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There is growing concern that global warming will change the building’s performance pattern in the future. This paper investigates the effects of climate changes on the heating and cooling energy demand, the overall energy performance and the overheating risk of typical residential buildings (existing and refurbished) in the biggest city of the most populated Italian climatic zone, Milan. The widely used morphing methodology was adapted for creating future weather data for different scenarios. Energy performance analysis was carried out using dynamic simulation for the near term (2021–2040)​ and the long term (2081–2099) periods. The results show decreases in heating energy demand up to 30.9%, intense increases in cooling energy demand, up to 255.1% and significant increases of overheating risk up to 155%. In addition, the effect of refurbishment on each parameter is also analysed and reported. The research demonstrates that climate change causes a paradigm shift in the building energy performance, while the magnitude of climate change impact is not equal for different building types, time periods, insulation levels, and future weather scenarios. Therefore, climate change must be considered for future energy performance assessment of buildings.

Buildings' facades significantly impact human thermal comfort and the energy budget of buildings. It is estimated that 73% of heat losses or gains are immediately linked to the configuration and types of materials in the buildings' envelope. Building styles in the Kingdom of Saudi Arabia witnessed a large and growing expansion in curtain walls, glass facades, metal cladding, and precast concrete. It is striking that terracotta cladding is most often associated with school building facades, especially the government ones, with very limited applications in other building types. This paper investigates the energy-related budget of using Aluminum and terracotta cladding in an educational facility in KSA. The article follows the experimental approach. Data about both cladding materials' specifications were obtained and input into the virtual model building in DesignBuilder software for simulation and analysis. The comparative analysis of energy consumption during the building's operational phase in both cases revealed that more energy budget was needed in the case of Aluminum cladding to provide thermal comfort to the occupants. The study concludes that the efficiency of thermal insulation of Terracotta is better than the Aluminum sheets. On the other hand, and in the long run, the study underscores the preference of using Aluminum cladding for its extensive reuse and recycling potential. Brittleness of Terracotta limits its prospects for recycling; therefore, it might be more energy-consuming when frequently reproduced for new applications or maintenance purposes throughout the building life cycle.

Office buildings built before the entry into force of the first thermal regulation in 1991 constitute a relevant group for analysing the energy performance of the Portuguese building sector. A dynamic energy simulation was used to assess the energy performance of an existing office building located in the town of Bragança, Portugal. Four energy efficiency measures were selected and a financial evaluation through the internal rate of return (IRR) method was undertaken to choose the best retrofit option for improving the building’s energy performance. An investment package consisting of the roof insulation and a new equipment for the domestic hot water system presented an IRR higher than the discount rate used in the analysis, and, thus, a positive financial return. The results of the study also suggest that the EU’s comparative methodology framework is not particularly suitable for assessing building retrofit investment at the private investor’s perspective and further refinement in the cost-effective approach to renovations is needed to help stimulate building’s energy renovation market. Suggestions for further studies conducted for office buildings in the different climate zones in Portugal are also proposed. info:eu-repo/semantics/publishedVersion

The study aims to calculate the technical and economic efficiency of adding hydrogen to natural gas to improve the energy characteristic of the fuel in gas-turbine plants during long-term gas field operations. Mathematical modelling techniques in the CAS CFDPT (computer-aided system for computational fluid dynamics of power turbomachinery) program were used to develop a mathematical model of the General Electric 6FA gas turbine engine. It was shown that a decrease in the calorific value of the fuel leads to an increase in fuel consumption by 11% and the amount of CO2, NO2 in the turbine exhaust gas. It was determined that, during the freezing season and peak power rating operations, the turbine power is limited by the fuel system capacity (its maximum value amounted to 5.04 kg/s). It was shown that energy characteristics can be improved by adding hydrogen to the feed natural gas. Energy efficiency was calculated at different fuel components (hydrogen and natural gas) ratios at variable-load operation in the range between 75 and 85 MW. Instant fuel gas flow amounted to 5.04 kg/s (with 4.5% hydrogen and 95.5% natural gas in the feed fuel) at 85 MW. Due to its high cost, the use of hydrogen is only advisable in peak power rating operations to reach the maximum capacity of the gas-turbine plant. The proposed method of adding 4.5% hydrogen to fuel gas allows the maximum fuel consumption to be maintained at a rate of 5.04 kg/s to reach the topping power of 85 MW. When using this method, there are no limitations on the maximum and peak capacity of the gas-turbine plant.

PurposeThis paper aims to address Passive Design Strategies (PDSs) in the traditional houses of Sabzevar and to assess the adaptation level of these strategies to the climate of the region.Design/methodology/approachIdentifying the Sabzevar climate, five samples of traditional houses have been chosen to be analyzed via two stages. In stage one, the efficiency of each strategy is weighted through qualitative analysis, and in stage two, the houses are simulated in EnergyPlus 9.3.0 to quantitatively evaluate their heating and cooling performances.FindingsThe obtained results from the energy performance analysis of the case studies indicate that the houses present diverse energy performances in different seasons. Those buildings with PDSs for both cold-arid and hot-arid climates, however, are more adaptable cases to the climate of the region.Originality/valueThe results of this study are expected to provide a basis of materials and methods for the climatic assessment of the traditional buildings, specifically traditional houses and will open new doors to future studies about the integration of these potential PDSs with the new technological developments and climate considerations as well as protecting the conservation policies of these buildings by means of optimizing and improving their energy performance and implementing effective retrofit scenarios.

