Improve Energy Performance Research Articles

Energy Efficiency Analysis of Building Envelope Renovation and Photovoltaic System in a High-Rise Hotel Building in Indonesia

The development of high-rise buildings worldwide has given rise to significant concerns regarding their excessive electricity consumption. Among the various categories of high-rise structures, hotels used for business and conferences stand out as particularly extravagant in their energy use. The consequence arising from excessive energy usage is an escalation in carbon emissions, which is a primary driver of global warming. Therefore, this study aims to investigate the energy use intensity (EUI) of a hotel building located in Jakarta, Indonesia. In order to improve energy performance, this study explored various options for renovating the building envelope, such as incorporating insulation and a roof covering, as well as implementing building-integrated photovoltaics (BIPV). The building envelope renovations demonstrated a notable reduction in energy use by 15.8–27.7% per year. BIPV, such as curtain walls and double-skin façades, generated an energy use reduction of 4.8–8.6% per year. Remarkably, by combining the two approaches (i.e., adding insulation and a roof covering in the building envelope and adopting BIPV as double-skin façades), the potential reduction in energy use reached up to 32.2% per year. The findings can assist decision-makers in developing building renovation strategies for high-rise buildings while considering energy conservation.

Renovation Wave in Europe: Low-Carbon Design for the Refurbishment of Social Housing in Southern Italy

The public housing stock, called social housing, in Italy was developed between the 1950s and the 1980s. As of today, the first residential developments are almost nearing their end-of-life age and are in need of urgent and intensive renovation. The European Commission, with the Renovation Wave, has set a goal of doubling the rate of building renovation over the next 10 years, reducing emissions, improving energy performance, and promoting decarburization. Renovation interventions, including structural, functional, energy, and plant upgrading interventions, etc., are to be preferred over integral demolition and reconstruction interventions, which have significant repercussions in terms of managerial and social discomfort. The case studies examined concern renovation interventions aimed at energy efficiency, functional adaptation of housing, as well as façade restyling. The design variants analyzed were evaluated in terms of CO2e emissions, according to life cycle inventory (LCI) and Environmental Product Declaration (EPD) approaches. This approach has a twofold purpose: to propose design guidelines, with low CO2e emissions, through hypotheses of variants in the case studies, and to propose, to the economic operators, economically advantageous bidding scenarios in the procurement process.

A novel intercooling carbon dioxide capture process using ionic liquids with ultra-low energy consumption

This study focuses on the use of ionic liquids as solvents for carbon dioxide capture due to their low energy demand. We screened an ideal ionic liquid, 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide ([emim][Tf2N]), based on its excellent absorption capacity and low viscosity. We performed thermodynamic modeling of the gas-liquid phase equilibrium to lay the foundation for process simulation. A basic process was designed for benchmarking performance, and various cases were compared by adjusting key operating parameters such as pressure and temperature. The results showed that the lowest specific capture energy achieved was 1.12 GJ/t at 20 bar and 5 °C. However, further improvements in energy performance were constrained by reduced absorption capacity and increased viscosity resulting from lower operating pressures and temperatures. To address these constraints, we proposed a novel process that optimized the temperature profile in the absorption column by dividing it into two sections with intercooling. This approach did not require significant changes to the base case but offered multidimensional benefits, including reduced energy demand and associated equipment costs. The specific capture energy was further reduced to 1.04 GJ/t. Economic analysis indicated that the capture cost at a production scale of 13.7 kt/a was 206 $/t but had the potential to be reduced to 82 $/t. The costs associated with compressors were found to be the major contributors to both equipment and capture costs. The proposed novel process demonstrates promising benefits and highlights the importance of further investigation into low-pressure operation.

