Building Envelope Parameters Research Articles

Finding the gaps in design strategies and technological advancements for net-zero energy buildings development in India

The climate-adaptive net-zero energy building design is an effective trend for achieving a carbon-neutral environment and reducing global energy demand, especially, in India where building energy consumption recorded substantial growth in the past decade. This review article focuses on the development of net-zero energy buildings in tropical climates through the analysis of 44 real case studies. This study investigates the building envelope parameters, advance technologies, and their effectiveness on the building energy models. In the first phase of this study, fourteen net-zero energy buildings or high-performance buildings in the USA, China, and India considering energy-efficient design features and their significant effect on energy consumption have been examined. Moreover, the role of building simulation tools in improving energy efficiency is discussed. The second phase investigates the thirty best practices of net-zero energy buildings in tropical climates worldwide based on envelope choices, heating, cooling, and lighting features. Furthermore, this review discusses the evolving definitions, challenges, and inconsistencies in terminologies of net-zero energy building and illustrates India's initiatives towards net-zero development. The objectives of this review study are to highlight the challenges in building material research, advanced lighting, heating, ventilation, and air conditioning technologies, and integration of renewable energy compared to developed nations. Additionally, the gaps that are the barriers to the development of net-zero energy building in India have been identified. The review eventually concludes by providing policy recommendations and suggesting areas for future research to facilitate net-zero energy-building development in India.

Effectiveness of building envelope parameters and adopting PV panels to reduce reliance on local generators in hot-dry climate

The growing energy demand, associated with the inability of the current infrastructure to satisfy this demand, has presented numerous challenges in Iraq's electricity sector. As a result, there has been an increased dependence on local diesel generators to mitigate power outages in homes. However, these generators raise environmental concerns and are associated with high operating CO₂ emissions. Here, using the DesignBuilder and EnergyPlus simulation software, the effectiveness of different building envelope modifications and photovoltaic panels as alternative energy sources was examined. Specifically, the impact of wall and roof insulation, window glazing, and shading devices on energy efficiency was analyzed. The results indicated that roof insulation is the most effective in reducing energy consumption by 28.8%, followed by wall insulation by 13.01%, while the effect of windows glazing and shading devices was insignificant. Furthermore, the installation of solar panels led to a significant reduction in energy demand by 53.6%, thereby decreasing operating carbon dioxide emissions and providing a practical alternative to the use of local generators. Our study offers valuable insights into the design of energy-efficient residential buildings in hot and dry climates. It highlights the importance of selecting appropriate building materials and integrating renewable energy sources, presenting a more environmentally effective solution to mitigate energy shortages.

The Application of Rivet, HAP, and Ecotect Programs for the Analysis of Building Envelope Parameters to Optimize Energy Efficiency and Energy Savings: A Case of Baghdad-Iraq

With the growing emphasis on energy conservation and emission reduction in Iraq, there has been a rising focus on the consumption of energy in buildings. This phenomenon is attributable to its substantial contribution to aggregate energy consumption within society. Consequently, the primary focus of energy conservation research has been directed towards this particular domain. There has been a growing emphasis in energy conservation research on public buildings characterized by elevated levels of energy consumption. The examination of energy conservation in expansive public structures carries substantial practical significance and societal value. This study employs a building in Baghdad City - Iraq, as a case study. The research was centred on the execution of experiments pertaining to insulation, the ratio of windows to walls, and the thickness of window glass. A comparative analysis was undertaken through the implementation of simulations that considered the climatic conditions of the Baghdad- Iraq region. In order to evaluate energy efficiency, a variety of software applications were utilized, namely Revit, Ecotect, and Hap. The results showed that when analyzing the climate of Baghdad, it was observed that the total cooling savings ranged from 2.34% to 2.45%. As a result, it was determined that the optimal insulation thickness is 11cm. Additionally, it was observed that the energy savings in cooling remained consistent. The analysis of window-to-wall ratios has shown that the highest level of savings can be achieved by maintaining a window-to- wall ratio of 50%. During the calculation of window glass thickness, it was discovered that in the city of Baghdad, the ideal glass thickness is 2mm. This thickness leads to a 1% reduction in annual energy consumption for cooling purposes. The results of this study are significant as they can significantly contribute to reducing energy consumption. Furthermore, the authors highlight the potential for improving energy efficiency in the buildings situated within the specified study area.

