Xin Zhou

• Doctor of Engineering
• Southeast University

To address the limitations of current urban building energy modeling (UBEM), which often neglects moisture effects, we developed a comprehensive roadmap for modeling urban heat and moisture flows. This effort included developing an urban-scale whole-building heat and moisture transfer (HAMT) model that considers wind-driven rain, integrated with a...

Simulating and predicting urban patterns enables evidence-based decision-making for urban planners. Given limited resources, understanding how to improve urban residential quality and rationally plan the distribution of different quality levels warrants further study. Using cellular automata (CA) and agent-based modules, this study proposes a multi...

The downscaling calculation of wind environment has a significant impact on the reliability of urban microclimate simulation. The setting of boundary conditions in numerical simulation affects the accuracy of wind environment simulation. However, urban morphology is complex, and commonly used downscaling simulation methods are time-consuming and co...

Occupancy information, especially the number of occupants, can effectively guide the operation of building systems. Capturing real-time and accurate occupancy information is critical. Passive infrared (PIR) sensors and smart meters have been deployed extensively. To improve the occupancy detection accuracy, this study proposes an innovative occupan...

To address the problems associated with the accuracy of existing resistance-capacitance (RC)-based urban building energy modeling (UBEM) being low, a novel RC-based UBEM was developed. This model takes into account construction boundary heterogeneity by clustering and lumping together building construction elements with similar boundary conditions....

The appropriate design of urban ventilation corridors (VCs) can improve the urban thermal environment, thereby reducing urban energy consumption and promoting sustainable urban development. However, existing research lacks a comprehensive grasp of the characteristics of VCs from multiple dimensions and quantitative analysis of its cooling effect. W...

Building energy simulation analysis plays an important supporting role in the conservation of building energy. Since the early 1980s, researchers have focused on the development and validation of building energy modeling programs (BEMPs) and have basically formed a set of systematic validation methods for BEMPs, mainly including analytical, compara...

Energy consumption in residential buildings accounts for a large portion of global energy use. Understanding residential building load characteristics is important in both the design and technical suitability analysis of residential air conditioning systems in terms of energy efficiency and carbon reduction. However, most current research mainly fo...

Among the sufficiency, efficiency, and renewable frameworks for reducing energy use and energy-related carbon emissions, Building Energy Sufficiency (BES) is gaining attention from policy makers and engineers. Despite the significant role of the building sector in the success of national energy and climate plans, there is a lack of research on the...

Occupant control behavior is a key factor affecting the energy consumption of building air-conditioners (ACs). The operating behavior of ACs and their models in office buildings have been investigated extensively. However, although the thermal sensation of occupants is affected by their previous thermal experience, few researchers have attempted to...

Planting trees around buildings has always been used as one of the most common viable landscaping strategies in schools. However, the impact of trees on natural ventilation inside the building has been neglected without investigation. The emphasis of this study related to the impact of outdoor trees around the academic building on indoor ventilatio...

Studies have shown that urban vegetation can be an effective strategy for reducing energy consumption in urban buildings by regulating the microclimate and shading solar radiation on building surfaces. However, an understanding of the potential energy savings of vegetation morphological planning at the urban scale is still lacking, particularly reg...

To address the challenges associated with the efficiency of calculating beam shadows on building exterior surfaces in dense urban contexts being low, a novel “neighbourhood shading building surfaces” determination criterion is proposed. The criterion was applied to the beam shadow calculation methods to evaluate its effectiveness in two case studie...

In order to address the increased urban heat island (UHI) effects and energy demand caused by global urbanization, it is imperative to seek sustainable urban design solutions. It is widely acknowledged that urban green infrastructure (UGI), which includes site-scale vegetation and building-integrated vegetation, influences the energy consumption of...

Occupancy patterns are key elements in improving our understanding of building energy usage and implementing demand-oriented strategies to reduce energy consumption. Occupancy pattern is changed over time driving by multiple factors, but there are lacks of research to reveal its temporal change. We analyzed occupancy pattern of residential building...

Thermal parameters of construction assemblies, e.g., the U-values of roofs, walls, floors, ground floors, windows and the solar heat gain coefficient (SHGC) of windows, are significant inputs for urban building energy models (UBEMs). However, estimating these values at the urban scale is difficult. A common practice to handle this issue is the use...

Urban building energy modeling (UBEM) is a promising tool to evaluate building energy consumption at high temporal-spatial resolution at urban scale. However, state-of-the-art UBEMs use identical building envelope thermal transmittance according to design specifications in model characterization, which neglects the uncertainty in U-values of the bu...

This paper introduces a database of 34 field-measured building occupant behavior datasets collected from 15 countries and 39 institutions across 10 climatic zones covering various building types in both commercial and residential sectors. This is a comprehensive global database about building occupant behavior. The database includes occupancy patte...

Buildings contribute to almost 30% of total energy consumption worldwide. Developing building energy modeling programs is of great significance for lifecycle building performance assessment and optimization. Advances in novel building technologies, the requirements of high-performance computation, and the demands for multi-objective models have bro...

