Green Walls Research Articles

Assessing the efficacy of green walls versus street green lanes in mitigating air pollution: A critical evaluation

Urban green spaces, particularly street trees and greenways, are increasingly recognized as tools for mitigating air pollution. However, their effectiveness can vary depending on their configuration and urban canyon geometry. This study, aimed at providing practical solutions, assessed the impact of different green space configurations, including street trees, green lanes, green walls, and hedges, on particulate matter (PM) concentrations within urban canyons of varying aspect ratios by employing environmental simulations and wind tunnel tests performed in ENVI-met software.Results demonstrate that green walls significantly outperform street trees in reducing PM concentrations by up to 43%, attributing this to reduced air flow disruption. Green walls also create a more uniform PM distribution within canyons, decreasing concentration differences by 31% compared to green (tree) lanes. Conversely, dense tree lanes exacerbate PM deposition due to wind flow interference.These findings suggest that incorporating green walls into urban design can be a highly effective strategy for improving air quality within densely built environments.

Sustainable Production of Ulva Oligosaccharides via Enzymatic Hydrolysis: A Review on Ulvan Lyase.

Ulvan is a water-soluble sulfated polysaccharide extracted from the green algae cell wall. Compared with polysaccharides, oligosaccharides have drawn increasing attention in various industries due to their enhanced biocompatibility and solubility. Ulvan lyase degrades polysaccharides into low molecular weight oligosaccharides through the β-elimination mechanism. The elucidation of the structure, catalytic mechanism, and molecular modification of ulvan lyase will be helpful to obtain high value-added products from marine biomass resources, as well as reduce environmental pollution caused by the eutrophication of green algae. This review summarizes the structure and bioactivity of ulvan, the microbial origin of ulvan lyase, as well as its sequence, three-dimensional structure, and enzymatic mechanism. In addition, the molecular modification of ulvan lyase, prospects and challenges in the application of enzymatic methods to prepare oligosaccharides are also discussed. It provides information for the preparation of bioactive Ulva oligosaccharides through enzymatic hydrolysis, the technological bottlenecks, and possible solutions to address these issues within the enzymatic process.

Innovative Sustainable Design Approaches in Urban Architecture: Balancing Aesthetics and Environmental Impact

Innovative sustainable design approaches in urban architecture play a crucial role in addressing the growing challenges of urbanization, environmental degradation, and the need for aesthetically pleasing living spaces. This study explores various sustainable design strategies, such as biophilic design, Net-Zero Energy Buildings (NZEBs), green roofs, vertical gardens, adaptive reuse, and circular economy principles, highlighting their ability to balance environmental impact with aesthetic appeal. Biophilic design integrates natural elements into urban environments, enhancing mental and physical well-being, while NZEBs focus on energy efficiency and reducing carbon footprints through renewable energy sources. Green roofs and vertical gardens provide ecological benefits, including air purification and biodiversity, while also creating visually engaging urban landscapes. Adaptive reuse and the circular economy emphasize the repurposing of existing structures and materials, promoting sustainability while preserving cultural heritage. Through a qualitative literature review, this research identifies the benefits and challenges associated with these design approaches and discusses their potential to transform urban architecture into more sustainable and livable spaces. The findings suggest that a holistic approach, integrating aesthetics and sustainability, is essential for creating urban environments that are resilient, environmentally responsible, and socially inclusive. This study provides valuable insights for architects, urban planners, and policymakers seeking to implement sustainable design principles in contemporary urban settings.

Building Information Modeling and AI Algorithms for Optimizing Energy Performance in Hot Climates: A Comparative Study of Riyadh and Dubai

