Papers by Mehdi Amirkhani
Land, 2023
Spatial evaluation of urban environment quality (UEQ) is a key prerequisite in urban planning and... more Spatial evaluation of urban environment quality (UEQ) is a key prerequisite in urban planning and development. The main goal of this study is to present a scenario-based spatial multi-criteria decision-making system for evaluating UEQ. Therefore, stakeholder involvement was conducted and eight environmental criteria and six spatial-functional criteria were identified for five districts of Tehran. The weight of the effective criteria was calculated using the analytic hierarchy process (AHP) model. Then, the ordered weighted averaging (OWA) model was used to prepare UEQ maps in different scenarios, including very pessimistic, pessimistic, intermediate, optimistic, and very optimistic. Finally, the spatial distribution of the district population in different classes of UEQ was evaluated. Among the spatial-functional and environmental criteria, the sub-criteria of population density and air pollution, respectively, had the greatest impact on UEQ. In very pessimistic, intermediate, optimistic, and very optimistic scenarios, approximately 76.7, 51.8, 36.4, 23.7, and 9.8 km2 of the studied area had unsuitable UEQ conditions, respectively. In the very pessimistic scenario, about 37,000 and 1,500,000 people lived in areas with suitable and unsuitable UEQ conditions, respectively. In the very optimistic scenario, the population increased to over 917,000 in areas with suitable UEQ and decreased to 336,000 in those with unsuitable UEQ conditions in terms of both environmental and spatial-functional criteria. The research results showed that a high percentage of the population in the study area live under unsuitable UEQ conditions, which indicates the need for attention to improving the current UEQ conditions. The proposed approach is timely to gain a better understanding of the adverse impact of climate change on human well-being in marginal societies and how climate-resilient urban planning can play a significant role.
MDPI, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Energies, 2022
In order to achieve Australia’s greenhouse gas emissions reduction targets, a majority of the exi... more In order to achieve Australia’s greenhouse gas emissions reduction targets, a majority of the existing residential building stock in Australia will require retrofitting in favour of energy-efficient solutions. This paper considers retrofitting for conditioning to be one of the most straightforward and offers the greatest potential to deliver significant comfort and energy-saving results. Radiant conditioning systems are not new, yet some game-changing innovations have taken place over the last decade that may require an entire paradigm shift in the manner we condition our buildings. The reiteration of the principle ‘thermally active systems’ suggests that our buildings need to accommodate these systems into the fabric of building components. However, extremely few products and/or innovative solutions for doing such seem to be provided by the industry. We seem incompetent with solutions that are not costing the Earth, insulating, lightweight, and offering an instant response time to conditioning. We still have the concept embedded in our minds that radiative systems consist of heavy ‘combat’ construction with time lags of a day or two and that they are very costly to implement, especially if we are to retrofit a project. The purpose of this paper is to rectify and change our understanding of radiant systems, namely through a review of the existing technology and its recent advancements. It intends to introduce the fact that radiant systems can become highly reactive, responsive, and thermally dynamic conditioning systems. Lightweight radiant systems can be 40% more energy-efficient than common air conditioners and can respond in less than 15 min rather than in the hours required of heavy radiant systems. Thus, an insulated, lightweight radiant system is ideal for retrofitting residential buildings. Furthermore, this paper supports and introduces various systems suited to retrofitting a residential building with hydronic radiant systems.
Energies, 2021
The world is looking to reduce carbon emissions, prevent global warming, and become more energy s... more The world is looking to reduce carbon emissions, prevent global warming, and become more energy sustainable. Despite the various strategies for mitigating climate change, the fact remains that 80% of greenhouse gas emissions are attributable to activities associated with the built environment, and this is where a concentrated focus is needed. Moreover, most buildings are residential, not commercial or industrial. In essence, ways must be found to reduce energy consumption and CO2 emissions from existing houses and apartments globally if sustainability is to be realised. The recognised way to achieve this is through the retrofitting of existing residential buildings. Studies in this area have increased in recent times, but the extent of the work remains unmapped and undescribed. If further progress is to be made in this field, researchers' knowledge domain so far must be documented. This literature review delivers that goal. A scientometric evaluation of research on residential retrofitting is here presented. VOSviewer, Gephi, and CiteSpace are the software packages used. Findings identify retrofitting as an emerging theme, taking off only as recently as 2017. The breadth of research is very limited, primarily concerned with calibrating trade-offs between energy costs and thermal comfort. Emerging and new opportunities to expand retrofitting research are identified. Finally, while several journals accommodate publications on this topic, analysis reveals Energy and Buildings to be the significant citation source.
