Bigger isn’t always better
Power usage effectiveness (PUE), a widely-used data centre metric employed by operators, exemplifies that mantra. The smaller the PUE number, the more efficient the data centre operations, which is the goal data centre managers strive to achieve.
At Colt Data Centre Services, we strive to achieve the lowest possible PUE scores across our vast data centre estate. Standard guidelines are followed by operations personnel to systematically ensure the lowest possible PUE score is achieved at each site.
Our focus on energy efficiency has resulted in significant savings across our estate over the past decade. We’ve learned many lessons about lowering PUE along the way that we’d like to impart.
Here are a few of the tactics Colt DCS has taken to improve PUE in past:
Measure power usage
‘If you can’t measure it, you can’t improve it,’ as management guru Peter Drucker once noted. Doing so regularly is the first step to a more efficient data centre.
Improve airflow management
There are many ways to do so.
Regulate airflow / prevent hot and cold mixing
Controlling airflow and limiting the mixture of hot and cold air, and the various steps to do so should be your priority.
Align hot and cold aisles
Servers within the racks and rows should face the same direction. These rows can be arranged into hot and cold aisles with the front of the servers facing one way and the back facing the other way. This tactic will allow for cold aisles to be created supplying colder air to the front of the servers, and hot aisles for the hot air to flow back to the cooling units.
Reduce airflow leaks
Install blanking plates to fill the gaps where no equipment is present. It’s a measure that can stop air escaping by preventing it from falling between or behind the racks.
Check flooring
Flooring and walls are potential sources of leakage. Check for gaps behind and beneath air cooling units or through air vents in floor tiles where air can escape.
Introduce aisle containment
Once airflow leaks and gaps have been plugged, containment can be introduced to ensure separation between hot and cold air and improve the direction of airflow. Introducing roofs and in particular doors to the end of aisles can result in significant energy savings.
Control air temperature
With better airflow management, greater air control is possible, which is ideal because cooling units can then operate more efficiently. An additional benefit is that data centre operators will be able to increase air temperature in the cold aisle which also allows the units to run more efficiently. As such, regulation of the data centre’s air temperature is more manageable once the flow of cold air through the server equipment is in and the hot air is directed without mixing of cold air.
Regulate humidity
It’s a good idea to manage humidity as operators can then open up humidity levels to more efficiently manage their data centre. By operating to a slightly wider humidity banding, the need for humidification and de-humidification is reduced, which saves energy.
Check transformer voltage
The voltage of a data centre’s electricity transformers should be checked to ensure the supply voltage required for your equipment matches it.
Remove isolation transformers
These are no longer required and are an unnecessary drain on your estate because of the energy inefficiencies caused.
Turn off ‘zombie’ equipment
Turning off redundant uninterruptible power supply units could represent a simple step to significant energy saving given the energy drain the groups represent.
Measure at regular intervals
A 12-month period of data should help operators determine whether the effort has been worth the trouble.
We’ve determined a number of steps to boost the efficiency of our data centres over several years. However, regular measurement is necessary to determine whether the actions you’ve taken have been worth the effort. The measures noted in this article are ones you can implement as well irrespective of the long-term plans for your data centre.