Reducing energy consumption in a factory and providing an upgraded energy system to improve energy performance

The industrial sector is a major energy consumer worldwide. Much of this consumption is due to air conditioning systems. In regions with extreme temperature conditions, the electricity consumption of these air conditioning systems increases significantly. This study was carried out with the objective of calculating the total energy consumption of the factory and identifying methods to decrease it. Furthermore, an enhanced energy system is suggested to lower energy consumption. This study was carried out with the objective of calculating the total energy consumption of the factory and identifying methods to decrease it. Furthermore, an enhanced energy system is suggested to lower energy consumption. It is also evident that the cooling load decreases by 21,661 kWh when thermal insulation is applied to the walls. Utilizing double-glazed windows for the skylight roof can lead to a reduction in the cooling load by 822 kWh. Additionally, the use of Light-Emitting Diode (LED) bulb lamps in the factory can further decrease the cooling load by up to 14,717 kWh.

Maximizing Building Energy Efficiency Through Zone-Based Conditions: An Advanced Dynamic Simulation Approach

Abstract The primary objective of this research is to maximize the building energy efficiency by identifying the zone-based conditions and employing an advanced energy simulation model. It is possible to achieve this by reducing periods of excessive heating and cooling by utilizing a calibrated energy model with 15-minute measured data. Further, by regulating the energy consumption of various functional zones corresponding to the work schedules, building's energy system timetables, and the sensible temperature comfort requirements, additional energy savings can be achieved. To show the effect of dynamic simulation on building energy consumption, periodic 15-min temperature data were collected in different zones to be used both in the calibration of the energy model and in the improvement of the current energy profile. Mean bias error and cumulative variation of the root mean squared error were chosen as a performance indicator. Utilizing measured data, over-heated and over-cooled periods were defined by manually identifying zone-based indoor comfort conditions to predict improvements in overall building energy performance. The potential energy savings that can be achieved by largely eliminating over-heating periods are calculated. In addition, energy needs of different zones were considered and zone-based scheduling and zone-based comfort conditions were applied with the implementation of demand-side management. As a result, 17% energy efficiency can be achieved with an automated heating system that controls the indoor temperatures and ensures that the temperature is always kept at the desired level. As a further improvement, 32% energy efficiency can be achieved by applying zone-based scheduling and comfort conditions.

Structural Assessment for Improving Energy Efficiency in Public Buildings

Abstract This paper explores the pivotal role of structural assessment in enhancing energy efficiency within public buildings. Structural assessment, a systematic evaluation of building components and systems, is essential for ensuring safety, longevity, and sustainability. By identifying weaknesses and improvement opportunities, structural assessment provides valuable insights for stakeholders to enhance operational efficiency and compliance with safety standards. The symbiotic relationship between structural integrity and energy efficiency underscores the significance of prioritizing structural considerations in sustainable building design. Material selection, design principles, and maintenance practices are crucial factors influencing energy performance. Structural assessments aid in pinpointing critical issues contributing to energy loss, such as air leaks, thermal bridging, and inadequate insulation. Recommendations derived from these assessments enable targeted interventions to improve energy performance and occupant comfort. Case studies of three schools highlight the tangible benefits of energy efficiency retrofits informed by structural assessments. These retrofits result in significant reductions in energy consumption, enhanced indoor comfort, and a diminished carbon footprint. A structured strategy for conducting seismic structural assessments and subsequent energy efficiency improvements is proposed, emphasizing the importance of a comprehensive approach to building sustainability. In conclusion, structural assessment serves as a linchpin for advancing energy efficiency in public buildings. By leveraging insights from structural assessments, stakeholders can drive transformative change towards a greener and more sustainable future, fostering environments that promote human well-being and environmental stewardship.

Study on Improving Energy Performance in Patient Rooms at Existing Hospitals in Cairo

Study on Improving Energy Performance in Patient Rooms at Existing Hospitals in Cairo

