Hua Ge

Concordia University · Department of Building, Civil and Environmental Engineering

Resilience has been used as a building performance metric that measures the building’s capability of absorption, response, and recovery from one or a series of disruptive events, e.g., extreme weather events or power outage events. With respect to resilience, in relation to the moisture performance of the building envelope (moisture resilience), th...

This review paper provides a comprehensive overview of hygrothermal modeling with a focus on its application in mass timber construction, a sustainable and innovative construction approach. The first part of the review investigates the recent advancements in modeling heat and moisture transfer in wood-based materials, focusing on the key factors th...

We present unprecedented datasets of current and future projected weather files for building simulations in 15 major cities distributed across 10 climate zones worldwide. The datasets include ambient air temperature, relative humidity, atmospheric pressure, direct and diffuse solar irradiance, and wind speed at hourly resolution, which are essentia...

We present unprecedented datasets of current and future projected weather files for building simulations in 15 major cities distributed across 10 climate zones worldwide. The datasets include ambient air temperature, relative humidity, atmospheric pressure, direct and diffuse solar irradiance, and wind speed at hourly resolution, which are essentia...

This paper investigates the impact of energy retrofits on life cycle greenhouse gas (GHG) emissions across different electricity grid profiles in Montreal, Ottawa, and Halifax, using an existing school building as a case study. Using DesignBuilder for energy simulations and OneClick LCA for GHG emissions estimation, this study evaluates whether the...

This IEA Annex 80 Subtask C report and the associated brochures provide examples of well-documented field studies. These field studies apply resilient cooling technologies to reduce energy demand and carbon emissions for cooling and reduce the overheating risk in different types of buildings, including newly constructed and existing buildings. Exam...

Wind-Driven Rain (WDR) loading on building facades is a crucial factor for designing sustainable and climateresilient buildings and preserving historical buildings. WDR loading on buildings has been studied previously but results for such a multi-parameter problem are not generally conclusive. Thus, the relevant provisions of ISO semi-empirical mod...

The use of heat recovery ventilators (HRVs) in cold climate housing is becoming increasingly common, to provide outside air to the occupied space while recovering heat from the exhausted air. However, frosting of the heat exchanger core impedes HRV operation in cold climate conditions. Strategies for defrosting the core include recirculating the ex...

The study of Wind-Driven Rain (WDR) loading on building facades is essential to design more sustainable and climate-resilient buildings, as well as to prevent further damage to old and historical buildings. Both WDR loading on buildings and façade responses to impinging raindrops have been studied previously but results for such a multi-parameter p...

The Urban Heat Island (UHI), a consequence of urban development, leads to elevated temperatures within cities compared to their rural counterparts. This phenomenon results from factors such as urban designs, anthropogenic heat emissions, and materials that absorb and retain solar radiation in the built environment. Materials commonly used in cities...

This contribution presents temperature and relative humidity data monitored over nearly two years for a case study building made of natural building materials. The case study building is a single-family house located in Denmark made of wood fiber insulation, wood fiber boards and indoor clay plaster without any membranes. Three different types of c...

For an efficient moisture performance analysis of walls, the selection of wall orientation for undertaking the hygrothermal simulations plays an important role. The wall orientation receiving the highest amount of annual wind-driven rain (WDR) and the one receiving the least annual solar radiation is that which is recommended in ASHRAE 160. There a...

This study explores the spatial variability of the thermal responses of older occupants’ in indoor environments at various locations in Montreal, Canada. Urban climate in and around the city over an extreme heat event in 2018 is simulated at 1 km spatial resolution using Weather Research and Forecasting (WRF) model, and data for 29 long-term care b...

Saturation water content and liquid diffusivity are two important parameters that influence hygrothermal simulation results, particularly when investigating the performance of wood-frame walls subjected to rainwater penetration. In this paper, the impact of saturation water content (free water saturation and effective saturation) of OSB in a wood-f...

There is no clear indication of critical moisture conditions for cross-laminated timber (CLT) envelopes exist regarding moisture content. Therefore, our main objective in this study was to set hygrothermal criteria for the design of CLT external walls in terms of moisture conditions. The focus is on five different types of CLT external walls that d...

Building integrated photovoltaic (BIPV) systems are being developed for exterior wall construction, but the effect of BIPV as a replacement for conventional cladding on durability must be considered. This study compares the hygrothermal performance of a low-rise residential wood-frame wall with different options for exterior cladding. These options...