The present study discusses alternative ways of achieving optimum energy efficiency for historic buildings in areas where sustainable energy projects are planned. About 25% of Europe’s building stock was constructed before the mid-20th century and despite EU’s strenuous efforts for the protection and conservation of historic buildings and complexes, achieving energy efficiency with the minimum or preferably no intervention remains as a requirement. The settlement of Monemvasia, has been selected as our case study. A model building was chosen, its special characteristics are presented, and four solutions to the energy efficiency upgrade of the building were tested: (a) the application of internal insulation, (b) a heat pump installation, (c) the application of roof insulation, and (d) the replacement of the internal doorframes. The four scenarios were simulated via the TEE-KENAK software and the percentage of the annual energy saved through the application of each one of the mentioned measures was estimated. The results proved that installing a heat pump and internal insulation would maximise energy savings. Coupling the energy demand of the settlement in correlation with a wind energy project in the wider area, and the available curtailment was explored. The results showed that if 300 houses decide on acquiring their electricity consumption from the local wind independent power producer, at a price of EUR 35/MWh, the possible profit from the market could reach EUR100,000 per year. Such a business-driven concept could be extrapolated and evolve into a holistic wind energy and historic environment symbiosis setting.

The use of halogen-based refrigerants in heat pump applications is restricted because of their high global warming potential (GWP). Therefore, it is necessary to identify a low GWP substitute for heat pump applications. This article presents the energy performance of a direct expansion solar thermal heat pump system (DXSTHPS) using R430A as an environmentally friendly substitute to phase out R134a. The effects of ambient parameters on compressor discharge temperature, compressor energy consumption, condenser heating capacity and coefficient of performance (COP) of a DXSTHPS using R134a and R430A are estimated and compared. Moreover, the total equivalent global warming impacts (TEGWI) of a DXSTHPS using R134a and R430A are evaluated. The results showed that the R430A has 0.7–1.9% lower compressor energy consumption than R134a. The condenser heating capacity and COP of a DXSTHPS using R430A are higher than R134a by 4.6–8.7% and 5.1–10.2%, respectively. The compressor discharge temperature observed in a DXSTHPS using R430A is 5.8 °C higher than R134a. The lubricant physical properties are retained at higher compressor operating temperatures, ensuring compressor reliability. The DXSTHPS using R430A has 4.2–12.9% lower TEGWI due to its lower GWP with lower compressor energy consumption than R134a.

The change over time of energy performance of large chillers used in commercial and institutional buildings is seldom presented in the literature. Most studies are based on measurements of small ca...

An energy performance comparison between a novel thermosyphon-assisted falling film distillation unit and a conventional tray unit was carried out for three mixtures with different relative volatil...

Energy use in buildings accounts for one-third of the overall global energy consumption and total building floor area continues to increase each year as new developments are constructed and delivered. If stringent climate goals are to be met, these buildings will need to consume less energy and emit less carbon. However, design intentions for energy efficient buildings are not always met in practice. This performance gap between calculated and measured energy use in buildings threatens the progress necessary to meet these energy targets. The aim of this paper is to identify the factors that contribute to the performance gap and propose solutions for reducing the gap in practice. A quantitative and qualitative analysis of two research programmes completed in the past few years was utilized for an in-depth look at the performance of around 50 non-domestic buildings in the United Kingdom. While no direct links were found between any one variable and the performance gap, several correlations exist between contributing factors indicating a complex, entangled web of interrelated problems. The multitude of the variables involved presents a formidable challenge in finding practical solutions. However, the results indicate that the combination of the ventilation strategy of a building and the building services control strategy during partial occupancy is a key determinant of the performance gap. A more straightforward procurement approach with clearly delineated targets and responsibilities, along with advanced and seasonal commissioning instituted at the beginning of a project and implemented after building completion can also be very effective in reducing the gap. Finally, mandatory requirements or an appropriate system of incentives for monitoring and disclosure of performance data can help identify many of the underlying issues affecting performance in-use and untangle some of the web of complex issues across the building sector. Practical application Awareness of the performance gap and knowledge of the factors contributing to its impact on the building industry is important for all stakeholders involved in the design, construction, operation and occupation of non-domestic buildings. Understanding potential solutions to mitigate these risks may help to reduce the prevalence and magnitude of the performance gap.

Energy performance of buildings is an important issue to estimate the energy waste of buildings and their impact on the environment, so designing energy-efficient buildings could improve their energy performance. In this case, the estimation of heating and cooling loads plays an important role in this regard. However, there are few factors with unpredictable influences on the heating and cooling loads. This study has attempted to analyze the eight parameters that can significantly affect the heating and cooling loads through the Neuro-fuzzy logic approach. Accordingly, the eight parameters of relative compactness, surface area, wall area, roof area, overall height, orientation, glazing area and glazing area distribution were considered as inputs and predicting the cooling and heating load changes was regarded as the output of this study. The model was developed and its results were measured in two regression indicators of r and RMSE. Based on the obtained results it was found that roof has the strongest impact on heating and cooling loads (RMSE: 4.3596), moreover, if two factors were concurrently changed, then the combination of relative compactness and wall area can significantly affect the heating and cooling loads (RMSE: 2.6312). The most influential combination of three factors is observed as well for the heating and cooling load and these factors are relative compactness, wall area and glazing area (0.5948). The most influential combination of three factors is observed as well for the hearing load and these factors are relative compactness, wall area and glazing area (RMSE: 0.5948 and RMSE: 1.5769 for heating and cooling load, respectively). However, Neuro-fuzzy logic showed overfitting for more than two inputs, therefore it is not recommended for more than two inputs.