Low carbon emission renovation of historical residential buildings

The urgency of renovating residential buildings in heritage conservation areas while addressing carbon emission reduction and energy performance has become a concern in the context of climate change. European directives stress the importance of enhancing existing buildings to achieve climate neutrality by 2050. An approximately 100-year-old wooden apartment building in the heritage conservation area in Võru, Estonia, was designed as a nearly zero-energy building (nZEB). This study examined the impact of different renovation scenarios, considering both embodied and operational carbon emissions. During the study, the technical requirements of the National Heritage Board were developed in several aspects. The results of this study indicate that it is possible to renovate buildings in heritage conservation areas and achieve great energy performance. In addition to improving energy performance, it is possible to make the restoration of a significantly damaged exterior with intermediate repairs more cost-effective for the owner. Deep renovation of a historical wooden building decreases its carbon footprint as it leads to more energy-efficient renovation solutions. This is because operational emissions dominate over embodied emissions in a cold climate. From an environmental perspective, it is more feasible to renovate historically valuable buildings more deeply than it is to upgrade the external appearance of buildings. Renovation work to achieve an nZEB building should include insulating the thermal envelope while restoring the historical appearance and preserving the original building profile. In conclusion, this study offers a comprehensive analysis of various scenarios, including carbon footprint, energy performance, and cost optimality, related to different renovation strategies for buildings located in heritage conservation areas. There is a need to align heritage board technical requirements with the environmental perspective. Given that major renovation is more cost-effective and better at preserving the exterior appearance compared to staged renovation, the former should be preferred to ensure the owner's willingness to pay.

The use of energy management ISO 50001 to increase the effectiveness of water treatment plants: An application study on the Zai water treatment plant

This study sought to determine the impact of implementing the energy management system ISO 50001 on the Zai Water Treatment Plant's energy efficiency performance and demonstrate how this implementation affected the cost and rate of energy consumption. The proposed study model contained three dependent variables—energy consumption, energy efficiency, and the cost of energy consumption. It also contained an independent variable—the energy management system ISO 50001. All these variables were used to develop various questions to help accomplish the study's goals. Planning was done by selecting pumping stations, selecting the most energy-consuming type of pump, and finally, choosing a pump maintenance project to improve energy performance. The researcher used the case of the Zai water pumping station as an example where the ISO 50001 energy management system was applied along with the stages of the Deming Cycle of management. Four pumping units from the Zai water pumping station served as the research sample for the study.•Find the impact of implementing the ISO 50001 energy management system on the energy efficiency performance of the Zai water treatment plant.•The effects of implementing ISO 50001 energy management system on cost and energy consumption at the Zai water treatment plant.•What effect does the ISO 50001 energy management system affect the Zai Water Treatment Plant's energy efficiency?After applying the ISO 50001 energy management system, several conclusions were drawn. Energy costs and consumption rates in the pumping units dropped while the energy efficiency in the chosen pumping units increased.

Optimization of the Air-Conditioning Energy Performance and Daylight Performance of AResidential Building According to the Bioclimatic Design Principles: An Application to the Moroccan Mediterranean

The bioclimatic architecture concept refers to an approach that takes into account the various characteristics of a building environment to make it more comfortable for its occupants. This work aims to improve the passive design parameters of an air-conditioned residential building located in the north of Morocco, in accordance with bioclimatic principles. The bioclimatic chart diagram is used to select the passive design measures that are the most appropriate for the north Morocco climate characteristics. Then, a set of design parameters are selected for more delimitation in the optimization study. The optimization problem is multi-objective and aims to find the design solution that simultaneously includes the best air-conditioning energy performance and daylight performance. The obtained results showed that the multi-objective optimum design solution is characterized by massive walls and roof, exterior insulation, double window glazing type, and a high summer ventilation rate. Also, a small glazing area with a large sun-shading covering is needed for the east facade. Ultimately, the building performance analysis revealed that the optimum bioclimatic design solution fully meets the requirements establishedby the Moroccan Building Thermal Regulation (MBTR), leading to an energy performance improvement of about 52%.