Buildings, 2021
Heat Pumps are becoming one of the most considered mechanical conditioning equipment in our build... more Heat Pumps are becoming one of the most considered mechanical conditioning equipment in our buildings. While they are popular, there appears to be quite a vast range of system types and applications in building conditioning. This paper primarily reviews the literature on heat pumps, the various types, and the consideration of design end uses. The fact that there are different energy sources for heat pumps is considered, as well as the different sinks in which energy is stored or dissipated. It is evident that advanced heat pump systems cater well to the use of renewable energy resources. Therefore, in the move towards net-zero energy building operation, the correct selection of a heat pump can help to increase self-consumption of solar PV generation and even make use of direct solar energy heating. This paper reviews the technologies for heat pump selection, application, and design for residential buildings.
Encyclopedia , 2021
Definition: Green buildings refer to buildings that decrease adverse environmental effects and ma... more Definition: Green buildings refer to buildings that decrease adverse environmental effects and maintain natural resources. They can diminish energy consumption, greenhouse gas emissions, the usage of non-renewable materials, water consumption, and waste generation while improving occupants’ health and well-being. As such, several rating tools and benchmarks have been de-veloped worldwide to assess green building performance (GBP), including the Building Research Establishment Environmental Assessment Method (BREEAM) in the United Kingdom, German Sustainable Building Council (DGNB), Leadership in Energy and Environmental Design (LEED) in the United States and Canada, Comprehensive Assessment System for Built Environment Effi-ciency (CASBEE) in Japan, Green Star in Australia, Green Mark in Singapore, and Green Building Index in Malaysia. Energy management (EM) during building operation could also improve GBP. One of the best approaches to evaluating the impact of EM on GBP is by using structural equation modelling (SEM). SEM is a commanding statistical method to model testing. One of the most used SEM variance-based approaches is partial least squares (PLS), which can be implemented in the SmartPLS application. PLS-SEM uses path coefficients to determine the strength and significance of the hypothesised relationships between the latent constructs.
Energy & Buildings, 2018
Novel lighting strategies have the potential to create luminous environments that are more satisf... more Novel lighting strategies have the potential to create luminous environments that are more satisfactory to building occupants and reduce occupants' interventions in lighting conditions. Testing innovative design systems in the immersive virtual reality (IVR) environment could be a useful approach to investigate these systems quickly and easily. This paper explores how increasing the luminance of areas surrounding the window using an electric wall-washing system could improve subjective rated contrast (RC) scores on the windowed wall, as well as reducing negative lighting interventions in an IVR office room with different window-to-exterior-wall ratios. The results indicate that participants report greater lighting contrast between the window and its surroundings in the room with a 15% window-to-exterior-wall ratio (WWR) compared with other lighting conditions. The findings of this research also show that the proposed electric wall-washing system with a low power level could significantly reduce the likelihood of users' propensity to intervene in lighting conditions in rooms with different window sizes.
Energies, Aug 1, 2017
A high luminance contrast between windows and surrounding surfaces can increase the risk of disco... more A high luminance contrast between windows and surrounding surfaces can increase the risk of discomfort glare, which can diminish office workers' satisfaction and productivity. Accordingly, it can lead to occupant interventions, such as drawing window blinds or increasing electric light levels, which are intended to enhance indoor visual comfort but counterproductively act to increase energy consumption. Increasing the luminance of the areas surrounding the windows using a supplementary lighting system, such as wall-washing with light emitting diode (LED) linear luminaires, could reduce discomfort glare arising from windowed walls. This paper reports on the results of a study in a typical office room in Brisbane, Australia. The outcomes of this study indicate that creating a luminance contrast of between 11:1 and 12:1 on the window wall in an office room with a 45% window-to-exterior-wall ratio using a supplementary LED system leads to improved subjective assessments of window appearance. The results suggest that such an enhancement could significantly reduce discomfort glare from windows, as well as diminishing the likelihood of the users intending to turn on the ceiling lights or to move the blinds.