Impact of building envelope parameters on occupants’ thermal comfort and energy use in courtyard houses

ABSTRACT Courtyard houses constructed recently with air-conditioning systems need to increase efficiency by simultaneously reducing thermal load and improving thermal comfort in all seasonal zones around the yard. The envelope design is one of the effective parameters in reducing energy consumption and increasing thermal comfort. Therefore, this study investigated the effect of some design parameters related to the envelope of the building on Predicted Mean Vote (PMV) and thermal loads. The design parameters were Wall Construction (WLC) and Window Construction (WID) with different U-values (thermal transmittance), Window to Wall Ratio (WWR), Depth of Shading (DSH), and the Number of Shading (NSH). This research proposed a parametric study process that can simultaneously help designers evaluate the PMV values and thermal loads of numerous design options in four seasonal zones around the courtyard and generate optimized design solutions. According to the results, the PMV of best design solution (BS) compared with the worst design solution (WS) increased by 8%, 9%, 8%, and 12% in different zones. The thermal load decreased by 21%, 26%, 22%, and 21%. According to the sensitivity analysis, PMV values for most zones were negatively affected (decreased) by WID.

Simulation-based sensitivity analysis of energy performance applied to an old Beijing residential neighbourhood for retrofit strategy optimisation with climate change prediction

Due to the high energy consumption in the building sector and the ever-increasing urbanisation rate, the demand for retrofitting old buildings in urban areas is increasing in China, especially in metropolitan cities like Beijing. However, despite national and local policies calling for extensive building retrofitting, it is a challenge to determine a cost-effective retrofit strategy. Considering this, the study establishes a novel approach that analyses the sensitivity of building energy consumption on parameters defining the materials used on the building envelope, as well as the solar shading and airtightness of the building. This research builds EnergyPlus models using geometric data captured from the map, building fabric data from local design standards, and a set of varying activity schedules, and carries out simulations to calculate the building energy consumption of a residential neighbourhood in Beijing, China. The energy consumption data is then used for a sensitivity analysis using the Morris Method on 14 building envelope parameters in total. For different building shapes, the sensitivity analysis results highlight that the energy is most sensitive to infiltration, followed by window U-value and window SHGC. The solar absorptances and U-values of external walls and roofs are also found to have a moderate influence on total energy consumption. By using predicted weather files, this research further discusses the changing influences of these parameters considering climate change over the next few decades. The approach of this research is instructive for the analysis of buildings in other cities in cold climate regions due to the generalisability of the studied neighbourhood, and the result has the potential to inform the building management teams and policymakers to determine suitable retrofit strategies.

Thermodynamic model of HVAC under building exterior wall

In order to solve the problem under the exterior wall of a building, the author proposes a thermodynamic model for HVAC. Scientific and technological progress has promoted social development, under the new development situation, people have higher requirements for living environment. In architectural design, residential environment design is the key content, especially the design of indoor temperature control system. With the continuous promotion of the national sustainable development strategy, the current architectural design pays more at?tention the green design concept, and the HVAC design is the key design content in realizing the green architectural design. In order to make HVAC design more scientific and reasonable, the author studied the concept that HVAC design needs to follow from the perspective of green buildings, and analyzed the specific ap?plication methods of HVAC design technology. The experimental results indicate that the building envelope parameters have a great impact on the building thermodynamic performance, and the annual cooling and heating loads of buildings should be comprehensively considered, reasonably determine the building envelope parameters. The building load has a low support value, so only low quality energy can meet the building load demand, when selecting the HVAC system, consider the matching of energy quality, try to introduce low grade energy, and improve energy utilization efficiency.

