Unenclosed racks are racks that are free-standing in a room. They may have a door in the back and panels on their sides, but they are not in closets or cabinets. Several ATM products are suitable for ventilating unenclosed racks; all swap fresh room air for the heated air within the rack.
For the small rack, or a small section of a larger rack, the Cool-stack I is ideal. Available as an intake or exhaust device, they’re only 1 rack space high and 8” deep.
For the mid-size rack without a door, the Cool-rack is a shallow 2 space cooling solution that includes a bright temperature display.
Another option for the mid-size to large rack is the 3U high Cool-rack III.