Patent ID: 7698095

Claim:
An apparatus to detect fan rotation direction, the apparatus comprising: a first temperature detection module that detects a first temperature at a first location, the first location comprising a location between at least one fan and at least one heat generating device, wherein the at least one fan provides cooling for the at least one heat generating device by drawing air from the at least one heat generating device across the first location to the fan when the at least one fan is rotating in a first direction such that the first location is downstream from the heat generating device when the at least one fan is rotating in a first direction; a second temperature detection module that detects a second temperature at a second location, the second location comprising a location wherein the at least one heat generating device is between the second location and the at least one fan such that heat from the at least one heat generating device is drawn away from the second location when the at least one fan is rotating in the first direction such that the second location is upstream from the heat generating device when the at least one fan is rotating in a first direction; a temperature comparison module that determines if the second temperature is above the first temperature; and a fan rotation error module that generates a fan rotation error signal in response to the temperature comparison module determining that the second temperature is above the first temperature.