Envelope Design Research Articles

Nudging debtors with non-performing loans: Evidence from three field experiments

This study aims to explore how various nudges that have successfully increased the payment discipline among borrowers with performing loans affect the behavior of the defaulted debtors. In three field experiments involving 32,000 borrowers, debtors were randomly assigned to receive reminders that used personalized language, mentioned economic consequences, and prosocial motives. In one experiment, the design of the envelope varied. The experimental results show that simply nudging defaulted individuals does not work. Although every next reminder that debtors receive increases the payment rate, the effect is rather small. Moreover, sending reminders when the promise to make a payment on a debt has already been made can trigger a repeated default. I also find that a red envelope design backfires on collection efforts. The findings offer a fuller understanding of the behavior of defaulted debtors and suggest policy implications in debt repayment and recovery of non-performing loans.

Hospital indoor air quality and its relationships with building design, building operation, and occupant-related factors: A mini-review.

Indoor air quality (IAQ) has recently gained substantial traction as the airborne transmission of infectious respiratory disease becomes an increasing public health concern. Hospital indoor environments are complex ecosystems and strategies to improve hospital IAQ require greater appreciation of its potentially modifiable determinants, evidence of which are currently limited. This mini-review updates and integrates findings of previous literature to outline the current scientific evidence on the relationship between hospital IAQ and building design, building operation, and occupant-related factors. Emerging evidence has linked aspects of building design (dimensional, ventilation, and building envelope designs, construction and finishing materials, furnishing), building operation (ventilation operation and maintenance, hygiene maintenance, access control for hospital users), and occupants' characteristics (occupant activities, medical activities, adaptive behavior) to hospital IAQ. Despite the growing pool of IAQ literature, some important areas within hospitals (outpatient departments) and several key IAQ elements (dimensional aspects, room configurations, building materials, ventilation practices, adaptive behavior) remain understudied. Ventilation for hospitals continues to be challenging, as elevated levels of carbon monoxide, bioaerosols, and chemical compounds persist in indoor air despite having mechanical ventilation systems in place. To curb this public health issue, policy makers should champion implementing hospital IAQ surveillance system for all areas of the hospital building, applying interdisciplinary knowledge during the hospital design, construction and operation phase, and training of hospital staff with regards to operation, maintenance, and building control manipulation. Multipronged strategies targeting these important determinants are believed to be a viable strategy for the future control and improvement of hospital IAQ.

Use of double skin façade with building integrated solar systems for an energy renovation of an existing building in Limassol, Cyprus: Energy performance analysis

The high percentage of energy consumption by fossil fuels in the building sector in combination with climate change across the globe increased the need to move into more sustainable building practices. Thus, the integration of sustainable strategies and active solar energy systems into the design process is becoming a tool for the reduction of the energy demand and improvement of the energy performance of existing and new buildings.This study investigates the energy performance of an existing residential apartment building in Limassol, Cyprus before and after its energy renovation, using a double skin façade combined with building integration of active solar energy systems. The proposed research starts with the analysis of the existing building energy performance, focusing on the energy loads for cooling, heating, and artificial lighting. Subsequently, the results of the existing situation are evaluated using digital energy simulations, and the process moves on to the renovation and energy upgrade of the building by integrating the aforementioned systems. Energy-Plus simulations are performed where the proposed systems’ contribution to the energy reduction is investigated including their energy reduction potential. The before and after simulations are compared, with the focus to prove whether the systems can be viable in terms of decreasing the energy demands of the building. Finally, a life cycle cost (LCC) analysis is performed, to determine the viability of the enterprise. The performed research proves that the application of the double façade, consisting of three main features — a building integrated photovoltaic system (BIPV), glazing system and rambling planting, can combine the positive effects of each individual system, if there is a combined systematic approach on the architectural design of the building envelope. The combination of the above led to a reduction of 83.5% in the energy consumption of the building, from 94,321 kWh of the existing situation to the 15,563 kWh of the proposed one. This reduction includes the contribution from BIPV system, which amounts to 26,706 kWh/ year of primary energy — thus covering the 63% of the proposed consumption of the building. On the other hand, the LCC analysis sums that a careful combination of bioclimatic design and active solar systems, can have a viable payback period, which in this case is 13 years.The overall aim of this research is to determine whether the use of a double skin façade combined with integrated active solar systems constitute an energy and cost-efficient solution for the viable refurbishment of an existing building in the south-eastern Mediterranean area.

