Knurr CoolTherm® racks are completely sealed off from the room air. The dissipation of the total power loss is made via an air-to-water heat exchanger in the base area or door of the rack, which is connected to the cold water system in the building. Redundant high-performance fans drive a closed cold air circulation in the racks interior. The built-in servers are supplied from the front with air that is brought to the right temperature of about 20-25°C (68 °F to 77 °F). The warmed air is collected at the rear topside in the rack, pushed down by the heat exchanger and back to the front, to the server front panels. There are no requirements for room thermal management; the rack system is fully independent from the room air.

The heat exchanger only requires 6 U per rack, which means that in a 46 U rack, 40 U remain for any kind of complete equipping with components. Apart from the heat exchanger, the user will find a perfectly normal 19 in. quote server rack. This means that there are absolutely no restrictions for installing components. Everything that can be installed in a conventional rack can also be located without change in the Knurr CoolTherm®.