The NTT data center in Frankfurt has one goal:
Save electricity when cooling

The amount of data worldwide is increasing exponentially, so the market for data processing and the data centers required for it are booming. Modern data centers are inconceivable without cooling due to the extreme packing density of computers with their high heat production. Both power supply and cooling are critical factors for the safe operation of such systems. Come what may, the following applies: save electricity when cooling!


By downloading the video you accept the privacy policy of YouTube.

Load video


Virtual tour

NTT's data center campus, Frankfurt 1 Data Center, is one of the largest locations for data backup, colocation services, complex IT applications and cloud solutions with 60.000 square meters of data center space. The buildings are specially built and equipped for use as a data center. The location was chosen due to the maximum security and availability of the infrastructure given here. Important aspects were above all the safe provision of electricity, the connection to data networks and protection against natural hazards. In order to meet the high customer demand, NTT Global Data Centers EMEA GmbH operates three other locations in the Frankfurt region alone, which can provide additional space of over 50.000 square meters when completed.

The challenge lies in the cooling

One of the greatest challenges for NTT, in addition to the continuous and secure power supply, is the enormous waste heat from the computers running around the clock 365 days a year: In addition to the redundant power supply with additional emergency power generators or buffer batteries, extremely reliable and efficient cooling of the computer cabinets and all other critical areas. On average, each kilowatt of computing power requires 0,2 to 0,5 kW of cooling power, so the cooling systems required are correspondingly large. In order to make the cooling process as safe and efficient as possible, NTT in Frankfurt relies on air cooling of the IT systems with a central cold water circuit for distribution within the building. Among other things, frequency converter from Danfoss Drives. The ingenious concept covers every area from the cooling air flow within the server rooms to the release of thermal energy to the environment.

Safe cooling at NTT: How it works

Christian Tietz, Sales Engineer at Danfoss Drives, explains step by step how the technology that cools the NTT data center works. Listen in and discover how the frequency frequency converters take over the pump control. Since the systems were first commissioned in 2003, they have always ensured the optimum flow rate and regulated the motor characteristics of the pumps using differential pressure measurement. In this way, consumers are constantly supplied with the required amount of cold water.

The system has both recooling plants, which emit waste heat via the outside air or supply cooling water, as well as chillers that can be switched on if the difference to the outside air is not sufficient in warm periods. It is switched on in stages in order to cool as energy-efficiently as possible. In the cold season, the outside air is often sufficient.

In addition to the frequency frequency converters of the VLT series for cold and cooling water pumps, NTT has been exclusively using Danfoss in continental Europe for about 2 years Turbocor as a compressor in the built-in chillers in order to be able to benefit from the stepless speed control of the built-in converter. The resulting significantly improved part-load efficiency is one of several factors that persuaded NTT to take this step.

> 100.000 operating hours without failures

The frequency frequency converters used optimize the running time of the pumps by changing the lead pump or the following pumps according to the operating time. All components of the refrigeration system are connected to a control center via Modbus and are controlled centrally via this. This allows the operating personnel to monitor the operating states of the individual system components at any time. Should the communication between the control center and the converter ever fail, the frequency converter automatically to a maximum rated fixed speed in order to ensure the cooling of the server in any case.

NTT has been using Danfoss technology in Frankfurt since the data center went into operation in 2003: in addition to the VLT HVAC Drives FC 102 are in the plant in some areas also VLT 6000 in use, which according to the operator should have run for around 100.000 operating hours - without ever causing any problems. The main outputs that are used are 11/15 kW up to 37 kW in the order of around 60 frequency frequency converters per building - a total of around 500-600 units.

Discover Danfoss Drives