In response to increasing global temperatures and energy demands, optimizing buildings’ energy efficiency, particularly in hot climates, is an urgent challenge. While current research often relies on conventional energy estimation methods, there has been a decrease in the efforts dedicated to leveraging AI-based methodologies as technology advances. This implies a dearth of multiparameter examinations in AI-driven extreme case studies. For this reason, this study aimed to enhance the energy performance of residential buildings in the hot climates of Dubai and Riyadh by integrating Building Information Modeling (BIM) and Machine Learning (ML). Detailed BIM models of a typical residential villa in these regions were created using Revit, incorporating conventional, modern, and green building envelopes (BEs). These models served as the basis for energy simulations conducted with Green Building Studio (GBS) and Insight, focusing on crucial building features such as floor area, external and internal walls, windows, flooring, roofing, building orientation, infiltration, daylighting, and more. To predict Energy Use Intensity (EUI), four ML algorithms, namely, Gradient Boosting Machine (GBM), Random Forest (RF), Support Vector Machine (SVM), and Lasso Regression (LR), were employed. GBM consistently outperformed the others, demonstrating superior prediction accuracy with an R2 of 0.989. This indicates that the model explains 99% of the variance in EUI, highlighting its effectiveness in capturing the relationships between building features and energy consumption. Feature importance analysis (FIA) revealed that roofs (29% in Dubai scenarios (DS) and 40% in Riyadh scenarios (RS)), external walls (19% in DS and 29% in RS), and windows (15% in DS and 9% in RS) have the most impact on energy consumption. Additionally, the study explored the potential for energy optimization, such as cavity green walls and green roofs in RS and double brick walls with VIP insulation and green roofs in DS. The findings of the paper should be interpreted in light of certain limitations but they underscore the effectiveness of combining BIM and ML for sustainable building design, offering actionable insights for enhancing energy efficiency in hot climates.

Vertical Green Wall Systems for Rainwater and Sewage Treatment

Rainwater and sewage are important pollution sources for surface water bodies. Vertical greening systems (VGSs) are extensively employed for these wastewater treatments due to the green and sustainable characteristics, as well as their high-efficiency in pollutant (organic matter, nitrogen, and phosphorus) removal. At present, more and more VGSs are designed with green buildings, serving city ecosystems. This study provides an overview of different kinds of VGSs for rain and sewage treatment, emphasizing their types, design, mechanisms, selection of plants, and growth substrate. Plants play a crucial role in pollutant removal, and different plants usually obtain different efficiencies of water treatment. Climbing plants and ornamental plants with fast growth rates are priority selections for VGSs, including Canna lilies, Jasmine, Grape vine, Boston ivy, Pittosporum tobira, Pelargonium australe, Mentha aquatica, and Lythrum salicaria. The substrate is the most critical part of the VGS, which plays an important role in regulating water flow, supporting plant growth, promoting biofilm growth, filtering pollutants, and adsorbing nutrients. The single substrate either has a blockage problem or has a short holding time. Therefore, a number of studies have mixed the substrates and integrated the advantages of the substrates to form a complementary effect, thereby improving the overall purification efficiency and stability. Novel substrates (sand, spent coffee grounds, date seeds, coffee grinds, reed-based, etc.) are usually mixed with coco coir, light-weight expanded clay, growstone, or perlite at a certain ratio to obtain optimum treatment performance. Moreover, plants in clay show more significant growth advantages and health statuses than in zeolite or soil. Operating parameters are also significant influences on the treatment performance. This review provides theoretical and technical support for designing sustainable, environmentally friendly, and cost-effective VGSs in treating rainwater and sewage.

Enhancing Urban Livability with Vertical Gardens in Mexico City Strategies for Sustainable Urban Development

This thesis explores the implementation of vertical gardens in Mexico City as a strategic approach to enhance urban livability and promote sustainable development. Faced with environmental challenges such as severe air pollution and the urban heat island effect, coupled with limited availability of green space due to high urban density, Mexico City requires innovative solutions to improve its urban ecosystem. This research examines the role of vertical gardens in addressing these challenges by purifying air, reducing temperatures, and supporting urban biodiversity. Additionally, it investigates the socio-economic and psychological impacts of increased greenery on the community. The study draws on case studies from cities with similar challenges and proposes tailored implementation strategies for Mexico City, assessing the potential benefits and impacts of vertical gardens on property values, community well-being, and public health. This thesis contributes to the field by providing a comprehensive framework for integrating vertical gardens into urban landscapes, potentially transforming them into more sustainable and livable environments.

