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Abstract Buildings in rural Central Asia have unique characteristics as they were built during the Soviet era (during 1950–1960) without any energy efficiency measures. The special and aged building stock pose a crucial challenge on energy security and energy supply. However, accurate scientific data on their energy usage is lacking, highlighting a research gap about robust and validated methodology to determine the energy use of rural Central Asian buildings. In response to this need, this research paper proposes a set of generalised residential building typologies for rural Central Asia, with a focus on Kyrgyzstan. The study combines quantitative and qualitative methods, including household surveys, energy demand modelling, EnergyPlus simulations, and result validation. It derives energy-based building typologies from construction year and building envelope characteristics. Through numerous validated simulations, it was identified that the heat demand for rural Kyrgyz houses is 3–5 times here compared to European houses (250–400 kWh/m2). The study revealed the estimated heat demand for homes in rural Kyrgyzstan, indicating a significant potential for improving building energy efficiency in the region. These results can inform specific approaches, such as building renovation plans, energy certification, and renovation strategies. Furthermore, the validated methodology introduced offers opportunities for researchers in the field of building energy efficiency and can be applied to similar regions in Central Asia with comparable building stocks and climates.

Buildings in rural Central Asia have unique characteristics as they were built during the Soviet era (during 1950–1960) without any energy efficiency measures. The special and aged building stock pose a crucial challenge on energy security and energy supply. However, accurate scientific data on their energy usage is lacking, highlighting a research gap about robust and validated methodology to determine the energy use of rural Central Asian buildings. In response to this need, this research paper proposes a set of generalised residential building typologies for rural Central Asia, with a focus on Kyrgyzstan. The study combines quantitative and qualitative methods, including household surveys, energy demand modelling, EnergyPlus simulations, and result validation. It derives energy-based building typologies from construction year and building envelope characteristics. Through numerous validated simulations, it was identified that the heat demand for rural Kyrgyz houses is 3–5 times here compared to European houses (250–400 kWh/m2). The study revealed the estimated heat demand for homes in rural Kyrgyzstan, indicating a significant potential for improving building energy efficiency in the region. These results can inform specific approaches, such as building renovation plans, energy certification, and renovation strategies. Furthermore, the validated methodology introduced offers opportunities for researchers in the field of building energy efficiency and can be applied to similar regions in Central Asia with comparable building stocks and climates.Article highlights: Novel energy-based building typologies for Kyrgyztsna, using quantitative & qualitative methods. Valuable insights from energy modelling & simulation using EnergyPlus. Significant potential for improving building energy efficiency in rural Kyrgyzstan. [ABSTRACT FROM AUTHOR]

Building retrofitting plays a critical role in achieving sustainable development and is an efficient way to improve the indoor air quality (IAQ) of existing spaces. The IAQ in classrooms has a significant impact on the health and academic achievement of students. However, improving the IAQ of existing classrooms is challenging if minimum architectural modifications are allowed. Different natural ventilation retrofitting techniques were proposed to improve the IAQ in existing classrooms at Jordan University of Science and Technology, which is located in a hot arid region. Computer simulations were used to analyze the ventilation rate, indoor operative temperature, relative humidity, and CO2 concentration in the base Case classroom and after the implementation of the proposed retrofitting techniques. Simulation results were compared with those obtained in the base case to determine the most efficient natural ventilation retrofitting technique. The best results were obtained by using a solar chimney to assist a wind tower, which resulted in an increase in the comfort hours during the occupation time, an improvement in the average monthly ventilation rate range, a decrease in the CO2 concentration, and an improvement in the relative humidity ratio. An energy-saving of 39% would be achieved compared with the use of split unit air condition systems. Economic assessment of the proposed system using net present value indicates positive economic viability.

This study aims to assess the difference between projects from versions 3 (v3) and 4 (v4) of the Leadership in Energy and Environmental Design Commercial Interiors (LEED-CI) rating system in China and the US at the Silver and Gold certificate levels. Non-parametric statistics are used to estimate these differences. We analyze the Sustainable Sites (SS), Location and Transportation (LT), Water Efficiency (WE), Energy and Atmosphere (EA), Materials and Resources (MR), and Indoor Environmental Quality (EQ) categories for the LEED-CI Silver and Gold projects. The results show that the WE and EA categories in v3 and the WE, EA, LT, and MR categories in v4 are implemented differently in China and the US. For the LEED-CI Silver and Gold projects, the MR and EQ categories in v3 and the EQ category in v4 show similar implementation in China and the US. The LEED-CIv3 SS category shows a different result at the Gold level but the same at the Silver level when comparing China and the US. Thus, at the Silver and Gold levels of the LEED-CI projects, v4, rather than v3, provides more opportunities to highlight the environmental priorities of China and the US.

