Search Results (72)

The construction sector presently consumes about 40% of global energy and generates 36% of CO₂ emissions, making facade retrofits a priority for decarbonising buildings. This review clarifies how ventilated facades (VFs), wall assemblies that interpose a ventilated air cavity between outer cladding and the insulated structure, address that challenge. First, the paper categorises VFs by structural configuration, ventilation strategy and functional control into four principal families: double-skin, rainscreen, hybrid/adaptive and active–passive systems, with further extensions such as BIPV, PCM and green-wall integrations that couple energy generation or storage with envelope performance. Heat-transfer analysis shows that the cavity interrupts conductive paths, promotes buoyancy- or wind-driven convection, and curtails radiative exchange. Key design parameters, including cavity depth, vent-area ratio, airflow velocity and surface emissivity, govern this balance, while hybrid ventilation offers the most excellent peak-load mitigation with modest energy input. A synthesis of simulation and field studies indicates that properly detailed VFs reduce envelope cooling loads by 20–55% across diverse climates and cut winter heating demand by 10–20% when vents are seasonally managed or coupled with heat-recovery devices. These thermal benefits translate into steadier interior surface temperatures, lower radiant asymmetry and fewer drafts, thereby expanding the hours occupants remain within comfort bands without mechanical conditioning. Climate-responsive guidance emerges in tropical and arid regions, favouring highly ventilated, low-absorptance cladding; temperate and continental zones gain from adaptive vents, movable insulation or PCM layers; multi-skin adaptive facades promise balanced year-round savings by re-configuring in real time. Overall, the review demonstrates that VFs constitute a versatile, passive-plus platform for low-carbon buildings, simultaneously enhancing energy efficiency, durability and indoor comfort. Future advances in smart controls, bio-based materials and integrated energy-recovery systems are poised to unlock further performance gains and accelerate the sector’s transition to net-zero. Emerging multifunctional materials such as phase-change composites, nanostructured coatings, and perovskite-integrated systems also show promise in enhancing facade adaptability and energy responsiveness. Full article

Seagrass ecosystems provide essential ecological services and are increasingly recognized for their potential as sustainable building insulation. While prior studies have examined seagrass insulation in temperate climates, its suitability for tropical construction remains largely unexplored. This study assesses the insulation performance, practical challenges, and adoption barriers of seagrass insulation in tropical climates, using building physics simulations and structured expert interviews, with case studies in Seychelles and Auroville, India. Simulation results indicate that seagrass insulation with its high specific heat capacity effectively reduces overheating risks and demonstrates consistently low mould-growth potential under persistently humid tropical conditions. Despite these technical advantages, expert interviews reveal significant non-technical barriers, including negative public perception, regulatory uncertainties, and logistical complexities. Seychelles faces particular hurdles such as limited coastal storage capacity and stringent environmental regulations. In contrast, Auroville emerges as an ideal demonstration site due to its strong sustainability culture and openness to innovative building materials. The study further identifies that integrating seagrass insulation into a structured, regulated supply chain—from sustainable harvesting and processing to quality assurance—could simultaneously enhance ecosystem conservation and material availability. Implementing a harvesting framework analogous to sustainable forestry could ensure environmental protection alongside supply stability. The findings emphasize the urgent need for targeted awareness initiatives, regulatory alignment, and economic feasibility assessments to overcome barriers and enable wider adoption. Overall, this research highlights seagrass insulation as a promising, climate-positive construction material with strong potential under tropical conditions, provided that identified logistical, societal, and regulatory challenges are addressed through dedicated research, stakeholder collaboration, and practical pilot projects. Full article

