When it comes to data centres, one of the most obvious and simple cooling solutions is often considered to be natural air. Using a supply of fresh air to directly cool data equipment can be incredibly cost efficient. However, there are a number of significant disadvantages to consider. Most data centres that are running on this type of cooling system are often situated somewhere there is a supply of fresh, clean, cold air – typically by large freshwater lakes or the coast. This therefore limits the functionality of naturally cooled data centres in both urban and rural areas. Here are five common cooling contamination sources that could damage the technical reliability of data centre equipment, should natural air cooling be conducted in an inappropriate environment.
Diesel
It only takes a visit to London to notice the pollution that is caused by congested traffic. Even rural areas can suffer from air contamination from nearby carriageways and motorways. Diesel vehicles, especially, can emit damaging air contamination that, when filtered into data centre cooling systems, can react with the equipment and cause breakdowns. Settled carbon particles can cause shorting across card components. Essentially, any air contaminated with diesel that is used for cooling, be it from a vehicle, a generating plant or any other machine, will cause problems for data centre servers.
Sea salt
Sea salt is an airborne contaminant that has damaging chemical properties when filtered into a data centre cooling system. Data centres that are susceptible to breezes that are laden with sea salt may find that metal-salt crystals will form. Once the humidity/temperature conditions have reached a certain threshold, a conductive film can form across card surfaces. This can lead to a variety of mechanical complications that can waste valuable time. Most coast-based data centres have the appropriate filtration systems to avoid this issue. However, a breeze coming from the coast can spell disaster for in-land data centres using a natural air system.
Plant pollen
Summer-time can prove a particularly difficult time for data centres. Especially those running on a natural air cooling system. Pollen and other air pollutants are rife in the summer, meaning that air filters have to work additionally hard during the hotter months, especially in data centres that are located rurally. Should these particles become drawn in to sensitive data equipment, irreparable damage, overheating and short-circuiting may be caused.
Natural and artificial fibre
Even the smallest amount of natural or artificial fibre can be catastrophic for a data centre. Circulating in the air flow of the data centre, fibres can easily become stuck inside high-tech equipment. Depending on the fibre, there may be a number of consequences. Zinc whiskers, for example are a form of corrosion that can cause small zinc fibres to grow and become several millimetres in length. These can often become airborne when surfaces are disturbed and will settle, like dust on circuit boards and other electronic components. This will cause short circuits and system malfunction, or failure.
Wind-blown dust
Once dust has infiltrated your cooling system, it is likely you will begin to have problems with over-heating. As a general rule, data centres are kept meticulously clean. However, once dust is being continuously circulated in the air handling units, it can be a difficult problem to tackle. A data centre that has a problem with dust will likely have a 2% higher power demand due to the need to maintain temperature limits, and will likely experience shortened equipment lifetime and hardware failure. This can mean significant down time for customers colocating their data.
It is for these reasons that many data centres are opting for water based or DX cooling solutions, especially those centres that operate in urban environments, such as central London. A natural air cooling system can be efficient in many circumstances. On the other hand, not using these systems can significantly decrease the risk of contaminants in data centre equipment. Any downtime can have a huge effect on businesses across the country, which is why it is always important to understand the cooling systems of your data centre.
To find out more about the advantages and disadvantages of data centre cooling systems, and why they’re so important, take a look at Roger Keenan’s video, Data Centre Cooling and Why It’s Needed.
