The Deutsche Historische Museum in Berlin recently made headlines for the new exhibition hall designed by Chinese-American architect Leoh Ming Pei and for the opening of the permanent exhibition Deutsche Geschichte in Bildern und Zeugnissen, which depicts German history in images and eyewitness reports. The spectacular architecture and permanent exhibitions in the modern new building are attracting visitors from all over the world and the optimal climate control for the protection of the exhibits and comfort of visitors is provided by three Global Chillers from Carrier.
Architect I.M. Pei has combined historic building substance with contemporary design as he did with the legendary East Wing of the National Gallery in Washington and the spectacular annex to the Louvre complex in Paris. The Baroque old armoury, where the permanent exhibition with its 7,500 square meters of exhibition space is located, is the oldest building on Unter den Linden. Pei added a triangular new structure to one side, with a glass foyer the same height as the building, the facade of which merges into a glazed stair tower. The new structure is an illuminated point of attraction in the evenings and reflects the historic facade of the building during the day.
A feature of the new design by I.M. Pei is the glass and steel roofing of the armoury’s inner courtyard. The roof covers 1,600 square meters and harks back to an earlier era when glass roofing protected the courtyard between 1880 and 1945.
The Berlin branch of ABB Gebäudetechnik GmbH was responsible for the building services engineering. Carrier Corporation supplied three water-cooled liquid coolers of the Global Chiller series, with a refrigerating capacity of 606kW each, making a combined capacity of 1,818kW. The cooling system is designed for constant standby operation with a cold-water flow temperature of 6°C to supply the air conditioning units in the Pei building. The underfloor heating areas in the roofed courtyard are also connected to the system and can be operated in either heating or cooling modes.
The 30HX Global chillers are fitted with two separate cooling circuits to ensure operational safety. Their Power³ screw-type compressors, designed for R134a refrigerant, have 30% higher performance compared with standard compressors. The vibration-free design and noise protection for the compression pipes ensure that the units are especially quiet to run. An electronic expansion valve, patented by Carrier, optimises the refrigerant filling so that the heat exchanger surfaces can be utilised in an optimal manner. Each of the 30HX Global chillers has a six-step performance control, with a total of 18 available performance levels. This enables considerable cost savings to be achieved in part-load operation, which typically makes up 80% of operating time for comfort air conditioning.
A Carrier systems manager regulates and monitors the interaction of the three liquid coolers. The system manager is integrated into the Building Management System (BMS) of the Pei building, which in turn is incorporated into a central BMS covering the complex as a whole. The building services are maintained by a facility management company.