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 center.

Read here how Daikin Applied UK supplied 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%

At 35%, the HVAC system massively impacts the efficiency of the data centre. The energy consumption used to carry out operations inevitably impacts the price of the service offered by the data centre.

Environmental impact and energy costs

In 2017, Greenpeace Association published a report showing the energy footprint of large Data Centre operators. According to the report, only a minor percentage of the energy used by a data centre was clean energy (from renewable resources). The report showed that most of the energy used is generated through combustion.

It is known that data traffic will increase over the coming years, increasing the need for data centres. This will have a greater impact on the environment if these facilities keep consuming dirty energy in ever-growing amounts. Therefore, data centres are more and more required to reduce their energy consumption and environmental impact.

Read here how Daikin managed to meet the project requirements of a negative CO2 emission data center in Sweden.

Temperature control

It is important to design and operate the HVAC system to the specific requirements of the data storage devices. Recommended temperature and humidity ranges (**), must be guaranteed through precise temperature control, allowing the equipment environment to operate safely and efficiently.

(**) ASHRAE® Technical Committee 9.9 published a book titled “Thermal Guidelines for Data Processing Environments” providing guidelines.

Free Cooling

Free cooling is a great way to save on operating costs while minimising the impact on the environment.

Nature can provide free air conditioning in many parts of the world for most of the year. Free cooling systems bring cold outside air or water inside to cool down indoor spaces, thereby reducing or even eliminating the need for mechanical cooling. Essentially, when outdoor temperatures are favourable, chillers can turn off compressors and take advantage of the low outdoor temperature.

Daikin Applied offers chillers with integrated hydronic-free cooling. By integrating the free cooling exchangers, plus the piping and valves directly onto the unit, Daikin have managed to keep the chiller’s footprint very compact despite the capacities that the units can offer.

System control, redundancy, and rapid restart

Controls can help groups of chillers to optimize and harmonise their performance. The Daikin iCM (Intelligent Control Manager) allows groups of chillers to operate with minimum effort, both mechanically and in terms of energy consumption. The iCM ensures a chillers’ durability, efficiency, and operating and maintenance cost savings. Being directly integrated in Daikin chillers, it does not require any external sequencer or optimiser integration, and with the Microtech 4 control logic, it ensures improved performance and extremely fast restart of the unit when combined with the ‘Rapid Restart’.

The rapid restart option is more and more important in applications where continuity of operations is crucial. For instance, if a Daikin chiller were to face a power loss event, with this option, it would restart compressors rapidly, allowing the chiller to immediately return to the same cooling capacity it was producing prior to the power loss event.

Redundancy is very important to ensure continuity of operations for chiller units and for controls. Every time a control needs to be disconnected for maintenance, for instance, the redundancy can instantly replace it, making the system even more reliable.

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.