Passive Design Research Articles

Buildings in Hot Climate Zones—Quantification of Energy and CO2 Reduction Potential for Different Architecture and Building Services Measures

Reducing energy and associated greenhouse gas emissions in buildings is one of the key aspects of climate change on a global level. To put the building sector on a low carbon development path, policies and adequate financing play a crucial role in each region. In the global South, policies and regulations related to the decarbonization of the building stock are increasingly being implemented. For policy and decision makers, adequate data on the status quo of the building stock, as well as the quantification of energy reduction measures, are essential to make informed decisions on the building regulatory and funding framework. The objective of this study is to provide data-driven insights into the potential for energy and CO2 reduction in buildings across various hot climate zones in the Global South. A simulation-based approach was employed to model five different building types, ranging from residential homes to office buildings, under a variety of architectural and building services scenarios. The simulations were conducted using the dynamic building energy simulation tool EnergyPlus, which assessed the impact of various energy-saving measures under both current and projected future climate conditions. This study concludes that optimizing passive design features, such as improved windows, solar shading, and reflective surfaces, in conjunction with active systems like decentralized cooling units and renewable energy integration, can result in a notable reduction in energy demand and emissions. Our findings provide a robust basis for policymakers to develop targeted energy efficiency strategies for buildings in hot climate zones, which will play a crucial role in achieving climate goals in the Global South.

Optimizing Outdoor Thermal Comfort for Educational Buildings: Case Study in the City of Riyadh

In hot, arid climates, educational buildings often face the challenge of limited outdoor space usage. This research, through comprehensive simulation, aims to propose practical solutions to enhance outdoor thermal comfort, particularly during school break times and student dismissal periods, thereby fostering more comfortable and functional outdoor school environments. That will happen through achieving the main objective of the study, which is evaluating the suggested passive strategies. Riyadh was selected as the case study, and four representative schools were analyzed through simulation and optimization processes to identify key areas for improvement. The research leveraged simulation tools such as Ladybug and Grasshopper in Rhino, highlighting the practicality and impact of this approach. Simulations were performed to assess the existing outdoor thermal conditions using the universal thermal climate index (UTCI) and to pinpoint regions with elevated thermal discomfort. Passive design interventions, such as shading devices and vegetation, were explored and optimized using the Galapagos in Grasshopper. This methodology supports the originality of this research in its integration of simulation tools, such as Ladybug and Grasshopper, with optimization techniques using the Galapagos plugin, specifically applied to the unique site-specific context of educational outdoor environments in a hot, dry climate in Riyadh. Additionally, insights for urban planners and architects demonstrate the possibility of integrating passive design principles to improve the usability and sustainability of outdoor spaces. The findings indicated that fewer apertures in shade devices combined with greater tree canopies might double the effectivity in lowering UTCI values, thereby enhancing thermal comfort, especially during peak summer months.

K/Ka‐Band–GaN–High‐Electron‐Mobility Transistors Technology with 700 mS mm−1 Extrinsic Transconductance

In this study, the impacts of fabrication technology and epitaxial layer design on the transconductance (gm) of radio frequency AlGaN/GaN high‐electron‐mobility transistors (HEMTs) are examined. Optimization of the SiNx passivation and AlGaN barrier design of 150 nm gate HEMTs enhances the extrinsic (at Vds = 10 V) and intrinsic (at Vds = 15 V) transconductance from ≈0.47/0.65 to ≈0.62/1.1 S mm−1. Notably, an extrinsic gm of 0.70 S mm−1 at Vds = 5 V is achieved, setting a new benchmark for the extrinsic transconductance of AlGaN/GaN HEMTs designed for the K/Ka frequency range with a breakdown voltage exceeding 100 V.

Bibliometric Review of Passive Cooling Design Strategies and Global Thermal Comfort Assessment: Theories, Methods and Tools

Globally, a variety of factors, ranging from ethnicity and occupants’ lifestyles to the local climate characteristics of any studied location, as well as people’s age, can affect thermal comfort assessments. This review paper investigates the energy effectiveness of state-of-the-art passive systems in providing neutral adaptive thermal comfort for elderly people by exploring passive design strategies in four distinct climates, namely Canada, India, Abu Dhabi and the Eastern Mediterranean basin. The aim of the study is to analyse the available data provided by the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE) Global Thermal Comfort Database II, version 2.1. The main objective of the study is to develop an effective methodological framework for the on-going development of adaptive thermal comfort theory. To this extent, this study presents a comprehensive review of the assessment of energy effectiveness of passive design systems. To accomplish this, the impact of climate change factors in passive design systems was investigated. A meta-analysis method was adopted to determine the input variables for the statistical analysis. Cramer’s V and Fisher’s Exact tests were used to assess occupants’ thermal sensation votes (TSVs). The findings revealed that there are discrepancies detected between the in situ field experiments and the data recorded in the ASHRAE Global Thermal Comfort Database II. The study findings contribute to the development of adaptive thermal comfort theory by reviewing the existing methodologies globally. Furthermore, a critical review of the significance of occupants’ age differences should be conducted in the identification of neutral adaptive thermal comfort.

