Research
In this page you can see my researches in the field of IEQ, energy efficiency, occupant behavior, and green building certificates.
Investigation of Heating Energy Performance Gap (EPG) in design and operation stages of residential buildings
Energy & Buildings journal, 2023, DOI: 10.1016/j.enbuild.2023.113747
The Energy Performance Gap (EPG) in buildings is a recognized phenomenon. However, its definition and underlying factors are extensive, necessitating a thorough investigation of the quantitative impact of each factor contributing to the EPG. In this research, a calibration-based approach is employed to identify and measure the contribution of these factors. Questionnaires, measurements, analyses, and calibrations are conducted on the energy performance of four residential units of an apartment block building in Iran as a case study. Subsequently, the impact rates of three key causes of the EPG, namely heating system efficiency, weather data in an EnergyPlus Weather (EPW) format file, and occupant behavior, are determined. By incorporating these causes into the model calibration process, the disparities between the design and operation stages are decreased. The study highlights the significance and quantifiable effects of accurate and measured boiler efficiency, utilizing a genuine EPW file rather than a convenient EPW file e.g., airport stations, and adopting precise and adaptable assumptions for occupant behavior modeling in bridging the EPG between the design and operation stages. There are a number of factors that impact the design stage gap, including boiler efficiency, occupant behavior, and a corrected EPW file, which contribute 43.9%, 26%, and 6.6%, respectively.
Assessing strategies for retrofitting cooling systems in historical buildings
Energy reports journal, 2024, DOI: 10.1016/j.egyr.2024.01.017
Historical buildings, such as the museum constructed in 1933 which is the focus of this study, often face challenges in maintaining thermal comfort due to aging air conditioning (AC) systems and changing environmental conditions. This study presents a building information modeling (BIM) framework for generating a building energy model (BEM) to evaluate different AC retrofitting strategies while preserving the building’s historical features. The study acknowledges the potential impact of climate change and urban heat islands on historical buildings but does not directly analyze these factors. Instead, it focuses on the deterioration of AC system components, which can lead to a decline in system efficiency and thermal comfort. This deterioration is treated as a maintenance issue, with the understanding that system operation can be restored through component repair or replacement. The decision-making matrix used in this study compared various AC options, with the variable refrigerant flow (VRF) system emerging as the preferred choice. This retrofitting strategy led to a significant improvement in the predicted mean vote (PMV) index of thermal comfort, reducing the average PMV index for the whole building during the cooling period by up to 31%. This study contributes to the body of knowledge by providing a detailed outline of the process of restoring an HVAC system in a historical building. The findings can be beneficial to designers and engineers involved in historical building restoration, offering a unique perspective on the use of BIM-based BEM in this context.
Review of energy performance gap and solutions in residential buildings
IOP Conference Series: Earth and Environmental Science, 2022, DOI: 10.1088/1755-1315/1085/1/012013.
The energy consumption in the world due to economic development, rising population, and technological developments is growing, which has led to an increase in global warming. Therefore, there is a strong need to develop new strategies to reduce energy consumption. Buildings account for about 40% of global energy consumption. Since occupancy time in residential buildings is longer than in commercial and office buildings, residential buildings have a more significant impact on energy consumption. Due to this issue, efforts are being made to optimize energy consumption in residential buildings. Evaluating the performance of a building through building certificates that include as-designed and in-operation is essential for improving energy efficiency. Building energy simulations must be performed before construction to ensure that energy consumption in buildings is acceptable. However, it is observed that the energy consumption of the building after construction is higher than what was designed. This difference is defined as the energy performance gap, which indicates extra energy consumption or failure to comply with energy standards in the operation of the building. There are several reasons for the increased energy consumption of an operating building compared to the designed model. So far, studies have been conducted to determine the factors affecting the energy performance gap, but it is necessary to analyze these studies comprehensively. This article investigates the causes of energy performance gaps and ways to reduce this difference through a comprehensive literature review study. In this way, it is possible to achieve solutions in the building certification criteria that minimize the difference in energy consumption between the as-designed model and the in-operation mode of the building. This article can help decision-makers select the certificate that best fits their purposes.
Investigating different approaches for quantifying the energy performance gap between the design and operation phases
Master thesis – 2022
In all societies today, energy is considered one of the most important issues. The energy sector is responsible for nearly three-quarters of greenhouse gas emissions, which have increased the average global temperature by 1.1 °C compared to pre-industrial levels. Among the various strategies available, the building sector has the greatest potential to reduce carbon emissions. By considering the different industrial and regional structures of the countries in the world, the best criteria for determining the quality of buildings is scoring based on the principles of the global standards of green architecture and also register in building certificates. Evaluating the performance of a building through building certificates which include design and operation stages helps to improve energy efficiency. Designers simulate the design before construction to ensure the reduction of energy consumption in the building. However, it can be seen that the energy consumption of the building after construction and operation is more than the amount obtained in the design stage. This difference is referred to as the energy performance gap. Due to the increase in greenhouse gas emissions and global warming, increasing the stability of buildings has become particularly important. Related criteria, certificates and standards can be used to reach sustainable buildings and reduce the energy performance gap. For this purpose, LEED and Building EQ certificates and topic 19 of Iran’s national regulations are used in this thesis. The ranks of the design and operation stages of four case studies are calculated based on the mentioned certificates. Then the reasons that have led to the energy performance gap in the design stage and the operation stage according to each certificate and also effective solutions to reduce this gap are provided. The rating of the design stage is based on the simulations according to the certificates and the rating of the operation stage is based on the actual consumption according to the bills. Also, the accuracy of the simulations has been checked by conducting a questionnaire from the residents and simulating according to the questionnaire. The investigations showed that the inaccuracy in the residents’ operation schedule in the certificates, the inaccuracy of the weather file, the incompatibility of the power and performance of the electrical equipment with the catalogs and the difference in the cooling and heating set points in the residents’ feelings leads to differences in the results of the simulations compared to the reality. Also, in the operation stage, the residents’ lack of knowledge about how to use energy optimally leads to a gap in the energy consumption of the operation stage compared to the design stage. Finally, according to the reasons obtained that lead to the creation of the energy performance gap in the design and operation stages in accordance with the certificates, solutions have been provided for the certificates and residents in order to reduce the energy performance gap.
Dimensions of historical urban walls of Iran
Co-author, Elmo Danesh publication, Book, 2020. [In the Persian Language]
Urban walls are one of the most important physical components of the urban landscape, which is in a significant relationship with the observers, so if these surfaces have features in harmony with the environment and substrate, they will have visual values. One of the very important elements that determine the quality of urban spaces is its landscape and especially urban walls, which is directly affected by the physical quality of the facade of the buildings that make up the walls.
Investigating the effect of implementation potentials of BIM technology on improving the performance of cultural heritage documentation
The 8th National Conference on Civil Engineering, Architecture and Urban Development, November 2019. [In the Persian Language]
Today, due to human and natural factors, the rate of destruction of cultural heritage is more than it is possible to document all of them. Also, documenting is a time-consuming process. Advances in computer science have helped human society to advance science and speed things up. Building Information Modeling (BIM) technology, due to the provision of rich information for building components, leads to optimal decision-making to repair and improve the building and reduce the time and cost of repair and improvement. It explains how computer science in the field of building information modeling (BIM) helps documenting cultural heritage. This method is known as historical building information modeling (HBIM). The above method has made significant progress in the field of documenting cultural heritage.