35 strategy . These steps include the implementation of basic , low cost hot / cold air segregation best practices at a raised floor & rack level , including sealing holes in the raised floor , blanking unused HU spaces between rack-mounted IT equipment , and working up to more significant investments at a room level that can include aisle containment solutions . Airflow optimisation should be part of any new data centre design brief , as well as forming part of efficiency and sustainability initiatives across legacy data centres .
COLD AISLE CONTAINMENT
35 strategy . These steps include the implementation of basic , low cost hot / cold air segregation best practices at a raised floor & rack level , including sealing holes in the raised floor , blanking unused HU spaces between rack-mounted IT equipment , and working up to more significant investments at a room level that can include aisle containment solutions . Airflow optimisation should be part of any new data centre design brief , as well as forming part of efficiency and sustainability initiatives across legacy data centres .
Beyond the basic raised floor and rack airflow management best practices , aisle containment systems create a physical barrier preventing the mixing of hot and cold air within a computer room or data centre hall . This is achieved by either , enclosing the cold aisle which feeds the IT equipment – cold aisle containment ( CAC ), or containing and removing the warm air that has been exhausted from the IT equipment - hot aisle containment ( HAC ). As part of a holistic approach , the implementation of aisle containment contributes to a greater level of control , which in turn allows significant improvements in the performance of the data centre environment as a whole while realising cost savings . If set points can be increased , CRAC unit fan speeds slowed down or CRAC units switched off altogether , data centre managers are able to find additional capacity within the same footprint , which can facilitate the deployment of more IT equipment and additional revenues being generated or services provided .
The contained data centre Within a contained data centre environment , end-of-aisledoors are normally used to prevent air mixing at the end of rows of cabinets . Roof systems can also be deployed to enclose the cold aisle completely . A number of different roof systems are available including fixed , passive drop away , or active roofs that are connected directly to a data centre ’ s fire suppression system and are triggered to pivot in an alarm state .
Aisle containment systems don ' t need to be rack manufacturer specific . In fact , some of the most flexible containment solutions are available from companies that specialise in bespoke aisle containment systems tailored to the clients ’ individual needs and data centre configuration . These can be retrofitted or used in new build applications irrespective of the brand of racks being used immediately , or in the future . Such systems are fully flexible and can be designed to fit with any rack configuration including aisles with varying rack heights , widths , depths and alignment . Even obstacles such as building column supports can be incorporated into the solution , as well as overhead power and data services , fire suppression , and security systems . The construction can be from steel , with Perspex or polycarbonate infill panels , or produced entirely from PVC curtains if a lower-cost or more temporary solution is required .
Full or partial containment Until recently it was thought that for aisle containment to work effectively , the aisle had to be fully enclosed or sealed with air leakage rates of less than 3 %. However , the recent introduction of an out-of-the-box modular containment solution alters this perspective . The solution consists of bi-directional doors and roof top baffles that attach to the racks in a non-intrusive way using magnets . The rack top baffles only partially seal the aisle , but in a recent white paper comparing full containment to partial containment ,
it concluded the difference in performance between the two was minimal . The report found that there was about 1 ° C difference in the average inlet temperature with the partial containment being slightly warmer , and the partial system enabled a reduction in CRAC energy usage by 30 % – only 5 % less than that achieved by the fully enclosed system . The partial system gave the biggest return on the cost of installation and reduction in the time to deploy the solution . And being modular it can be easily reconfigured when racks are added or removed from a row , or if a data centre is closed down and equipment migrated to a new facility .
Finding the right balance Installing an aisle containment solution , whether it ' s a fully enclosed or partial system still requires on-going airflow management to obtain the best long-term results . Bypass airflow , or the conditioned air that doesn ’ t pass through the IT equipment to cool the micro-chips , will still be present unless CRAC units are correctly balanced to provide the right amount of cold air needed to cool the IT equipment . If cold air is over-supplied to the contained aisle the excess conditioned air will escape through small gaps or get pushed through the IT equipment . The correct balance can only be achieved by reducing fan speeds and raising set points . It ' s these changes that enable a reduction in operating costs , help reduce carbon emissions , extend the lifetime of equipment and provide the maximum return on investment .
Every data centre will have its own set of design constraints & considerations which will shape its airflow management strategy and , ultimately determine which aisle containment solution , if any , is most suitable for achieving the outcomes required by the business it supports . The good news is that there are a range of flexible systems available to suit the needs of any data centre targeted for improvement , so don ’ t hesitate to implement your airflow optimisation strategy . n
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