Public Defense in Mechanical Engineering, M.Sc. Ilia Kravchenko

Performance of modern mechanical and natural ventilation systems in apartment buildings under a changing Nordic climate

In modern cities and societies, the impact of indoor environments on human health and comfort is crucial, as people spend the majority of their time indoors. However, it is often a challenge to balance creating a great indoor environment with saving energy. This requires modern approaches in Heating, Ventilation, and Air-Conditioning (HVAC) systems that can meet both goals simultaneously. In Finland, modern ventilation systems of new buildings feature demand-based mechanical ventilation, while retrofitted heritage buildings use natural ventilation with self-regulating inlets for consistent airflow. This study evaluates these systems in various scenarios, including occupant behavior, maintenance issues, risk of microbial pollution, and system performance under changing climates. Analysis reveals that new buildings often experience supply and exhaust airflow imbalances, especially during periods of exhaust boosting. Buildings with natural ventilation are heavily influenced by occupant behavior, maintenance quality, and window opening, impacting indoor air quality and overheating risk, especially for vulnerable populations. Additionally, the study assesses how urban microenvironment factors impact Helsinki building stocks during heatwaves. These factors showed the most significant effect during short heatwaves, influencing building resilience to heatwaves. This research underscores the importance of performance analysis of Nordic residential ventilation systems in existing and future climates. The main goal of the thesis was to create an insight into the influence of ventilation design, operating life-cycle and urban microenvironment conditions on the building stock. 

Doctoral Student: Ilia Kravchenko

First Opponent: Associate Professor PhD Jakub Kolarik, DTU, Denmark

Second Opponent: Associate Professor PhD Anna Bogdan, Warsaw University of Technology, Poland

Custos:Professor Risto Kosonen, Aalto University School of Engineering, Department of Mechanical Engineering

The public defense will be organized in Lecture Hall 216, Otakaari 4.

Thesis is publicly displayed 10 days prior to the defense in the publication archive Aaltodoc of Aalto University. 

Contact information of the doctoral student: Ilia Kravchenko, ilia.kravchenko@aalto.fi

Doctoral theses in the School of Engineering: https://aaltodoc.aalto.fi/handle/123456789/49