid in a more efficient manner. The heat transfer fluid nozzles which are positioned around the interior of the rotating drum deliver the heat transfer fluid to the product in the drum when the nozzles are positioned under the product and prevent delivery of the heat transfer fluid when the nozzles are not under the product. This improves the efficiency of the heat transfer system substantially over known systems in which the heat transfer fluid is delivered continuously and a large portion of the heat transfer fluid is exhausted from the rotating drum before contacting the product. The heat transfer system also provides a self cleaning system for the nozzles which deliver the heat transfer fluid to the drum.