Research on effects of reducing temperature and CO2 emissions by green wall: Case study of G city

Climate change is currently the most crucial environmental problem, and policies on responses to climate change are actively being promoted worldwide. Particularly, greenhouse gas emissions in the city have been a continuous reminder of the need to reduce the effects of climate change. There has been interest in reducing greenhouse gas emissions using the green wall. Therefore, this research analyzed the temperature reduction characteristics and performance evaluation of the green wall system based on monitored data. The target area selected was public building. The monitoring point of the wall was the front of the wall with the installation point (glass and behind the green wall), and readings were taken for 10 min. The results of the analysis showed that the surface temperature of the building was affected by the performance of the green wall point during working hours (09:00 to 18:00). Finally, the data and greenhouse gas emissions were analyzed the data and greenhouse gas emissions of 45 to 72 %.

Sonic crystal green walls based on a combination of cylinder scatterers and vegetation for noise mitigation in urban design

Sonic crystal green walls based on a combination of cylinder scatterers and vegetation for noise mitigation in urban design

Lessening the energy usage of buildings: An exploration into green walls practicalitie

The article provides insights into green walls’ potential and energy-saving mechanisms in Melbourne, Australia. The use of vegetation on a building’s façade has been shown to positively affect the building’s demand for heating and cooling and a range of additional benefits. A mixed research study has been developed to explore and quantify using vegetated facades as a feasible option for reducing energy usage in commercial buildings. These results show that a green wall of building construction holds a similar level of thermal resistance as a 2.5cm layer of expanded polystyrene building insulation, at an R-value of 0.38m2 K/W. Combining this calculation with speculations as to the benefits of shade, evapotranspiration, and wind production has produced data showing a typical green wall can reduce the energy usage of a commercial building by up to 12%. This figure supports the use of vegetated façade systems to reduce energy usage in the built environment. This study can be instrumental in raising awareness for building and property professionals, as well as occupants, of the positive effects of green (vegetated) walls on the façades of buildings as a viable option for reducing heating and cooling loads and consequently, reducing spending on energy usage.

Exploring the impact of plant growth-promoting bacteria in alleviating stress on Aptenia cordifolia subjected to irrigation with recycled water in multifunctional external green walls

BackgroundRapid urbanization and population growth exert a substantial impact on the accessibility of drinking water resources, underscoring the imperative for wastewater treatment and the reuse of non-potable water in agriculture. In this context, green walls emerge as a potential solution to augment the purification of unconventional waters, simultaneously contributing to the aesthetic appeal and enjoyment of urban areas. This study aims to optimize water management in green walls by investigating the impact of bacterial strains on the biochemical properties and performance of the ornamental accumulator plant, Aptenia cordifolia, grown with various unconventional water sources. The experiments were designed as split plots based on a completely randomized block design with three replications. The main factor was recycled water with three levels (gray water, wastewater from the Kashfroud region of Mashhad, and urban water (control)). The sub-factor included different bacterial strains at four levels, composed of various bacteria combinations, (B1: Psedoumonas flucrecens + Azosporillum liposferum + Thiobacillus thioparus + Aztobactor chorococcum, B2: Paenibacillus polymyxa + Pseudomonas fildensis + Bacillus subtilis + Achromobacter xylosoxidans + Bacillus licheniform, B3: Pseudomonas putida + Acidithiobacillus ferrooxidans + Bacillus velezensis + Bacillus subtilis + Bacillus methylotrophicus + Mcrobacterium testaceum, and the control level without bacterial application (B0).ResultThe findings revealed significant differences at the 5% probability level across all morphophysiological traits, including plant height, the number and length of lateral branches, growth index, and plant coverage. Moreover, superior morphophysiological traits were observed in plants cultivated in substrates inoculated with wastewater irrigation. Substrates inoculated with bacteria exhibited the highest relative water content (RWC) and chlorophyll levels, coupled with the lowest relative saturation deficit (RSD), electrolyte leakage (EL), and carotenoid levels. Furthermore, plant growth-promoting bacteria (PGPB), from a biochemical perspective, were associated with increased carbohydrates, total protein, and anthocyanin. They also contributed to controlling oxidative stress caused by free radicals by enhancing the activity of antioxidant enzymes, such as guaiacol peroxidase (GPX), polyphenol oxidase (PPO), ascorbate peroxidase (APX), and peroxidase (POD), while reducing catalase enzyme (CAT) activity. This led to increased resistance to stress, as evidenced by a decrease in malondialdehyde and proline levels. The study concludes that the MIX B3, being both ecofriendly and economical, represents an effective strategy for mitigating the adverse effects of wastewater on plants.ConclusionThis study showed that plant irrigation using wastewater increases the levels of proline, phenols and oxidative stress. However, the application of plant growth promoting bacteria (PGPB) reduced oxidative damage by increasing antioxidant activity and decreasing proline and phenol levels. These findings show the potential of bacterial treatments to improve plant growth and reduce adverse effects of recycled water irrigation.

