Towards zero energy hospital buildings: a polyclinic building as case study

The need for (nearly) Zero Energy Buildings (nZEBs) becomes increasingly important due to climate change and increasing energy prices. Considering that, on average the existing hospitals use 3.5 times more energy than the nZEB requirement, reaching zero energy a very challenging task. However, monitoring hospitals’ energy flows together with a holistic view on building functions and occupancy can contribute to achieving potential energy savings, which is lacking in the current hospital buildings. Therefore, in this study, the energy saving potentials of a polyclinic building of a hospital in the Netherlands was investigated through a holistic inspection of the building and its occupancy. The analysis is performed in order to investigate the building characteristics, energy supply and demand. It was found that the number of people present was considerably lower than the full capacity, with 30% average occupancy in the medical facilities and 70% for the administrative areas. The air supply of the current ventilation system was found to be constant irrespective of the number of people present in these rooms. Furthermore, a discrepancy of 30- 50% was found between designed and installed lighting systems. The analysis of the polyclinic showed possible energy-saving measures with controlled ventilation rates and lighting according to the occupancy