The building airtightness is essential to achieve a high energy performance. In most countries however, it is not mandatory to measure the airtightness. In the Netherlands it is common practice to ...

A proper evaluation of the building energy consumption implies an accurate assessment of the solar gains and consequently an exact estimation of the direct and diffuse solar radiation on tilted and oriented surfaces. The new standard EN ISO 52016-1: 2017 introduces a new hourly methodology for the calculation of energy performance of buildings and is complemented by EN ISO 52010-1:2017, which specifies the procedure for the conversion of climate data for energy calculations. These standards represent a good compromise between the old EN ISO 13790:2008 and Trnsys, since they allow for a more accurate evaluation of energy consumption than the former, while being less onerous than the latter. In the present work, EN ISO 52010-1:2017 is analysed for the first time and an alternative calculation procedure is proposed. These two algorithms are then compared with two other irradiance splitting methods implemented in Meteonorm and Trnsys code. In order to test performance and limits of the different calculation algorithms, we make a comparison among such methods on five European cities characterized by different climatic characteristics. Results show that the model implemented in EN ISO 52010-1:2017 overestimates the diffuse solar irradiance on horizontal plane for all the considered locations, while the proposed procedure and those implemented in the Trnsys and Meteonorm softwares show similar results. Using Trnsys algorithm as a baseline, the proposed calculation algorithm gives the best approximation among the considered models for what concerns the direct, diffuse and global irradiance on vertical surfaces exposed to south, east and west.

In the present work, simulation and energy analysis of a grid-tied 100 kWp solar photovoltaic power plant mounted on an institute's building rooftop in Bhopal city of India are carried out. The present study provides insight into the solar power plant's performance linked to the medium range grid under actual operating conditions in Central India. It is observed that the standard performance ratio and the capacity factor of the plant are 80.72% and 19.27% respectively. The average monthly energy produced is highest in April and lowest in July. Simulation results using different simulation tools have been compared and are shown to be in near agreement with the real calculated values. This plant set-up is expected to gain profit after a period of 5.9 years with a capacity to mitigate 136 tons of CO2 emission annually. Practical application: This study estimates the energy output, system losses and performance parameters for a 100 kWp rooftop grid connected solar photovoltaic system. This helps to check the feasibility of such a system at this location. Also the payback period and reduction in carbon footprint are calculated to highlight the economic and environmental benefits. This would attract public interest for installation of more such plants on rooftops of buildings in the near future.

The paper analyzes utilization of a PV system driving a heat pump in the low energy house in the Polish climate during winter. Based on meteorological data and technical data for the PV modules the energy output for all hours of the year is calculated. The duration of the heating season and the quantity of energy that must be supplied to the heat pump over all the days of the year to keep the indoor air temperature at a constant level are calculated and an estimate of the time of its operation for every day of the year is made. The share of PV energy and energy from the grid towards the total energy supplied to drive the heat pump is determined. Two cases of PV systems are considered: with batteries and without (but the time of the heat pump operation coincides with the time of the availability of solar radiation). The impact of the PV operation on indices of energy consumption is analyzed according to Polish energy sector rules. The results show that reduction of primary energy consumption is not significant. However, to give a definite answer on reduction of energy consumption a study of the operation over a whole year is needed.

Spain has a high level of energy consumption and CO2 emissions in detached houses, being the lack of an adequate insulation level and efficient energy systems the main causes. The Spanish Government has been performing modifications on its Building Technical Code (BTC) to address this issue, following European Directives. An assessment of the development of the Spanish BTC from its first 2006 version has been conducted in this work. A standard Spanish detached house was placed in the different Spanish climatic zones, designed with the minimum requirements of the 2006 and 2013 BTCs, and was then analyzed using the software Cerma. The results show that energy demand is reduced and the energy rating is improved with the stricter requirements introduced in the 2013 BTC. Although energy demand and CO2 emissions vary significantly among the 13 different climatic zones studied, the BTC modifications allow to reach a minimum energy rating independently of the climatic zone where the house is located. Opaque enclosures and internal loads were found to be the main contributors to building-related emissions. Additionally, possible actions to improve energy rating in detached houses are evaluated, finding that a moderate insulation thickness increase and the installation of heat pumps allow to reach the highest energy rating, being the improvement more apparent in northern and central regions. The results of this work may be extrapolated to other countries with similar climatic conditions to the studied zones, providing guidelines to fulfill energy saving regulations, evaluate emission sources and improve building energy efficiency.

The variable refrigerant flow air-conditioning system is an HVAC system that can perform at a high capacity with low consumption thanks to its variable-speed compressor. The paper introduces a TRNS...