Traditional photovoltaic-powered forced air-cooling systems face significant challenges in balancing energy efficiency and thermal comfort due to temperature sensitivity, mechanical ventilation energy consumption, and spatial constraints. This study aims to enhance building energy efficiency by integrating a radiant cooling ceiling (RCC) with a phase change material (PCM) thermal storage system, addressing the limitations of traditional photovoltaic-powered cooling systems through optimized material design and dynamic energy management. A ternary PCM mixture (glycerol–alcohol–water) was optimized using differential scanning calorimetry (DSC), demonstrating superior latent heat storage (361.66 J/g) and phase transition temperature (1.91 °C) in the selected “Slushy Ice” formulation. A 3D transient thermal model and experimental validation revealed that the RCC system achieved 57% energy savings under quasi-steady operation, with radiative heat transfer contributing 55% of total cooling capacity. The system dynamically stores cold energy during peak photovoltaic generation and releases it via RCC during low-power periods, resolving the “cooling energy consumption paradox”. Key challenges, including PCM cycling stability and thermal response time mismatches, were identified, with future research directions emphasizing multi-scale simulations and intelligent encapsulation. This work provides a viable pathway for improving building energy efficiency while maintaining thermal comfort and for improving building energy efficiency in temperate zones, with future extensions to arid and tropical climates requiring targeted material and system optimizations. Full article

As concerns about sustainable energy solutions grow, the exploration of bio-inspired techniques for optimizing renewable energy systems becomes increasingly important. This study presents a theoretical application of bio-inspired algorithms, specifically the Particle Swarm Optimization (PSO) algorithm and the Genetic Algorithm (GA), to enhance the energy availability of a renewable energy system in an existing university building in a tropical climate. The research followed a multi-step process. First, a renewable energy generation system was designed for the building, considering available resources and space limitations. Next, we optimized both electricity production and overall energy management. Using the PSO algorithm to find the ideal combination of power generators that would fit within the available space resulted in a 10% increase in the energy deficit. Additionally, PSO was used to optimize the discharge management of the battery bank, independently demonstrating a 2% efficiency improvement when incorporated into the original pre-optimization system. These findings highlight some of the challenges with integrating renewable energy systems into existing buildings while showcasing the potential of biomimetic algorithms, like the PSO and the GA, for targeted optimization tasks. Further research is warranted to refine such algorithms and explore their tailored applications for enhancing the performance of renewable energy systems within the often-restrictive parameters of existing infrastructure. Full article

The Urban Heat Island’s (UHI) effect intensifies thermal discomfort for urban communities, increasing energy requirements. This study assesses the incorporation of Phase Change Materials (PCMs) into building envelopes to reduce Urban Heat Island (UHI) impacts in the Trichy urban area, characterised by a dry-summer tropical savanna environment. To evaluate energy efficiency and indoor temperature regulation, simulations were conducted using Design Builder and Climate 6.0 software. The results show that overall room electricity consumption decreased from 480 kWh to 380 kWh, demonstrating the energy-saving benefits of the modifications. Overall energy consumption was reduced to 271.9 kWh/m²/year from 312.23 kWh/m²/year in the base case, a 13% decrease, equating to 40.33 kWh/m²/year in energy savings. The payback period for PCM installation was predicted to be around 30.64 years. These results show that PCM-enhanced building envelopes reduce UHI effects and improve thermal comfort and energy efficiency, making them a feasible, sustainable urban development strategy. Full article

This work analyzes the potential impact of thirteen passive and active factors on a low-income housing (LIH) model in a tropical climate. For this purpose, a study of material properties and energy modeling using Building Information Modelling (BIM) is carried out, which helps to evaluate these factors’ energetic and economic implications. Two significant assessments are highlighted, namely active and passive factor analysis and dominant factor analysis. The research studied the architectural design of a one-story house measuring thirty-six square meters outlined by the Ecuadorian Construction Standard (NEC) chapter 15 part 4. A 3D architectural model was generated using Revit 2024 simulation software and subsequently employed to establish an energy model used in Autodesk Insight Software 2024 to assess the factors influencing energy consumption and annual energy expenses. The analysis included a comparison with a model of the house based on the ASHRAE 90.2 standard. The active and passive factors were ranked according to their impact on energy efficiency in the model. The results show that Energy Use Intensity (EUI) has a higher reduction for the ASHRAE model of 4.63%, with 21.60% for the Energy cost. The active factors exhibited a greater impact on the energy performance of the LIH than the passive factors, with the PV-Surface coverage being the factor that generated the highest EUI reduction, with 39.66% and 78.51% for both models. The study concluded by emphasizing the importance of adopting active strategies to achieve energy efficiency and economical house design. Full article