Optimization of energy transmittance through building envelope for hot dry climate

Fenestrations of the buildings are playing an important role in the building’s energy efficiency for the tropical climate. The energy that comes from the glass window into the building can be restricted by providing shading on the windows. So, to provide the shading on the window, the most common way is fixed shade like overhang and fin. Shading devices are very helpful to control the SHGC and light transmittance through the fenestrations of the building. Most of the studies analyze the impact of WWR, shadings, and SHGC on a building’s energy demand but did not consider the combined effect of these parameters. By considering all the parameters of the building envelope in the analysis like WWR, orientation, shading devices, projection factor, and type of glass, the energy demand in the building can be significantly reduced. The goal of this paper is to analyze the variation of residential envelope transmittance value with the window-wall ratio, projection factor, and fixed shading devices and also to optimize the energy from building envelope elements in residential buildings using a statistical method, namely the Taguchi method. The transmittance of energy through the building envelope is calculated in 8 cardinal directions by providing shading with the fin and overhang. Based on the result, the optimum energy saving achieved by selecting the optimum combination of the process parameters for minimizing the energy from the building envelope is A1B1C3D2 i.e. window to wall ratio 7%, triple glazing type of glass used, shading with the overhang fin, and orientation in the west direction. The result shows the most significant factor among the selected parameter is the window to wall ratio. Also, by focusing on the building envelope parameters, an architectural designer may reduce the building energy demand significantly and offer more alternatives to achieve energy-efficient buildings.

Energy and economical optimal of Nzeb design under different climate conditions of Türkiye

Numerous studies are being carried out in the literature to reduce the energy consumption of buildings under the concept of zero energy buildings. However, there is no neither widely accepted NZEB definition nor a specific design standard to achieve NZEB. This study proposes a complete design methodology from preliminary stage up until construction to achieve NZEB. In the proposed methodology, unlike the other methods, design process has been split into 2 stages. Prior to reaching zero energy balance by renewables, Pareto front solutions related to building envelope parameters were found at the first stage. Subsequently, renewable energy systems, including PV array and wind turbines, were integrated into building energy model and pareto optimal solutions have been obtained for NZEB. NSGA-II genetic optimization algorithm has been implemented with developed code, to couple optimization algorithm and energy analysis software (Energyplus), in Matlab environment. Diverse climatic conditions of Türkiye have been used since it allows simulating heating and cooling dominated building loads along with the balanced loads. Outcomes of the study showed that NZEB designs that have excess energy of up to 23 kWh/m2, 9 kWh/m2 and 3 kWh/m2 was achieved for hot semi-arid climate, Mediterranean climate and cold semi-arid climate, respectively. It was also revealed that although the share of renewable energy equipment in the initial investment cost, which corresponds to an average of 19% of overall initial cost, is not too high, the influence of renewable systems on both achieving the net energy balance and reducing LCC is very significant. Besides, the payback period of integrating renewables for NZEB is around 3.5 years if the proposed methodology is followed.

Sensitivity of buildings’ carbon footprint to electricity decarbonization: a life cycle–based multi-objective optimization approach

PurposeLife cycle assessment (LCA) is a widely used method for the evaluation of buildings’ environmental impacts, but these analyses contain high levels of uncertainty. Decarbonization of electricity production is key to reach climate goals, influencing all sectors including construction The objective of this paper is to study the sensitivity of the environmentally optimum building design solution to a changing electricity mix to assist decision-making.MethodsIn this paper, multi-objective optimization was applied to minimize the life cycle global warming potential and life cycle costs of a building at the same time, using dynamic energy simulation and LCA. The variables include building envelope parameters such as window ratio, insulation type and thickness in a typical new multi-family apartment building heated with a heat pump. A static, largely fossil-based electricity mix and a dynamic, gradually decarbonizing alternative are considered, as well as two electricity price increase scenarios. New metrics have been introduced to explore the results and describe the Pareto-optimal solutions, for example the improvement potential to contextualize the achievements through the optimization.Results and discussionThe results show that, with the current electricity mix, building envelope optimization can improve the design by 18% on average in terms of the life cycle greenhouse gas emissions compared to typical new designs and by 10% with a dynamic mix in Hungary. With today’s static electricity mix, the optimization proved that the minimum energy efficiency requirements in force are close to cost optimality. However, from an environmental point of view, much higher insulation thicknesses have been shown as justified (U-values of less than 0.1 W/m2K).ConclusionsOptimization of building design based on LCA is still not widely applied and the effect of a decarbonizing electricity mix on the optimum has not been studied before. The results of the paper demonstrate the importance of this question. Optimal solutions are different depending on the applied mix but an energy-efficient building envelope remains important: today’s cost-optimal building envelope proves to be both cost- and environmentally optimal in the long run.

