Enhancing Climate Resilience in Mixed-Mode Buildings: A Study of Hybrid Ventilation Strategies in a Cold Climate

In Europe, where buildings are responsible for about 36% of total greenhouse gas emissions, largely due to their operational energy use, addressing climate change necessitates reducing buildings’ energy consumption, particularly for climatization. Despite its energy demands, climatization is crucial for a healthy indoor environment. Thus, efforts to enhance climatization efficiency must aim to both lower energy use and preserve indoor comfort. This research explores resilience of a hybrid ventilation strategy in a mixed-mode office building in a cold climate. The study evaluates the energy performance of two ventilation strategies—full mechanical ventilation and hybrid ventilation—under future conditions relative to contemporary scenarios. Two distinct emission scenarios, RCP 4.5 (mid-emission) and RCP 8.5 (high emission), are considered, spanning three periods: near future, far future, and a reference period. Oslo, the capital of Norway, serves as the selected case study because it exemplifies a relatively large city by Nordic standards, situated in a cold and humid continental climate. Weather data were compiled in accordance with EN ISO 15927-4 standards, using a 30-year period for reference. Subsequently, the Perez model was applied to separate global radiation into its direct and diffuse elements. Following this, simulations of the indoor climate and energy requirements were conducted using IDA ICE. The results indicate that adopting hybrid ventilation can lead to energy savings of up to 40% in scenarios of high emissions during the far future. This efficiency gain is primarily attributed to an extension of the window opening period, which is approximately 6% longer than the baseline period. Such an increase in window opening duration notably contributes to the reduction of indoor CO₂ levels, as illustrated by the case of Norway. These findings emphasize the critical role of incorporating passive design solutions, like hybrid ventilation through window openings, into both architectural design and urban planning practices in cold climates.