Abstract

In the past decades, the world has experienced rapid urbanization that caused increasing climate change challenges, pollution, energy consumption, and greenhouse gas (GHG) emission. More frequent and more prolonged extreme weather events such as heatwave and cold-wave and urban heat island phenomena are some negative impacts of climate change. The building sector is an essential source of urban energy consumption, GHG emission, and Urban Heat Island (UHI) formation. Different energy efficiency measures can be implemented to reduce building energy consumption, such as retrofitting existing building stock and deploying new technologies. These scenarios will also contribute to the mitigation of UHI, heatwaves, and climate change. Urban building energy models are simulation tools developed to study these kinds of problems. There are several challenges with existing Urban Building Energy Modelling (UBEM) tools, including creating a 3D model of buildings, estimating buildings’ properties, and using urban microclimate data for simulation.
On the other hand, accurate building energy simulation and fluxes from buildings to the atmosphere can impact forecasting accuracy by numerical weather prediction tools. Therefore, developing a multi-scale integrated urban building energy and climate simulation tool is essential for modeling both buildings’ energy performance and atmospheric fields. In this work, a new urban building energy model called City Building Energy Model (CityBEM) is developed to solve UBEMs' current challenges. First, a building-scale energy and airflow simulation model is developed for modeling a single building. It is based on a coupled thermal/airflow multi-zone network model. The multi-zone network model is then modified for calculation of urban scale buildings’ energy performance. A new method is developed to create the 3D model of buildings by integrating buildings’ footprint data obtained from OpenStreetMap and Microsoft and building height information by Google Earth Application Programming Interface (API). An archetype library is developed for the estimation of buildings’ non-geometrical properties. Buildings are classified based on usage type and age obtained from city shapefile datasets. The geometrical and non-geometrical datasets are joined using the QGIS tool and Mapbox platform.
To use local microclimate data for buildings’ energy performance, CityBEM is integrated with different microclimate simulation tools. First, CityBEM is fully integrated with the CityFFD tool to model the two-way interaction between buildings and microclimate. In the second method, a multi-scale urban climate and buildings energy simulation tool is developed by one-way integration of CityBEM with 3D Global Environmental Multiscale Model (GEM) and Surface Prediction System (SPS) developed by Environment and Climate Change Canada (ECCC). The one-way multi-scale model cannot capture the impact of CityBEM on the atmospheric fields; therefore, to model this impact, the CityBEM is added as a new module to the SPS model. SPS includes a Town Energy Balance (TEB) scheme for modeling the urban surface. In this thesis, CityBEM is added to the TEB for modeling the buildings. Using the developed TEB-CityBEM model in GEM simulations, near-surface forecasting accuracy can be improved, and buildings’ energy simulation is added as a new feature to the GEM model. The multi-scale model can be used to study different mitigation strategies such as retrofitting existing buildings, modeling natural ventilation and its impact on reducing energy consumption, model new technologies to reduce energy consumption, etc. The TEB-CityBEM model can also be added to the air quality model of ECCC called GEM-MACH to study the impact of urban building modeling on air quality in urban areas.
Finally, due to the importance of aerosol transmission of covid-19 in indoor spaces, it is essential to develop a model to study the impact of different mitigation strategies on reducing the risk of infection in the rooms and their corresponding energy consumption effects. In this thesis, a city-scale model (CityRPI) is developed to estimate airborne transmission of COVID-19 in indoor spaces. The CityRPI model is integrated with the CityBEM. The integrated model is applied to Montreal, and the impact of mitigation strategies on the infection risk and energy consumption is studied for different types of buildings.