Determination of Optimum Building Envelope Parameters of a Room concerning Window-to-Wall Ratio, Orientation, Insulation Thickness and Window Type

The building envelope includes all materials (glazing, external walls, doors, etc.) that separate the conditioned space from the outside environment. Building envelope characteristics significantly influence the energy consumption of buildings. In this study, research was carried out to find optimum building envelope design parameters, such as insulation thickness, orientation, glazing type, and the window-to-wall ratio of a room, using actual climatic data of two cities with different characteristics according to the Köppen climatic classification. The insulation thickness and the window type that minimizes the net present worth of the building façade over 20 years of a lifetime gave the optimum values. In addition, the effect of the various parameters, such as the infiltration rate through the envelope, room set-point temperature, and the fuel type, on the net present cost was also analyzed. It was found that appropriate selection of windows, orientation, and insulation thickness would lead to a significant reduction in the annual energy consumption. Despite having the lowest initial investment cost, the room with single glazed windows had the highest energy requirement and the net present cost. The building façade with double glazed windows, oriented towards the south-west, yielded the minimum net present cost in both locations. Results showed that the optimum external wall thickness is 9 cm in Hakkari (Dsa—Continental Climate) and 6 cm in Istanbul (Csa—Mild Climate).

Analysis on the Influence of Building Envelope on Building Energy Efficiency in Severe Cold Area

With the rapid development of the global economy, the world energy consumption is increasing day by day. Mankind is facing the problem of energy shortage. Energy conservation and emission reduction has become the focus of countries all over the world. In order to study the influence of building envelope on building energy efficiency in severe cold area, the sensitivity analysis is used to analyze the influence relationship between building envelope and building energy efficiency. Combined with DeST simulation software, the building model is established, and the arc mean elasticity method is used to analyze the sensitivity of building energy load to different building envelope parameters. The results show that the external windows of the building envelope have the greatest impact on the building energy efficiency, followed by the external walls, and the roof has the least impact on the energy efficiency. The sensitivity coefficients of the annual cumulative load to the external windows, exterior walls and roofs of buildings are 7.93%, 5.76% and 5.75% respectively. Studying the influence of enclosure structure on building energy efficiency in severe cold areas has important practical value for reducing building energy consumption in severe cold areas, and provides data reference for scientifically improving building energy efficiency and building skill transformation in severe cold areas.

SMART BUILDING ENERGY MODEL USING ARTIFICIAL INTELLIGENCE

This paper presents a Smart Building Energy Model of Residential Building using Artificial Neural Network model (ANN) to assist architects and engineers in selecting the optimum alternative design of building envelope parameters such that external wall and roof insulation material types and window types that minimizes the cost of energy consumption of a residential building to transform it to a green building.

Comparison between Energy Simulation and Monitoring Data in an Office Building

One of the most important steps in the retrofitting process of a building is to understand its pre-retrofitting stage energy performance. The best choice for carrying this out is by means of a calibrated building energy simulation (BES) model. Then, the testing of different retrofitting solutions in the validated model allows for quantifying the improvements that may be obtained, in order to choose the most suitable solution. In this work, based on the available detailed building drawings, constructive details, building operational data and the data sets obtained on a minute basis (for a whole year) from a dedicated energy monitoring system, the calibration of an in-use office building energy model has been carried out. It has been possible to construct a detailed white box model based on Design Builder software. Then, comparing the model output for indoor air temperature, lighting consumption and heating consumption against the monitored data, some of the building envelope parameters and inner building inertia of the model were fine tuned to obtain fits fulfilling the ASHRAE criteria. Problems found during this fitting process and how they are solved are explained in detail. The model calibration is firstly performed on an hourly basis for a typical winter and summer week; then, the whole year results of the simulation are compared against the monitored data. The results show a good agreement for indoor temperature, lighting and heating consumption compared with the ASHRAE criteria for the mean bias error (MBE).

