Why is so much cold air in data centres being wasted?

Despite rising energy costs, data centres are spending an unnecessary amount of money on cold air to ensure there is no impact on data integrity or even loss of functionality. The IT equipment in a data centre should be kept at a temperature of between 18oC and 27oC degrees in order to run at optimum levels but, according to 8 Solutions, a specialist at increasing efficiency and mitigating against the risk of down-time in critical facilities, many data centres are producing nearly 4 times the amount of cold airflow than is needed.

The findings follow a large number of airflow audits that 8 Solutions has undertaken for major data centres over the last six months, revealing the cold air excesses of the majority of those audited. This trend is also backed up by Upsite Technologies who recently reported that, over the course of 45 audits performed within the USA, data centres were producing 3.9 times the amount of air really needed.

8 Solutions is a market leading data centre service company in the UK, with over 23 years’ experience, serving approximately 80% of the FTSE100 data centres, as well as having a major presence within the data centre colocation market.

David Hogg, Managing Director at 8 Solutions, believes not enough is being done to manage airflow correctly and as a result data centres are simply injecting more cold air than is needed. He explains: “As new IT equipment is added to data centres the solution to maintain the correct temperature is usually to increase the cooling by adding further cold supply-air capacity to the environment. But, most data centres have sufficient cooling capacity available, it’s simply that a lot of the current cold air is being wasted and, critically, is not being directed to the IT kit.”

Excessive cold air supply is costing data centres thousands of pounds in unnecessary energy. The main areas of wasted airflow found by 8 Solutions, included:
· Unsealed firewalls allowing the cold air to escape the room or even leak out of the DC entirely
· Unsealed cable cutouts meaning the cold air is released into inappropriate areas
· Poor management of hot/cold aisles including having grilles located within the hot aisles and also having IT equipment installed in reverse
· Poor delivery of cold air through the subfloor due to poor cable management causing blockages
· Bypass air circulating back to the AHU without going near to the IT kit
· Mixing of cold and hot air reducing the effectiveness of the cold air
· Incorrect airflow balance between Supply (installed capacity) & Demand (IT equipment)

David continues, “With better airflow management we have seen that data centres can make average energy savings of £48 per m2 per annum. For a typical 500 m2 data centre, this can save £24,000 per annum on energy costs and also show an improvement in PUE. This improvement is providing a return on investment of between 12-24 months.”

Recent reports by the Uptime Institute conclude the same, where average self-reported PUE levels have reduced significantly from 2.5 in 2007; 1.89 in 2011, & 1.65 in 2013, with airflow optimisation identified as the main contributor.

8 Solutions Airflow audits and comprehensive feedback reports include on-site analysis and measurement, typically conducted in one day and includes: an analysis of the current IT load, static pressure readings, CRAC unit input and output temperatures, airflow analysis both above and below the raised access floor, thermal images, and identification of hot spots throughout the data centre. In addition, the company will also provide a detailed report with measurements and analytics covering the current state within the data centre showing the amount of cooled air reaching the server rack and fully costed recommendations for rectification of any current airflow losses. Finally, a fully detailed return on investment calculation will also be provided.