Development of a prediction-based scheduling control strategy with V2B mode for PV-building-EV integrated systems

Extending the energy boundary from the building-integrated photovoltaic to E-mobility is an effective alternative to further improve the integrated energy system performance. In this study, a new prediction-based scheduling control (PSC) strategy was developed considering vehicle-to-building mode for PV-building-EV integrated systems. The control strategies consisted of three components, model predictive control (MPC), simple operation mode, and schedule control. First, the MPC was based on the weather forecast, while the calculated daily renewable power generation and building energy consumption were used for mode selections. Second, the simple operation mode was based on system operation using conventional methods. Third, the developed scheduling control strategy was activated based on the periods of the day, involving different operating modes (e.g., V2B mode, renewable-to-building mode, etc.). Overall, the developed PSC can effectively improve energy performance and achieve cost savings. Validation tests were conducted for an office building, whose results showed higher renewable energy penetration and renewable power use efficiency at 9.56% and 30.48%, respectively. The levelized cost of energy (LCOE) values for building energy consumption and EV charging decreased to 0.4561 CNY/kWh and 0.6304 CNY/kWh, respectively. It indicated that the annual cost savings of building energy consumption and EV charging decreased by 16.5% and 42.7%, respectively.

A Parametric Modelling Approach for Energy Retrofitting Heritage Buildings: The Case of Amsterdam City Centre

The city of Amsterdam has ambitious goals to achieve a 95% reduction in carbon emissions by 2050 and to phase out natural gas by 2040. Disconnecting the building stock from natural gas requires well-ventilated and well-insulated buildings and a switch to renewable energy sources, making optimal use of heat pumps and sustainable heating solutions available locally. Most buildings in the historical city centre are protected and often insufficiently insulated, leading to increased energy use and a poor thermal environment. Standard retrofitting interventions may be restricted, requiring new approaches to balancing the need for energy efficiency and the preservation of heritage significance. With the case of the Amsterdam City Centre, the goal of this research is to present a parametric modelling approach for energy retrofitting heritage buildings and to identify minimum requirements for preparing the residential stock to lower temperature heat (LTH). Using parametric design and bottom-up energy modelling, the research estimates that a 69.1% of natural gas reduction could be achieved when upgrading the buildings to lower temperature (LT). Results of this paper also demonstrate how the applied approach can be used to guide decisions on the improvement in energy performance of the historic built environment.

Technical State, Renovation Need and Performance of Renovation Solutions of Estonian Wooden Log Houses

The wooden log house serves as a prevalent architectural archetype in rural regions of several Nordic and Baltic countries. To ensure the long-lasting nature of these buildings, proper maintenance is imperative. However, in order to meet the evolving expectations of residents and minimize the environmental impact, a deep renovation is currently required. To successfully achieve the goals of this renovation wave and effectively address the personal needs of the homeowners, it is crucial to develop systemic renovation solutions that can be offered through a digital renovation passport. Consequently, the purpose of this study is to identify common damages, renovation requirements, and evaluate current renovation practices. The findings will serve as a crucial resource for the development of a digital renovation passport. In our study, we utilize rural wooden log houses (comprising 208 houses, 4 years of data) as our research subject. The building elements that are most in need of renovation are the external walls, roofs, and foundations, which require renovation in 77%, 63%, and 63% of the buildings, respectively. The primary cause of damage to the vulnerable structures is excessive moisture. Additionally, decay in the foundation can be attributed to factors such as erosion of mortar, frost, insufficient plinth height, inadequate foundation depth, and inadequate moisture protection. Recommendations provided by consultants primarily focus on restoring and preserving the dwellings' original architectural appearance. As a result, they are deemed insufficient in terms of improving energy performance and indoor climate. This lack of comprehensive consultation is concerning as it fails to consider the potential for cost efficiency, minimizing disruption to occupants, and achieving a comprehensive end result. The absence of recommendations for enhancing indoor climate, energy efficiency, general living quality, and reducing the building's carbon footprint performance the necessity for such renovation solutions and the importance of educating professionals and homeowners. The study's novelty lies in the establishment of statistical probabilities for damages and their causes, as well as the assessment of renovation and maintenance needs and the quality of existing recommendations. Results are scaled to the Estonian building stock, showing the renovation need on national scale. The findings can be incorporated into the digital renovation passport, along with specific renovation goals related to a given house.