A Holistic Framework for Determining the Trade-off between Embodied and Operational Carbon Emissions of High-rise Residential Buildings

Buildings’ carbon emissions consist of embodied carbon (EC) associated with the production and transportation of materials and operational carbon (OC) generated from consumed energy during daily use. However, previous studies concentrated on either EC or OC but ignored an integrated analysis of their relationships. Therefore, this paper aims to explore appropriate building envelope design solutions by examining the trade-off between EC and OC of high-rise residential buildings. To achieve this aim, the life cycle assessment method was used to evaluate the EC and OC of the residential buildings using SimaPro and DesignBuilder software. A building information modelling (BIM) model was developed to extract the geometric data and material consumption. A typical 30-story public residential building in Hong Kong was examined. The EC and OC of the case building were calculated as 561 kg CO2e/m2 and 50.18 kg CO2e/m2/yr, respectively. Different low carbon design scenarios were identified from the literature review and the semi-structured interviews with designers and contractors. Results indicate that low carbon concrete is an effective approach for not only reducing the EC by 5%-15%, but saving a mild percentage of OC, and is therefore encouraged. However, changing the thickness of external walls leads to a very limited life cycle carbon reduction (0.99%). Lower U-value of envelopes is recommended as 2.84% and 2.89% life cycle carbon is reduced when adopting insulations for external walls and triple-glazing windows. The findings are valuable for examining the relationships between EC and OC and can support low carbon building decision-making.

Impact of built-in moisture on the design of hygrothermally safe cross-laminated timber external walls: A stochastic approach

In terms of hygrothermal performance, solid wood panels composed of cross-laminated timber (CLT) are sensitive to moisture. However, to the best of our knowledge, no clear indications of critical initial moisture conditions for CLT envelopes regarding the dry-out of built-in moisture have been provided. Therefore, our main objective was to set critical limit values for CLT external wall design in terms of their initial moisture content (built-in moisture) and dry-out capacity (vapour resistance of wall layers) using a stochastic approach. The focus is on five types of CLT external walls that differ in their dry-out capacity. The key factors in the hygrothermally safe design of the CLT external envelope are sufficient dry-out capacity and control of the CLT initial moisture content level during the construction phase. The results of our stochastic analysis confirmed that a high initial moisture content in CLT causes a high mould growth risk when CLT is covered with vapour tight layers. Therefore, the limit values for critical initial moisture content of CLT and the water vapour resistance of the wall layers that ensure dry-out capacity of different external walls to prevent the risk of mould growth on the CLT surface in a cold and humid climate were determined. These limit values take into consideration the weather conditions during the construction phase and classes of material sensitivity to mould growth.

On the tradeoffs between embodied and operational carbon in building envelope design: The impact of local climates and energy grids

The building envelope has a substantial influence on a building’s life cycle operational and embodied carbon emissions. Window-to-wall ratios, wall assemblies, shading and glazing types, have been shown to have a significant impact on total emissions. This paper provides building designers, owners, and policy makers with actionable guidance and a prioritization framework for establishing co-optimized lifecycle carbon performance of facade assembly components in a broad spectrum of climate contexts and energy carbon intensities. A large parametric study of building envelopes is conducted using building performance simulation and cradle-to-gate embodied carbon calculations in 6 US cities. The authors derive the total carbon emissions optimization for commercial office and residential space types using standard code-reference models and open-source lifecycle data. Comparisons between optimal total carbon solutions and (i) optimal operational carbon and (ii) minimum required assemblies, show the impact of under and over investing in envelope-related efficiency measures for each climate. Results show how the relationship between embodied and operational carbon is highly localized, that optimal design variables can vary significantly. In low carbon intensity energy grids, over investment in envelope embodied carbon can exceed as 10 kgCO2e/m2, while under investment in high carbon intensity grids can be higher than 150 kgCO2e/m2.

Identification of the key design parameters of Zero/low energy buildings and the impacts of climate and building morphology

Load reduction is a fundamental means for achieving the zero/low-energy goal of buildings and for accomplishing carbon-neutrality. However, there is a lack of systematic and comparative study on the key design parameters of building envelopes, particularly under different climate conditions and building morphologies. In this study, the most influential design parameters of high-rise and low-rise buildings in different climate zones are identified by sensitivity analysis and the impacts of climate and building height are studied and compared. The sensitivity analysis is performed using Morris, while a total of thirty-five design parameters under five categories are considered. Five Chinese climate zones covering three typical climates in the world are researched. A wide range of local design and operation constraints are considered when evaluating the building performance in different climate zones. Furthermore, the key design parameters affecting winter thermal discomfort in the climate zones typically without heating provision are also identified. The impact of thermal bridge on building energy performance is further investigated. A remarkable finding is that the overhang is among the most important elements of the high-rise buildings in all climate zones concerned, while skylight is among the most influential elements of the low-rise buildings concerning building load. The results of the studies provide valuable references for the building envelope design for different climate conditions.

