Intelligent Data Centres Issue 45 | Page 41

EXPERT OPINION sustainability is now a key element of any business process .
Chilled water systems are a viable way for data centre providers to not only support their growth cost-effectively and with minimal disruption , but also reduce their carbon footprint and help meet sustainability objectives . The reduction of emissions goes through two fundamental aspects : the reduction of direct emissions and the reduction of indirect emissions .
Reduction of the direct emissions ( refrigerant GWP )
Global warming potential ( GWP ) describes the relative impact of a greenhouse gas and the timespan that it remains active in the atmosphere , compared to a base of CO 2 . The lower this metric , the lower the atmospheric impact .
The traditional refrigerants can now be replaced by modern HFO ( hydrofluoroolefin ) refrigerants , which have a lower GWP . It is expected that this will prevent the emissions of up to 105 million tons of equivalent CO 2 by 2040 . However , most of these new refrigerants are classified by ASHRAE ( American Society of Heating , Refrigerating and Air-Conditioning Engineers ) as mildly flammable , therefore requiring a new design for the cooling system , potentially impacting the broader data centre design .
Chilled water systems offer an excellent solution as the refrigerant is contained within chiller units and , in most applications , these are installed outside of the data centre , thus simplifying the use of flammable fluids . Chilled water systems are one of the first cooling technologies to apply low GWP refrigerants in data centre applications and therefore are an example of a valid alternative for reducing direct environmental impacts .
Reduction of the indirect emissions ( cutting energy consumption )
Reducing carbon footprint also means cutting the electricity consumed by a data centre during its operation . This is where chilled water systems can play a big part . In recent years , they have applied a range of cooling system efficiency improvements that allow a reduction of electricity usage .
For example , in a chilled water system , the chiller compressor is the greatest consumer of electricity and the warmer the external climate , the greater the electricity demand of the compressor . www . intelligentdatacentres . com