Air Temperature Reduction Research Articles

Assessment of salicylic acid and potassium nitrate to mitigate frost stress in autumn-sown potato crop cv. Sutlej

Potato is cultivated all the year round in Pakistan. However, the major crop is the autumn crop which is planted in mid-October and contributes 80–85% of the total production. The abrupt climate change has affected the weather patterns all over the world, resulting in the reduction of the mean air temperature in autumn by almost 1.6 °C in Pakistan, which in turn, has adversely affected the crop performance and tuber yield. This trial, therefore, was conducted to optimize and evaluate the concentration of salicylic acid (SA) and potassium nitrate (KNO3) for inducing frost stress tolerance in an autumn-sown potato crop cv. Sutlej. The findings revealed that the foliar application of 0.5 mM SA significantly enhanced the growth, yield, fluorescent, and biochemical indices of potato plants outperforming 100 mM KNO₃ application in comparison with the control. This included increased plant height by 14% and 17.6%, leaf area index by 6.3% and 26.3%, shoot biomass by 15.4% and 46.2%, crop growth rate by 16.7% and 43.3%, average tuber weight by 8.2% and 23%, tuber diameter by 6.8% and 12.2%, tuber yield by 26.1% and 46.3%, leaf angle by 16.2% and 21.6%, quantum yield of photosystem II by 20.6% and 28.2%, photosynthetically active radiations by 20.5% and 32.4%, chlorophyll content by 6.3% and 14.6%, leaf thickness by 14% and 29%, linear electron flow by 20% and 32.7%, O–2 by 6% and 14.4%, H2O2 by 11.7% and 27.6%, enzyme activities of catalase by 20.7% and 28.5%, superoxide dismutase by 28.6% and 28.5%, peroxidase by 8.3% and 13.5%, ascorbate peroxidase by 17.2% and 37.8%, total protein by 21% and 37%, proline by 36.2% and 114%, and phenolic content by 33% and 63.3% with a reduction in non-photochemical quenching by 12.7% and 29.6%, non-regulatory energy dissipation by 169.5% and 268.5%, and leaf electrolyte leakage by 57.5% and 180%, compared to KNO3 and the control, respectively. Based on the above findings, it can be concluded and recommended that 0.5 mM foliar spray of SA can be utilized on potato crop cv. Sutlej in frost-sensitive regions. However, the application rate of KNO3 needs to be optimized in order to use its maximal frost stress tolerance potential.

A health relevant approach for assessing urban green spaces

This study constitutes a first step towards a better understanding of the associations between human Health and Well-Being (H&WB) and urban green space characteristics. Utilizing various Key Performance Indicators for two green spaces in the city of Chania, we report their capacities in terms of greenness availability, accessibility, usage, air temperature reduction, as well as air pollution removal. Our report consists of in-situ measurements, modelling results and questionnaire data. Despite Municipal Garden of Chania’s (MGC) lower total carbon storage, it demonstrates denser vegetation, leading to efficient carbon sequestration and higher Normalized Difference Vegetation Index values. Accessibility favors MGC, with both spaces offering similar attractiveness, safety and acoustic comfort. Saint Apostoles Park (SAP) proves more effective in air pollutant reduction. Temperature differentials between green and urban areas are pronounced, with SAP and MGC showing lower temperatures. The findings underscore the importance of strategic urban planning to bolster human H&WB.

Greening the arid: the impact of urban vegetation on the outdoor thermal comfort in hot and dry city

This article examines the impact of urban vegetation on outdoor thermal comfort in the hot and dry city of Biskra, Algeria. The study employs the ENVI-met model to simulate various vegetation arrangement scenarios and evaluate their effectiveness in improving microclimate parameters and thermal comfort. The results show that the scenario with the densest and most extensive vegetation cover (90% of the sample area) provided the greatest reduction in air temperature, mean radiant temperature, and duration of severe thermal stress, compared to the baseline scenario with minimal vegetation. However, even the best-performing scenario did not achieve a thermally comfortable outdoor environment, likely due to the heat-absorbing properties of the asphalt ground and the reduced wind speeds caused by the dense vegetation. The study highlights the importance of considering vegetation type, cover density, and strategic placement in urban planning to mitigate the harsh climatic conditions in hot and dry cities like Biskra.

