Data centres tend to be energy guzzlers, using vast amounts of power not only for running the equipment, but also for maintaining the temperature and humidity at the levels required by the servers for them to be able to operate correctly.
Revised operating temperatures and humidity levels open the way
Recently the major computer manufacturers have revised their recommendations, raising permissible operating temperatures to between 18ºC and 25ºC and humidity to 80% RH, and allowing the temperature to rise up to 27ºC for short periods. This opens the way for evaporative cooling – and considerable energy savings.
Energy efficiency with a quick payback
Evaporative cooling offers a highly effective solution for new data centres. It can also bring about huge savings to existing facilities and will pay back very quickly the cost of replacing the large, energy-hungry A/C systems that were necessary with the previous tougher recommendations for operating conditions.
An effective solution for all seasons
Evaporative cooling systems use the cooling power of water to reduce the temperature inside the data centre and only require a small quantity of electricity to operate the fans that circulate the air. The hotter the outside temperature, the more efficient they are in dealing with the high levels of heat generated by the servers and the excess humidity. During the colder winter days, hot extract air can be recirculated into the supply air so that the temperature is maintained within desired levels.
A safe solution
The recent cases of Legionnaire’s disease in Scotland have brought to the fore some of the risks associated with water-based cooling systems.
These incidents don’t detract from the value and safety of evaporative cooling systems, but they do remind us that there are precautions we must take when we are commissioning this type of technology, beginning with checking that the system has the right certification. And they remind us of the importance of a sound maintenance programme and rigorous controls.
If you are considering evaporative cooling for your data centre, you can also read our article on how to make sure the evaporative cooling system you install is safe.
Paul Langford is an Engineering Director experienced in product development, manufacturing & testing for HVAC, louvre and smoke control systems.