A literature review on thermal comfort performance of parametric façades

Thermal performance is a major part of the building envelope and is getting more attention globally. Nowadays, parametric design methods are used in building envelope design, such as facade design, for optimization of building envelopes, which could affect thermal performance and energy consumption. Moreover, new technologies applied to building design have not only changed the appearance of cities but also increased occupant comfort. This paper illustrates a systematic review that explains some tools and techniques that have been used in recent years to improve thermal comfort by applying parametric design panels to a second skin façade for residents. It attempted to collect and synthesize the most relevant evidence and methodologies. In this paper, 30 articles have been analyzed. They are classified by methodologies, years, and climate zones. Results suggest that simulation is the most accurate in comparison with other methodologies.

An assessment of the impact of passive design variations of the building envelope using thermal discomfort index and energy savings in warm and humid climate

Over the years, the commercial buildings sector has emerged as one of India’s fastest-growing sector and the commercial space is expected to grow four fold between 2015 and 2030. Due to the absence of thermal comfort regulations in India, designers frequently overdesign cooling systems in accordance with international norms, leading to unsustainable practises and energy wastage. The conventional building construction in India’s warm and humid climate make people uncomfortable due to heat gains, forcing the use of cooling equipment that require a lot of energy. Use of passive design options in the building envelope is thought to be a viable strategy for lowering energy usage. The different effects of building exterior components and passive design solutions on the indoor thermal environment can be effectively integrated using the criterion of thermal comfort. A new thermal discomfort index based on adaptive comfort using the numerical method and trapezoidal rule is established and used as a basis of comparison to assess the relative performance of building envelopes. In comparison to the reference building envelope in warm, humid climate, the research shows that careful attention to building envelope design with consideration of various passive options can improve the indoor thermal environment by 5.82 °C, reduce thermal discomfort by 80.75 percent and save energy up to 77 percent.

Low-energy building envelope design in Lebanese climate context: the case study of traditional Lebanese detached house

Low-energy building envelope design in Lebanese climate context: the case study of traditional Lebanese detached house

Identifying relative importance of solar design determinants on office building façade for cooling loads and thermal comfort in hot-humid climates

Solar radiation makes great influence on cooling load and occupants’ well-being in hot and humid climate zone. Particularly, occupants suffered different extent of solar radiation owing to their positions; thus, assessing the spatial and temporal thermal comfort is essential. It is worthwhile to identify the relative importance of passive solar design parameters for building envelope that these parameters directly affect thermal comfort and energy use. This study confirmed the distribution frequency of cooling loads and temporal thermal comfort usability of the simulation cases in selected cities based on the MRT algorithm that considered the impact of solar radiation. Based on the results, sensitivity analysis was used to analyze the relative importance of passive solar design parameters to clarify the priority when drawing up the façade design strategies. Eventually, correlation among facade parameters, energy use, thermal comfort, and geographic location is revealed. Furthermore, the improvement potential for energy-saving and thermal comfort by adjusting the variables in specific ranges is also demonstrated. The results indicated that within all selected cities, adjusting glazing type makes greatest influence on improvement potential that ranges from 22.8% to 39.5% in annual cooling load and 58.6%–87.5% in temporal thermal comfort usability, whereas the improvement potential for orientation is weaker than other parameters. Moreover, the absolute effect of solar design determinants is also disclosed respectively to discuss the importance of each parameter. Comprehensively, the proposed findings are expected to act as instruction when formulating the passive building envelope design related to solar radiation.

Modeling and demand-based control of responsive building envelope with integrated thermal mass and active thermal insulations

The static nature of current envelope design and operation is diametric to the mutable and transient forces and energies acting on our building stocks. Responsive building envelopes (or RBEs) have shown substantial energy saving potential for buildings by adaptively providing passive cooling/heating. In this research, an easy-to-implement yet flexible ‘demand-based’ control rule is proposed based on demand analysis to optimally control RBEs that integrate active insulation systems (AISs) and a sensible thermal energy storage (TES) layer. The controller developed herein calculates the desired thermal resistance for AIS layers and provides on-demand control of the heat flow into and out of the thermal mass to reduce AC load. It provides several benefits over the simple temperature-based controllers while does not require the complex formulation as needed for model predictive control. To quantify the thermal behavior and energy performance, a thermal network model is developed for RBEs to perform wholebuilding energy simulations of a residential thermal zone in six representative cities in the US. The results show apparent benefits of demand-based control strategy over traditional temperature-based control by offering higher energy savings and LPD reduction, especially in mild climate zones and during transitional seasons. Some design and implementation considerations for REBs with integrated AISs and TES are also discussed.

