Energy upgrading of buildings. A holistic approach for the Natural History Museum of Crete, Greece

This article presents the fundamental points of the accomplished work regarding the energy upgrading of the building of the Natural History Museum of Crete, Greece, based on a cluster of passive and active measures. The main target was the building's energy efficiency upgrading from D to A+ rank. Among the passive measures, insulation of the building's envelope, installation of new windows and doors, construction of a green roof and planting of an outdoor space at the south side of the building to improve the ambient climate locally are included. Furthermore, small wind turbines and a photovoltaic station on the roof, geothermal heat pumps with an open loop system operating with seawater, new lighting equipment controlled by a central management system and reactive power coefficient compensation constitute the proposed active systems. Energy saving percentages from 40% to 93% are achieved with all the proposed technologies. In total, the primary energy specific consumption is reduced from 273.65 kWh/m2 at 18.36 kWh/m2, giving a total energy saving percentage of 93.29%. The building's energy efficiency is upgraded from the rank D to the rank A+, according to the European Union's standards. The total cost of the proposed measures is estimated approximately at 900,000€.