2. Programming feature of the ICP40 Adaptive Fan Controller: Once being switched on, the controller starts working in auto mode. When the heat sensor detects an excess of switch- on temperature threshold, fans start working at minimum speed. Fan speed grows linearly according to heat increase, until they reach maximum speed activation temperature. Fans keep working at max speed when heat exceeds that level. You may want to adjust the speed of the fans and make it faster during the moderately cold season to avoid buzzing of the fans on the automatically set low speed. In case of emergency, such as heat sensor failure, fan speed jumps on maximum level automatically.