I thought about the temperature controlled fan. I like the idea of the fan running at higher speeds if the exhaust temps rise. I'm concerned if the fan will compensate enough if it  is only 1 miner overheating out of 10. I have been doing some testing and I'm using a double pole relay to turn power off to one of my miners if the exhaust temp rises above 113 deg F. I need it since I can't be home to babysit these things all the time. Later down the road I could put smoke or flame detectors on the same relay circuit to kill power.