Urban green infrastructures (UGIs) play an essential role in reducing urban building energy consumption by cooling surrounding areas and shielding buildings from direct solar radiation heat gain. Although the energy-saving effect of UGIs is widely agreed upon, there is a lack of systematic knowledge about how UGI morphology affects urban building e...

Urban Building Energy Modeling (UBEM) is essential for urban energy-related applications. Its generation mainly requires four data inputs, including geometric data, non-geometric data, weather data, and validation and calibration data. A reliable UBEM depends on the quantity and accuracy of the data inputs. However, the lack of available data and t...

Solar hot water (SHW) systems are widely used to save energy and reduce CO2 emissions. The domestic hot water (DHW) usage behavior of occupants has a significant influence on the energy consumption of SHW systems; the operation of SHW systems also affects the DHW usage of occupants. However, there is a lack of quantitative analysis for coordinating...

As the number of high-rise buildings increases, so does the demand for meteorological data at different heights. The difference in meteorological elements in the vertical direction should be considered in heating, ventilation, and air conditioning design and building performance simulations (BPS). This study uses a meteorological tower in Beijing a...

The urban thermal and wind environment (UTWE) has become a major concern in urban planning design. Consideration of the UTWE involves steps of modelling, assessment, and improvement on multiple scales. However, the method specifications of each step on different scales are unclear, and a comprehensive review of relevant studies is thus required. On...

To improve the solution efficiency of coupled heat and moisture model for porous media, the tridiagonal matrix algorithm (TDMA) was adopted to solve the model, and the comparisons between the TDMA and the iteration method were conducted. The sensitivity analysis between the TDMA calculation error and the time increment was conducted. Based on the s...

The mountain or hill with lots of natural vegetation in a city has obvious cooling effects, so it can play a significant role in the regulation of urban microclimate and mitigation of urban heat island (UHI). In this paper, the influences of wind direction on the cooling effects of the Zijin Mountain in Nanjing were evaluated. Firstly, the land sur...

Understanding window operating behavior in offices is important in terms of its influence on reducing energy consumption and improving indoor comfort. Researchers have applied different mathematical methods to develop useful window operating behavior models, however, the applicable machine learning algorithms are still in their preliminary research...

Three dimensional (3D) geometric models of buildings are foundational for urban building energy modeling. A complete 3D geometric model contains building-relevant information like building footprint, height and Window-to-Wall Ratio (WWR). Existing methods creating these models have certain limitations, such as unavailability of Geographic Informati...

Air conditioning (AC) operating behavior has a significant influence on the energy consumption of buildings. Machine learning (ML) methods have recently been developed and have shown a high performance in predicting occupant behaviors. However, owing to a lack of comparison of different ML algorithms based on the same database and evaluation indica...

The concept of net zero energy building (NZEB) has attracted worldwide attention and has the potential to achieve significant energy and emissions reductions. Various technical strategies have been demonstrated to be able to achieve the net-zero-energy target. However, this issue becomes more complex when the economic performances of these strategi...

Data-driven green building design in BIM is challenged by the lack of a comprehensive data integration framework with the capabilities of building life-cycle performance data management and application. This paper proposes a performance integrated BIM (P-BIM) framework for building life cycle energy efficiency and environment optimization. A school...

The thermal performance of building walls could be improved by using phase change material (PCM), and there is already a lot of research about the heat transfer characteristics of PCM walls. However, the moisture transfer characteristics of PCM walls have rarely been studied. It is known that the heat transfer and the moisture transfer in the walls...

In this paper, a transient model for coupled heat and moisture transfer in building materials based on phase change criterion (PCC) was built. The PCC was introduced in both the energy conservation equation and the moisture conservation equation to simplify the model. The relations between PCC and usual material hygrothermal properties under isothe...

The heat and moisture transfer in building materials has significant effects on the energy consumption and indoor thermal comfort. In this paper, an improved heat and moisture transfer model based on temperature gradient coefficient (TGC) and phase change criterion (PCC) was built. The effects of relative humidity and temperature on liquid water co...

The morphology of urban green infrastructure (UGI) will affect the quality of urban environment and the way people perceive. The three-dimensional morphological features of UGI have been proven to be the key factors to effect urban ecological environment, which have rarely been incorporated into the UGI morphology in the previous researches. In thi...

Research on the window operating behavior of offices is of great significance for reducing building energy consumption and improving indoor comfort. The open-plan office is a common office form that involves a large number of people and a complex staff composition. The window operating behaviors in open-plan offices are also random and various. Thi...

Reliable energy and performance prediction for building design and planning is important for newly-designed or retrofitted buildings. Window operating behavior has an important influence on the ventilation and energy consumption of these buildings under different realistic scenarios. Therefore, quantitatively describing this behavior and constructi...

