HVAC Systems for Data Centres

Optimum Solutions for Reliability and Energy Consumption

A data centre’s main function is to gather and manage huge quantities of online data.

To do that, these facilities operate 24/7/365, consuming vast amounts of energy and generating a lot of heat. Removing the heat is crucial, to prevent electrical components from overheating, which could lead them to fail or even catch fire. A reliable HVAC system is fundamental to guarantee the continuous operation of the data centre.

Daikin Applied UK recently supplied 19 off-pressurisation AHUs to a key player in the Data Centre market; working closely with a large-scale mechanical contractor to provide the best possible solutions that met the stringent specification requirements of the hyperscale data centre.

The energy consumption for a typical data centre is usually split as follows:

• IT equipment 50%
• Cooling and HVAC systems 35%
• Electrical Infrastructure & Support 10%
• Lighting 5%

HVAC systems account for approximately 35% of a data centre's energy consumption, significantly influencing its overall efficiency. The energy required for operations directly affects the cost of services provided by the data centre.

Environmental Impact and Energy Costs

In 2017, Greenpeace published a report highlighting the energy footprint of major data centre operators, revealing that a significant portion of their energy consumption came from fossil fuels. While some companies, such as Apple, Google, and Facebook, had begun transitioning towards 100% renewable energy commitments, the industry as a whole was still heavily reliant on non-renewable sources.

Since then, progress has been made, with companies like IBM reporting that 74% of their data centre electricity comes from renewables, and Digital Realty achieving 100% renewable coverage for its European and U.S. colocation facilities. 

As data traffic continues to rise, the demand for data centres will grow, making energy efficiency and sustainability more critical than ever. 

To address these challenges, Daikin played a key role in delivering a carbon-negative data centre in Sweden, implementing innovative HVAC solutions to enhance energy efficiency and sustainability.

Temperature Control

It is crucial to design and operate HVAC systems according to the specific requirements of data storage devices. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Technical Committee 9.9 provides industry-recognised guidelines for recommended temperature and humidity ranges in data centres. These ranges must be maintained through precise temperature and humidity control to ensure safe and efficient operation of IT equipment.

According to ASHRAE’s “Thermal Guidelines for Data Processing Environments”, the recommended temperature range for Class A1-A4 data centres is 18–27°C (64.4–80.6°F), with a relative humidity range of 8–60% (dew point between 5.5°C and 15°C). Adhering to these standards helps prevent equipment failures, reduces energy consumption, and enhances overall system reliability.

Free Cooling

Free cooling is an excellent way to cut operating costs while reducing environmental impact.

In many parts of the world, nature provides free air conditioning for most of the year. Free cooling systems take advantage of this by using cold outside air or water to cool indoor spaces, reducing—or even eliminating—the need for mechanical cooling. When outdoor temperatures are low enough, chillers can switch off their compressors and rely on the naturally cool air or water to maintain the required conditions.

Daikin Applied offers chillers with integrated hydronic free cooling, combining free cooling heat exchangers, piping, and valves directly into the unit. This smart design keeps the chiller’s footprint compact without compromising capacity, making it an efficient and space-saving solution.

System Control, Redundancy, and Rapid Restart

Advanced control systems help groups of chillers operate more efficiently and in perfect harmony. The Daikin iCM (Intelligent Control Manager) is designed to optimise chiller performance with minimal effort—both mechanically and in terms of energy consumption. By enhancing efficiency, durability, and cost savings, the iCM ensures smooth operation while reducing maintenance and energy costs.

Unlike external sequencers or optimisers, the iCM is fully integrated into Daikin chillers, eliminating the need for additional components. Combined with Microtech 4 control logic, it enhances performance and enables an extremely fast restart when paired with the Rapid Restart feature.

Why Rapid Restart Matters

In critical applications where operational continuity is essential, Rapid Restart plays a key role. If a Daikin chiller experiences a power loss, this feature allows compressors to restart almost immediately—bringing the unit back to its previous cooling capacity in no time.

The Importance of Redundancy

Ensuring system reliability is crucial for chiller units and their controls. Redundancy mechanisms ensure that if a control system needs maintenance or becomes disconnected, a backup seamlessly takes over, maintaining uninterrupted operation and enhancing overall system reliability.

Monitoring, Maintenance, and Reliability

Operation monitoring and maintenance planning are also aspects to consider, to ensure chiller plants’ durability and reliability. Daikin on Site (DoS) is the tool offered by Daikin for this purpose.

Daikin On Site (DoS) is a remote monitoring tool, that can provide 24/7/365 real-time data, tracking chiller plant operations and functionality. This allows plant owners to take preventive actions and avoid extra costs associated with breakdowns and downtime.

From a plant manager’s perspective, Daikin on Site can be beneficial in many ways. In the event of an alarm, plant managers can easily recognise the problem and find the right solution. Through this platform, they can evaluate all the parameters in real-time and if there is a need for any settings adjustment, they can act remotely. All of this allows to improve the units’ performance and management, planning preventive maintenance and increasing systems’ reliability.