Loss-less passive polarization rectifier design with minimal etendue and size increase

We describe an approach allowing the passive rectification of the polarization of light with approximately the same beam size, minimal increase of the etendue of the beam and with negligible reduction of its power. This is done for arbitrary (including chaotic) input polarization states and without their prior identification. The tradeoff is the partial increase of the angular spectrum of light. Theoretical estimations are provided along with some preliminary experimental results describing the possible use of this approach with large diameter beams as well as in optical fibers.

Optimization of three-dimensional Tesla valve-based passive micromixer for gradient functional materials mixing

With the rapid development of three-dimensional (3D) printing technology, the field of multi-material fabrication, particularly in the production of functionally graded materials, has achieved revolutionary advancements. However, the structures of micromixers, which are central to this technology, have not been sufficiently studied. This study introduces an optimized passive micromixer design based on a 3D Tesla valve, specifically engineered for the efficient mixing of Fe3O4 particles within an epoxy resin E51 matrix. The micromixer leverages the fluid dynamics of the Tesla valve, where sudden changes in flow direction generate secondary flows that enhance mixing performance by disrupting laminar flow and inducing chaotic advection, thereby increasing the interfacial area between different material components. This process significantly improves mixing efficiency in the fabrication of gradient materials. Through theoretical analysis and computational simulations, the study identifies optimal configurations for the Tesla valve system, emphasizing mixing dynamics that enhance material gradient formation. The findings reveal that optimal mixing efficiency is achieved with a configuration comprising three Tesla valves. This optimal setup includes a 0.5-mm opening width at the turning point, an immediate transition from the turning point to the straight pipe (0 mm length), a 0.25-mm structural height for the Tesla valve, and an outlet distance of 0.25 mm from the curved pipe. Hopefully, this study can provide a robust reference for the significant potential of future applications in the realm of multi-material 3D printing, thereby fostering its substantial growth prospects.

Passive House Design: A Possible Energy Efficient Option in the Building Sector of Nepal

The diversified geography of Nepal creates huge variations in the country's climatic zones; however, the building industry has so far used standardized methods that tend to neglect local climate conditions. Most of these standards then rely on energy-intensive mechanical systems to maintain indoor thermal comfort, without considering more viable and climate-responsive design methods. In this light, the development of a climate classification related to building design will help develop and encourage energy- and climate-effective building architecture in Nepal. The existing energy-saving practice in the building sector of the country is reviewed in this paper, and it outlines ways to improve the adaptation of energy-efficient methodology. It shows that passive houses are performing much better in comparison with modern constructions that are behind in terms of energy efficiency when compared with traditional homes. The study outlines the climate-specific design criteria and methodologies for various regions and sets the path for exploration of the passive house design process challenges and opportunities that might exist for wider diffusion. Also discussed are strategies to overcome the barriers and promote passive house construction, offering a pathway toward sustainable building practices in Nepal.

Carving a niche in building energy using modern vernacular house with passive wall materials - A multi-criteria decision-making framework

The building sector, one of the world's largest energy consumers, includes vernacular houses that offer good living conditions. However, increasing population and energy demands have caused vernacular houses to impact the ecosystem negatively, thus losing popularity. Passive design features can alleviate this problem but entail several factors and alternatives. This study aims to develop a fuzzy-based multi-criteria decision-making framework for selecting an optimal wall material for vernacular house that satisfies the technical, economic, environmental and social factors. Seven different wall materials, along with governing factors like room temperature, humidity, cooling and heating loads, cost, comfort index, CO2 emission, job creation and social acceptability, are considered. Four fuzzy-based decision-making tools are used, followed by sensitivity analysis to examine the results. A test cell of an established 3BHK vernacular house is made using design-builder and is simulated with Energy plus software. The error indices confirmed the design-builder model's accuracy, with NMBE and CV-RMSE values for room temperature and relative humidity both under 1 %, well within ASHRAE 14's threshold limits. From the results, cinder concrete is found as optimal passive wall material, resulting in lower cooling and heating loads and CO2 emission by 0.68 %, 9.64 %, and 2.27 %, respectively, than traditional vernacular house.