Cooling towers or recoolers are one of the major consumers of electricity in a HVAC plant. The implementation and analysis of advanced control methods in a practical application and its comparison with conventional controllers is necessary to establish a framework for their feasibility especially in the field of decentralised energy systems. A standard industrial controller, a PID and a model based controller were developed and tested in an experimental set-up using market-ready components. The characteristics of these controllers such as settling time, control difference, and frequency of control actions are compared based on the monitoring data. Modern controllers demonstrated clear advantages in terms of energy savings and higher accuracy and a model based controller was easier to set-up than a PID.

Jordan imports 94% of its oil and gas (fossil fuels) to meet its energy needs, leaving it vulnerable to variations in fuel price. Jordan's demand for energy is growing at a rate of 3% annually. In response, the government set a target of obtaining 10% of its energy needs from renewable energy resources by increasing electricity generation share from the present 1.13 GW–1.8 GW by 2020. The sources of generation include abundant solar, wind, and biomass resources, which also enhance economic growth and reduce pollution. This article analyzed the current energy situation in Jordan and assessed the available renewable energy resources potential for direct investments. The actual contribution of clean energy is still moderate at roughly 7% of total energy demand, despite the efforts placed on the development of alternative energy resources. The national electricity supply and demand are presented, and the government initiatives, financial incentives, and tax exemptions to encourage investments in clean energy are also discussed. The renewable energy policy generates future opportunities for investors with an ambitious $20 billion energy plans as does its strategy to improve energy efficiency. This article will benefit interested clean energy investors and developers and plans for 2,000 MW investments in wind and solar energy are ready for bidders. Such an endeavor and model will also benefit neighboring countries in the region.

Energy is vital recourse for economic development of today's business. The services demanded of residential and commercial buildings require substantial energy use. Energy consumption in this sector has been growing in total, gradually. As a result the high emission of greenhouse gases is released and, hence, the saving energy with better building management have made a major priority of the energy and environment sectors throughout the world. In this direction, to reduce energy consumption and mitigate environmental impacts in buildings, net-zero energy buildings (NZEB) is a very effective solution. As a result, a multi-objective model is developed to identify the best combination of materials and construction options considering their related costs, energy efficiency, and environmental impacts of buildings, simultaneously. This sustainable model is presented to construct a building considering the construction costs and energy consumption of the design options. To design the NZEB, while minimizing costs and carbon emissions, use has been made of a combination of different types of active/heating and cooling systems and renewable equipment through such high-efficiency, effective, and updated technologies as the solar panel. Finally, the case study of a residential building with two scenarios is used to demonstrate the proposed framework. The results show that, for scenarios1 and 2 respectively using insulation thickness such as (wall, roof, and windows) and renewable equipment have the highest sustainable impact in NEBZ's performance.

Deterioration of cable insulation during its normal operation is a major concern. Usually, electric cables receive less periodic maintenance compared to the other electric components, although they are subjected to several environmental conditions during operation such as high temperature and oxidative atmospheres.In this study, a standardized accelerated thermal ageing technique was used, with the application of the Arrhenius model. This technique is commonly used in accelerated life testing to establish a lifetime-stress relationship and estimate cable lifetime. Two types of Cross-Linked Polyethylene (XLPE) material working at elevated temperatures between 95 and 105 °C were selected for testing. In such accelerated ageing processes, it is required for the insulation to reach a degradation level, which is considered the end of life for the material under evaluation. The end of life criteria (also called endpoint) is defined as a percentage reduction of elongation at break, which is considered in this study to be 50% retention of elongation at break. Thermal ageing was carried out according to the BS 7870-2 standard, while elongation at break was evaluated at several ageing stages. The uncertainty in the measurement was estimated. The short-term data points determined by ageing treatment is represented graphically in the Arrhenius plot. The extrapolation of such data was used to predict the long-term performance and estimate the cable lifetime. The lifetime for XLPE is expected to be between 40 and 60 years at 90 °C rated operating temperature. Experimental findings of this study show an estimated cable lifetime between 7 and 30 years for rated operating temperatures between 95 and 105 °C.

