An air removal unit configured for removing exhaust air from an equipment rack or enclosure includes multiple fans to achieve a high airflow capacity while defining a compact and portable structure. The unit removably installs along an exhaust side of an equipment rack or enclosure to provide capabilities for managing the thermal output of equipment, such as servers, CPUs, communications, internetworking and other types of equipment. The unit includes one or more upper fan modules and one or more lower fan modules positioned below the upper fan modules. The upper and the lower fan modules are arranged in a stacked configuration along the depth of the unit with the lower fan modules positioned in an offset orientation relative to the upper fan modules. The stacked configuration and the offset orientation of the fan modules help to incorporate multiple fans with the unit while maintaining the compact and portable design. The unit is further configured to serve as a door of an equipment rack or enclosure to thereby provide access to the unit and the rack or enclosure during operation. The unit can be incorporated with a ventilation system or a cooling air system associated with an equipment room or data center.