CIE x042:2016, Mar 5, 2016
High luminance contrast between windows and surrounding surfaces could cause discomfort glare, wh... more High luminance contrast between windows and surrounding surfaces could cause discomfort glare, which could reduce office workers' productivity. It might also increase energy usage of buildings due to occupants' interventions in lighting conditions to improve indoor visual quality. It is presumed that increasing the luminance of the areas surrounding the windows using a supplementary system, such Light Emitting Diodes (LEDs), could reduce discomfort glare. This paper reports on the results of a pilot study in a conventional office in Brisbane, Australia. The outcomes of this study indicated that a supplementary LED system could reduce the luminance contrast on the window wall from values in the order of 24:1 to 12:1. The results suggest that this reduction could significantly reduce discomfort glare from windows, as well as diminishing the likelihood of users' intention to turn on the ceiling lights and/ or to move the blind down.
Living and Learning: Research for a Better Built Environment, 49th International Conference of the Architectural Science Association, 2015
High contrast ratios between windows and surrounding surfaces could cause reduced visibility
or d... more High contrast ratios between windows and surrounding surfaces could cause reduced visibility
or discomfort for occupants. Consequently, building users may choose to intervene in lighting conditions
through closing blinds and turning on the lamps in order to enhance indoor visual comfort. Such
interventions increase projected electric lighting use in buildings. One simple method to prevent these
problematic issues is increasing the luminance of the areas surrounding to the bright surface of windows
through the use of energy-efficient supplementary lighting, such Light Emitting Diodes (LEDs). This paper
reports on the results of a pilot study in conventional office in Brisbane, Australia. The outcomes of this
study indicated that a supplementary LED system of approximately 18 W could reduce the luminance
contrast on the window wall from values in the order of 117:1 to 33:1. In addition, the results of this
experiment suggested that this supplementary strategy could increase the subjective scale appraisal of
window appearance by approximately 33%, as well as reducing the likelihood of users’ intention to turn
on the ceiling lights by about 27%. It could also diminish the likelihood of occupants’ intention to move
the blind down by more than 90%.
IASDR 2015 Doctoral Colloquium Conference, 2015
A high contrast ratio between windows and surrounding walls may lead to office workers visual dis... more A high contrast ratio between windows and surrounding walls may lead to office workers visual discomfort that could negatively affect their satisfaction and productivity. Consequently, occupants may try to adapt their working environment by closing blinds and/ or turning on the lights to enhance indoor visual comfort, which can reduce predicted energy savings. The hypothesis of this study is that reducing luminance contrast ratio on the window wall will improve window appearance which potentially will reduce visual discomfort and decrease workers interventions. Thus, this PhD research proposes a simple strategy to diminish the luminance contrast on the window wall by increasing the luminance of the areas surrounding the windows using supplementary light emitting diode (LED) systems. To test the hypothesis, this investigation will involve three experiments in different office layouts with various window types and orientations in Brisbane, Australia. It will assess user preferences for different luminance patterns in windowed offices featuring flexible, low-power LED lighting installations that allows multiple lighting design options on the window wall. Detailed luminance and illuminance measures will be used to match quantitative lighting design assessment to user preferences.
Proceedings of the Asia-Pacific Lighting Systems Workshop 2015, May 2015
Vertical windows are the most common and simplest method to introduce daylight to interior spaces... more Vertical windows are the most common and simplest method to introduce daylight to interior spaces of office buildings, while also providing a view and connection to the outside. However, high contrast ratios between windows and surrounding surfaces can cause visual discomfort for occupants and can negatively influence their health and productivity. Consequently, building occupants may try to adapt their working environment through closing blinds and turning on lights in order to improve indoor visual comfort. Such interventions defeat the purpose of daylight harvesting systems and can increase the forecast electric lighting consumption in buildings that include such systems. A simple strategy to prevent these problematic consequences is to reduce the luminance contrasts presented by the window wall by increasing the luminance of areas surrounding the window through the sparing use of energy-efficient supplementary lighting, such light emitting diodes (LEDs). This paper presents the result of a pilot study in typical office in Brisbane, Australia that tests the effectiveness of a supplementary LED lighting system. The study shows an improvement in the appraisal of the visual environment is achieved using the supplementary system, along with up to 88% reductions in luminance contrast at the window wall. Also observed is a 36% reduction in the likelihood of user interventions that would increase energy usage. These results are used as the basis of an annual energy simulation of the test office and indicate that supplementary systems could be used to save energy beyond what is typically realised in side lit office spaces.