Passive Energy-Saving Optimal Design for Rural Residences of Hanzhong Region in Northwest China Based on Performance Simulation and Optimization Algorithm

The rural residences of Northwest China are characterized by a state of high energy consumption and low comfort due to the limited economic level and awareness of energy-saving compared with the urban residences. To remedy this, appropriate passive design strategies should be adopted first, in order to provide a design mode with low energy consumption and low cost for rural residences under the premise of thermal comfort. In this paper, taking Hanzhong region (Shaanxi Province, China) as an example, we establish a benchmark model based on a field survey and develop an optimization process by combining EnergyPlus simulation software, the MOBO optimization engine, and weighted sum method. The action mechanisms of passive design parameters, including the building orientation, length–width ratio, building envelope parameters, external shading system, and window–wall ratio, on heating, cooling, and total energy consumption are analyzed, and the quantitative relationships between single-parameter and energy consumption are established. Then, the mutually restricted indices of total energy consumption and initial investment cost are taken as optimization objectives, and 17 design parameters are selected as the optimization variables. The NSGA-II algorithm is adopted to conduct the multi-parameter, multi-objective optimization design for rural houses in Hanzhong area, through coupling of the EnergyPlus and MOBO software. In this way, Pareto solutions are obtained and the value distributions of the multi-objectives and design parameters are analyzed. Based on the actual requirements of decision-makers and using the weight method, three design schemes focusing on different performance tendencies are proposed. The results indicate that by using the proposed optimization process, the building energy consumption can be significantly reduced while taking initial investment costs into account, where the energy-saving rate is in the range of 31.9–61.5%. When the EC/IC ratio is 1:1, 2:1, and 1:2, the energy-saving rate can reach 51.5%, 57.8%, and 43.5%, respectively. It can provide a beneficial pattern for the energy-saving design and renovation of rural residences in Hanzhong area of China.

Design and Energy Performance Analysis of a Hotel Building in a Hot and Dry Climate: A Case Study

In times of unprecedented climate change and energy scarcity, the design and delivery of energy-efficient and sustainable buildings are of utmost importance. This study aimed to design a hotel building for hot and dry climate conditions and perform its energy performance analysis using energy simulation tools. The model of the hotel building was constructed by a graphical tool OpenStudio and EnergyPlus following the ASHRAE Standard 90.1. To reduce the energy demand of the hotel, parametric analysis was conducted and building envelope parameters such as the thickness of insulation layer in the exterior wall and the roof, thermal conductivity of insulation layer, rate of infiltration, U-factor of windows, and thermal resistance of air gap in the interior walls (R-value), window-to-wall ratio, and orientation of the building were tested and the impact on the energy use of the building was analyzed. It was found that most of the design assumptions based on the ASHRAE standard were already optimal for the considered locality, however, were still optimized further to reach the highest efficiency level. Apart from this, three sustainable technologies—thermochromic windows, phase change materials, and solar panels—were incorporated into the building and their energy consumption reduction potential was estimated by energy simulations. Cumulatively, these sustainable technologies were able to reduce the total energy use from 2417 GJ to 1593 GJ (i.e., by 824 GJ or 34%). Calculation of payback period and return on investments showed that thermochromic windows and solar panels have relatively short payback periods and high return on investments, whereas PCM was found to be economically nonviable. The findings of this study are deemed to be useful for designing a sustainable and energy-efficient hotel building in a sub-tropical climate. However, the overall design and energy performance analysis algorithm could be used for various buildings with varying climate conditions.

Sensitivity analysis on energy performance, thermal and visual discomfort of a prefabricated house in six climate zones in Australia

In prefabricated buildings distinctive construction process and lightweight components affect design strategies and consequences. Therefore, to create more sustainable prefabricated buildings, it is important to understand the effects of their envelope parameters on energy performance and indoor environmental quality. Although previous research have investigated the effects of envelope on energy and indoor comfort outputs, the parameters of lightweight prefabricated envelope are not thoroughly considered. This article quantifies the effects of building envelope parameters on the energy use, thermal comfort and daylighting levels of a prefabricated house built in Australia. A building simulation model was developed and validated by comparing predicted with measured indoor temperatures of the house. The baseline performance for evaluation of energy consumption, thermal discomfort hours and daylight unsatisfied hours were carried out using Transient System Simulation (TRNSYS) tool. Series of regression-based sensitivity analyses (SAs) to identify the most sensitive parameters were conducted by coupling TRNSYS, jEPlus and SimLab. Applications in six climate zones were investigated. The important focus areas found by SA in each climate and their corresponding design responses can be applied across ranges of prefabricated building projects if built in similar climatic conditions. SA results revealed window glazing and shading among the most influential parameters on all targeted performance outputs. The relationship between sensitivity levels to energy consumption and degree days indicated that the type of window has a higher impact on the reduction of energy use in the cooling dominated climates while insulation of wall was found a more effective strategy in heating-dominated climates.