Finite element analysis of beam optics, high voltage ceramic seal and focusing magnet for CEPC C-band 80 MW klystron

For CEPC LINAC, the first 80 MW class klystron at C-band (5720 MHz) has been proposed to accelerate a high-current beam at an acceleration gradient of 45 MV/m. This paper discusses the design and simulation of beam optics, beam envelope, drift tube, and solenoid of the klystron. Space charge beam current of 390 A at an acceleration potential of 410 kV is obtained with average cathode loading of less than 6.0 A/cm2. The maximum surface electric field at the beam optics and high voltage ceramic seal have been evaluated less than 22 kV/mm and 4.50 kV/mm, respectively. The electron beam with an average beam radius of 5.40 mm has successfully been transported to the interaction cavity with beam ripple rate around 4.0% with low scalloping factor and a fill factor of 0.670. 2-D, DGUN & POISSON simulations results are validated by the 3-D CST simulation and found in agreement.

Evaluating Danish undergraduate and postgraduate choice for flap designs utilised in third molar surgery

AbstractIntroductionThe surgical removal of an impacted lower third molar (LM3) is a common operation that generally requires the elevation of a mucoperiosteal flap. The triangular and envelope flap designs have been extensively studied and are mostly described in the literature. However, in Denmark, a technique where the papilla between the adjacent second and first molar is spared (papilla sparing flap [PSF]), is used. This has limited presence in the literature. The aims were to identify which flap dental students and professionals utilised in LM3 removal, and to evaluate the evidence‐based approach that was taken.Materials and MethodsDental students and dental professionals were invited to complete a 10‐item questionnaire on flap technique in third molar removal.ResultsThe majority of respondents were dental practitioners (N = 141) stating that they used the PSF design. Almost half that undertook the PSF were aware of the envelope and triangular designs. The majority (N = 159) did not know where to locate the body of evidence to support their technique.ConclusionThe majority (N = 131) of respondents used the PSF. To align to a more evidence‐based approach, it may be that a re‐evaluation of the design taught/used is needed, which can also aid in better predicting postoperative outcomes.

Bina Kabuğunda Isı Ve Ses Yalıtım Performansı Optimizasyonu: Antalya 100.Yıl Bulvarı Üzerinde Bir Bina Örneği

The most important point to be considered in terms of ‘sustainability’ and ‘energy conservation’ in a building is the design of the building envelope. Although the importance of thermal and sound insulation in the envelope has increased in Turkey, various problems are experienced due to regulations that have not been strictly implemented. In particular, the fact that people spend most of their time at home due to the COVID 19 pandemic has increased the importance of indoor comfort conditions. In order to increase user comfort, the first thing to do is to take the necessary measures for sound and thermal insulation, which have different physical working principles and parameters on the facades of existing buildings. It is important to design optimal facades that will meet the needs of both types of insulation. In this study, the existing building stocks that emerged as a result of the deficiencies in the zoning plans within the settlement pattern of Antalya 100. Yıl Boulevard are examined. Necessary improvement suggestions are presented in order to increase the performance, depending on the envelope. Within the scope of the study, both insulation performances of the facades are compared and solutions for the optimal envelope design were revealed.

Constraint handling methods for a generative envelope design using genetic algorithms: The case of a highly constrained problem

The use of genetic algorithms as generative and performance design techniques often involves, in practice, constraint handling, which can be a complex task. Moreover, environmental simulations are computationally expensive and managing constraints can avoid wasting time on infeasible solutions. Despite these two incentives, and the benefits of an immense literature, both applied and theorical, on constrained optimization, there are only few guidelines and tools directly applicable by architects to address this issue. This paper proposes to fill this gap by identifying, classifying, and implementing different constraint management techniques available to architects. Seven methods have been tested for a highly constrained envelope design problem, consisting in the optimization of a sun-shading system. Three of them are easily replicable to different types of projects while the four others need to find a problem-specific heuristic. It appears that the second category is more efficient but implies the use of generative techniques that are more difficult to implement than parametric models.