This study analysed the impact of living walls on energy-efficient residential buildings in major Australian cities with varying climates. The aim was to identify and quantify the shading and evapotranspiration benefits of living walls using calibrated thermal simulation software. Empirical correlations were applied to replicate the evapotranspiration effect in the simulation. Building dynamic thermal modelling was undertaken with the widely-used AccuRate Sustainability energy rating software. Two house designs were used in the simulation, applying various scenarios to assess the benefits of living walls in various Australian cities. The results showed that living walls provided the most cooling in warm and dry climates such as Perth and Adelaide, with minimal benefits in tropical regions such as Darwin. In temperate climates, living walls had little impact on heating, but in colder climates, they increased heating demand. Homes with insulated walls are common in modern residential construction. For such homes, the evapotranspiration effect rather than the shading or insulation characteristics of the living wall became the primary mechanism for reducing cooling loads, particularly in drier climates. When applying a single living wall for idealized models a potential cooling savings in cooling energy of 10–16% was determined, whereas for typical home designs this saving reduced to below 1%. It was found that the benefits of living walls are comparable to or lower than simpler, more cost-effective passive strategies such as adjusting building orientation or using light-coloured walls. Full article

The rapid urbanization of developing cities has intensified the challenge of maintaining thermal comfort in buildings, particularly in hot–humid climates. This study investigates the impact of floor level on airflow patterns and indoor temperatures in multi-purpose mid-rise buildings in Onitsha, Nigeria, where increasing urban density and frequent power outages necessitate effective passive cooling strategies. Through a mixed-method approach combining empirical measurements, computational fluid dynamics (CFD) simulations, and thermal performance analysis, the research examined variations in ventilation rates and temperature distributions across different floor levels of a six-story educational building over an annual cycle, focusing on the hottest (27 February), coldest (28 December), most windy (3 April), and least windy (17 September) days. Results revealed distinct floor-level ventilation patterns: upper floors (fourth–fifth) achieved 39–40 air changes per hour (ACH) during hot periods while maintaining temperatures of 30–35 degrees Celsius (°C); middle floors (second–third) showed moderate ventilation (15–22 ACH) but experienced heat accumulation (35–42 °C); and lower floors reached 20 ACH during windy conditions. Temperature stratification varied from 15 °C between floors across the entire building during peak conditions to 7 °C during windy periods. Stack-driven ventilation in upper floors contributed to temperature reductions of up to 3 °C, while wind-driven ventilation promoted uniform temperature distribution across all levels. These findings informed floor-specific design recommendations: hybrid ventilation systems with automated controls, strategic architectural features including a minimum floor level area of 15% for the central atrium, and comprehensive monitoring systems with six temperature sensors per floor. This study provides evidence-based strategies for optimizing thermal comfort in tropical urban environments, particularly valuable for designing energy-efficient buildings in rapidly developing cities with hot-humid climates. Full article

Ambient air pollution is the most important environmental factor impacting human health. Urban landscapes present unique air quality challenges, which are compounded by climate change adaptation challenges, as air pollutants can also be affected by the urban heat island effect, amplifying the deleterious effects on health. Nature-based solutions have shown potential for alleviating environmental stressors, including air pollution and heat wave abatement. However, such solutions must be designed in order to maximize mitigation and not inadvertently increase pollutant exposure. This study aims to demonstrate potential applications of nature-based solutions in urban environments for climate stressors and air pollution mitigation by analyzing two distinct scenarios with and without green infrastructure. Utilizing low-cost sensors, we examine the relationship between green infrastructure and a series of environmental parameters. While previous studies have investigated green infrastructure and air quality mitigation, our study employs low-cost sensors in tropical urban environments. Through this novel approach, we are able to obtain highly localized data that demonstrates this mitigating relationship. In this study, as a part of the NERC-FAPESP-funded GreenCities project, four low-cost sensors were validated through laboratory testing and then deployed in two locations in São Paulo, Brazil: one large, heavily forested park (CIENTEC) and one small park surrounded by densely built areas (FSP). At each site, one sensor was located in a vegetated area (Park sensor) and one near the roadside (Road sensor). The locations selected allow for a comparison of built versus green and blue areas. Lidar data were used to characterize the profile of each site based on surrounding vegetation and building area. Distance and class of the closest roadways were also measured for each sensor location. These profiles are analyzed against the data obtained through the low-cost sensors, considering both meteorological (temperature, humidity and pressure) and particulate matter (PM₁, PM_2.5 and PM₁₀) parameters. Particulate matter concentrations were lower for the sensors located within the forest site. At both sites, the road sensors showed higher concentrations during the daytime period. These results further reinforce the capabilities of green–blue–gray infrastructure (GBGI) tools to reduce exposure to air pollution and climate stressors, while also showing the importance of their design to ensure maximum benefits. The findings can inform decision-makers in designing more resilient cities, especially in low-and middle-income settings. Full article

