FanGrid: A great deal with quan­tity

Online trans­ac­tions, mp3 down­loads and video chats – day in and day out, hundreds of thou­sands of terabytes of data cause the wires of data centres world­wide to glow. To keep that from being more than a figure of speech, powerful air-condi­tioning units provide a remedy. That often happens at the expense of energy effi­ciency: A study of the German Energy Agency (dena) shows that cooling equip­ment alone consti­tutes 25 percent of a data centre’s total power consump­tion. That is a condi­tion that one of Menerga’s inno­va­tions now plans to change. In addi­tion to the common mechan­ical cooling, the “Adcoolair” air-condi­tioning unit also uses free cooling and “adia­batic” evap­o­ra­tion cooling, and saves a consid­er­able amount of energy doing so. Even with regard to air conduc­tion, maximum effi­ciency is the objec­tive: so far up to eight Green­Tech EC fans can operate in parallel in the air intake and exhaust of the device cube, thereby achieving combined output.

Since air-condi­tioning units do not run all year round with the same output, the contin­uous control­la­bility of Green­Tech EC fans is a deci­sive advan­tage. Unlike other solu­tions, they feature high effi­ciency even at low output levels. The energy balance speaks for this solu­tion: The cube already outper­forms EU require­ment 640/2009 for central air condi­tioners, which will not fully come into force until 2017.

Strength in numbers

When devel­op­ment began, however, there was a crit­ical limi­ta­tion to Green­Tech EC tech­nology: An indi­vidual fan works with a maximum air flow volume of 10,000 cubic metres per hour, while a data centre requires many times that. But if one fan is not enough, why not have more fans do the job? Menerga had corre­sponding tests carried out in ebm-papst’s test chamber – with posi­tive results: “With an optimum arrange­ment, the air flows add up without any loss in output,” confirms Project Engi­neer Ralf Mühleck, who super­vised the devel­op­ment for ebm-papst. The tests also dealt with the topic of oper­ating reli­a­bility, which plays a large role precisely for data centres. In addi­tion to the redun­dancy provided by combining several systems, each system has built-in redun­dancy for air flow. Even if one fan unit fails, most of the required air flow can be main­tained by the remaining devices. despite its many advan­tages, the fan unit is no larger than compa­rable solu­tions; in contrast, “The compact EC motors are directly inte­grated in the centrifugal impeller, meaning the total design turns out substan­tially shorter.” Main­te­nance is also very user-friendly, as Mühleck describes, “Each fan has a service life of at least 40,000 hours. And if one ever does fail, it can be replaced without much effort.”