Abstract: An equipment cabinet (1) has a first compartment (3), a second compartment (5), and a ventilation system. The first compartment (3) may be an inner or electronic compartment and the second compartment (5) may be an outer or battery compartment. The ventilation system has at least one operating configuration which enables air to flow from outside the second compartment to the first compartment then to the second compartment, and which enables little or no air to flow from the second compartment to the first compartment. The ventilation system has another operating configuration in which little or no air can flow from outside the second compartment to the first compartment, little or no air can flow from the second compartment to the first compartment, and air is able to substantially recirculate through or in the first compartment.

Abstract: An air circulation and ventilation unit is provided including a housing configured to fit at least partially over the ceiling of an equipment cabinet including fitting over at least one vent in the ceiling of the cabinet, so that the interior of the housing is in communication with the interior of the cabinet, the housing includes a housing vent moveable between an open position in which air may flow between the outside of the housing and the inside of the housing and a closed position in which little or no air can flow between the outside of the housing and the inside of the housing, and a controller to control the position of the housing vent.