Devices, systems, and methods are provided for monitoring air flow through a server using differential pressure measurements. The device includes an external pressure sensor, an internal pressure sensor, and a controller that receives the pressures from the external and internal pressure sensors. The external pressure sensor detects air pressure of the ambient air around a server enclosure, the internal pressure sensor detects air pressure through a server enclosure, and the controller calculates a pressure differential between the pressure from the external pressure sensor and the internal pressure sensor. The controller can then generate a signal based on the pressure differential, the signal optionally controlling a cooling fan, generating an interrupt for the server circuitry, or performing some other action.