Additive manufacturing (AM) is seen as a promising technology to improve the resource efficiency and environmental performance in manufacturing systems. However, recent studies have shown that the ecological advantages of AM are dependent on the design of the manufactured parts. This leads to the requirement of the implementation of eco-design for AM (Eco-DfAM). Therefore, this paper presents a case study in which an industrial part has been analyzed and optimized using the energy performance assessment (EPA)-based Eco-DfAM method. In the first step of the case study, generative design has been applied and different design solutions with varied lightweighting factors were proposed. The energy consumption of each design solution is then quantified using a simulation method. Based on the defined energy performance indicators, the energy performances of different solutions are evaluated and compared. Finally, the optimized part with the best evaluation result is produced using the selective laser melting (SLM) process. The results of this case study provide valuable experience for designers who are facing decision-making issues in Eco-DfAM.

The construction of green, or vegetated roofs, can mitigate the heat island effect, reduce the energy required for cooling of buildings, allow for efficient precipitation management, improve air quality, increase biological diversity, reduce noise, etc. This paper uses the method of dynamic simulation to investigate how different green roof types influence the energy properties of an individual residential building with a sunspace located in the city of Niš. The obtained results show that when the extensive type of green roof is used on the model of the building with a sunspace, there are no significant changes in the required energy for heating or cooling. The biggest reduction of the energy required for heating and cooling occurs when an intensive green roof is used. In the subvariant of the model with an intensive green roof, the required energy for heating was 0.34% lower while the required energy for cooling was 2.32% lower compared to the model of the building without a green roof

Concerns about the energy sustainability of the existing building stock and about changes in both climatic conditions and comfort requirements, in recent years have put a lot of research focus on energy performance evaluation of buildings, which also need detailed assessment of material properties. Most often, historic masonry buildings present both structural and material typicality owing to local material availability and technical know-how at time of construction. Further, the available energy efficiency assessment methodologies demand a detailed diagnostic of the material behaviour. Along with this, the heritage status and the conservation policies attached to these buildings pose special requirements of on-site measurement and non-invasive analytical tools. Presently, as carried out, commonly the evaluation of all these aspects is undertaken separately. The paper highlights the need for an integrated investigative approach considering the need of material investigations and input requirements of advanced analytical tools like the simulation software systems. The paper also highlights the available literature references and practices presently followed in the energy efficiency studies for documenting material properties and identifies a vast scope for further study in the domain.

Thailand committed to achieving the Sustainable Development Goals to increase urban livability and reduce energy use in the building sector. However, the design information to achieve those challenge goals has been undefined. This study aimed to investigate and examine potential improvements for outdoor thermal comfort and energy efficiency in 136 designs of the two-type residential cluster in Pathum Thani, Thailand, via designs of building orientation, geometry and window-to-wall ratio (WWR). The daily cooling energy consumption in residential clusters was performed using eQuest under the modified weather data from the prior microclimate analysis. The energy-saving scenarios were calculated and compared to the acceptable outdoor thermal comfort hours. It is found that the row house cluster had the potential to be more sustainable than a single house. The row house clusters on orthogonal street orientation offered the highest percentage of hours in outdoor thermal comfort of 46% and energy efficiency below the new standard of Thailand. The cooling energy savings through increasing H/W with lowering WWR was up to 32%. This study’s results could provide urban planners and architects with the new design guidelines and improvement potentials to make cities more energy efficient and environmentally friendly for outdoor living in Thailand.

Multiphase pump is widely applied for the exploitation of oil-gas resources in off-shore platforms. It is essential to investigate the performance of multiphase pumps when handling high viscosity fluid. A three-stage helico-axial multiphase pump with working fluids under various viscosities is investigated in the present study. Both energy performance and flow fields have been discussed with different viscosities. The influences of viscosity, flow rate and blade height on the distribution of turbulence kinetic energy are analyzed. Results show that both pump head and efficiency gradually reduce with the rise of viscosity when handling high viscosity fluid. The rise of viscosity and blade height, and the decline of flow rate will lead to an increase of turbulence kinetic energy. Characteristics of partial differential equations are employed to reveal the influence of viscosity, and a theoretical model has been established to predict the influence of flow rate.

The growth of volume of tunneling, power supplied per job, and consumption of fuel and energy resources makes it necessary to increase energy performance of production processes with reducing energy losses. Tunneling conditions are determined by a combination of mutually influencing factors (geological, technological and organizational), and assessing their impact on tunneling energy performance requires a deep detailed study. For criterion assessment of tunneling performance, indicators of energy consumption, performance, and quality of tunneling performed by shift crews, allowing to objectively assess their work, were proposed. Indicators of process and specific power consumption in the process of tunneling vary over a wide range, therefore, to ensure smooth equipment operation, shift crews must adhere to the recommended indicators that determine the optimum rates of tunneling and enables adherence to permissible operation modes. Statistical models of energy performance indicators of heading sets of equipment operation were investigated using the example of the Severnaya coal mine. Indicators of energy consumption, energy performance, and tunneling (on shift basis) were proposed. Distribution laws have been determined for the main indicators characterizing tunneling energy performance. Recommendations have been developed to ensure sustainable operation of heading sets of equipment throughout the entire period of tunneling. Tunneling requires permanent monitoring its parameters and rates of advance, the quality of face preparation, timely maintenance and repair of machinery and equipment, control of the process through ensuring optimal operating modes of the heading sets of equipment.