Phase change materials (PCMs) can be used to store solar energy. The heat released from PCMs is directly influenced by the efficiency of thermal energy storage and the scope of application. In this study, paraffin was used as the PCM, and was encapsulated in an aluminum tube. The temperature of the inner PCM was measured, and the heat release process of the PCM was simulated. The results indicate that the melt temperature of the PCM ranged from 45 °C to 60 °C, and the latent heat was 177 J/g. The heat release processes of the PCM in different aluminum tubes included three stages: 1) the stage during which no phase change occurred at temperatures above the melt temperature and at a rapidly decreasing temperature; 2) the stage during which phase change occurred at very slowly decreasing temperatures; 3) the stage during which no phase change occurred at temperatures lower than the melt temperature. The temperature of the PCM decreased when the radius of the aluminum tube increased. The temperature results obtained via simulation were similar to the actual temperature data. The total energy released from the PCM increased linearly with the time required to complete the energy release process of the PCM in aluminum tubes with different diameters, as well as with the increase in the aluminum tube diameter. The diameter of the PCM exerted no significant influence on the energy release rate. The relationship between the tube diameter and the time required to complete heat release, and the relationship between the amount of heat released, the diameter of the aluminum tube, and the release time, were established. These equations could predict actual values and provide theoretical guidance for heat release in heat storage systems. They could also be used as a guide in practical production.

A ground heat exchanger is the most important part of a ground source heat pump system. Soil properties and ground heat exchanger performance strongly depend on soil temperature profile and vary with time and space. Also, soil temperature profile is a function of heat transfer rate extracted or transferred to soil. Studies in the literature either use the unaffected soil temperature obtained from meteorological data or fail to run for long time periods to obtain a steady periodic soil temperature profile and over-predict the ground heat exchanger performance. Therefore, steady periodic temperature profile should be used for sizing ground heat exchanger for efficient operation of ground source heat pumps for longer periods of time. Experimental studies are carried out on a ground-source heat pump established at Yıldız Technical University, Davutpaşa Campus and the newly developed numerical model is validated with experimental results. For the numerical study, the hourly required heat load of a 200 m 2 office in Istanbul during the heating season is calculated by using HAP software. The transient soil temperature profile is obtained numerically for longer periods of time with realistic boundary conditions using meteorological data. The fluid inlet temperatures equivalent to the hourly need for heating load of the office during the heating season are simulated for a ten-year period in accordance with the different heat amounts extracted from unit pipe length in soil (21, 10.5 and 7 W/m). The effects of burial depth, distance between pipes and surface effects on soil temperature are also investigated. Horizontal and vertical temperature distribution in soil at the beginning (November 10th), middle (January 21st) and end (April 3rd) of the first, fifth and tenth years are represented. [ABSTRACT FROM AUTHOR]

Abstract: In order to reduce the energy use in the building sector there is a demand for tools that can identify significant building energy performance parameters. In the work introduced in this paper presents a methodology, based on a simulation module and graphical figures, for interactive investigations of the building energy performance. The building energy use simulation program is called TEKLA and is using EN832 with an improved procedure in calculating the heat loss through the floor and the solar heat gain. The graphical figures are simple and are illustrating the savings based on retrofit measures and climate conditions. The accuracy of the TEKLA simulation was investigated on a typical single-family building in Sweden for a period of time in a space heating demand of relatively cold and mild climate. The model was found applicable for relative investigations. Further, the methodology was applied on a typical single family reference building. The climate data from three locations in Sweden were collected and a set of relevant measures were studied. The investigated examples illustrate how decisions in the early stages of the building design process can have decisive importance on the final building energy performance. [Copyright &y& Elsevier]