Evaluating passive PCM performance in building envelopes for semi-arid climate: Experimental and numerical insights on hysteresis, sub-cooling, and energy savings

This study evaluates the performance of macro-encapsulated Phase Change Materials (PCMs) integrated into building envelopes for semi-arid climates, focusing on typical Moroccan construction using hollow concrete blocks. The primary objective is to assess the discrepancies between experimental and numerical analyses, particularly in hysteresis, sub-cooling, and energy savings. Given the widespread reliance on numerical tools like EnergyPlus for PCM simulations, the accuracy of manufacturer-provided latent heat values is investigated. The methodology involves constructing two identical test buildings, one equipped with PCM panels and another as a reference. Experimental data were collected in June 2023, assessing temperature fluctuations and energy savings. Differential Scanning Calorimetry (DSC) tests at varying scanning rates were conducted to analyze PCM behavior, including hysteresis and sub-cooling effects. Numerical simulations were then performed to compare energy performance. Besides, the results reveal that sub-cooling significantly limits PCM efficiency, with only 43 % of the PCM's latent heat capacity utilized. At the same time, hysteresis was found to be negligible in the field test. Cooling energy consumption was reduced by 20 %, with a corresponding 2.3 °C reduction in temperature fluctuations. However, the PCM's latent heat potential is underutilized due to sub-cooling. This research underscores the need for conducting DSC measurements at specific scanning rates to reflect regional climate conditions and suggests that simulation models should adjust latent heat utilization of the PCM. The study advocates for the use of composite PCMs, which could mitigate sub-cooling and enhance overall performance. These findings contribute to improving PCM integration in passive building designs, offering practical recommendations for better energy efficiency in semi-arid climates.

Design of a positive energy district: A Nigerian case study

The potential of possible solutions for the design and implementation of a 50-house Positive Energy District (PED) in Southern Nigeria is presented in this study. Using a transient energy systems simulation software (TRNSYS 18), the energy demand of a typical building is estimated. Different passive design options considering building materials, window sizes, building orientation, roof ventilation are studied to determine the most energy efficient building envelope. TRNSYS and PVSyst (another energy simulation software), are also used to simulate the dynamics of a positive energy building and operation of solar energy systems used for electricity generation, domestic hot water heating and space cooling for Lagos weather conditions. In terms of electric energy balance, the total annual electricity demand is 598,000 kWh while the electricity generated by PV is 728,600 kWh in a year. As regards to site energy balance, annually, the district exports more electricity than it imports. The difference is 110,200 kWh. These results show that in such climatic conditions, despite economic poverty, it is possible to implement the modern PED principles. However, first, it is necessary to reduce energy consumption as much as possible, including solar passive solutions to the building architecture.

Sustainable Logistics: Synergizing Passive Design and PV–Battery Systems for Carbon Footprint Reduction

As more companies strive for net-zero emissions, mitigating indirect greenhouse gas emissions embedded in value chains—especially in logistics activities—has become a critical priority. In the European logistics sector, sustainability and energy efficiency are receiving growing attention, given the sector’s intersectional role in both transportation and construction. This transition toward low-carbon logistics design not only reduces carbon emissions but also yields financial benefits, including operational cost savings and new market opportunities. This study examines the impact of passive design strategies and low-carbon technologies in a Swedish logistics center, assessed using the low-carbon design criteria from the BREEAM International standard, version 6. The findings show that passive energy-efficient measures, such as the installation of 47 skylights for natural daylighting, reduced light power density in accordance with AHSHARE 90.1-2019 and the integration of free night flushing, contribute to a 23% reduction in total energy consumption. In addition, the integration of 600 PV panels and 480 batteries with a capacity of 268 ampere-hours and 13.5 kWh storage, operating at 50 volts, delivers a further 56% reduction in carbon emissions. By optimizing the interaction between passive design and active low-carbon technologies, this research presents a comprehensive feasibility analysis that promotes sustainable logistics practices while ensuring a future-proof, low-carbon operational model.