The objective of this study was to establish the draft of the minimum energy performance standard (MEPS) and high energy performance standard (HEPS) for electric motorcycles in Thailand. Type approval of the electric motorcycles was referred to the Regulation (EU) No 168/2013. The testing setup and procedure to measure the electric energy consumption were conducted following the Regulation (EU) No 134/2014. During the measurement in electric energy consumption, the tested electric motorcycle was run on the chassis dynamometer by following the ECE R47 driving cycle for the L1e-A and L1e-B sub-category, and the WMTC, stage 2 driving cycle for the L3e-A1 sub-category. The draft of MEPS/HEPS was established as 30.6/20.4 Wh/km, 42.8/26.4 Wh/km, and 57.9/36.8 Wh/km for a case of the L1e-A, L1e-B, and L3e-A1 electric motorcycles, respectively. In addition, if all electric motorcycles are promoted to qualify the HEPS, the nationwide electric energy saving potential will predicted to be 115,789,656 kWh throughout the Thailand’s energy saving plan during 2015–2036.

Tip clearance results in tip leakage flow from blade pressure side to suction side, and further deteriorates the energy performance and operation stability. In the present work, the influence of rotating speed on tip leakage vortex in a mixed flow pump as turbine at pump mode is investigated. As rotating speed increases, the pump head increases according to the similarity law and the best efficiency point shifts towards large flow rate. Meanwhile, the tip leakage flow and axial momentum also increase. A prediction model for separation angle of tip leakage vortex is proposed, and its relative error is below 5%. As rotating speed increases, the oscillating frequency of primary tip leakage vortex increases from 201.92 Hz to 215.60Hz, and the high pressure fluctuation region develops from leading edge to nearly the whole blade-to-blade passage.

Summarization: The significance of the temperature effect on the performance of photovoltaics (PVs) has implied the necessity to develop PV cooling methods in recent years. In this research, the inclusion of phase change materials (PCMs) through an alternative type of enclosure in tubular shape was proposed and investigated as an option of mitigating the PV operating temperature to enhance their efficiency and lifetime. Two PVs incorporating different PCMs (PV + PCM systems) and a conventional PV module (reference case) were experimentally tested to assess their energy performance under the Mediterranean conditions in Chania, Crete. As PCMs employed were selected Paraffins RT 27 and RT 31. The results indicated that a peak temperature decrement of 6.4 °C and 7.5 °C could be observed by using 260 g of PCM27 and PCM31, respectively. Hence, PV + PCM27 and PV + PCM31 systems exhibited increased energy generation by 4.19% and 4.24%, respectively, while the increment in the PV conversion efficiency by PCM integration ranged from 2.86 to 4.19%. The proposed configuration of PCM enclosures took advantage of the synergistic effect of wind, as demonstrated by the recorded daily temperature profiles of the PV + PCM27 and PV + PCM31 systems, even after the time of complete PCMs' melting. Presented on: Solar Energy

Energy performance improvement has become a priority for current buildings in recent years. To achieve expense-efficient solutions, retrofitting approaches should be defined based on the regulations This approach balances the economic and energy objectives, but some significant factors are neglected in current studies, like internal thermal comfort. In this paper, the association of the primary features of residential buildings and the description of the best solutions of retrofitting concerning the lowest energy use toward NZEBs with the minimum thermal inconvenience or the highest economic performance is assessed. A couple of a TRNSYS and the Improved Seagull Optimizer (ISO) were applied for the optimization and simulation objectives. It has resulted that zero-energy objectives can be achieved by common energy-saving actions considering that the internal thermal convenience can be compromised and the presentation of incentive is necessary for the development of the solutions. Here, the consistent energy-saving above 59% is achieved by the multi-objective evaluation but worsening the indoor thermal convenience.

A new assessment method for the “Energy Performance” issue in the Green Standard for Energy and Environmental Design (G-SEED) was developed in this study. First, the corresponding issues in green b...

The application of renewable technologies and in particular solar photovoltaic (PV) market has grown rapidly throughout the past 15 years worldwide. Despite the market growth, one of the main factors limiting the application of PV panels is the degradation issue or power decline over time, highlighting the need of further studies on degradation rate and reliability assessment to predict panel life expectancy, economic values and financial risks. PV panels behave differently under certain conditions, and energy production of panels varies not only with the capacity of the system but also with the type of modules in panel. Researchers have also studied how different modules/panels perform for long periods of time, when exposed out in the field. In this article, a literature review of PV panel performance over time was accumulated from different resources to identify the sources of uncertainty about their performance, reliability, and durability under internal and external factors. The results show that both the internal factors such as cell interconnect breakages alongside external ones such as the sunlight, temperature change or dirt accumulation were determined to be the primary causes for the power loss and reduced energy generation in the PV panels and highlights further research in this area.

This study investigated the energy conservation of a non-insulated old apartment with a ventilated sunspace in Qingdao, China. The ventilation between the bedroom and sunspace of the apartment was ...

The present experimental work was carried out on a live plant at Sultanate of Oman for enhanced crude oil recovery by steam injection. The plant mainly consists of Glasshouse enclosed Parabolic Tro...