Solar energy is considered the greatest source of renewable energy. In this paper, a case study was performed for a single-axis solar tracking model to analyze the performance of the solar panels in an office building under varying ambient temperatures and solar radiation over the course of one year (2018). This case study was performed in an office building at the College of Engineering at Shaqra University, Dawadmi, Saudi Arabia. The office building was supplied with electricity for a full year by the designed solar energy system. The study was conducted across the four seasons of the studied year to analyze the performance of a group of solar panels with the total capacity of a 4 kW DC system. The solar radiation, temperature, output DC power, and consumed AC power of the system were measured using wireless sensor networks (for temperature and irradiance measurement) and a signal acquisition system for each hour throughout the whole day. A single-axis solar tracker was designed for each panel (16 solar panels were used) using two light-dependent resistors (LDR) as detecting light sensors, one servo motor, an Arduino Uno, and a 250 W solar panel installed with an array tilt angle of 21°. Finally, an artificial neural network (ANN) was utilized to estimate energy consumption, according to the dataset of AC load power consumption for each month and the measurement values of the temperature and irradiance. The relative error between the measured and estimated energy was calculated in order to assess the accuracy of the proposed ANN model and update the weights of the training network. The maximum absolute relative error of the proposed system did not exceed 2 × 10−4. After assessment of the proposed model, the ANN results showed that the average energy in the region of the case study from a 4 kW DC solar system for one year, considering environmental impact, was around 8431 kWh/year. [ABSTRACT FROM AUTHOR]

Building retrofitting plays a critical role in achieving sustainable development and is an efficient way to improve the indoor air quality (IAQ) of existing spaces. The IAQ in classrooms has a significant impact on the health and academic achievement of students. However, improving the IAQ of existing classrooms is challenging if minimum architectural modifications are allowed. Different natural ventilation retrofitting techniques were proposed to improve the IAQ in existing classrooms at Jordan University of Science and Technology, which is located in a hot arid region. Computer simulations were used to analyze the ventilation rate, indoor operative temperature, relative humidity, and CO 2 concentration in the base Case classroom and after the implementation of the proposed retrofitting techniques. Simulation results were compared with those obtained in the base case to determine the most efficient natural ventilation retrofitting technique. The best results were obtained by using a solar chimney to assist a wind tower, which resulted in an increase in the comfort hours during the occupation time, an improvement in the average monthly ventilation rate range, a decrease in the CO2 concentration, and an improvement in the relative humidity ratio. An energy-saving of 39% would be achieved compared with the use of split unit air condition systems. Economic assessment of the proposed system using net present value indicates positive economic viability., (© 2020 The Author(s).)

This study aims to assess the difference between projects from versions 3 (v3) and 4 (v4) of the Leadership in Energy and Environmental Design Commercial Interiors (LEED-CI) rating system in China and the US at the Silver and Gold certificate levels. Non-parametric statistics are used to estimate these differences. We analyze the Sustainable Sites (SS), Location and Transportation (LT), Water Efficiency (WE), Energy and Atmosphere (EA), Materials and Resources (MR), and Indoor Environmental Quality (EQ) categories for the LEED-CI Silver and Gold projects. The results show that the WE and EA categories in v3 and the WE, EA, LT, and MR categories in v4 are implemented differently in China and the US. For the LEED-CI Silver and Gold projects, the MR and EQ categories in v3 and the EQ category in v4 show similar implementation in China and the US. The LEED-CIv3 SS category shows a different result at the Gold level but the same at the Silver level when comparing China and the US. Thus, at the Silver and Gold levels of the LEED-CI projects, v4, rather than v3, provides more opportunities to highlight the environmental priorities of China and the US., (© 2020 The Author. Published by Elsevier Ltd.)

Jordan imports 94% of its oil and gas (fossil fuels) to meet its energy needs, leaving it vulnerable to variations in fuel price. Jordan's demand for energy is growing at a rate of 3% annually. In response, the government set a target of obtaining 10% of its energy needs from renewable energy resources by increasing electricity generation share from the present 1.13 GW-1.8 GW by 2020. The sources of generation include abundant solar, wind, and biomass resources, which also enhance economic growth and reduce pollution. This article analyzed the current energy situation in Jordan and assessed the available renewable energy resources potential for direct investments. The actual contribution of clean energy is still moderate at roughly 7% of total energy demand, despite the efforts placed on the development of alternative energy resources. The national electricity supply and demand are presented, and the government initiatives, financial incentives, and tax exemptions to encourage investments in clean energy are also discussed. The renewable energy policy generates future opportunities for investors with an ambitious $20 billion energy plans as does its strategy to improve energy efficiency. This article will benefit interested clean energy investors and developers and plans for 2,000 MW investments in wind and solar energy are ready for bidders. Such an endeavor and model will also benefit neighboring countries in the region., (© 2020 The Author(s).)

