Dynamic Model-Driven Energy Retrofit of Bøgevangen and Runevej Daycare Centers in Aarhus

Abstract

With the huge ambition to achieve a fossil fuel-free energy sector by 2050, the Danish government has targeted the building stock as a priority, offering large potential for feasible and cost-effective energy savings. Around 75% of the existing buildings in Denmark were constructed before 1979 and therefore a special focus has been directed in the recent years towards buildings’ energy renovation especially non-residential and public buildings. A comprehensive strategy for energy renovation of the existing Danish building stock was established with multiple initiatives to enhance cost-effective and energy-efficient renovation of buildings. In this context, Aarhus Municipality is investing 450 million DKK for public buildings energy renovation covering an area of about 1 million m2 and aiming to cut CO2 emissions by 40%. Thus, two daycare centers, Bøgevangen 101 and Runevej 107-109, have been selected as case studies under the international research project COORDICY aiming to improve the centers energy performance implementing renovation techniques. A detailed energy model was developed for each center employing a package of Google Sketchup, Open Studio and Energy Plus energy modelling and simulation tools. The energy model was calibrated against actual meter data. Using the developed model, multiple energy management and retrofit combinations were analyzed and evaluated from both technical and economic perspectives. Conventional envelope insulation and windows upgrade were found unfavorable from the economic perspective and thus were not prioritized. It was shown that employing a retrofit package consisting of installing LED lights, implementing demand-controlled ventilation, and installing efficient equipment could lead to an overall reduction of 30.2% and 31.1% on the energy consumption in Bøgevangen and Runevej respectively, improving the thermal comfort and indoor air quality with an acceptable payback period of around 3 years.