An Overview of the Effects of Passive Solar Strategies on Thermal Comfort

The paper presents the impact of passive solar strategies on residential buildings concerning the thermal comfort factor. This study focuses on passive solar design elements like orientation, shading, and thermal mass to offer improved energy efficiency and occupant comfort. With a global natural gas crisis looming, interest in alternative heating and cooling is surging. With the growing concern of reducing the energy use by buildings while maintaining proper thermal comfort, both in cold and hot climates, the interest shifts to passive solar strategies. In this view, 547 publications have been analysed to reveal knowledge gaps and trends in the research. The bibliographic and thematic analysis techniques identified some approaches to passive solar design but no dominant method. Further, the study found under-researched areas within themes that appeared established. The authors have finally concluded with calls for further research and collaboration across institutions and nations to address these gaps and develop effective passive solar strategies. These findings contribute to sustainable architecture by pointing out the pros of applying passive solar strategies to reduce heating and cooling loads. In this respect, this was an original approach since it brought both quantitative and qualitative data together to measure thermal comfort. This is further underpinned by raising the need for energy-efficient building designs as measures toward mitigating climate change impacts.

Deep Learning as a New Framework for Passive Vehicle Safety Design Using Finite Elements Models Data

Deep Learning as a New Framework for Passive Vehicle Safety Design Using Finite Elements Models Data

Climate-Responsive Architectural Design: Analyzing and Adapting to Diverse Climates in U.S. Cities

The energy consumption challenge within the built environment is growing in urgency, underscoring an imperative for climate-responsive design solutions. This paper presents an in-depth analysis of the climatic characteristics of 12 U.S. cities, with a parametric platform, categorized under different Köppen climate classifications, with the aim of informing effective passive design strategies. Upon meticulously assessing the efficacy of various passive strategies tailored to distinct climate zones, this paper distills actionable guidance for deploying architectural methods that embody climate-responsive design principles. Theoretical models are developed to correlate climatic variables with specific passive design interventions. The research contributes to the theoretical discourse on passive design by advocation for a data-driven, climate-responsive design guidance that aligns with contemporary sustainability goals.

THE HOUSING UNITS OF THE POSITIVE CLIMATE NEIGHBORHOOD PEDRA BRANCA SC/BR

In response to the global climate crisis, urgent measures are required to reduce greenhouse gas emissions in alignment with the goals of the Paris Agreement. As energy consumption accounts for 36% of total emissions, and buildings contribute significantly to both direct and indirect emissions, it is crucial to enhance the energy efficiency and self-sufficiency of buildings. This article conducts a case study to evaluate the formal structure, spatial layout, and sustainable strategies employed in residential units within the Pedra Branca neighborhood (Santa Catarina, Brazil), using the methodology developed by Brandão and Schneider. The findings indicate that the housing units predominantly consist of three bedrooms, along with two to four bathrooms. The analysis revealed partial integration between the kitchen and service areas, with full integration being less common. Corridor layouts were found to make the greatest contribution to sustainability and internal space quality. Although some configurations did not directly support cross-ventilation, there was a clear focus on environmental comfort and the use of passive design strategies. This study highlights the potential of such configurations to improve energy performance and contribute to the development of climate-positive neighborhoods.

Analyzing Passive Design Retrofits using Pareto Front Optimization to Reduce Operational Carbon in Commercial Laboratory Spaces

Buildings are one of the leading sources of carbon emissions in the world. Most of the carbon emissions are released during the operation phase of the building. It is essential for buildings to provide thermal and visual comfort for the users. In the case of existing buildings, it is necessary to offer retrofit solutions so that the operational carbon emissions can be reduced without compromising on the other essential factors. In this study a Multi-Objective Optimization (MOO) of passive design strategies was conducted for a commercial laboratory in India situated in a moderate climate zone. The design variables considered for the study are wall and roof insulation, glazing material, window-wall ratio (WWR), depth of shading device and the number of shading devices used. The objective functions are: 1. reduced energy use intensity and operational carbon emissions, 2. increased thermal comfort hours and 3. increased daylight autonomy. Rhinoceros and grasshopper software along with Ladybug and Honeybee plug-ins were used for the study which resulted in 1296 iterations. MOO technique namely Pareto front optimization was used to optimize the objective functions. Out of 1296 solutions (excluding base case), 72 solutions were non-dominated. Two methods are described in the study to identify the recommendations for retrofit. The first method describes a Heuristic method of selection using Design Explorer recommending 5 good solutions. In the second method a factor is evolved to identify the 5 best solutions in sequential order. The overall study recommends the use of EPS insulation for the RCC roof, WWR of 20% on all sides, 3 horizontal shading devices of depth 0.75 m for all window openings. When compared with the base case scenario, this solution minimizes the EUI by 3.7%, maximizes average TCH by 106.6% and maximizes average DA by 66.9%. The overall operational carbon emissions are reduced by 7095.6 kgCO2.

