Keeping data centres cool is more than just a technical necessity – it is integral to modern business continuity. As the demand for processing power increases, so does the heat generated by servers and IT infrastructure. An estimated 40% of total energy used by data centres is for the use of data cooling (McKinsey & Company). Without effective cooling, data centres risk costly downtimes, shortened hardware lifespans, and skyrocketing energy costs.
What is data centre cooling?
Data centre cooling refers to the systems and processes used to regulate the temperature, humidity and airflow in data centres, where large amounts of servers and other IT equipment generate significant heat. Effective cooling is essential to prevent servers from overheating, which can lead to performance degradation, hardware failure and data loss.
Traditional cooling methods use air conditioning and chilled water systems to manage heat, while emerging solutions incorporate techniques like liquid cooling to reduce power consumption and optimise performance. Cooling is critical to maintaining the reliability, safety and efficiency of data centre operations.
What are the different types of data centre cooling?
Liquid cooling
Immersion cooling
Immersion cooling is a relatively new and innovative approach to managing heat in data centres, where servers are fully submerged in a thermally conductive liquid (mineral oil) which absorbs and dissipates heat directly. The idea behind this method is to bypass traditional air-based cooling, eliminating the need for fans and reducing energy consumption.
While this approach has gained attention for its potential to lower costs and increase efficiency in specific use cases, it is still seen by many as a novelty. The method presents some potential challenges, such as health, rust, corrosion and safety concerns. Once these issues are addressed, immersion cooling may break out of experimental projects and enter more widespread data centre cooling practices as future predictions suggest.
Direct-to-chip liquid cooling
Direct-to-chip liquid cooling is an advanced method designed to target and remove heat directly from the most heat-intensive components in servers, such as CPUs, GPUs and other high-performance processing units. In this system, a network of liquid coolant-filled tubes is routed directly to the chips, where the coolant absorbs the heat and transports it away from the components. This liquid is then circulated through heat exchangers, cooling towers, or chillers, allowing it to be cooled and recirculated.
By directly addressing these high-temperature areas, this method can significantly reduce energy consumption and improve performance of high-density data centres. Although it is complex to install and maintain, direct-to-chip liquid cooling offers scalability and efficiency, particularly for handling intensive computing workloads, such as AI and machine learning operations.
Chilled water cooling
Chilled water cooling is a widely used method for managing heat in data centres. In this system, chilled water is circulated through pipes to air handling units or cooling coils within the data centre. As air passes over these chilled coils, it is cooled down and then distributed throughout the data centre to maintain a stable temperature, while the warm air is drawn back to be cooled again in a continuous cycle. The chilled water itself is cooled by a central chiller plant, which may be located on-site or nearby.
This method offers precise control over temperature and humidity levels, making it highly effective for large-scale data centres which require stable and reliable cooling across a variety of equipment. One of the major benefits of chilled water cooling is its scalability. It can be easily expanded or adjusted as the data centre grows. Although it requires significant infrastructure, including chillers, pumps and cooling towers, chilled water cooling remains one of the most dependable options for cooling data centres with high workloads.
Air cooling
Cold/hot aisle containment
Cold/Hot aisle contaminants is an airflow management strategy used in data centres to improve cooling efficiency by separating hot and cold air streams. In this method, server racks are arranged in alternating rows, with the fronts (cold aisles) of servers facing each other to take in cool air, and the backs (hot aisles) facing each other to expel warm air. Containment systems – typically panels, doors or barriers – are then installed to physically separate these aisles, preventing hot and cold air from mixing. By controlling the airflow and preventing recirculation, this approach allows cooling systems to work more efficiently, ensuring that servers receive cooler air while preventing hotspots.
This is a simple but highly effective solution which reduces energy consumption by ensuring that cooling systems don’t have to overwork to compensate for temperature imbalances.
Computer room air conditioning (CRAC) vs computer room air handler (CRAH)
Computer room air conditioning (CRAC) and computer room air handler (CRAH) units are traditional cooling solutions designed for data centres, providing precise temperature and humidity control.
CRAC units operate similarly to standard air conditioners, using refrigerant-based systems to cool the air. They draw in warm air from the data centre, pass it through refrigerant-filled cooling coils and then blow the cooled air back into the room to maintain a stable temperature. CRAC units are highly effective in small to medium data centres.
CRAH units are typically used in larger, more energy-efficient facilities. Rather than using refrigerants, CRAH systems rely on chilled water from an external chiller plant. They draw in warm air from the data centre, pass it over cooling coils filled with chilled water and circulate the cooled air back into the room. CRAH units tend to be more energy-efficient than CRAC, especially in data centres with large cooling loads, as they use external chilled water systems that can be optimised for energy savings.
Evaporative cooling (swamp cooling)
Evaporative cooling is an energy-efficient method which uses the natural process of water evaporation to cool data centres. In this system, warm outside air is drawn through water-saturated pads or misting systems, where the water absorbs heat from the air and evaporates, lowering the temperature. The cooler, moist air is then directed into the data centre, helping to reduce the need for mechanical cooling systems like traditional air conditioning.
This method works particularly well in regions with dry climates, where the air has a high capacity to absorb moisture and cool down. However, in more humid environments, its effectiveness can be limited due to the lower evaporation potential.
Adiabatic cooling
Adiabatic cooling is an increasingly popular method in data centres for enhancing traditional air-based cooling systems by using the natural process of water evaporation to cool the air. It is a pre-cooling method, where the warm outside air is passed through a water-saturated medium or misted water droplets. Similarly to evaporative cooling, the air cools as the water evaporates, and this cooler air is used to assist traditional cooling methods such as CRAC or CRAH units. Adiabatic cooling is used alongside conventional systems to improve efficiency and save energy, rather than a standalone solution.
Our data centres
We partner with data centre providers Equinix and Telehouse, where we primarily use air-based cooling methods, specifically cold and hot aisle containment. This approach allows us to manage airflow efficiently by separating cool intake air from the warm exhaust air, preventing them from mixing and ensuring that servers operate at optimal temperatures. This containment strategy maximises cooling efficiency, reduces energy consumption and ensures stable performance for the critical data we store.
Compared to more experimental cooling methods like immersion cooling, cold and hot aisle containment is a proven, reliable solution which offers both operational scalability and cost-effectiveness. Given the often sensitive nature and high volumes of data we manage, this system provides the precision and control needed to ensure excellent uptime and performance.
We partner with data centres across 35+ global locations – find out more about our strategically located data centres. To speak to one of our cloud experts, fill out our contact form today and we will be in touch.
