Data Centres. Best Practice in HVAC.

Temperature and humidity control in server rooms and data centres is critical. Ignore it at your peril.

Even a slight variation in temperature or humidity from recommended tolerances can lead to system failure and serious consequences. From localised network failures to the horror of total data loss it is easy to see why the right cooling system is a necessity for any space containing sensitive hi-tech equipment. To leave it to chance, or cut corners, is to court with potentially catastrophic consequences.

You know that noise. The frenetic whirr of the fan on your laptop as it kicks in to save your precious data from component meltdown. Now imagine the server room for an office block, or larger still a complete data centre filled to capacity with power hungry, heat generating computers. 

And it’s not just data centres that may require a closely controlled environment – think laboratories, research facilities, hospitals, operating rooms, telecommunication centres or museums with precious works of art. These are all places that demand precise climate control. 

So our blog this month considers why close control of the temperature and humidity in a data centre, server room or similar premises is so critical. We then explore best practices to create such an environment.  

Choosing the right cooling contractor and the right air conditioning system

So much comes down to the experience of the air conditioning contractor who you choose to design and install your cooling and ventilation system. Forgive the plug, but you really do need an expert like Clean Air Group.

A major consideration at design and specification will be the type of air conditioning system that is best suited to your needs and organisation. And it is not necessarily a traditional inverter driven air conditioner that might be best for you. It is possible to use evaporative cooling as the technology to cool, saving on the environment and on running costs (we will talk more about this in a future blog). 

A part of the process will involve a full audit of the computers and other heat generating equipment within the area being cooled. This together with a number of other factors – for example the construction of the room or building – will provide an approximate value for the heat gain, measured in BTUs (British Thermal Units). Our engineers will then use sophisticated tools and computer modelling software to measure the heat loads and decide what is the right air con equipment for the job.  

So just how cool should a data centre be?

Forgive the pun but there is a lot of heated debate over just what the optimum temperature should be. Indeed our understanding is continually evolving. 

On the one hand, and quite understandably, facilities managers tend to err on the side of caution by keeping data centres below 20 degrees C.

On the other hand, data centres are massive consumers of energy and analysis suggests that over a third of this is used on cooling. Thus the cost, both financial and environmental, to lower the temperature and create an overly chilly environment can be significant and unnecessarily wasteful. The same study suggests that while increasing the temperature by a single degree may reduce the consumption of energy by 2-5% the effects on the components in servers is not yet fully understood.

Some reports even suggest that raising the temperature in server racks can make for more efficient performance. For example Data Centre Dynamics (DCD) report that Google data centers run at 26.6°C (80°F) to help efficiency – though it has been suggested that the servers it uses may be custom-built, with specifically designed cooling systems that enable efficient running at higher temperatures.

In the same article DCD also mention the Environmental Guidelines for Datacom Equipment by ASHRAE (the American Society of Heating, Refrigeration and Air Conditioning Engineers) in 2008. This appears to recommend that data centre facilities operate within a temperature range between 18°C and 27°C.

Making the informed choice

By now you will be beginning to appreciate that debate is rife over what the optimum temperature should be for a data centre. There appear to be no hard and fast absolutes. However with careful consideration of current research and by keeping within the heat, humidity and ventilation tolerances recommended by the manufacturers of the equipment that is being protected, a good air conditioning engineer will be able to help guide you to the right climate control strategy for your data room. Or indeed any such premises that require precise control of the environment.