Case Study: Sky Office Zagreb Croatia

The Sky Office building connects design, functionality and energy efficiency and sets new standards for commercial buildings.

Sky Office was designed in such a way that its technological, functional, mechanical, physical and energetic properties would ensure the profitability of the building and the long term cost efficiency during operation. The project – volume of investment: €100 million – consists of two towers with 22 floors that act as single buildings, although being connected with each other from 2nd up to 15th floor.

The Sky Office is climate-conditioned by means of district heating and energy efficient air-cooled chillers installed on the roof. Forced changes of air with the necessary filtration and control of the air humidity is provided, too.

Furthermore, there is a maximum use of the rooms’ waste heat. If required, the supply of fresh air is cooled or heated with it. The exhaust air serves to partly aerate the underground floors. A fully integrated building automation controls and inspects all systems, representing a reliable operation with rational usage of energy. In addition, a double-aerated glass façade with integrated sunscreen offers best protection against heat and sound. All temperature control zones are supplied by a four-pipe system which makes a simultaneous heating or cooling possible, as well as an independent zone control. The pipeline in the heating and cooling system is installed with aquatherm blue (Climatherm) faser composite pipes.

To provide as pleasant and microclimatic conditions as possible, it was refrained from traditional heating and cooling systems that are based on convection or air circulation. The rooms are consequently climate conditioned by the aquatherm black (Climasystem) surface heating and cooling system. In the office rooms aquatherm black (Climasystem) grids are installed in suspended ceilings and in the walls of corridors.

A very pleasant climate without airflow, development of dust and noise is achieved by
means of this innovatively designed system with highest comfort. 

Facts about the Sky Office:

• Number of floors (aboveground): 22
• Height of building: 81 m
• Number of underground floors (garage): 4
• Total area: 73,010 m2
• Total area of aquatherm black (climasystem) grids: 17,000m2
• Total length of aquatherm blue (Climatherm) pipes installed: 80,000m
• Number of fittings: 178,000