Air conditioning is one of the largest consumers of power in a data centre, often consuming 30% or more of total facility power(Chan and More, 2009). With such a big contribution to power consumption it is no wonder it offers sizeable increases in efficiency. Air Conditioning power consumption can be split into two categories(Hamann et al., 2008). 1) THERMODYNAMIC – power consumption associated with generating the cool air. 2) TRANSPORT – power associated with the transportation of the cool air such as blowers and fans. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) are responsible for publishing guidelines on the allowable temperatures for use within data centres (ASHRAE, 2011). In 2008, ASHRAE updated their range of allowable stating that data centres can safely operate between 18 to 27 Celsius. The majority of data centres operate at unnecessary low temperatures (Rongliang et al., 2012). This of course means power is being wasted to excessively cool the data centre to unnecessarily low temperatures. Lower temperatures = increased thermodynamic power consumption. Research suggests increasing the temperature slightly within the allowable temperatures can save large amounts, whilst operating safely (Barouldi et al., 2009). When adjusting temperatures, it is important to consider adjusting the humidity figures in line with ASHRAE guidelines. However it is critical to get this adjustment right as too high humidity could lead to hydroscopic dust failures and too low humidity can generate electrostatic discharge (Wang, 2006). It is possible to reduce the transport power consumption, by reducing the fan speed of the AC units (Hamann et al., 2008) The relevance of air conditioning is high for this project. The client’s data centre is currently cooled at around 19 Celsius which is almost at the low end of ASHRAEs guidelines.
(References provided upon request)
Fragment of Green Data Centre project I have managed. Report by Auzzam Chaudhri.