Corrigendum: An experimental analysis and deep learning model to assess the cooling performance of green walls in humid climates

Corrigendum: An experimental analysis and deep learning model to assess the cooling performance of green walls in humid climates

Optimizing green infrastructure strategies for microclimate regulation and air quality improvement in urban environments: A case study

With an increasing global urban population andassociated health concerns, understanding the effects of urban microclimate and air quality is crucial. This study aims to assess the influence of different types and locations of greenery, along with building heights and wind orientation, on urban canyon microclimate and air quality. Focusing on PM10, PM2.5, and NOx concentrations in a hot-arid district, the research employs simulation-based analysis. Results indicate that stepped buildings with green walls exhibit the highest temperature (18.02°C), while scenarios featuring two rows of deciduous trees showcase the lowest temperature (17.56°C) but higher pollution levels. Notably, scenarios lacking trees exhibit elevated temperatures. The study introduces a novel ventilation design pattern for effective air pollutant removal and proposes a scenario with extensive green coverage on streets, walls, and rooftops, incorporating appropriate planting techniques and plant selection. The findings offer valuable insights for urban designers and architects seeking to create more sustainable and environmentally friendly cities.

An experimental analysis and deep learning model to assess the cooling performance of green walls in humid climates

Introduction: Amidst escalating global temperatures, increasing climate change, and rapid urbanization, addressing urban heat islands and improving outdoor thermal comfort is paramount for sustainable urban development. Green walls offer a promising strategy by effectively lowering ambient air temperatures in urban environments. While previous studies have explored their impact in various climates, their effectiveness in humid climates remains underexplored.Methods: This research investigates the cooling effect of a green wall during summer in a humid climate, employing two approaches: Field Measurement-Based Analysis (SC 1: FMA) and Deep Learning Model (SC 2: DLM). In SC 1: FMA, experiments utilized data loggers at varying distances from the green wall to capture real-time conditions. SC 2: DLM utilized a deep learning model to predict the green wall’s performance over time.Results: Results indicate a significant reduction in air temperature, with a 1.5°C (6%) decrease compared to real-time conditions. Long-term analysis identified specific distances (A, B, C, and D) contributing to temperature reductions ranging from 1.5°C to 2.5°C, highlighting optimal distances for green wall efficacy.Discussion: This study contributes novel insights by determining effective distances for green wall systems to mitigate ambient temperatures, addressing a critical gap in current literature. The integration of a deep learning model enhances analytical precision and forecasts future outcomes. Despite limitations related to a single case study and limited timeframe, this research offers practical benefits in urban heat island mitigation, enhancing outdoor comfort, and fostering sustainable and climate-resilient urban environments.

Towards promoting sustainability in the learning environment – a focus on green walls and green roofs

Environmental concerns have gained international attention as a result of rising urbanisation and population expansion. One of the main sectors responsible for the devastation of the environment is the construction industry. It is responsible for approximately 40% of global energy consumption and nearly 30% of greenhouse gasses. Aside from the energy crisis, climate change, global warming, declining biodiversity, and health issues are some of the challenges facing current society. Those have led to the amalgamation of natural vegetation into the built environment. Amongst several forms of natural vegetation such as rain gardens, street trees, urban drainage systems, green roofs, and green walls, etc., Due to the limited availability of land and the multiple advantages that it offers in terms of three sustainability pillars, green walls and roofs represent the most technologically sound solutions.

