I knew that info at one time. It should be posted somewhere in the archives, but I can't remember where. I do know that there are two fan speeds. I'm going to make a guess about the exact temp. I think the first fan turns on somewhere around 200-205, and runs until the temp gets down to around 190-195 or so. If the temp gets hotter, let's say 210-215, the high speed fan should turn on, and run until the temp drops down to around 200-205 or so, at which point the low speed should take over. Don't hold me to these temps, but I'm somewhere close.