The Frank­furt 1 data center campus has around 50,000 square meters of IT space, making it one of the largest data center loca­tions in Europe. Customers benefit from a variety of services, including the oppor­tu­nity to rent server cabi­nets, specially parti­tioned high-secu­rity areas (“cages”) and office space here or have their servers hosted. The services offered include moni­toring and main­te­nance of the systems, because nothing here matters more than secu­rity: NTT offers customers 99.999 percent avail­ability  meaning that servers will continue to run even in the event of a disaster.

If you want to perform around the clock, 365 days a year, you have to stay cool. In data centers, preci­sion air-condi­tioning units take care of that. They draw in exhaust air at a temper­a­ture of around 36 to 39 degrees Celsius, filter, cool and humidify it, then direct the air, which has been cooled to 23 to 24 degrees, through a raised floor and outlets directly to the server racks. At the explicit request of NTT’s data center (DC) experts, three EC centrifugal fans from ebm-papst’s RadiPac series are respon­sible for contin­u­ously moving the air in each of the air condi­tioners.

Preci­sion air condi­tioning unit

In the preci­sion air condi­tioning units, the air is filtered, cooled and humid­i­fied.

RadiPac

Three centrifugal fans per preci­sion air-condi­tioning unit draw in the warm return air and convey the cooled air further.

Warm return air

The warm return air at 36-39 degrees Celsius is drawn in by the preci­sion air condi­tioning units.

Cold supply air

The supply air cooled to 23-24 degrees Celsius is conveyed by the preci­sion air condi­tioning units.

Raised floor

The three RadiPac sit at the level of the raised floor under the server racks.

Air outlets

The cold supply air reaches the server racks through the air outlets.

Server racks

The server racks must always be cooled to provide constant computing power.

Data center secu­rity is the busi­ness of DC Experts

The DC experts are part of Central Engi­neering within NTT. Together with the design depart­ment, they take care of the entire data center infra­struc­ture. Their tasks include the concep­tual design, devel­op­ment of spec­i­fi­ca­tions and commis­sioning of the preci­sion air-condi­tioning units. The main focus is on ensuring that customers’ require­ments regarding secu­rity and effi­ciency are met. This applies not only to protecting the server rooms, but also to the cooling system. RadiPac centrifugal fan meets the neces­sary require­ments for this, the DC experts explain: “For example, the excel­lent service life, energy effi­ciency, and its control and moni­toring prop­er­ties.”

“We adapt every­thing to customer require­ments”

When it comes to data secu­rity, special requests are the rule. For example, one customer requested a partic­u­larly close-meshed intake and exhaust air grille on the raised floor. To ensure that the servers continue to get enough cold air, the fans have to deliver more power while remaining effi­cient. The DC experts were partic­u­larly impressed here by the infi­nitely vari­able, econom­ical EC motor: “We operate the RadiPac in partial load at low speed. In this range, EC fans are simply unsur­passed in effi­ciency.”

 “The reli­a­bility and ­effi­ciency of the ­RadiPac fans play a big part in the resilience of the data center.”

Data Center Experts NTT

Save 30 % energy with RadiPac

This also increases the service life, as impres­sively demon­strated in Frank­furt 1, where around 1,500 RadiPac fans have been in oper­a­tion for more than eight years. “We run the standby preci­sion air-condi­tioning units in parallel at low speed instead of setting them up just for emer­gen­cies. This allows us to increase the service life of the fans and boost effi­ciency. Thanks to precise differ­en­tial pres­sure control in the range of four to six pascals, the fan speed of all air condi­tioners auto­mat­i­cally adjusts when a preci­sion air-condi­tioning unit fails or if the server perfor­mance changes dynam­i­cally.”

Because the standby air condi­tioners run contin­u­ously, all fans consume an impres­sive 30 percent less elec­tricity. This is also good news for customers who are increas­ingly demanding infor­ma­tion about energy consump­tion. They usually ask for the EER value, which indi­cates how high the cooling capacity of a preci­sion air-condi­tioning unit is compared to its power consump­tion. “The econom­ical RadiPac are crucial for achieving a good EER value.”

Service and perfor­mance convince NTT

In addi­tion to effi­ciency, personal inter­ac­tion is partic­u­larly impor­tant to the DC experts. Depending on what customers want, different air condi­tioner manu­fac­turers are approached and the units are inspected on site: “For us, tech­nical data is not enough, because it is measured in the suppliers’ test rooms. But that doesn’t corre­spond to the final instal­la­tion situ­a­tion in our company.”

There must be no surprises in this respect, which is why the DC experts also monitor compa­nies supplying their suppliers on site for example, at ebm-papst. “What matters to us first and fore­most is the quality of the prod­ucts and that they have been tested to perfec­tion. The reli­a­bility and effi­ciency of the RadiPac fans play a big part in the resilience of the data center. ”