On the Role of the Building Envelope on the Urban Heat Island Mitigation and Building Energy Performance in Mediterranean Cities: A Case Study in Southern Italy

The urban heat island (UHI) effect is one of the largest climate-related issues concerning our cities due to the localized temperature increase in highly urbanized areas. This paper aims to investigate the impact of UHI mitigation techniques in promoting climate resilience, by reducing urban air temperatures and cooling energy consumption in buildings. To this end, four mitigation solutions regarding the building envelope—green roofs, green walls, cool roofs, and cool walls—were investigated for the city of Bari in Southern Italy and compared with the current baseline scenario. Hence, five scenarios were simulated—using the ENVI-met microclimate software—during three representative summer days, and the resulting microclimate changes were assessed. Based on these analyses, new climate files—one for each scenario—were generated and used as input to run energy simulations in EnergyPlus to estimate the building cooling consumption. Coupling the microclimate and the consumption outcomes, the mitigation strategies were evaluated from both an urban and building point of view. The study shows that urban characteristics, mainly geometry and materials, are crucial for the UHI phenomenon. All the applied technologies seem to be effective. However, green walls proved to be more efficient in reducing outdoor temperatures (1 °C reduction in daily temperatures), while cool walls performed better in reducing cooling energy consumption, with an overall saving of 6% compared to the current scenario.

Adding Green to Architectures: Empirical Research Based on Indoor Vertical Greening of the Emotional Promotion on Adolescents

Good architectural space design can bring positive emotional stimulation and relaxation to users, but few studies have investigated the quantitative indicators in architectural space design and their impact on user emotions. This study takes the right-angle sandwich interface system in architecture as an example to guide the next vertical greening simulation experiment by comparing the spatial quantitative differences in connection value, integration degree, and population agglomeration. Eighty adolescent volunteers were recruited into a control (artificial decorative wall) and experimental (green wall) group based on wall type. We compared their physiological and psychological indicators, including blood pressure and blood oxygen, and psychological indicators, including POMS and SIAI-S scales. Then, we made predictive factor judgements on vertical green elements. The quantification of the interior space of the building showed consistency in parameter changes, with the central area being the area of connectivity, integration, and crowd aggregation values. After the experiment, the experimental group showed a significant decrease in diastolic blood pressure, systolic blood pressure, and heart rate (p = 0.00) and a significant decrease in tension, anger, fatigue, depression, and panic (p = 0.00). The quantitative relationship between vertical greening elements and emotional promotion using stepwise linear exploration shows that the “vine” element is a significant predictive factor for diastolic blood pressure, T-A emotion, and SIAI-S values. The results enrich the indoor optimization and creation expansion paths of interface systems for various spatial experiences and further provide guidance for urban indoor green construction plans and green landscape facility planning via the emotional influence of indoor vertical space greening on young people.

Enhancing the city-level thermal environment through the strategic utilization of urban green spaces employing geospatial techniques.

Smart urban planning needs to have a multicriteria-based approach to prevent the deteriorating local thermal climate. Maximizing the cooling potential using the available grey infrastructure would be the utmost priority of future smart cities. Remote sensing and GIS can be the appropriate tools to develop a climate-resilient urban planning framework. Studies are needed to include different features of vertical and horizontal landscaping to mitigate heat stress and enhance liveability at the city level. With this goal, the current work outlined a holistic approach to efficiently using green spaces with minimal reconstruction. The problem of regional climate threat was evaluated with urban heat island characterization. Moran's I clustering identified nearly 12% of the study area to be under considerable heat stress during summer days. Multiple techniques, such as mapping local climate zones, segment mean shift-based roof extraction, vegetation index computation, solar azimuth-based green wall site selection, etc., were applied to formulate solutions and provide an integrated method for city-level environment enhancement. A considerable area was identified as most suitable for green roof cover, and it was also computed that the transition towards green roof at only these locations may bring down the maximum heat island intensity by 0.74°C. Additionally, solar zenith, illumination effect, and building height information were combined to create a distinct method where vertical plantation would flourish exceptionally. A rigorous assessment of more than 130 urban green spaces further quantified the relation between landscape geometry and cooling effect to provide optimum green space designs for future urban planning.