Ecological benefits of artificial vegetation restoration on local climate condition in abandoned mining area

The abandoned mining area in Hami, Xinjiang, suffers from severe ecological degradation, necessitating urgent vegetation restoration to improve local climate conditions. This study examines the ecological benefits of artificial re-vegetation conducted by our team since 2021. Using the Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) backward trajectory model and Global Data Assimilation System (GDAS) meteorological data, the long-range movement paths of air masses reaching the study area were identified. Simultaneously, on-site monitoring of meteorological factors (air temperature and humidity) was conducted to compare differences between the control point (non-vegetated area) and the artificially vegetated area. Additionally, wind speeds were monitored on both the windward and leeward sides of the vegetation restoration area for 66 days. Wind directions perpendicular to vegetation, to assess windbreak efficiency. The results indicated that the HYSPLIT model and the K-means clustering technique classified air masses’ long-range transportation into three categories: NW, N, and ES clusters. This classification illustrated the impact of regional climatic systems on local conditions. It showed cooler and more humid air masses from the northwest contributing significantly to local climate improvements. In the restored areas, high vegetation coverage and height significantly reduced air temperature by up to 1.5 °C and increased humidity by 2.7 % compared to the control area. Windbreak efficiency was notably enhanced, with wind speeds at 0.5 to 1 m heights on the leeward side reduced by approximately 1.2–1.7 m/s. This study underscores the critical role of artificial vegetation restoration in mitigating mining activities’ adverse effects, improving local climatic conditions, and promoting sustainable ecological rehabilitation in arid regions. The findings provide valuable insights for future ecological restoration projects and sustainable environmental management in similar degraded landscapes.

The Scientific Case Against Net Zero: Falsifying the Greenhouse Gas Hypothesis

The UK Net Zero by 2050 Policy was undemocratically adopted by the UK government in 2019. Yet the science of so-called ‘greenhouse gases’ is well known and there is no reason to reduce emissions of carbon dioxide (CO2), methane (CH4), or nitrous oxide (N2O) because absorption of radiation is logarithmic. Adding to or removing these naturally occurring gases from the atmosphere will make little difference to the temperature or the climate. Water vapor (H2O) is claimed to be a much stronger ‘greenhouse gas’ than CO2, CH4 or N2O but cannot be regulated because it occurs naturally in vast quantities. This work explores the established science and recent developments in scientific knowledge around Net Zero with a view to making a rational recommendation for policy makers. There is little scientific evidence to support the case for Net Zero and that greenhouse gases are unlikely to contribute to a ‘climate emergency’ at current or any likely future higher concentrations. There is a case against the adoption of Net Zero given the enormous costs associated with implementing the policy, and the fact it is unlikely to achieve reductions in average near surface global air temperature, regardless of whether Net Zero is fully implemented and adopted worldwide. Therefore, Net Zero does not pass the cost-benefit test. The recommended policy is to abandon Net Zero and do nothing about so-called ‘greenhouse gases’.

Effects of vertical greening on the thermal environment and energy consumption in different street canyons

Vertical greening is vital for energy conservation and urban sustainability. However, previous studies have seldom considered the energy-saving effects of vertical greening within street canyons—an important representative urban model. This study employs ENVI-met and EnergyPlus to evaluate the energy savings of vertical greening in twelve typical street canyon scenarios with varying aspect ratios (H/W = 1, 2, 4) and orientations (North–South, East–West, Northeast–Southwest, Northwest–Southeast). We quantified the relative contributions of building surface temperature reduction (Δ Tse) and air temperature reduction (ΔTa) to overall energy efficiency. Remarkably, our findings reveal that Δ Tse accounts for over 97 % of the total energy-saving contribution—a novel insight contrasting with previous studies that emphasized combined impacts. Additionally, the results indicate that stronger solar radiation in street canyons leads to greater reductions in building surface temperatures. To achieve maximum daily energy savings, the optimal combinations of street orientation and aspect ratio are: North–South orientation when H/W = 1, Southwest–Northeast when H/W = 2, and Northwest–Southeast when H/W = 4. This study is among the first to quantify the combined effects of different street canyon configurations and vertical greening on urban energy savings, providing effective methodologies and new insights for implementing sustainable urban vertical greening.

Case Study: Impact Analysis of Roof-Top Green Infrastructure on Urban System Sustainability in San José, CA

This paper presents results from a case study focusing on analyzing impacts of Green Infrastructure (GI) on sensible and latent heat fluxes, urban microclimate and the subsequent water–energy nexus components of an urban infrastructure system. The case study, focusing on the campus of a public university in San José, CA, aimed to quantify the pre- and post-conditions for a hypothetical GI implementation, which is in support of San José State University’s (SJSU) robust sustainability initiatives, which are also aligned with Silicon Valley’s broader strategic goals. The results revealed that a reduction of 0.3 °C in the average daily peak maximum temperature on campus could be achieved by the GI implementation. Air-conditioning related energy use was projected to decrease by 1.28%, monthly water use by 7052 m3, and it would result in an estimated reduction of approximately 2800 kWh in the water–energy nexus. In addition to lowering the campus’s carbon footprint, GI therefore offers significant economic and environmental benefits in terms of reductions in the urban air temperature, energy usage and water demand. This study provides valuable information for policy makers and low impact development water infrastructure managers considering GI implementation.

Influence of view factors on outdoor thermal comfort of residential areas in hot-humid regions.

