Electrical Energy
The redesign of the HVAC system and the electric lighting installations leads to a reduction of the electricity consumption close to 50%. Before retrofit the specific consumption was 189 kWh/m²a, after retrofit the consumption is predicted to be 94,7 kWh/m²a. Before retrofit the air handling units were the most dominant consumers of electric energy followed by electric lighting. The separation of heating and cooling from the ventilation system and the variable control of the air flow results in a predicted saving of more than 70% of the electricity consumption for ventilation. The installation of energy efficient luminaires combined with a better placement of luminaires with respect to the bookshelves and an enhancement of daylight use results in relative savings of about 50% of the electric lighting consumption. These considerable electric lighting savings could be achieved although the lighting level was increased by the retrofit. After refurbishment electric lighting will be the most dominant user of electricity. Since the building is connected to a local grid of district cooling, the savings on cooling consumption do not decrease the electricity consumption. However, the specific average cooling consumption of 42 kWh/m²a before retrofit is predicted to decrease to 30,4 kWh/m²a.