A systematic review on the role of nature-based solutions (NbS) in housing delivery in Africa

Purpose The study aims to examine the potential benefits of integrating nature-based solutions (NbS) in the housing sector. Design/methodology/approach The approach adopted was a systematic literature review aided by the Preferred Reporting Items for Systematic Reviews criteria and the VOSviewer software. Abductive reasoning was used to analyze the collected data, which was then subjected to content analysis through an iterative read-and-review procedure. Findings The study identified green walls, indoor greenery, porous pavement and landscaping, rainwater harvesting and water purification and green roofs as elements of buildings where NbS should be incorporated. Although nature-based research on integrated greenery facades and roof applications was noted, rainwater harvesting and water purification-oriented research remained dominant. These findings demonstrate the advantages of implementing NbS in the housing sector, including energy efficiency, environmental development, flood prevention and sustainable water management. Integrating NbS into housing designs can considerably contribute to the creation of more resilient, eco-friendly and comfortable living environments. However, the adoption of NbS faces hurdles, including a lack of awareness, limited policy support and economic constraints. Practical implications This study recommends that NbS be mainstreamed into housing development and knowledge exchange opportunities between sub-Saharan Africa and Europe, as well as other regions, to promote the adoption of NbS through research and collaborations. Also, it contributes to the discourse of sustainable affordable housing in the Global South while addressing United Nations Sustainable Development Goals 11, 12, 13 and 15. This study offers valuable guidance to stakeholders, thereby fostering the development of more sustainable and resilient housing practices and policies. Originality/value The study used VOSviewer software visualization to identify structural patterns and track prominent research frontiers, allowing for a more thorough yet concise mapping and capture of a scientific knowledge domain.

Exploring the impact of green wall and its size on restoration effect and stress recovery using immersive virtual environments

The study investigated the influence of a green wall and its size on stress and restoration within the biophilic design integrating natural objects into environments. Despite its benefits in enhancing access to nature and stress reduction, visual stimuli properties may affect design outcomes. This research employed Immersive Virtual Environments (IVEs) combined with a climate chamber for thermally controlled conditions, where sixty participants experienced different virtual settings with and without green walls after performing a stressor task. The evaluation of stress involved recording physiological responses, including heart rate (HR), heart rate variability (HRV), and electrodermal activity (EDA) along with eye movements. Participants also completed a restoration state survey. Comparing physiological responses found no significant stress recovery in settings with green walls compared to baseline. Stress recovery was similar regardless of green wall size, indicating size may not affect stress. Restoration votes did not vary significantly across settings. These results were discussed focusing on the perceived lack of “naturalness” and “engagement” in virtual environments, as fixation time analysis indicated limited engagement: participants spent 18.63 % and 19.65 % of their time fixated on the green wall in small and large settings, respectively. The authors suggest design solutions to enhance the realism and engagement of virtual natural objects. Although this study did not find the impact of size, the minimum size of natural objects required for restoration is still unknown, suggesting a need for future research on different natural coverages to develop design guidelines for the successful integration of biophilic design into the built environments.

Climate-Induced Migration: Conflict Resolution and Legal Efforts in Pacific, Africa, and South Asia

Climate-induced migration involves people relocating caused by detrimental climate changes affecting their living environment. Pacific, Africa, and South Asia have experienced climate-induced migration resulting from extreme weather events, sea level rise, drought and desertification, and temperature extremes. The purpose of this research is to find out in terms of conflict resolution, what legal efforts have been made by the government of the affected regions to address climate-induced migration. This study uses descriptive qualitative method and case studies. Based on the results obtained from the data, it was found that the affected governments are pursuing various legal efforts to be able to tackle climate-induced migration. Several efforts made, namely “Migration with Dignity” policy, the Pacific Adaptation to Climate Change (PACC) Project, Great Green Wall initiative, the African Union’s Regional Economic Communities (RECs), Bangladesh’s Climate Change Strategy and Action Plan (BCCSAP), the South Asian Association for Regional Cooperation (SAARC) Disaster Management Centre, and India’s National Action Plan on Climate Change (NAPCC). The regional initiatives mentioned earlier play pivotal roles in implementing these frameworks and fostering collaborative endeavors, whilst the innovative legal frameworks, guided by SMART (Specific, Measurable, Achievable, Relevant, and Time-bound) indicators, ensure that climate-induced migration is addressed effectively. To sum up, dealing with climate-induced migration requires a holistic approach involving regional collaboration and innovative legal frameworks.