An Evaluation of the Luminous Performance of a School Environment Integrating Artificial Lighting and Daylight

The energy performance of buildings has been extensively studied at the Federal University of São Carlos, Brazil in order to achieve energy conservation and reduce environmental impacts. Artificial lighting is one of the systems that consume the most electricity in educational buildings; therefore, by adopting measures to improve energy performance, the luminous performance can also be improved. Artificial lighting allows for visual tasks to be accurately and safely carried out by means of lamps of varied temperatures, color rendering index, and luminous performance. Providing adequate lighting in school environments can influence both the health and well-being of school members, contributing positively to productivity. The present study aimed to evaluate the luminous performance of the existing artificial lighting system in a classroom by considering the minimum requirements recommended by the Brazilian standard NBR ISO/CIE 8995-1/2013. Through computer simulations using the DIALux evo program, it was possible to propose actions to improve the existing lighting system in order to offer better visual comfort to users and ensure electricity savings. The artificial lighting system consisted of LED luminaires integrated with daylight and the use of a manual control device, thus generating electricity savings of almost 65% when compared with the existing artificial lighting system in the room.

Influence of urban density on energy retrofit of building stock: case study of Spain

ABSTRACT Energy retrofitting of existing buildings plays a key role in the European targets of Green House Gas reduction. The addition or substitution of construction materials is needed to improve energy performance of buildings and its environmental impact must be considered. This paper proposes a model for the assessment of the environmental impact of neighborhood retrofit in relation with urban density. The model is based on the decomposition of buildings into functional elements and the quantification of construction materials used in building energy retrofitting. As a novelty, the need of road rehabilitation was also considered. The environmental impact was assessed in terms of Embodied Energy (EE) and Embodied Carbon (EC). The operational energy after retrofit was also calculated. The results bring the evidence of the relation between the urban density and the EE and EC derived from building retrofit, which can be up to 60% higher in low density areas. The sensitivity analysis carried out demonstrates the influence of the urban compactness on the environmental assessment results. The model proposed can assist in the design of retrofit plans at urban level by highlighting those retrofit measures with most significant environmental impact depending on the urban density.

Improvement in energy performance from the construction of inlet guide vane and diffuser vane geometries in an axial-flow pump

Advanced inlet guide vane (IGV) and diffuser vane (DV) geometries were constructed in an effort to increase the energy performance of an axial-flow pump at the best efficiency point (BEP). DV setting angles were also investigated to increase energy performance at the off-design points. By integrating the advantages of an adjustable IGV, combinations of adjustable IGV and DV geometries were constructed and thoroughly analyzed by way of energy loss. The asymmetrical geometry of the IGV, upgraded through the use of a hydrofoil profile, resulted in higher hydraulic performance compared to that of the reference model. The efficiency and total head at the BEP increased significantly with the implementation of the new DV, by 1.456% and 5.756% over those of the reference model, respectively. Using the new DV reduced the unsteady turbulent flow behind the trailing edge of the DV under all flow rate conditions, resulting in a reduction in vibration and noise. The positive setting angles of the DV increased the energy performance in the high-flow-rate region, whereas the negative DV setting angles produced a good performance in the low-flow-rate region. Combining an adjustable IGV with an adjustable DV model resulted in a significant increase in the total head, with more optimal energy performance provided by the positive IGV setting angles. At the BEP and under high-flow-rate conditions, the low-velocity zone is closely related to high entropy generation. Furthermore, these high-entropy generation regions follow the trajectory of the low-velocity zones. However, the low-velocity zone is not strongly associated with the high-entropy generation region when operating under low-flow-rate conditions.

EPBD 2023, F-GAS 2024, Eco-design and safety standards: Which design margins to be compliant with? An assessment of heat pumps for cooling

