green IT
Minimise mechanical cooling power , increase free cooling The amount of energy used to create cool air can be highly variable . Traditional mechanical cooling systems can consume significant energy , but their efficiency can be improved . Increased temperature set points and increased difference between supply and return air temperatures will reduce the amount of work that mechanical cooling systems have to do . Fortunately , the containment methods used to optimise airflow also support opportunities for improving mechanical cooling efficiencies . Because containment eliminates mixing of cool supply air with warm exhaust air , IT inlet temperatures are much more uniform . This means that temperature set points for the supply air can be very close to the temperature required by the IT equipment – overcooling is not necessary . Also , because of the lack of air mixing , the temperature of the air returning to the cooling equipment is hotter , promoting more efficient heat transfer within the cooling coils .
An even bigger reduction can result from curtailment or complete elimination of mechanical cooling . The same increase in temperature set points that air containment allows can greatly increase the amount of time that free cooling can be utilised . Air-side economisation methods can substitute outside air for mechanically cooled air allowing cooling systems to run less . Water-side economisation lets the cooling systems substitute air cooling and / or evaporative cooling for compressor cycles . IT equipment that supports operation at higher temperatures or geographic location of data centres in cooler climates can greatly extend the ability to avoid the use of power-hungry mechanical cooling systems . Panduit ’ s own data centre , hosted in our LEED Gold World Headquarters building , operates 50 per cent of the time with free cooling .
Minimise other power The final segment of the data centre energy consumption breakdown represents additional opportunities . Power conversion losses are included . Data centre electrical power is typically transformed down in voltage from the main feed to the facility , converted to direct current at battery voltage in an uninterruptable power system , converted back to alternating current at higher voltage for distribution , and finally converted back to lower voltage direct current by IT power supplies . Every conversion step results in losses , causing more energy to be consumed than is used by the IT equipment . Energy loss by conversion is typically in the range of 5-10 per cent . Progressive data centres have worked to eliminate some of this energy waste by reducing the number of power conversions . This could include power distribution at higher voltages within the data centre , with a final conversion very near the IT equipment . Alternatively , direct current power can be distributed , without the need for transformation at an IT power supply .
Lighting energy is another opportunity area . LED illumination uses less energy than fluorescent lighting . Replacing typical lightabsorbing black IT cabinets with a more reflective colour can reduce the amount of light needed . Simply turning off lights when they aren ’ t needed is of course very effective . Timers or occupancy sensors can also greatly reduce the energy consumed for lighting a data centre .
Renewable energy Improving efficiency to reduce energy requirements is critical , but an additional factor in conservation is the source of energy . Power generated from fossil fuels has a large negative environmental impact . Even partial offset with renewable energy can be beneficial . Solar , wind , hydroelectric and geothermal all have great potential depending on the facility ’ s location .
Energy reuse No matter how effectively a data centre reduces energy consumption it ’ s still going to create waste heat . The final opportunity to be environmentally friendly is to use waste heat for another purpose . Unfortunately , IT exhaust temperatures are too low for common reuse opportunities – they don ’ t support generation of steam or electricity . However , many data centers have utilised waste heat for environmental heating in cooler climates , even integrating into community heating systems .
Integrated approach At Panduit , we believe that obtaining the greatest energy conservation benefits requires a strategy that considers all areas of opportunity . Designing and building the facility with energy use optimisation as a priority facilitates taking advantage of the opportunities discussed here . An integrated design that includes extensive monitoring and control components allows the data centre to be highly adaptive to the variations in demand that the data centre will undergo , keeping the level of energy conservation optimum , as activity levels and environmental conditions change .
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