The global data centre market is rapidly growing, with around 10,978 data centres worldwide. These facilities consume 1.3% of the world’s electricity, making energy efficiency a top priority. Cooling systems account for approximately 30% of a data centre’s energy use, so optimising these systems is vital to reducing operating costs and CO2 emissions.
This article focuses on Computer Room Air Handling (CRAH) units, a key component of Daikin’s HVAC solutions for data centres. We’ll explore the challenges of designing efficient cooling systems and how Daikin’s innovative technology can help UK businesses optimise performance and reliability.
Overview of a data center cooling system
The schematic above illustrates a typical HVAC system for a data centre, highlighting the core components of Daikin’s solution:
- Air-to-water free cooling chillers
- Computer Room Air Handling (CRAH) units
- Control systems
- After-sales services
While each component is crucial to optimising a data centre’s cooling system, this article focuses on Computer Room Air Handling (CRAH) units. We’ll explore key considerations for selecting CRAHs and how Daikin’s innovative solutions address these needs effectively.
Challenge #1: Ensuring Efficient Use of Limited Space
Space is often at a premium in data centres, making it essential to select cooling equipment that delivers high capacity without requiring excessive room.
Daikin’s Pro-W CRAH units are designed with flexibility and scalability in mind. Their modular design allows for easy maintenance and capacity redundancy, with units that can be stacked or positioned side-by-side without compromising airflow. Available in four sizes, Pro-W units provide between 175 kW and 700 kW of cooling capacity, making them suitable for large to hyperscale data centres.
Challenge #2: Reducing Operating Costs and Improving Energy Efficiency
With energy costs continuing to rise, data centres must focus on keeping operating expenses low while improving energy efficiency. Key strategies to achieve this include:
- Using electronically commutated (EC) fans for high efficiency.
- Maintaining adequate water velocity in part-load conditions.
- Stabilising water flow with pressure-independent control valves (PICVs).
- Employing advanced control systems to optimise performance.
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EC Fans for Maximum Efficiency: Daikin Pro-W CRAHs are equipped with IE5-class EC fans with aluminium impellers. These offer greater energy efficiency and durability compared to traditional motors, reducing both running costs and environmental impact.
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Water Velocity Optimisation: Daikin’s water coils are engineered for efficient performance at part loads and high delta T conditions, focusing exclusively on sensible heat exchange. Robust aluminium fins ensure durability, even in 24/7 operations.
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Stable Water Flow: Pressure-independent control valves integrated into Pro-W units stabilise water flow, enhance temperature control, and lower energy consumption.
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Intelligent Control Systems: Daikin’s Intelligent Data Centre Manager (iDCM) allows seamless communication between all HVAC components, including primary pump management and free cooling modes. Using advanced machine learning algorithms, iDCM boosts system efficiency by up to 10% for mechanical cooling systems and up to 15% for free cooling systems.
Optimised Water Coil Design for Efficiency
Efficient operation at part load and high delta T conditions requires maintaining adequate water velocity and focusing on sensible heat exchange.
Daikin Pro-W units feature optimised water coil circuiting, enhancing efficiency and performance, particularly in scenarios with significant temperature differentials. Standard thick aluminium fins provide durability and long-term reliability, essential for 24/7 data centre operations.
Stable Water Flow for Better Performance
Proper water flow management is critical for maintaining temperature control and minimising equipment running time.
Pro-W units can integrate pressure-independent control valves (PICVs) to stabilise water flow, improve temperature regulation, and reduce operating costs.
System Control for Lower Operating Costs
Managing multiple CRAHs in large data centres requires a unified control system to optimise performance and improve Power Usage Effectiveness (PUE).
Daikin’s Intelligent Data Centre Manager (iDCM) enables seamless communication between all HVAC components, including primary pump management and free cooling modes. Using advanced machine learning, iDCM improves system efficiency by up to 10% for mechanical cooling and 15% for integrated free cooling systems.
