A ventilation unit and controller device comprises a ventilation unit with a housing. The housing has an intake port permitting flow of gas into the housing and an exhaust port permitting flow of gas out of the housing. Within the housing, a motorized fan is positioned to direct gas into the housing via the intake port and out of the housing via the exhaust port. A controller capable of controlling the ventilation unit communicates with a sensor capable of detecting an environmental stimulus. A source of electric current provides power to the ventilation unit and controller device. The device further comprises a switch capable of interrupting the electric current that powers the device. The device is capable of being removably attached via fasteners to an arc flash hood, and the arc flash hood comprises a ventilation opening to permit gas discharged by the device to enter the arc flash hood.