This article has attempted to investigate the patterns of traditional architecture in Iran's warm... more This article has attempted to investigate the patterns of traditional architecture in Iran's warm and dry climate and whether these patterns have been attended to in Iran's contemporary architecture or not. Since the two elements of culture and climate are much significant in Iran's traditional constructions, this article aimed at dealing with subjects such as the causes of the shapes of traditional buildings in Iran's warm and dry climate in constructions like houses, schools, mosques and bazaars, and why they were constructed in those shapes, and also considering their patterns in these places in the light of cultural and climatic aspects, and their cultural and climatic relationships and investigating cultural-climatic causes of the directions and situations designed for the spaces present in these buildings and finally it is intended to classify the conceptual patterns of the traditional architecture of Iran's warm and dry climate. The article is going to consider the amount of using these patterns in Iran's contemporary architecture. The study has been conducted using library and field method.
Books by Mehdi Amirkhani
MDPI, 2023
Homes need to be mass-customised to accommodate today’s diverse needs and demands of individuals ... more Homes need to be mass-customised to accommodate today’s diverse needs and demands of individuals and societies for humans’ sound living conditions and activities. Social justice and climatic change within built environments in global contexts are a significant part of Zero Energy Mass Custom Home (ZEMCH) R&D action. Due to growing housing needs and demands, the global market required the initiation of the ZEMCH R&D movement so as to ensure the delivery of socially, economically, environmentally, and humanely sustainable built environments to privileged and unprivileged families, communities, and nations that are sharing our common future. This book aims to encompass a wide spectrum of ZEMCH research and development knowledge that concerns design engineering, construction management, material innovation, renewable energy technology, community planning, marketing strategy, and education.
MDPI, 2022
The impact of buildings on the environment is nothing short of devastating. In recent years, much... more The impact of buildings on the environment is nothing short of devastating. In recent years, much attention has been given to creating an environmentally friendly built environment. Nonetheless, it has been levied on new buildings. Residential buildings make up at least 80% of the built environment, most of which were built before any energy efficiency guidelines or regulations were introduced. Retrofitting existing residential buildings is a key yet neglected priority in effecting the transition to an environmentally friendly, sustainable built environment. It is pivotal to reducing a building's energy consumption while simultaneously improving indoor environmental quality and minimizing harmful emissions. This Special Issue showcases studies investigating applications of environmental technology that is tailored to enhance the sustainable performance of existing residential buildings. It helps to better understand the innovations that have been taking place in retrofitting residential buildings, as well as highlighting many opportunities for future research in this field.
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Papers by Mehdi Amirkhani
or discomfort for occupants. Consequently, building users may choose to intervene in lighting conditions
through closing blinds and turning on the lamps in order to enhance indoor visual comfort. Such
interventions increase projected electric lighting use in buildings. One simple method to prevent these
problematic issues is increasing the luminance of the areas surrounding to the bright surface of windows
through the use of energy-efficient supplementary lighting, such Light Emitting Diodes (LEDs). This paper
reports on the results of a pilot study in conventional office in Brisbane, Australia. The outcomes of this
study indicated that a supplementary LED system of approximately 18 W could reduce the luminance
contrast on the window wall from values in the order of 117:1 to 33:1. In addition, the results of this
experiment suggested that this supplementary strategy could increase the subjective scale appraisal of
window appearance by approximately 33%, as well as reducing the likelihood of users’ intention to turn
on the ceiling lights by about 27%. It could also diminish the likelihood of occupants’ intention to move
the blind down by more than 90%.
Books by Mehdi Amirkhani
or discomfort for occupants. Consequently, building users may choose to intervene in lighting conditions
through closing blinds and turning on the lamps in order to enhance indoor visual comfort. Such
interventions increase projected electric lighting use in buildings. One simple method to prevent these
problematic issues is increasing the luminance of the areas surrounding to the bright surface of windows
through the use of energy-efficient supplementary lighting, such Light Emitting Diodes (LEDs). This paper
reports on the results of a pilot study in conventional office in Brisbane, Australia. The outcomes of this
study indicated that a supplementary LED system of approximately 18 W could reduce the luminance
contrast on the window wall from values in the order of 117:1 to 33:1. In addition, the results of this
experiment suggested that this supplementary strategy could increase the subjective scale appraisal of
window appearance by approximately 33%, as well as reducing the likelihood of users’ intention to turn
on the ceiling lights by about 27%. It could also diminish the likelihood of occupants’ intention to move
the blind down by more than 90%.