Facilities
Data Centre Cooling Technologies in Plain English
7 min read
Data centre cooling removes heat from IT equipment using airflow management, chilled water, evaporative systems and increasingly liquid cooling.
Why cooling is essential
Servers convert most of the electricity they consume into heat. If that heat is not removed, component temperatures rise, performance can be reduced and equipment may shut down or fail. Data centre cooling systems keep air or liquid within operating limits while managing humidity, airflow and efficiency. Cooling capacity must match the IT load, including local hotspots. A room may have enough total cooling on paper but still perform poorly if hot exhaust air recirculates into server intakes or high-density racks are placed incorrectly.
Air cooling and aisle containment
Traditional data centres move conditioned air to the front of server racks and remove hot exhaust from the rear. Hot-aisle or cold-aisle containment separates supply and return airflow to reduce mixing. Cooling may be delivered through raised floors, overhead ducts, in-row units, fan walls or computer-room air-conditioning systems. Good blanking panels, cable management and rack layout are part of the cooling design. Air cooling remains suitable for a large share of enterprise equipment, but very dense racks can exceed practical airflow limits.
Chillers, free cooling and evaporative systems
Chilled-water systems transfer heat from data halls to external plant. Economiser or “free cooling” modes use favourable outdoor conditions to reduce mechanical refrigeration. Evaporative cooling uses water evaporation to lower air temperature and can improve energy efficiency in suitable climates. Each design involves trade-offs in water use, maintenance, climate suitability and resilience. Australian facilities may combine several technologies depending on location and building generation. Buyers should focus on supported rack density, redundancy and environmental operating range rather than a single technology label.
Liquid cooling for high-density computing
Liquid can absorb and transport heat more efficiently than air. Direct-to-chip systems circulate coolant to cold plates mounted on processors or accelerators. Rear-door heat exchangers remove heat at the back of a rack, while immersion cooling places equipment in a specialised dielectric fluid. These approaches are increasingly relevant for AI and high-performance computing. They require compatible hardware, manifolds, leak management, monitoring and operational procedures. Not every data hall supports them, and “liquid-cooling ready” can describe different levels of capability.
Cooling questions for buyers
Ask for the maximum supported kW per rack, whether that density is available in the proposed hall and what cooling method is used. Confirm temperature and humidity ranges, redundancy, maintenance arrangements and the effect of a cooling-system failure. For GPU deployments, provide equipment specifications early and discuss liquid-cooling requirements, water quality and responsibility boundaries. Review efficiency metrics carefully: power usage effectiveness is useful for facility benchmarking but does not directly state the efficiency of your own servers or applications.
Frequently asked questions
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