The objective of this research is to investigate the effects of different bias correction (BC) methods applied to climate data used to assess the hygrothermal performance on building envelopes based on simulations. To this end, a univariate and two multivariate distribution based bias correction methods were used to prepare weather files to assess...

In this study, a comparison is made of overheating in multiple field-monitored buildings using several different overheating indices, including dry-bulb temperature, the heat index (HI), humidex (H), standard effective temperature (SET), wet-bulb globe temperature (WBGT), discomfort index (DI), and summer simmer index (SSI). The field monitoring wa...

Defining and quantifying building thermal resilience is important given that this helps determine the capability of a building system to tolerate disturbances from exposure to extreme heat events, and from which to compare different retrofit strategies to enhance the robustness of a building system to such events, and as well, to estimate the rapid...

Wind-driven rain (WDR) causes negative consequences such as degradation of surface material, frost damage, salt efflorescence, structural cracking, interior damage, etc. WDR has been studied extensively through experimental measurements, numerical simulations, and semi-empirical methods. The previous WDR studies, can be categorized into two areas:...

Numerous studies have been conducted on the retrofitting of brick masonry walls with thermal insulation. However, these studies did not explore the concurrent aspects of increasing internal insulation, wind-driven rain levels, brick durability, and varying brick properties. This work therefore investigates the impact of adding thermal insulation on...

Waste management systems have always been considered complex. Scholars have studied waste management mostly from a macro perspective for a long time, considering waste management policies as a fraction of this complex system. This study presents the causal variables and feedback relationships related to waste management from another perspective, fr...

In the extreme cold of the Arctic, ERV effectiveness is reduced due to core frosting. This simulation study investigates the performance of an open loop air-based building integrated photovoltaic/thermal collector (BIPV/T) designed to preheat ERV supply air and to generate electricity. A finite difference model of the BIPV/T system was simulated, u...

To design more climate-resilient buildings and to prevent deterioration of historical buildings, Wind-Driven Rain (WDR) loading on facades must be studied. Among the three methods (experimental, CFD, and semi-empirical) of investigating WDR loading on buildings, several sources of errors have been identified using relevant provisions of ISO semi-em...

Many countries across the globe have set targets for different economic sectors, aiming to tackle global warming by reducing the overall carbon footprint of human-related activities. Among these sectors, the building industry stands out as a major consumer of materials and energy resources, making it a key player in achieving carbon neutrality. It...

The study of Wind-Driven Rain (WDR) loading on building facades is essential to design more sustainable and climate-resilient buildings, as well as to prevent further damage to old and historical buildings. Both WDR loading on buildings and façade responses to impinging raindrops have been studied previously but results for such a multi-parameter p...

This paper aims to develop long-term adaptation strategies for the existing Canadian school buildings under extreme current and future climates using a developed methodology based on global and local sensitivity analysis and Multi-Objective Optimization Genetic Algorithm. The calibrated simulation model based on indoor and outdoor measured temperat...

The building sector is responsible for nearly 40% of the total global direct and indirect CO2 emissions. Urban green infrastructure, which includes features such as urban trees, vegetation, green roofs, and green facades, are examples of nature-based solutions often employed as municipal climate mitigation and adaptation strategies. This approach o...

Reducing energy consumption and Greenhouse Gas (GHG) emissions is an essential part of the clean growth and climate change framework recently developed by the Canadian government, which emphasizes the importance of energy-efficient building constructions. In this paper, the effects of thermal mass and placement of the thermally massive layer within...

Cross-laminated timber (CLT) is one of the most important mass timber materials that are commonly used in mid-rise or even high-rise timber buildings. However, exposure to moisture during construction may increase the moisture damage risks, and impact the durability performance of CLT buildings. To investigate potential solutions for avoiding wetti...

In response to Canada’s commitment to reducing greenhouse gas emissions and to making pathways to achieve carbon neutral buildings, this paper presents two real case studies. The paper first outlines the potential of trees to absorb CO2 emissions through photosynthesis, and the methods used for the estimation of their annual carbon sequestration ra...

Canadian buildings have been primarily designed to withstand cold and long winters, not hot summers. With climate change and the increase in the intensity and severity of heatwaves, it has become important to investigate overheating in buildings. However, there are limited studies on assessing and mitigating the overheating risk in existing buildin...

In the past few years, significant efforts have been made to investigate the transmission of COVID-19. This paper provides a review of the COVID-19 airborne transmission modeling and mitigation strategies. The simulation models here are classified into airborne transmission infectious risk models and numerical approaches for spatiotemporal airborne...

