Data Center Group implements state-of-the-art and energy-efficient data center air conditioning with MARC O'POLO

What trends are to fashion, technology and not least legal framework conditions are to IT: Both have in common that they move with the times. In order to meet the constantly changing requirements, the Data Center Group, together with the fashion manufacturer MARC O'POLO, has commissioned a data center whose air conditioning system is unique in this form in Germany. The result was the first air conditioning system with a chiller that uses water (R718) as a coolant. The aim was to use natural, resource-saving refrigerants. An innovation for data centers with a cooling capacity of 15 to 35 kW. This is because water was previously only used as a refrigerant in large megawatt ranges. Such turbines operate in the 2,000 kW power range. Thus, the MARC O'POLO system is compact and highly effective at the same time. Above all, it is ecological and sustainable. With a view to the F-Gas regulation, which will ban certain refrigerants for new air conditioning systems from 2030, alternative refrigerants that will also be approved in the future are already being used here. 

A special feature of the system is the free cooling integrated in the chiller. This means that it can operate both in free cooling mode and in pure compression or mixed mode - even in two stages, as a result of two turbocompressors that compress the water vapor, one after the other if necessary. These turbocompressors were specially developed, tested and inspected for the plant. In addition, the entire plant was designed for energy efficiency. For example, not only are pressure losses, piping or heat exchangers minimized. Recirculating chillers, chilled water and cooling water pumps are also very efficient thanks to their high efficiency. Side coolers were installed inside the data center. Adjustable fans also made it possible to integrate a setpoint shift. Accordingly, when there is little power inside, the sidecoolers regulate the setpoint value of the chiller in the outer area, making it even more effective.

To avoid a complicated conversion of the extinguishing system, a cold aisle lake was built. In contrast to a cold aisle containment, this is an area that is open at the top. The system is regulated by having cold air in the server area and only a little flowing above it. Like cold air in a lake, an air flow is created in this way. A special water treatment system regulates the water filtration of the chilled water and cooling water circuits by mixing pure monoethylene glycol into the cooling and chilled water so that the ph value can be optimally regulated via the filter. Since cold water sweats, the complete piping is made of stainless steel to prevent corrosion. This eliminates the need for priming and painting. 

Three air-conditioning specialists from the Data Center Group completely set up the system in four weeks during ongoing operation. The air conditioning system was started as a field trial. A cooperation from which both partners benefit. 
 

"MARC O'POLO can use the air conditioning system for two years free of charge. Meanwhile, we can further expand our market leadership and test this highly efficient air conditioning in the field," explains Ulrich Mickler, technical manager at Data Center Services, the business unit of the Data Center Group that also specializes in air conditioning for data centers. Due to the degree of innovation, the project is also being funded by BAFA (the German Federal Office of Economics and Export Control). To this end, the complete power consumption of the air-conditioning components is monitored, recorded and documented using a special measuring device. The data will be stored for five years and made available to BAFA.

"Data Center Group convinced us with the professional conceptual design and implementation of a back-up solution for one of our data centers. We value them highly as a partner for the support, maintenance, upkeep and service of our three data centers. Ingo Kessler " Head of IT Service & Network Engineering, MARC O'POLO

Distribution and project management: Ulrich Mickler