From about two decades passed, a new expression was proposed for the first time: “Virtual Power Plants (VPPs)”. At this moment, a question was asked about if the VPPs can contribute as a trustworthy and environmentally oriented energy supply, or not? From this instant, over two hundred articles was presented for the management and optimal utilization of such a system, reliability and adaptation of VPP with the network connected to, retail and wholesale markets … etc. Most or approximately all articles intended with VPPs focused on studying VPPs from economical point of view only and did not studied the electrical and energy performance of VPPs. This paper represents a novel combined model for economical and electrical performances together of a generic VPP (GVPP); the electro-economical model (EEM). Two main targets are required from the proposed GVPP EEM: best performance and active network energy management of this GVPP. Also, a proposal for the first real case study in Egypt is taken under consideration: Siwa Oasis, Egypt. Siwa Oasis proposed VPP is modeled also with EEM. EEM for these two cases (GVPP and Siwa Oasis VPP) are simulated to obtain best performance and active network energy management for these VPPs. All data and results are stated and discussed.

Biomass consumption, energy performance of cookstoves and emission factor of cattle dung cake, used as a main source of energy, in EIGP was evaluated. Average biomass consumption was recorded as 2....

Office lighting installations often inefficiently expend energy illuminating space that is unoccupied and/or already receiving adequate daylight. Illuminance and occupancy sensors can enable substa...

The research project DPE-IITI aims to carry out the in situ diagnosis of energy performance of buildings by quantifying the insulation level of walls. The on site monitoring method is based on the ...

China is the world's largest energy consumer, and coal accounts for a higher proportion of the country's total energy consumption, yet during its 12th five‐year plan (2011–2015), the coal share among total energy consumption significantly decreased. Previous studies exploring energy performance typically used energy consumption as an input, but this lacks the analytical capacity for the structure of energy consumption. Thus, this study splits energy input into two different inputs, coal consumption and non‐coal energy consumption, and based on their differences with other variables, uses the hybrid dynamic data envelopment analysis model to assess the energy performance of China's provincial industrial sector during the period 2011 to 2015. We then compare coal consumption's and non‐coal consumption's rooms for improvement and conclude that provinces in eastern and central China should reduce the amount of coal consumption, thereby improving energy performance. Conversely, provinces in the western region should target a balance between energy utilization efficiency and coal consumption.

In this study, R404A and R452A refrigerants used in refrigeration systems were compared experimentally. The energy performance of the system was investigated for widely used evaporation temperature...

PurposeArguments for the design of sustainable university buildings have emerged in South Africa. Energy being a major determinant of the sustainability of buildings, the purpose of this study was to examine the influence of various building and indoor environmental parameters on the energy performance of university buildings in South Africa.Design/methodology/approachA quantitative survey research method, administered within the context of university buildings in South Africa, was used. Data about 16 buildings from three universities were collected. Relevant, inferential statistical analyses were conducted to examine the relative influence of the building parameters on the energy consumed in the buildings. Also, regression models within building parameters were developed independently and in a combination that could be used to estimate energy consumption in the university buildings.FindingsFindings suggested that building and indoor environmental parameters of humidity, indoor temperature, volume, illumination, and window width ratio (WWR), in that order, influenced energy consumption significantly, and also, had direct empirical relationships.Practical implicationsOptimising the building and indoor environmental parameters in design will enhance energy-efficiency in university buildings in South Africa.Originality/valueThis study contributes to the literature in terms of understanding the order of influence of building parameters on energy consumption in university buildings in the temperate climatic zone of South Africa. It also established empirical models between building and indoor environmental parameters and energy consumption, both independently and in combination, that could assist in designing energy-efficient and sustainable university buildings.

This article evaluates the thermal and energy performance of mortar blocks containing local agricultural waste. The mortar blocks were cast by the replacement of ordinary Portland cement (OPC) with varying amounts of date palm ash (DPA) in the range of 10–30%. Experiments and simulations were carried out to assess the thermal characteristics and energy performance of the specimens. A prototype office building was modeled and simulated in DesignBuilder (Version 6.1.06) with modified blocks prepared with DPA under the Arabian Gulf environment characterized by hot and humid climatic conditions of Dhahran, Saudi Arabia. The developed blocks are characterized as lightweight blocks based on density data which satisfy the requirement of ASTM C55-11. The analysis and simulation indicate that the incorporation of DPA improves the thermal resistance of up to 47%, enhances the indoor environment and yields annual energy consumption of up to 7.6%, consequently reduces the cost of masonry block production by ~ 11% without compromising the physical, chemical, and mechanical properties. The masonry blocks prepared with DPA found to be economical than conventional masonry blocks. It is postulated that the novel DPA-based developed blocks are significantly sustainable products which will contribute to the valorization of DPA waste along with the reduction in the cost of construction and operational cost of the building.