Mitigating Harmonic Distortions for Improved Power Quality
Harmonic distortions, caused by nonlinear loads like variable frequency drives, can increase power consumption and reduce system efficiency.
Daikin offers Active Harmonic Filters (AHFs), which dynamically correct harmonic currents in real-time, ensuring total harmonic distortion (THD) stays below 5%. AHFs also optimise fan motor power factors, reducing energy losses. These filters can be integrated into Pro-W units on request, enhancing system performance and reliability.
Challenge #3: Ensuring Reliability for Continuous Operations
Downtime in data centres is costly, with 14% of outages caused by cooling system failures, according to the Uptime Institute. Reliable HVAC systems are critical to maintaining 24/7 operations.
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Redundant Design for Fans: Pro-W CRAHs are built with N+1 redundancy, meaning that if one fan fails, the others maintain airflow and cooling performance, ensuring uninterrupted operation.
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Advanced System Controls: The Daikin iDCM adjusts the operation of other CRAHs to maintain optimal conditions in case of a unit failure.
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Power Failure Protection: Pro-W units include Automatic Transfer Switches (ATS) and an integrated uninterruptible power supply (UPS) capacitor, ensuring fans restart within one minute of a power restoration.
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Factory Acceptance Testing (FAT): Daikin offers FAT services to guarantee that CRAH units meet design specifications and performance requirements before delivery.
Redundant Design for Enhanced Reliability
CRAHs play a vital role in maintaining precise temperature control within the data hall. As their primary components, fans require particular attention to ensure reliability and uninterrupted operation.
Why Daikin?
Daikin Pro-W CRAHs are equipped with N+1 redundant fan designs, ensuring that even if one fan fails, the remaining fans maintain the required airflow. This redundancy strengthens the overall system’s reliability, safeguarding data centre operations.
System Controls to Support Reliability Management
HVAC system controls are essential in data centres, which require continuous operation around the clock. These controls must not only monitor air handler performance but also address potential downtime in the event of equipment failure.
Daikin’s Intelligent Data Centre Manager (iDCM) ensures seamless system management. In the event of a failure in any CRAH unit, iDCM adjusts the operating conditions of other units to maintain stable temperatures throughout the data hall, ensuring uninterrupted operation.
Protecting Equipment Against Power Failures
Power outages pose a significant risk to data centre operations, making robust protections essential when selecting air handlers.
Daikin Pro-W CRAHs include Automatic Transfer Switches (ATS) as standard, providing swift power restoration. Additionally, an integrated uninterruptible power supply (UPS) capacitor ensures fans restart immediately after power is restored via ATS, reaching full speed in less than one minute.
Factory Acceptance Testing for Guaranteed Performance
In critical environments like data centres, pre-delivery testing of CRAH units is often required to verify performance and compliance with project specifications.
Daikin offers Factory Acceptance Testing (FAT) to ensure every unit meets specified design criteria and functionality before delivery. This rigorous testing process guarantees reliability and performance under the demanding conditions of data centre operations.
Challenge #4: Choosing a Specialist Manufacturer
Data centre projects are complex, requiring HVAC solutions tailored to specific operational demands. Partnering with an experienced and capable manufacturer is essential.
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Global Expertise: Daikin has over 50 years of experience in designing and manufacturing air-handling units in Europe. Facilities in the UK (Cramlington, Northumberland) and Italy ensure proximity to project sites, reducing transportation costs and lead times.
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Proven Track Record: Daikin has supplied 105 MW of cooling capacity for a single data centre project in Northern Europe, demonstrating its ability to handle large-scale, complex installations.
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Comprehensive Support: With a global service network, Daikin provides reliable maintenance and support for critical data centre applications, ensuring peace of mind for UK businesses.
Daikin’s HVAC solutions for data centres offer exceptional performance, reliability, and energy efficiency. From advanced CRAH units to intelligent control systems, Daikin has the expertise and technology to meet the needs of UK data centre operators.
Contact us today to learn more about how Daikin can help optimise your data centre’s cooling system.