Compiled by Eamonn Ryan
Efficient cooling solutions and sustainability are pivotal to the success of modern data centres.
By embracing heat recovery, reducing refrigerant usage, addressing water and power scarcity, exploring innovative cooling technologies and adopting modular designs, data centre operators can create sustainable and energy-efficient environments. The insights shared in this panel discussion provide valuable guidance for industry professionals seeking to optimise cooling solutions while minimising their environmental impact. By prioritising sustainability, data centres can contribute to a greener future while meeting the increasing demand for digital infrastructure.
Data centres house numerous servers, storage systems, networking equipment and other hardware that generate a significant amount of heat during operation. This excess heat, if not adequately managed, can lead to catastrophic failures, reduced equipment lifespan and costly downtime. Therefore, implementing effective air conditioning and cooling systems is essential to dissipate heat and maintain an optimal operating environment.
One of the primary reasons HVAC&R is crucial in data centres is temperature regulation. Data centres require precise temperature control to prevent overheating, as excessive heat can cause equipment malfunctions and potential data loss. The ideal operating temperature for most data centres ranges between 18°C and 27°C. Maintaining a consistent temperature within this range ensures that the equipment operates reliably and efficiently.
To achieve the required temperature control, data centres employ various cooling methods. One commonly used approach is the use of computer room air conditioning (CRAC) units or computer room air handlers (CRAH). These units circulate cool air throughout the facility, extracting hot air generated by the equipment. They often incorporate advanced sensors and control systems to monitor temperature and adjust cooling capacity accordingly, ensuring precise and efficient cooling. In addition to temperature control, proper humidity levels are critical in data centres. High humidity can lead to condensation, which poses a significant risk to sensitive electronic components and can cause corrosion, short circuits and equipment failure. On the other hand, low humidity levels can increase the risk of electrostatic discharge, damaging delicate components. Therefore, data centres maintain humidity levels between 40% and 55% to create a safe and stable environment for the equipment.
Air filtration is another essential aspect of data centre cooling. The air quality within data centres must be free from dust, particles and contaminants that can harm sensitive hardware and hinder performance. Air filtration systems ensure clean air is circulated throughout the facility, minimising the risk of equipment damage and maintaining optimal operational conditions. Energy efficiency is a growing concern in data centre design, given the immense power requirements of these facilities. Efficient cooling systems can significantly contribute to reducing energy consumption and operating costs. Modern data centres employ innovative cooling techniques such as hot aisle or cold aisle containment, in-row cooling and liquid cooling to maximise cooling efficiency, while minimising energy usage. These methods focus cooling precisely where it is needed, reducing wasted energy and promoting sustainable operations.
Moreover, effective HVAC&R systems in data centres contribute to the overall reliability and uptime of the facility. By maintaining the optimal operating conditions, the risk of equipment failures and subsequent service interruptions is minimised. Reliable cooling infrastructure ensures that data centre operations continue uninterrupted, safeguarding critical data and preserving the trust of customers and stakeholders. With the increasing demand for data storage and processing, ensuring the proper management of heat, temperature, humidity and air quality is essential.
Implementing efficient and reliable cooling systems not only protects valuable equipment but also optimises energy consumption, reduces downtime and contributes to the overall success and longevity of data centres in the digital era. According to Trafo Power Solutions managing director David Claassen, there is a significant amount of data space currently being constructed in South Africa. Alongside the issue of data security, says Claassen, the top priority in these facilities is uptime – as a data centre can simply never be offline.
“The volume of equipment in these large server rooms creates considerable heat and therefore requires extensive cooling facilities – all leading to high levels of energy demand,” says Claassen. “Transformers therefore play an important role in these operations, and they must function to the highest levels of safety and reliability.” He notes that South Africa faces a significant additional challenge, with unreliable electricity supply from the national utility. This requires backup power facilities to be installed, so that 100% uptime can be guaranteed.
“Even aside from the power supply issues, data centres must deliver a constant service without interruption, so redundancy capacity is required should any of the system components go down,” he says. “This redundancy can effectively double the design capacity of these centres.” In these applications, dry-type transformers are well suited in terms of safety and risk, he explains. As the units are cooled by air and not oil, there is zero risk of fire and no chance of oil leakage. These transformers have an F1 fire rating, demonstrating their resistance to flammability – they are designed to be flame-retardant and do not generate harmful emissions. By not having oil as a coolant, the maintenance of dry-type transformers is also reduced substantially. Oil-cooled transformers, by contrast, experience frequent oil temperature variations as load rises and drops. This variation creates opportunities for moisture ingress, making regular oil sampling and testing vital. If this is not conducted regularly, performance becomes unreliable.
“Dry-type transformers can be installed inside or outside of a building or substation, with no special fire protection systems needed,” he says. “As oil testing is not required, dry-type transformers need very little maintenance – adding to their cost-effectiveness.” He explains that data centres have high levels of non-linear loading, so these transformers must be designed for a high K-factor of typically around 13. The quick pace of construction of these facilities also often favours a modular approach to which the dry-type transformer lends itself well.
“Modular substations can be rapidly manufactured, and dry-type transformers can be readily incorporated without the need for any special fire suppression,” says Claassen. “Another important factor is efficiency, as large data centres could consume as much power as a mining operation.”