Cooling towers or recoolers are one of the major consumers of electricity in a HVAC plant. The implementation and analysis of advanced control methods in a practical application and its comparison with conventional controllers is necessary to establish a framework for their feasibility especially in the field of decentralised energy systems. A standard industrial controller, a PID and a model based controller were developed and tested in an experimental set-up using market-ready components. The characteristics of these controllers such as settling time, control difference, and frequency of control actions are compared based on the monitoring data. Modern controllers demonstrated clear advantages in terms of energy savings and higher accuracy and a model based controller was easier to set-up than a PID., (© 2020 The Authors.)

Energy is vital recourse for economic development of today's business. The services demanded of residential and commercial buildings require substantial energy use. Energy consumption in this sector has been growing in total, gradually. As a result the high emission of greenhouse gases is released and, hence, the saving energy with better building management have made a major priority of the energy and environment sectors throughout the world. In this direction, to reduce energy consumption and mitigate environmental impacts in buildings, net-zero energy buildings (NZEB) is a very effective solution. As a result, a multi-objective model is developed to identify the best combination of materials and construction options considering their related costs, energy efficiency, and environmental impacts of buildings, simultaneously. This sustainable model is presented to construct a building considering the construction costs and energy consumption of the design options. To design the NZEB, while minimizing costs and carbon emissions, use has been made of a combination of different types of active/heating and cooling systems and renewable equipment through such high-efficiency, effective, and updated technologies as the solar panel. Finally, the case study of a residential building with two scenarios is used to demonstrate the proposed framework. The results show that, for scenarios 1 and 2 respectively using insulation thickness such as (wall, roof, and windows) and renewable equipment have the highest sustainable impact in NEBZ's performance., (© 2020 The Authors. Published by Elsevier Ltd.)

Deterioration of cable insulation during its normal operation is a major concern. Usually, electric cables receive less periodic maintenance compared to the other electric components, although they are subjected to several environmental conditions during operation such as high temperature and oxidative atmospheres. In this study, a standardized accelerated thermal ageing technique was used, with the application of the Arrhenius model. This technique is commonly used in accelerated life testing to establish a lifetime-stress relationship and estimate cable lifetime. Two types of Cross-Linked Polyethylene (XLPE) material working at elevated temperatures between 95 and 105 °C were selected for testing. In such accelerated ageing processes, it is required for the insulation to reach a degradation level, which is considered the end of life for the material under evaluation. The end of life criteria (also called endpoint) is defined as a percentage reduction of elongation at break, which is considered in this study to be 50% retention of elongation at break. Thermal ageing was carried out according to the BS 7870-2 standard, while elongation at break was evaluated at several ageing stages. The uncertainty in the measurement was estimated. The short-term data points determined by ageing treatment is represented graphically in the Arrhenius plot. The extrapolation of such data was used to predict the long-term performance and estimate the cable lifetime. The lifetime for XLPE is expected to be between 40 and 60 years at 90 °C rated operating temperature. Experimental findings of this study show an estimated cable lifetime between 7 and 30 years for rated operating temperatures between 95 and 105 °C., (© 2019 The Author(s).)

Phase change materials (PCMs) can be used to store solar energy. The heat released from PCMs is directly influenced by the efficiency of thermal energy storage and the scope of application. In this study, paraffin was used as the PCM, and was encapsulated in an aluminum tube. The temperature of the inner PCM was measured, and the heat release process of the PCM was simulated. The results indicate that the melt temperature of the PCM ranged from 45 °C to 60 °C, and the latent heat was 177 J/g. The heat release processes of the PCM in different aluminum tubes included three stages: 1) the stage during which no phase change occurred at temperatures above the melt temperature and at a rapidly decreasing temperature; 2) the stage during which phase change occurred at very slowly decreasing temperatures; 3) the stage during which no phase change occurred at temperatures lower than the melt temperature. The temperature of the PCM decreased when the radius of the aluminum tube increased. The temperature results obtained via simulation were similar to the actual temperature data. The total energy released from the PCM increased linearly with the time required to complete the energy release process of the PCM in aluminum tubes with different diameters, as well as with the increase in the aluminum tube diameter. The diameter of the PCM exerted no significant influence on the energy release rate. The relationship between the tube diameter and the time required to complete heat release, and the relationship between the amount of heat released, the diameter of the aluminum tube, and the release time, were established. These equations could predict actual values and provide theoretical guidance for heat release in heat storage systems. They could also be used as a guide in practical production., (© 2019 The Author(s).)