This paper analyzes detached residential buildings with a sunspace and a thermal storage wall made of 20 cm thick concrete and either containing or not containing a phase-change material (PCM). Four building models are considered: P0, P1, P2, and P3. Model P0 has a 0.2 m thick thermal storage wall without PCM, while the other models contain PCM in the wall (PCM 1-M182/Q21, PCM 2-M182/Q25, and PCM 3-M182/Q29). The study focuses on the buildings’ performance in terms of heating and cooling energy consumption over one year at five locations in Serbia (Nis, Belgrade, Novi Sad, Kopaonik, and Zlatibor), depending on the type and position of PCM within the wall. The observed locations are found either in urban areas with moderately warm and humid climate or in mountain tourist centers with a humid boreal climate. The analysis of annual heating and cooling energy requirements of the building models in all locations with different climates (Koppen classification Cfa, Dfc, and Dfb), revealed model P3, with PCM 3-M182/Q29 within its wall to be the most efficient. Less heating and cooling energy is required for model P3 than for the other models. The total energy requirement for P3 is lower than P0 by: 1.90% for the Nis climate, 1.79% for the Belgrade climate, 1.77% for the Novi Sad climate, 0.91% for the Kopaonik climate, and 1.27% for the Zlatibor climate. Since model P3 was shown to be the best in terms of heating and cooling energy requirements, the positions of PCM within its wall were analyzed for each location, namely the PCM positions just beneath the exterior wall portion, in the middle of the wall, and just beneath the interior wall portion. The results showed that the mid-wall PCM position was the most efficient for each location. Compared to P0, the total energy requirement for P3 with a mid-wall PCM position is 2.37% lower in Nis, 2.41% lower in Belgrade, 2.14% lower in Novi Sad, 1.06% lower on Kopaonik, and 1.77% lower on Zlatibor.

PurposeOccupants are one of the most impacting factors in the overall energy performance of buildings, according to literature. Occupants’ behaviours and actions may impact the overall use of energy in more than 50%. In order to quantify the impact that occupant behaviour has in the use of energy, this study simulated interactions between occupants and the systems present in two actual buildings. The main aim was to compare the deviations due to occupant behaviour with the actual conditions and energy use of the two buildings.Design/methodology/approachThe buildings used as a case study in this research were green buildings, rated according to the Australian Green Star certification system as a 6-star and a non-rated building. The two buildings are university buildings with similar characteristics, from Western Sydney University, in Sydney, Australia. A comparison was performed by means of building simulations among the use of energy in both buildings, aiming to understand if the green rating had any impact on the energy related to occupant behaviour. Therefore, to represent the actual buildings' conditions, the actual data related with climate, geometry, systems, internal loads, etc. were used as input variables in the simulation models of the green and the non-rated buildings. Both models were calibrated and validated, having as target the actual monitored use of electricity.FindingsOccupants were categorized according to their levels of energy use as follows: saving, real and intensive energy users. Building simulations were performed to each building, with varying parameters related with lighting, plug loads, windows/doors opening, shading and air conditioning set points. Results show that occupant behaviour may impact the buildings' energy performance in a range of 72% between the two extremes. There is no significant relationship between the green rating and the way occupants behave in terms of the energy use.Originality/valueThis study intends to show the impact of different categories of occupant behaviour in the overall energy performance of two university buildings, a non-rated and a green-rated building, having as reference an actual representation of the buildings. Additionally, the study aims to understand the main differences between a green-rated and a non-rated building when accounting with the previous categories.

Aquatic centres are unlike any other type of buildings in terms of energy and water consumption. Aquatic centres can expend around seven times more energy for every square metre of building area compared to an average commercial office building and consume as much as 1,000 million litres of water each year. There has been insufficient research that examines the energy performance and water usage of aquatic centres worldwide compared to other types of buildings. Also, there are very limited studies that modelled an entire aquatic centre that has multiple indoor pools within a pool hall. The main difficulty is to model the interaction of water evaporation with the mechanical equipment which is not able to be controlled by most of the energy modelling software. Using the indoor swimming pool module integrated into the surface heat balance procedures in EnergyPlus 8.7, this paper investigates the factors that influence the energy and water performance of an aquatic centre in Victoria, Australia. Detailed information about the building envelope, electromechanical systems and operational data have been obtained from the aquatic centre. The model is calibrated against measured energy and water data (utility bills obtained from the aquatic centre). Parametric studies of several energy and water efficient features are undertaken. The simulation results revealed that the incorporation of solar pool-heating systems resulted in 15.4% energy reduction and the use of vacuum filters for backwash water usage resulted in 20% water reduction. Through creating detailed procedures and processes, this paper demonstrates that an aquatic centre can be modelled successfully despite its noted complexity.

Energy performance certificates (EPC) are obligatory for new and existing buildings in all European Union (EU) Member states, and provide not only the characteristics of individual buildings but ar...

This paper investigates the impact of uncertain shade behavior on three facades (east, south and west) on energy performance. A previously developed stochastic shade behavior model and an occupancy...

Ineffective policies, missing technical information, large volumes of inappropriate luminaires, malpractice and several such reasons act as a hinderance for the adoption of LEDs in road lighting design despite being the most efficient sources of light. In national roads, the decision makers are sometimes confused by the low efficacy values of the luminaires. The tools for lighting simulation and projects in street lights require several energy performance indicators as described in EN13201-5 which is a novel system. This paper presents an optimal evaluation technique that involves the environmental criteria and can be implemented in the future energy policy. Evaluation of lighting tender and lighting designs is performed using a decision tool while analysing the significance of these factors. The corresponding offers and their ranking is evaluated by the decision tool. Several environmental benefits as well as improved energy saving can be achieved on implementation of this system. Simulation results shows reduced emission of CO2 and 75% energy saving using the best solution.