With the rise of building thermal comfort issues, the Bioclimatic Design Guideline for Cambodia (BDGC) has been developed to help architects make informed decisions during their design process to achieve maximum thermal comfort with minimum energy consumption. This paper aims to investigate the reliability of this guideline as decision support to enhance residential building thermal performance by using two research approaches: usability tests and calibrated thermal performance simulations based on real buildings monitoring and simulations using DesignBuilder. Five groups of architects and students in architectural engineering participated in the usability test to redesign two common typologies of single-family homes with weak thermal performance by using bioclimatic design guidelines, such as orientation, improved ventilation, shading, and green rood, to enhance their comfort level. The simulation shows that, by applying bioclimatic design strategies, the indoor temperature in the base case house can be lower from 2 to 4 °C. Various benefits are identified from the integration of the BDGC during the design process for improving residential building design. Moreover, the proposed methodology can be applied to develop and validate bioclimatic guidelines in other regions and various countries worldwide. Full article

Thermal comfort is a fundamental goal of architecture aiming at protecting individuals from harsh weather conditions. In Nigeria’s savanna climate zone, such as Kaduna, poor indoor thermal comfort leads to over-reliance on air-conditioning systems. There is limited research on the application of passive design strategies in the Nigerian savanna climate, which creates a barrier to their widespread implementation in residential buildings. In response to the increased awareness of climate change and the need for sustainable design, this study explores the potential of passive design strategies, focusing on the combination of rooftop insulation and reflective materials with mechanical ventilation as a means of improving indoor thermal comfort solutions. This study conducted a 3-day field experiment of typical dwellings in Kaduna, a major city in the Nigerian savanna climate zone. The data collected from this experiment served as the basis for a simulation study using EnergyPlus software, which tested and evaluated 3 different strategies: passive design (roof insulation + reflective materials), mechanical ventilation, and a combination of passive design and mechanical ventilation. This study highlights the potential for passive design strategies to provide a more sustainable, cost-effective solution, reducing dependence on air conditioning while supporting indoor comfort. Additionally, the research methodology and insights gained offer a basis for developing future building codes in Nigeria that emphasize sustainable practices. Such codes would guide architects, builders, and policymakers in designing homes that respond to local climate needs and align with broader sustainability goals. Further research could explore additional passive measures, including advanced window technologies, shading, and natural ventilation, to maximize sustainable residential design potential in tropical savanna climates. Full article

This study examines existing buildings in Haikou in China under tropical island climate conditions. It presents three retrofit design models for greenhouses roofs (GHR), green roofs (GR) and photovoltaic roofs (PVR). The carbon cost of each retrofit roof model is calculated in the production and transportation phases of building materials, construction, and demolition. The changes in electricity consumption, water consumption, and plant carbon reduction are coupled to calculate the carbon reduction generated by each phase of the use of the retrofitted roofs. The carbon reduction per unit area for GHR, GR and PVR over the life cycle (20 years) is then comprehensively calculated. The life cycle carbon reduction per unit area is 262.57 kg·m⁻² for GHR, 127.41 kg·m⁻² for GR and 2567.12 kg·m⁻² for PVR. Among the three retrofit methods, PVR has the greatest potential for reducing carbon emissions. The study can as a guide for implementing carbon reduction measures in tropical island areas. Domestic research on rooftop greenhouses also focuses on technology, yield, and energy consumption, mostly for northern regions with cold winters, and less research on rooftop greenhouses applied to regions with hot summers and warm winters. But domestic and foreign studies on the potential of rooftop greenhouses to reduce emissions have not yet been combined with plant cultivation of hydroelectric carbon emissions and plant carbon sequestration. Full article

