The most important cooling concepts include room cooling, controlled airflow, row cooling, rack cooling, and direct liquid cooling. They differ primarily in how close the cooling is located to the IT equipment or the heat source. In practice, several of these concepts are often combined.

The cooling concept describes where heat is absorbed—for example, in the room, in the rack row, at the rack, or directly from processors and GPUs. The cooling supply, on the other hand, determines how the heat is transported and dissipated. This includes, among other things, direct evaporation, water-based systems, free cooling, and chillers.

Room cooling is particularly well-suited for traditional server, storage, and network infrastructures with relatively evenly distributed heat loads. Central air conditioning or recirculating air cooling units cool the heated room air and return it to the server racks. When rack power loads vary significantly or are very high, supplemental row, rack, or liquid cooling systems may be advisable.

Enclosures prevent cold supply air and warm server exhaust air from mixing uncontrollably. As a result, the supplied cooling air is directed more precisely to the IT systems, while the warm exhaust air is removed in a controlled manner. This improves cooling performance and can reduce the data center’s energy consumption.

In row cooling, the cooling units are located within or at the end of a rack row. They specifically cool individual rows or areas with a higher heat load. In rack cooling, on the other hand, heat is removed directly from or within the server cabinet, for example, through a rear-door heat exchanger or a closed-loop rack cooling system.

In direct liquid cooling, a liquid coolant is directed directly to components that generate a particularly high amount of heat. Cold plates absorb heat directly from processors, GPUs, or accelerators. A Coolant Distribution Unit (CDU) distributes the coolant and transfers the heat to the building’s cooling circuit.

Our DC AI Container comes standard with liquid cooling.

Yes. Even in servers with direct liquid cooling, components such as memory, power supplies, and network components often continue to dissipate heat into the air. For this reason, direct liquid cooling and air cooling are combined as a hybrid cooling solution in many data centers.

Free cooling utilizes suitable outdoor conditions to dissipate heat with reduced or no active compressor operation. In direct free cooling, treated outdoor air is incorporated into the cooling process, whereas in the indirect variant, outdoor air and the data center coolant remain separate. The potential operating duration depends, among other factors, on the location, the outdoor temperature, the humidity, and the temperature level of the cooling circuit.