To decarbonize Europe achieving almost zero emissions in 2050, more stringent regulations are going to be applied. Particularly, Europe is investing in the emissions’ re-duction of buildings (existing and new ones), and strong improvements in energy performance of building are expected according to novel energy performance of building directive (at last phase of negotiation). At the same time, the production and use of fluorinated gases will be further reduced with the novel F-Gas regulation (under Parliament approval). New F-Gas will affect remarkably the small size, air-to-air split systems for air-conditioning, since no fluorinated gases will be used after 2035, forcing manufacturers to the use of natural refrigerants. Being propane the most efficient among the non-toxic natural refrigerants, less refrigerant would be charged into systems according to current safety standards: this would potentially reduce the heat transfer surfaces and, consequently, for the same capacity, the energy efficiency or, for the same efficiency, the capacity would decrease. In this paper, some scenario analyses, complying with actual and future plausible dispositions, are presented, in order to showing the margins for de-sign and commenting criticalities. In particular, the optimal design options are proposed for different fluids, in terms of costs vs energy performance, under representative cases, in terms of weather conditions and building types in Italy (existing ones and new ones respecting high-efficiency standards, trying to meet the requirements of hypothesized national law following the draft of the novel EPBD).

Timber-Based Strategies for Seismic Collapse Prevention and Energy Performance Improvement in Masonry Buildings

This study investigates the effectiveness of a range of timber-based solutions for the seismic and energy retrofitting of existing masonry buildings. These solutions are designed not only to prevent structural collapse during earthquakes but also to create integrated interventions that enhance thermo-physical performance and reduce emissions in existing buildings. Various case scenarios were considered and both mechanical and energetic behaviour post-intervention were evaluated. Timber-engineered products serve as foundational components for the retrofit approach, encompassing one-dimensional vertical elements (strong-backs) and various types of panels (cross-laminated timber panels, laminated veneer lumber panels, and oriented strand board panels). The analyzed retrofit techniques share a common principle involving the attachment of these timber-based elements to the building’s wall surfaces through mechanical point-to-point connections. The proposed solutions integrate strong-backs and timber panels with membranes and insulation layers, yielding cohesive, and highly effective interventions. Finite element modeling was employed to analyze the mechanical and thermal responses of the retrofitted walls. A comprehensive comparative analysis of various techniques was conducted to determine the most effective solution for each specific scenario.

Performance analysis of a new combined absorption-adsorption refrigeration system to improve energy performance

Performance analysis of a new combined absorption-adsorption refrigeration system to improve energy performance

Optimization of Mechanical Thermal Energy Audit At Pelabuhan Ratu Unit 2 With Pi Vision

The percentage of coal PLTUs in Indonesia reached 45% of the capacity of 64,000 MW in 2018, and in the Java, Madura Bali (JAMALI) system it reached 74.84% of the total generating capacity of 46,958 MW in 2023. It is projected that coal PLTUs will continue to dominate the generation sector with a contribution of 50% of total generating capacity in 2050. The energy crisis is a strategic issue in current national development both in terms of price and availability. This is of course a result of the condition of world oil supplies which has an impact on domestic fuel conditions, considering that the majority of domestic fuel needs must be imported from other countries. This research aims to analyze the deviation of NPHR in the conditions of actual performance test results with commissioning, analyze the factors that cause an increase in NPHR, analyze the contributing contribution of each factor that causes an increase in NPHR by designing correction and reference factors related to the influence of changes in the main operating parameters of PLTU equipment on NPHR and look for energy saving opportunities and prepare recommendations for improving plant efficiency performance. This research was conducted at the coal-fired PLTU Pelabuhan Ratu Unit 2 which has an installed power capacity of 350 MW gross and is located in Sukabumi, West Java. In this research, an analysis of the boiler, turbine-generator, condensate, and feedwater systems was carried out. Actual data was obtained through a performance test procedure carried out under maximum load conditions of net capacity (DMN) for 2 hours in November 2022. Based on the research that has been carried out it can be concluded that there was an increase in NPHR during the actual performance test compared to the baseline of 72.38 kcal/kwh, from 2,621.82 kcal/kwh to 2,694.20 kcal/kwh. The increase in NPHR has the potential to result in potential energy losses equivalent to IDR 15,365,850,000 per year. 3. Overall there are 7 goals for improving energy performance with improvements without investment, 4 improvements with low costs, and 4 improvements without costs. The total potential reduction in NPHR, if all recommendations are implemented, is 86.78 kcal/kWh or equivalent to a reduction in potential losses of IDR 44,792,896,565 per year with a total required repair cost of IDR 9,305,960,000.