Joint LPI waveform and passive beamforming design for FDA-MIMO-DFRC systems

Dual-functional Radar-Communication (DFRC) systems have been recognized as one of the most promising technologies in the field of wireless communications. Nevertheless, the low probability of intercept (LPI) performance in the DFRC systems cannot be overlooked. Based on the frequency diverse array multiple-input–multiple output (FDA-MIMO) radar, a DFRC system is proposed to enhance target detection in clutter environment and achieve desirable LPI against an underlying hostile interceptor. The issue can be cast into an optimization problem that maximizes the radar signal-to-interference-plus-noise ratio (SINR) while satisfying the communication quality-of-service (QoS) requirement of each user under one of three metrics, the required LPI performance and the constant-modulus waveform constraint. To solve this challenging problem, we reformulate it into an equivalent but more tractable form by resorting to an auxiliary variable. Subsequently, we employ the alternative direction method of multipliers (ADMM) and majorization-minimization (MM) algorithms to solve the resultant problem. Simulation results validate that the proposed LPI FDA-MIMO-DFRC scheme exhibits superior sensing performance over the conventional scheme with MIMO.

Passive Design Strategy of Vertical Housing for Optimizing Energy Efficiency

Abstract Passive design is crucial for sustainable building, maximizing comfort while minimizing energy use and environmental impact. It optimizes heating, cooling, ventilation, and lighting through natural energy sources like sunlight and wind, promoting responsible energy consumption. As the Indonesian economy continues to grow, urbanization rates in major cities are rapidly increasing, leading to urban sprawl. One proposed solution is densification through vertical housing construction. However, a concern with vertical housing is the energy consumption for thermal and lighting comfort, particularly in Indonesia’s tropical climate. Passive design presents an effective energy efficient solution for optimizing comfort in vertical housing. This study explores various passive design strategies based on six basic principle. Firstly, it presents local climatic conditions. Then, it discusses lessons learned from traditional buildings and modern buildings. Finally, it introduces a passive design method for high-rise housing, focusing on six points: massing and orientation, building envelope, passive cooling, thermal mass storage, natural air circulation and daylighting. The study presents results and potential recommendations for passive design to optimize energy efficiency.

Passive Cooling Design Opportunities: Lessons Learned from Traditional Banjar Houses

Abstract Indonesia is an archipelago country that encompasses many different ethnicities across five large islands, one of which is Kalimantan (Borneo) Island. The river has become the lifeline in Borneo, especially for Banjar people. Banjar people have eleven types of traditional houses, each designed for specific social classes, which differ from one another in terms of materials, layout, and roof proportions. In this paper, three different types of Banjar traditional houses are compared to study the passive cooling conditions related to the proportions of the floor plan and cross-section. These three types are: (1) Bubungan Tinggi House, (2) Palimbangan House, and (3) Lanting House. The three types of houses are modelled and simulated using RWIND CFD software, by inputting the maximum and minimum wind speed (3.5 and 17 m/s), to study the potential of imitating vernacular forms that assures effective passive cooling. The result is that the Palimbangan house has the most balanced passive cooling performance through wind movements and direction. The findings could serve as an alternative for application in modern housing architecture that is sustainable and energy-efficient.

A Systematic Literature Review on Energy Efficiency Analysis of Building Energy Management

Government agencies, energy consumers, and other societal groups have all shown concern and attention for the energy management of buildings. Relevant statistical data, however, indicate that most public buildings continue to consume large amounts of energy overall and that the issues of low energy usage and energy waste have not materially improved. As a result, this study reviewed the state of progress and potential directions for future research in the field of building energy management in public buildings using a data-driven approach. Relevant studies were obtained from three databases—Web of Science, Scopus, and China National Knowledge Infrastructure—based on certain search phrases. The text mining program VOS viewer was then used to examine the material. We provide a thorough examination of the study techniques and material, as well as a visual representation of the keywords and current state of the field. According to this study, the range of data processing outcomes; the flexibility of research system standards; and the availability of a comprehensive, unified assessment system are the main factors contributing to the practical issues facing building energy management today. Based on the geographic distribution and state of energy development, this study is the first to examine possible research avenues for building energy management in public buildings through cross-fusion research on passive energy-saving design and subjective behavioral energy-saving. It offers a foundation for developing the building energy management system best practice model in the future.