Existing data quality criteria often focus on the quality of the data itself while overlooking other aspects such as the relevance between data and downstream tasks. Furthermore, prior to data collection, policy-makers lack ground truths or labelled data, and are unable to filter data using quantitative criteria. To ensure the collection of reliabl...

In terms of hygrothermal performance, solid wood panels composed of cross-laminated timber (CLT) are sensitive to moisture. However, to the best of our knowledge, no clear indications of critical initial moisture conditions for CLT envelopes regarding the dry-out of built-in moisture have been provided. Therefore, our main objective was to set crit...

With the rapid development of nearly zero-energy buildings, the establishment of a nearly zero-energy community composed of concentrated and contiguous nearly zero-energy buildings constitutes the future architectural trend. However, configuration and optimization research of distributed energy systems combining multiple energy storages (DES-MESs)...

Numerous studies have been conducted on the retrofitting of brick masonry walls with thermal insulation. However, these studies did not explore the concurrent aspects of increasing internal insulation, wind-driven rain levels, brick durability, and varying brick properties. This work therefore investigates the impact of adding thermal insulation on...

In this study, a comparison is made of overheating in multiple field-monitored buildings using several different overheating indices, including dry-bulb temperature, the heat index (HI), humidex (H), standard effective temperature (SET), wet-bulb globe temperature (WBGT), discomfort index (DI), and summer simmer index (SSI). The field monitoring wa...

The objective of this research is to investigate the effects of different bias correction (BC) methods applied to climate data used to assess the hygrothermal performance on building envelopes based on simulations. To this end, a univariate and two multivariate distribution based bias correction methods were used to prepare weather files to assess...

The objective of this study was to develop a prediction model for predicting the mould growth risk in wood-frame walls. A machine learning algorithm, the Partial Least Squares (PLS) regression was used for developing the model. Hygrothermal simulations were performed for a wood-frame wall with brick cladding using hourly historical and projected fu...

Wind-driven rain (WDR) causes negative consequences such as degradation of surface material, frost damage, salt efflorescence, structural cracking, interior damage, etc. WDR has been studied extensively through experimental measurements, numerical simulations, and semi-empirical methods. The previous WDR studies, can be categorized into two areas:...

This study explores the spatial variability of the thermal responses of older occupants' in indoor environments at various locations in Montreal, Canada. Urban climate in and around the city over an extreme heat event in 2018 is simulated at 1 km spatial resolution using Weather Research and Forecasting (WRF) model, and data for 29 long-term care b...

Defining and quantifying building thermal resilience is important given that this helps determine the capability of a building system to tolerate disturbances from exposure to extreme heat events, and from which to compare different retrofit strategies to enhance the robustness of a building system to such events, and as well, to estimate the rapid...

For an efficient moisture performance analysis of walls, the selection of wall orientation for undertaking the hygrothermal simulations plays an important role. The wall orientation receiving the highest amount of annual wind-driven rain (WDR) and the one receiving the least annual solar radiation is that which is recommended in ASHRAE 160. There a...

Canada is warming at double the rate of the global average caused in part to a fast-growing population and large land transformations, where urban surfaces contribute significantly to the urban heat island (UHI) phenomenon. The federal government released the strengthened climate plan in 2020, which emphasizes using nature-based solutions (NBSs) to...

To assess the impact of future climate on the hygrothermal performance of walls when considering different types of walls, geographical locations, and various climate change scenarios, a significant number of simulations will be required. To address this issue and thereby reduce the number of simulations and calculation time, regression models can...

Wind-driven rain (WDR), as one of the environmental loads, is an important factor in designing durable and climate-resilient buildings. The negative consequences of moisture intrusion caused by WDR include degradation of surface material, frost damage, salt efflorescence, structural cracking, interior damage, etc. WDR has been extensively studied t...

Contradictory findings are reported in the literature showing that high energy-efficient buildings have either higher or lower overheating risks compared to old buildings. A methodology is developed using the Global and Local Sensitivity Analysis to quantify the contribution and correlation of individual building envelope parameter to the change in...

Pulmonary rehabilitation (PR) is an essential method for Acute exacerbation in chronic obstructive pulmonary disease (AECOPD) recovery. We perform a meta-analysis to compare early PR with usual care. A literature search was performed through these databases: PubMed, MEDLINE database, Google Scholar, Cochrane, Embase from inception to July 2021. Eli...

