I have an in wall AV rack that is ventilated by a small array of fans. I’ve installed a thermostat in the cabinet that can turn on these fans at full speed if the temperature goes over the temperature I set it to. When the equipment is on it powers the fans at a lower silent speed. My question is what temperature should I set the thermostat to, and when setting the slower speed of the fans, what temperature should I try to keep it under? Just for clarification, the thermostat is a backup system to make sure the equipment doesn’t overheat, should the slower fan speed be insufficient (perhaps when running the system harder then normal). It also protects the equipment when the system is off by powering on the fans if heat builds up. Under normal operation I want the slower silent fan speed to be sufficient and will adjust the slower speed to keep the temperature below the point where the thermostat would turn on. Again the questions are: 1) What operating temperature should I aim for as a maximum? 2) What temperature should I set as the point where the fans go full speed to prevent any further increase in temperature at the expense of noise?