Domestic electricity consumption in the Kingdom of Bahrain accounts for 48% of total national electricity consumption, increasing between 1.5 and 3.5% annually. This increase is due to indoor cooling electricity accounting for up to 80% of domestic electricity consumption. The Kingdom is aiming for a reduction in carbon emissions of 30% by 2035 and to achieve carbon neutrality by 2060. Hence, reducing electricity consumption is necessary. Recently, the Kingdom’s Electricity and Water Authority has issued updated building regulations regarding the maximum thermal transmittance allowed for residential buildings. This study employed a quantitative simulation of a typical housing unit (T8) in the Kingdom of Bahrain, assessing building envelope materials and air conditioning efficacy following the updated building regulations via DesignBuilder V. 7.0.2.006 software. Additionally, this study examined the potential of building regulations to facilitate the transition to net-zero energy buildings by comparing electricity consumption with renewable energy generated from rooftop photovoltaic panels. It was determined that electricity consumption could be reduced by up to 52% by following building regulations and relying on current materials in the residential sector. Furthermore, this reduction may facilitate the Kingdom’s attainment of net-zero energy status through onsite power generation of 12,500 kWh/year. This study concluded that achieving net-zero energy status is possible by following building regulations and relying on commercially accessible construction materials; however, guidelines for energy storage or a feed-in tariff for the residential sector must be established. Full article

This study investigates the application of dynamic window technologies in condominiums located in hot and humid climates, focusing on Thailand. The research integrates both passive and active window designs aimed at reducing energy consumption by maximizing natural ventilation and daylight, while minimizing heat gain. Dynamic windows, equipped with shading devices, automated controls, and stack-effect ventilation, can achieve significant energy savings by decreasing the need for air conditioning and artificial lighting. The energy performance was assessed through simulations based on Thailand’s Building Energy Code (BEC), resulting in a potential reduction in energy consumption by 3.29 kWh/m² annually or approximately 1.6% annually. Moreover, economic analysis showed that applying dynamic windows in condominiums could save up to 506.38 baht per room per year. The lifecycle cost analysis supports their long-term financial viability, achieving payback within 18.4 years and generating further net savings post-payback. The study concludes that dynamic windows are both scalable and sustainable, offering a viable solution for urban developments in tropical regions. Full article

Water, a fundamental and indispensable resource necessary for the survival of living beings, has become a pressing issue in numerous regions worldwide due to scarcity. Urban areas, where the majority of the global population resides, witness a substantial consumption of blue water, particularly in commercial buildings. This study investigates the potential for enhancing water efficiency within an ongoing high-rise office building construction situated in a tropical climate. The investigation utilizes the green building guidelines of leadership in energy and environmental design (LEED) through a case-study-based research approach. Strategies included using efficient plumbing fixtures (such as high air–water ratio fixtures and dual-flush toilets), the selection of native plants, implementing a suitable irrigation system, introducing a rainwater harvesting system (RWHS) and improving the mechanical ventilation and air conditioning (MVAC) system. The results showed a 55% reduction in water use from efficient fixtures, a 93% reduction in landscaping water needs and a 73% overall water efficiency with a RWHS from the baseline design. Additionally, efficient cooling towers and the redirection of condensed water into the cooling tower make-up water tank improved the overall water efficiency to 38%, accounting for the water requirements of the MVAC system. The findings of this study can contribute to more sustainable and water-efficient urban development, particularly in regions facing water scarcity challenges. The significance of these findings lies in their potential to establish industry standards and inform policymakers in the building sector. They offer valuable insights for implementing effective strategies aimed at reducing blue water consumption across different building types. Full article