**2. Materials and Methods**

The investigated test facility is located on the campus of Hamburg University of Technology. Figure 1 shows some impressions of the installation and its relevant components. In total, the test facility consists of eight 20 ft. containers. The four containers on the lower floor contain the air handling unit and further technical installations. An office and conference room with a net floor space of 56 m<sup>2</sup> is located in the four upper containers. This area is used as reference room for the air conditioning system. System operation is investigated throughout the year.

**Figure 1.** Test facility, air handling unit and heat pump with parts of the header system.
