Information handling system thermal conditions are controlled by hybrid interaction between a system thermal manager and a power supply thermal manager. The system thermal manager sets a speed for system cooling fans and for a power supply cooling fan. The power supply thermal manager determines a speed for the power supply cooling fan and also receives the speed for the power supply cooling fan determined by the system thermal manager. The power supply thermal manager commands the power supply fan to run at a selected of the determined speeds based upon one or predetermined conditions, such as by the selecting the greater of the determined speeds.