Energy-saving of passive ventilation systems in thermally modernized residential buildings – a review

The increasing global focus on energy-efficient construction, driven by climate change and the depletion of fossil fuels, has renewed interest in passive ventilation as a low-energy alternative to mechanical systems. Despite growing evidence of their benefits, the application of passive and hybrid ventilation in thermally retrofitted buildings remains underexplored. Addressing gaps related to environmental adaptation, renewable integration, and long-term cost–benefit evaluation will support the development of resilient, sustainable, and energy-efficient ventilation strategies for modern housing. This review paper highlights the challenges associated with improved air tightness in retrofitted buildings, which may limit natural ventilation and degrade indoor air quality, and explores hybrid solutions that integrate passive components, such as Trombe wall, solar chimney and wind catcher, with renewable energy systems to improve year-round performance. Thermally modernized buildings, characterized by improved insulation, upgraded windows, and enhanced heating and ventilation systems, achieve reduced heat loss and energy demand. However, they often face challenges related to increased airtightness and limited natural air exchange. Key aerodynamic and thermal factors affecting passive airflow, including wind pressure distribution and buoyancy effects, are analyzed with emphasis on multi-storey urban buildings. Advanced simulation tools, including CFD and Building Energy Simulation, are discussed in the context of optimizing design and assessing performance.