The aim of this work is to analyse the thermal comfort and energy performance of a thermal heating chair for open plan office using field experiments, thermal comfort survey and energy simulations. A comprehensive review on the development of thermal chairs was carried out to highlight the present research gaps. The study developed a thermal chair prototype with controllable heating pads, incorporated into the back of the seat and back rest fabric. The field test was carried out in an office building in the UK during the winter. The study showed that the users set the thermal chair temperature between 29-45 °C. The field survey results of the thermal satisfaction survey showed that 19 out of 44 participants felt satisfied before using the device. While after using the thermal chair, the number of satisfied respondents increased to 34. The work also utilised Building Energy Simulation to further assess the thermal comfort and energy performance of the thermal chair. Three cases were simulated: non heated office chair with the zone thermostat maintained at 22 °C, non heated office chair with the zone thermostat at 16-20 °C and thermal chair with the zone thermostat at 16-20 °C.

This study focuses on energy performance investigation and environmental impact analysis of various new ecofriendly refrigerant blends as alternatives to high global warming potential refrigerant R22 theoretically. In this study, 23 refrigerants were considered at various composition. The present work considered the practical vapour compression refrigeration cycle for the performance assessment of various R22 alternatives. Essential studies such as toxicity, flammability, and total equivalent warming index of various novel refrigerants were also conducted in this study. Results obtained from practical vapour compression refrigeration cycle revealed that the energy efficiency ratio of refrigerants such as R1270 (2.860) and RB03 (R290/R152a of 60/40 in mass %) (2.854) was closer to the energy efficiency ratio of R22 (2.940). Volumetric refrigeration capacity (VRC) of R1270 (3293 kJ/m3) was similar to that of R22 (3297 kJ/m3) whereas VRC of RB03 (2908 kJ/m3) was almost similar to that of R407C (2925 kJ/m3) which was an alternative to R22. Compressor discharge temperature of RB03 was 15.78 ℃ lower when compared to R22. Flammability study revealed that all the new refrigerant blends (RB01 to RB04) were classified into weakly flammable (A2) and flammable (A3) category refrigerants whereas toxicity study revealed that all the investigated refrigerants were classified into non-toxic group (A). Refrigerant blend RB03 was less flammable compared to R1270. Total equivalent warming index analysis revealed that the environmental impact of R422A was 27.88% higher than R22 whereas RB03 has 4.97% lower environmental impact compared to R22. Overall, performance of refrigerant blend RB03 was better compared to 23 investigated refrigerants and it was very nearer to the performance of R22 and hence, it could be considered as an ecofriendly alternative to replace high global warming potential refrigerant R22 used in air conditioners.

This paper proposes an integrated simulation framework for both building design and energy performance analysis. Literature review shows that, although many studies exist, most of them did not full...

Altuntas, Onder/0000-0001-9271-1309; AKYUZ, MEHMET KADRI/0000-0003-0229-2943 WOS: 000538590700001 Airports are very important facilities for global transportation. Energy plays a key role for the comfort needs of passengers and the safe operation of aircraft. In airports with high energy consumption areas, energy management allows the reduction of both costs and environmental impacts. Therefore, the phenomena that affect energy consumption in airports need to be identified. In this study, the factors affecting energy consumption in airport terminal buildings were determined by regression analysis and mathematically modeling. In addition, energy-induced Global Warming Potential (GWP) was determined and its change was explained mathematically. It was seen that with each change in passenger causes a 1.59 kWh energy and 1.44 kg CO2 eq. change. However, each increase in the number of degree days causes a 3468.6kWh energy and 1428 kg CO2eq. increase. Mula Stk Kocman University Research Projects Coordination Office [19/079/06/2]; YDA Dalaman Airport This paper has been granted by the Mula Stk Kocman University Research Projects Coordination Office through Project Grant Number: 19/079/06/2. Authors would like to thank native speaker Anthony David PLANCHEREL who is a lecturer at Anadolu University for providing proof reading on this paper. Authors would like to thank YDA Dalaman Airport for their support.

The uncertainty and sensitivity analyses for multivariables of the optimal system based on deterministic parameters are necessary, as multivariables are full of uncertainties in the real operation. However, the generic methodology for multi-dimensional uncertainties quantification is rare, and the energy performance simulation is normally at high computational cost, especially considering a huge amount of parameters’ uncertainties. In this study, the on-site renewable electricity generation of an optimal hybrid renewable system based on deterministic parameters, was investigated, under high-level parameters’ uncertainties. A generic uncertainty quantification methodology was proposed using the two-dimensional Markov Chain Monte Carlo to quantify multi-dimensional uncertainties. A machine-learning based data-driven model, using the supervised machine learning with high computational efficiency, was developed to predict the on-site renewable electricity generation, and thereafter used for the uncertainty and sensitivity analyses. Compared with the deterministic scenario parameters, the cases with the scenario uncertainties can increase the peak power and the total amount of the on-site renewable electricity generation. This study proposes a novel generic uncertainty quantification methodology, together with a machine-learning based data-driven model for conducting the uncertainty analysis of an optimal renewable system based on deterministic parameters, which are important for the promotion of renewable and sustainable buildings.