With the increased severity, intensity, and frequency of “heatwaves” due to climate change, it has become imperative to study the overheating risks in existing buildings. To do so, a building simulation model needs to be calibrated based on measured indoor temperatures under the current weather conditions. This paper presents a robust automated met...

The present global trend towards decarbonization under the Paris Agreement encourages regions and economies to explore possible ways to reduce energy intensity and minimize emissions into the environment. The Asia-Pacific Economic Cooperation (APEC), which accounts for 60% of world energy demand, aims to reduce energy intensity by 45% from 2005 lev...

Well-designed ventilated air-spaces behind external claddings in the building envelope can potentially reduce thermal energy flow in the entire wall structure. In this study, the impact of the dynamic thermo-hydraulic behavior of the flow in the naturally ventilated cavity on the performance of lightweight and heavyweight wall assemblies with tradi...

The use of single-core energy recovery ventilator (ERV) reduces the heating energy use in northern houses, but has the disadvantage of reducing the required outdoor air supplied to the house during the defrost operation by air recirculation, which might affect the indoor air quality. A dual-core ERV also reduces the heating energy use, but in addit...

Several studies have novel distributed energy systems combining solar energy utilization and hybrid energy storage technology. However, the research on thermodynamic performance and optimization design of the novel system is still insufficient. Therefore, a novel distributed energy system uses a jacket water heat exchanger and a waste heat boiler t...

One of the parameters that influences the moisture performance of the wood framed wall assembly is the material properties of exterior cladding. The uncertainties of its properties, would result in a range of wall performance. The objective of this study was to investigate the impact of uncertainties in cladding material properties on moisture perf...

The increased requirements of buildings to reduce energy use have highlighted the importance of accounting for all factors that influence energy use in buildings. One consideration that requires further study in the envelope design of concrete-based wall assemblies is the placement of the thermal mass layer. In this study, two thermally massive wal...

Due to global climate change, the world has been experiencing significant increases in average temperatures and the frequency and intensity of extreme weather events such as heatwaves. The overheating problem in indoor spaces of buildings has become a concern to the comfort and health of building occupants, especially vulnerable populations such as...

This study aims to investigate the performance of an open loop air-based building integrated photovoltaic/thermal collector (BIPV/T) to preheat Energy Recovery Ventilator (ERV) supply air and to generate electrical energy. ERVs have proven successful in cold climates, but in the extreme cold of the arctic frequent frosting and defrosting cycles red...

Hygrothermal simulations can be used as a reliable tool in analysing moisture performance. For an efficient analysis, it is important to appropriately select the wall orientation in the simulations. ASHRAE 160 recommends to using orientation with highest amount of annual wind-driven rain (WDR) and the orientation with the least annual solar radiati...

This paper evaluates the reliability of the currently used climate-based indices in selecting a moisture reference year (MRY) for the freeze-thaw (FT) damage risk assessment of internally insulated solid brick walls. The evaluation methodology compares the ranking of the years determined by the climate-based indices and response-based indices from...

As sustainability becomes increasingly important, product design is taking a proactive role in producing products that are both useful and sustainable. This paper introduces and discusses a tool named Environment-based life cycle decomposition (eLCD) to adapt the Environment-based Design (EBD) methodology to sustainable design. The eLCD brings to E...

Hygrothermal simulations can be used to evaluate the hygrothermal response of building envelope to the effect of climate change. However, to account for the uncertainty in projected future climates, a large number of simulations are required. To reduce computational time, hygrothermal performance of walls is typically evaluated using Moisture Refer...

As the urban population grows and the global economy develops, municipal solid waste management (MSWM) has become an increasingly prominent global issue. MSWM is particularly difficult in developing countries due to its high cost and time-consuming nature. The Environment-based design (EBD) can potentially contribute to global MSWM by reducing cost...

Coupling electric vehicles (EV) and hybrid energy storage (HES) with the distributed energy system (DES) can improve energy-saving and emission reduction efficiency and reduce system investment operating costs. However, the system modeling, optimization design, application site, and comprehensive performance analysis of the novel DES need to be fur...

The application of hybrid energy storage to distributed energy systems can significantly improve energy efficiency and reduce the investment operating cost of the system. However, inadequate efforts are found focusing on the investigation of the integration of the two systems and optimization configuration and operation strategy of systems. Therefo...

Currently, many scholars have researched distributed energy systems (DES) from different dimensions. However, the load forecasting on both source-side and load-side, the optimal design of DES, and the multi-attribute decision making need further research. Therefore, a novel DES combining solar photovoltaic and hybrid energy storage is proposed. Com...