Airflow containment is a critical aspect of data centre design. Containment solutions, like aisle curtains, doors or rigid panels are used to separate hot and cold aisles. When properly sealed, containment ensures that cold air is directed precisely where it's needed and hot air is effectively removed, reducing energy consumption and enhancing cooling performance.
Temperature and Humidity Monitoring
Temperature monitoring is essential for maintaining the operational integrity of a data centre. Temperature sensors should be strategically placed throughout the facility, including within hot and cold aisles and inside server racks, helping to maintain a consistent temperature within the recommended range, typically between 18-24°C.
Meanwhile, proper humidity levels prevent the build-up of static electricity, which can damage sensitive electronic components. Additionally, they help prevent corrosion and other moisture-related issues that can harm IT equipment. Humidity sensors should be used to help maintain the correct humidity level, typically between 40% and 60%.
Selecting the most suitable HVAC system and designing the cooling infrastructure with precision are vital steps in ensuring that a data centre can effectively handle the heat generated by servers. Common HVAC systems used here include:
- Precision Air Conditioning (PAC): PAC units are specifically designed for data centres. They provide precise control over temperature and humidity by cooling the air before it enters the data centre space. PAC units are highly accurate and energy-efficient.
- Chilled Water Systems: These systems use a network of chilled water pipes and air handlers to cool the data centre air. Chilled water systems are suitable for larger data centres and can be energy-efficient when designed and operated correctly.
- Direct Expansion (DX) Systems: DX systems use refrigerant to cool the air directly. They are often cost-effective for smaller data centres but may be less energy-efficient at larger scales.
Redundancy and Capacity
Redundancy in the HVAC system is vital for ensuring continuous cooling even in the event of a system failure. Common configurations include N+1, where there is one additional backup unit for every N units, or 2N, which provides complete redundancy.
Properly sizing the cooling capacity is also crucial to handle the current and future IT loads. Insufficient capacity can lead to overheating during peak usage, while excessive capacity can result in unnecessary energy consumption.
Airflow optimization involves designing the data centre layout and cooling infrastructure to maximise the efficiency of air movement. This can include using raised floors for underfloor cooling or overhead ducts for overhead cooling.
Positioning Computer Room Air Conditioning (CRAC) or Computer Room Air Handling (CRAH) units strategically ensures that cooling air is efficiently distributed to where it's needed most.
Ultimately, achieving optimum cooling in a hot/cold aisle data centre arrangement is a complex task that requires meticulous planning and attention to detail. Each element, from aisle design to HVAC systems, plays a crucial role in maintaining a controlled and efficient data centre environment.
By carefully considering and implementing these design considerations, data centre operators can ensure reliable operation, extend equipment lifespan and reduce operational costs while minimising energy consumption.