A reversible air flow fan system is described. A fan tray assembly is coupled with a chassis and a removable fan and bracket assembly that is oriented in a first direction. This removable fan and bracket assembly is configured to be removable from the fan tray assembly and being recoupled with the fan tray assembly in a second direction opposite the first direction. An air duct is coupled with and enables the exchange of air between the removable fan and bracket assembly and a first surface of the chassis. A sensor coupled with the fan tray assembly is configured for coupling with at least one bracket of the removable fan and bracket assembly when the removable fan and bracket assembly is oriented in the first direction.