The number of occupants and its changing pattern over time are key information for building and urban energy simulation. However, the commonly used assumption and simplification of a fixed occupancy schedule does not reflect the complicated reality, leading to significant errors in energy simulation. Therefore, dynamic occupant density models which...

In summer, a ceiling fan has a tremendous potential to cool rooms, resulting in energy saving and a peak load reduction. During the critical peak pricing (CPP) period of the electricity, one method to attain substantial energy cost saving is to turn off the heating, ventilating and air conditioning (HVAC) system, but this may result in overheating....

The performance gap of buildings is commonly defined as the difference between the performance value predicted in the design stage and that measured in the post-occupancy stage. Knowledge about the performance gap of buildings is valuable in many aspects and thus is a research subject drawing much attention. Important questions that should be asked...

Assessing the performance of algorithms in solving building energy optimization (BEO) problems with different properties is essential for selecting appropriate algorithms to achieve the best design solution. This study begins with a classification of the properties of BEO problems from three perspectives, namely, design variables, objective functio...

Building energy optimization (BEO) is an emerging technique for achieving energy-efficient building designs. The performance of optimization algorithms is crucial for achieving effective and efficient BEO techniques. In some cases, optimization algorithms can be ineffective, which results in the failure of the BEO process to identify an optimal des...

For improving the accuracy of the effective heat capacity model and increasing the computing speed of the enthalpy model, an improved numerical model for phase change material wallboard was proposed in the research. This improved model was expected to combine the advantages of the enthalpy model and the effective heat capacity model. This improved...

Energy use in buildings has great variability. In order to design and operate low energy buildings as well as to establish building energy codes and standards and effective energy policy, it is crucial to understand and quantify key factors influencing building energy performance. This study investigates air-conditioning (AC) energy use of four off...

The melting process and the solidifying process of phase change material (PCM) are usually considered symmetrical in the traditional PCM heat transfer models, but there are inevitable calculation errors using these models. In this paper, a new heat transfer model of PCM based on the energy asymmetry was built, and it was validated by experimental d...

The phase change material (PCM) location in the building walls has great effects on the thermal performance improvement of PCM walls. In this paper, a numerical model was built to estimate the optimal PCM locations in the wall during different seasons under Nanjing (China) weather conditions. The heat flux fluctuation reduction rate was used to eva...

Two types of air conditioning (AC) systems generally exist, namely, centralized and decentralized AC systems. This study focuses on three actual engineering projects of residential communities where centralized AC systems are adopted. The applicability of centralized AC systems in residential buildings is discussed and analyzed. In addition, the ke...

Building energy efficient design optimization is an emerging technique that is increasingly being used to design buildings with better overall performance and a particular emphasis on energy efficiency. To achieve building energy efficient design optimization, algorithms are vital to generate new designs and thus drive the design optimization proce...

On-site investigations show that an asynchronous load feature would influence the operation of centralized air conditioning (AC) water systems greatly. However, the manner of defining the load feature and relating it to its influence quantitatively is still unclear. This paper quantitatively describes the asynchronous load demand feature and reveal...

District cooling systems are widely promoted in China now because of their higher coefficient of performance (COP). However, through the investigation of case studies, it was found that the energy use of these systems is usually much higher than that of decentralized systems. The increase of energy use is caused by the change of occupancy behavior...

During technical evaluations of cooling systems in residential buildings, it is necessary to consider the influence of the household air-conditioning (AC) use modes. In other words, how the occupants control the AC, for instance, when it is turned on, what the temperature setting is, and how long it is used. Field measurements and spot interviews i...

Load feature includes how load requirements distribute among different zones and how load requirements change along the time. These characteristics influence the energy consumption and efficiency of the HVAC system significantly. Traditional method can hardly describe the load feature in a clear and straightforward way. This paper examines the load...

Lighting consumes about 20% to 40% of the total electricity use in large office buildings in China. Commonly in building simulations, static time schedules for typical weekdays, weekends and holidays are assumed to represent the dynamics of lighting energy use in buildings. This approach does not address the stochastic nature of lighting energy use...

Lighting consumes about 20% to 40% of the total electricity use in large office buildings in China. Commonly in building simulations, static time schedules for typical weekdays, weekends and holidays are assumed to represent the dynamics of lighting energy use in buildings. This approach does not address the stochastic nature of lighting energy use...

Building energy modeling programs (BEMPs) are effective tools for evaluating the energy savings potential of building technologies and optimizing building design. However, large discrepancies in simulated results from different BEMPs have raised wide concern. Therefore, it is strongly needed to identify, understand, and quantify the main elements t...

Building energy modeling programs (BEMPs) are effective tools for evaluating the energy savings potential of building technologies and optimizing building design. However, large discrepancies in simulated results from different BEMPs have raised wide concern. Therefore, it is strongly needed to identify, understand, and quantify the main elements t...

Building energy simulation programs are effective tools for the evaluation of building energy saving and optimization of design. The fact that large discrepancies exist in simulated results when different BEMPs are used to model the same building has caused wide concern. Urgent research is needed to identify the main elements that contribute toward...