Energy Efficiency in High-rise Office Buildings: An Appraisal of its Adoption in Lagos, Nigeria

High-rise office buildings are naturally energy-intensive as energy is required in large quantities to run modern building services and to power equipment needed for a hitch-free operation of the buildings. It was found in studied literature that maintaining good indoor environmental quality through air-conditioning, lighting and powering of office equipment contribute the most to an office building’s total energy consumption. Hence, over time, various strategies have been employed to reduce the intense energy demand in high-rise office buildings. This paper adopted the use of both literature review and case study methods. The paper identifies the key energy efficiency strategies that have been successfully deployed in high-rise office buildings using the literature review approach. Also, case studies were conducted on three relatively new high-rise office buildings in Lagos, Nigeria by evaluating them against the background of the best practices in energy efficiency. The study found that deployment of energy efficiency strategies in high-rise office buildings in the study area is still very low especially in the areas of building orientation, building envelope design and the use of renewable energy. However, the use of day-lighting techniques and sustainable lighting systems are quite prominent in the office buildings studied. The study underscores the need to make high-rise office buildings more sustainable through energy efficiency strategies across the whole building life cycle of design, construction, use and end of life.

Coordinated optimal design of school building envelope and energy system

In the design of school buildings, it is necessary to trade off the effects of energy, thermal comfort, daylighting, and life cycle cost. In this paper, a multi-objective coordinated design optimization method of school buildings is proposed to realize the efficient global design optimization of school building envelopes and energy systems. The method is mainly divided into three modules: coordinated design variables, envelope optimization and energy system optimization. In the process of coordinated design optimization, through the iterative method based on multi-objective optimization of envelope, multi-attribute decision-making for Pareto scheme set and single-objective optimization of energy system, the error between the optimal values of the coordinated design variable of the envelop and the energy system is reduced, and finally the global optimal design scheme is obtained. The effectiveness of the proposed optimization method is verified by a case study. The results show that the proposed coordinated design optimization method is stable and reliable. Under the policy of selling electricity, the life cycle cost of the building energy system is -$665,459.50 and the payback period is 6.12 years. Under the policy of not selling electricity, the life cycle cost of the building energy system is $75,292.50, which is 2.75% lower than the traditional multi-stage optimization.

Multi-objective optimization of energy, visual, and thermal performance for building envelopes in China's hot summer and cold winter climate zone

The building envelope design parameters including windows, apertures, shading, and materials have a significant interactive impact on the performance of a building. However, few studies simultaneously optimize these parameters to determine the trade-off solutions between energy consumption, indoor daylighting, and thermal comfort. This study presents a multi-objective optimization (MOO) framework evaluating Useful Daylight Illuminance (UDI), Energy Use Intensity (EUI), and Thermal Discomfort time Percentage (TDP) with a wide range of parameters to investigate the interactive relationships between multiple building design and performance parameters. The openable-window-area-ratio (OWR), window-wall-ratio (WWR), solar-heat-gain-coefficient (SHGC), louver depth, and wall thickness are integrated into the optimization process. Taking a building in the Hot Summer and Cold Winter Zone as an example, the results show that a large south-openable-window-area-ratio (OWRs), south-window-to-wall-ratio (WWRs), SHGC, and wall-thickness with a small north-window-wall-ratio (WWRn) and louver depth are most suitable for improving energy performance without sacrificing thermal and visual comfort. The trade-off solution represents noticeable improvements by 18%, 48.4%, and 2.5%, respectively, compared with the initial solution in EUI, TDP for the transition seasons, and UDI. The outcomes help the architects to obtain an optimal solution for the design, refurbishment, and renovation of building envelopes in the HSCW zone towards the construction of sustainable cities.

Effect of balcony forms difference on indoor thermal environment and energy saving performance of multiple-dwelling house

By optimizing the design of the building envelope, it is possible to create a more comfortable and energy-efficient indoor environment for the occupants. However, due to environmental issues in high-density cities, open balconies might affect the health of occupants. The current research focuses on the effect of a single balcony form in different climates, which could be detrimental to the diversity of balcony designs. Therefore, it is necessary to re-examine the rationality of traditional Japanese open balconies in terms of building envelope design and living environment to optimize the indoor thermal environment and reduce the energy consumption of dwellings. Focusing on Kitakyushu, Japan, which is in a warm climate, this paper conducts a comprehensive comparative study of the effects of building envelope design for residential buildings, including balcony form, thermal insulation performance, room orientation, and the window-to-wall ratio of balcony facades. The results of the study indicate that 1) the closed balcony design is strongly applicable to houses in warm climate regions in winter; 2) closed balconies facing south have a more positive impact on the indoor thermal environment, and energy-saving performance than open balconies; 3) even closed balconies without insulation could achieve higher thermal environment gains than open balconies with insulation. Designing a special type of closed balcony for residences in winter is more energy-efficient than insulation. This study proposes architectural envelope designs that are adapted to specific environmental and climatic conditions. It contributes to providing residential designers with a measure of how to provide a comfortable residential thermal environment and energy efficiency for occupants through architectural envelope design.