Investigation of a passive design approach for a building facility: a case study

ABSTRACT Educational buildings represent an indivisible part of every society, and it is necessary to make them energy efficient. In the current research on the energy-efficient retrofit of school buildings, the impact of several passive design strategies is studied. These interventions include improvement of the building envelope characteristics and parameters related to select passive design systems. In order to determine whether applying a green roof, double-skin facade, or Trombe wall, with or without shading contributes to heating and cooling energy consumption reduction, building energy performance was simulated using the EnergyPlus and jEplus software. This holistic approach takes into consideration parameters that may be critical for the success of the energy-efficient retrofit of school buildings. The results revealed which parameters provide the most significant heating and cooling energy savings of the modeled school buildings in local climatic conditions. By applying the appropriate combination of interventions, the heating energy saving can be up to 77%, while with a proper mix of the proposed measures, the maximum cooling energy savings are up to 79%.

Thermal and noise insulation performance interaction of building envelope during building simulation optimization in tropical climates

Building simulation optimization is being increasingly adopted by researchers and designers as an efficient methodology for early-stage design and selection of building envelope parameters. Thermal performance has been the focus of many of the proposed methodologies owing to large energy consumption in buildings to maintain thermal comfort for the occupants. While the envelope is optimized to enhance its thermal performance, the effect on its noise insulation performance is not paid any attention as both performance objectives are assumed to be non-interacting or non-conflicting. It may be possible that the optimization for thermal performance may lead to degradation in noise insulation performance or vice versa. The present work aims to study the interaction between the thermal and noise insulation performance of the building envelope during a building simulation optimization process when both the performance objectives are optimized independently and simultaneously. The results obtained show the adverse effect of independent thermal and noise insulation optimization on noise insulation and thermal performance of the building envelope walls respectively. An exception was observed in the case of independent noise insulation optimization of both 8-hour and 24-hour conditioned buildings where average thermal performance of the final population was enhanced along with the noise insulation performance.

Optimisation of building envelope parameters in a semi-arid and warm Mediterranean climate zone

There has been increased focus across the world on enhancing the efficiency of energy consumption in multiple sectors. The overall aim is to find solutions to eliminate problems caused by the expanding demand for energy while ensuring that natural resources are not depleted. This paper presents an optimisation of the parameters of the building envelope of a single-storey residential building in the semi-arid and warm Mediterranean climate zone of the city of Amman, Jordan. The objective was to achieve a reduction in cooling and heating loads while ensuring that the existing levels of thermal comfort can be sustained through the use of mechanical systems for cooling and heating. A typical Jordanian single-storey residential building with dimensions of 187 m2 was chosen to modify its design variables and examine their effect on the overall thermal performance. The process of optimisation was initiated by performing a simulation using DesignBuilder software, followed by a sensitivity analysis of 12 design variables to evaluate their importance for cooling and heating loads. An optimisation using the genetic algorithm was then implemented. The final results indicated that the total energy consumption could be reduced to 293.74 kWh/year (99.79 kWh/year in terms of the cooling and 193.95 kWh/year in terms of the heating), compared with 5225.97 kWh/year for the reference module (separated into 4075.41 kWh/year for the heating and 1150.56 kWh/year for the cooling).

Multi-objective optimization of building envelope components at the preliminary design stage for residential buildings in Turkey

This paper focuses on the multi-objective optimization of building envelope parameters in order to enhance the energy and economic performance of buildings. The study carried out for the climates zoned as; cooling dominated and heating dominated. All possible solution scenarios (more than 13 million) that might be encountered in practice, were included in the optimization process. Two conflicting objectives were pursued: to minimize overall thermal energy need and to lower the initial investment cost of the building envelope. NSGA-II genetic algorithm was implemented via developed code in Matlab environment and convergence time of that was shortened. Pareto-Front solutions were presented for two provinces (Osmaniye and Erzurum) of Turkey and life cycle costs of the Pareto-Front solutions have been compared, after the envelope optimization process. The results clearly showed that, the appropriate selection of the building envelope parameters at the preliminary design stage could significantly reduce life cycle cost, beside providing better solution options for zero energy buildings.