Sky View Factor (SVF) is commonly used to describe the impact of urban geometry on the urban thermal environment. Shading effects from plants and buildings also exert a considerable influence. To investigate the influence of view factors on outdoor thermal comfort in residential areas, we employed the Physiological Equivalent Temperature (PET) and view factors (SVF, TVF, BVF) as indicators to determine outdoor thermal comfort and the quantity of shaded spaces. Thermal measurements collected from 13 points in Guangzhou, China, Our findings revealed that high TVF points exhibited more stable air temperature throughout the daytime, with average temperature differentials ranging 0.4-1.9°C lower than other points. Air temperature demonstrated a positive correlation with SVF (R2 = 0.53), while exhibiting a negative correlation with TVF (R2 = 0.45). Additionally, shading provided by plants and buildings manifests heterogeneity. At similar SVF levels, points predominantly shaded by plants (TVF > BVF) showcased lower Mean Radiant Temperature (MRT) and PET compared to points shaded mainly by buildings (BVF > TVF). The maximum reduction in air temperature and PET reached 1.1°C and 1.2°C, respectively. BVF exerted greater influence earlier in the morning, as solar altitude angle rises, the average thermal parameters of sites with BVF > TVF escalated rapidly until eventually surpassing sites with TVF > BVF. Last, superior thermal conditions were only ensured under high shading conditions. When the effective shading ratio of plants and buildings diminished (SVF > 0.3), the microclimate of measurement points might be impacted by the long-wave radiation from the underlying surface.

Evaluating the cooling performance of vegetation combined with a fountain in horizontal and vertical urban environments

Urban greenery and fountains effectively mitigate the urban heat island (UHI) effect. While many studies have assessed individual vegetation configurations (grass, shrub, and tree) and fountains at pedestrian heights, few have explored their combined effects horizontally and vertically. This study uses the ENVI-met model to evaluate the cooling effects of three vegetation configurations and their combinations with fountains in a typical historical and cultural neighborhood. The “grass, shrub, tree and fountain” scenario achieved the most substantial cooling, reducing air temperature (Ta) by 5.61 °C and mean radiant temperature (Tmrt) by 17.39 °C. Adding shrubs to the existing trees had minimal impact on Ta and Tmrt. Incorporating fountains into various vegetation configurations scenarios further lowered Ta by 3.58°C-3.66 °C and Tmrt by 2.97°C-3.27 °C. Trees primarily improved Tmrt through shading, while fountains were more effective at reduce Ta. This study offers theoretical and scientific guidance for optimizing urban street microclimate design from horizontal and vertical perspectives.

Advancing energy recovery ventilators with phase change materials for cooling load reduction and heat exchange efficiency improvement

Efforts to reduce building energy emissions and achieve net-zero carbon scenarios globally have increasingly focused the building sector on improving energy efficiency. Heating, ventilation, and air conditioning (HVAC) systems play a vital role in providing comfortable indoor environments but significantly contribute to energy consumption and greenhouse gas emissions. Energy recovery ventilators are efficient active systems that prevent unnecessary indoor heat loss and gain, regardless of outdoor climate, making them excellent technologies for achieving zero energy. In a hot and humid summer climate, such as in Korea, it is crucial to enhance the efficiency of energy recovery ventilators and reduce cooling energy consumption. A Green HVAC design aimed at reducing the energy consumption of active systems to near zero was proposed by applying phase change material-based modules with high heat storage performance to energy recovery ventilators. The phase change material module is stabilized with high thermal conductivity aluminum packing and is configured as a mesh-type structure to amplify heat exchange efficiency with air. Compared to the energy recovery ventilator, the application of the module demonstrated a reduction in supply air temperature by an average of 2.6 °C in high-temperature outdoor. During the effective operating period, a continuous indoor intake temperature reduction effect was observed, and the sensible heat exchange efficiency showed a 21.32 % improvement with the module using n-octadecane. Phase change material modules that can enhance ventilation and improve energy efficiency in high-temperature environments can be proposed as a technology to achieve Green HVAC.

Influence of urban morphology on potential of green roofs in regulating local microclimate: A case study of Liège, Belgium

Urban microclimate varies for different urban morphologies in a city necessitating the assessment of impact of green roofs on the local microclimate in such typical morphologies. This paper explores the role of roof greening in regulating the local microclimate in Liège, Belgium, for nine realistic and unique urban morphological archetypes during a heatwave. The urban morphological archetypes are obtained based on a systematic data-driven approach using an extensive list of morphological parameters. Nine scenarios without green roofs and nine scenarios with green roofs are simulated using Solene-microclimat model. Green roofs are introduced only on the existing flat roofs identified using remote-sensing to analyse the realistic impact of roof greening. Our findings suggest that distinct morphologies in the archetypes result in distinctive impact of roof greening on these archetypes. For instance, green roofs can reduce surface temperature effectively in compact high-rise archetypes, whereas green roofs' potential to reduce air temperature is limited. While green roofs can effectively reduce surface and air temperature in compact low-rise archetypes, most compact low-rise archetypes are residential and have fewer flat roofs to green. However, large low-rise archetypes, which are predominantly industrial/commercial, can be retrofitted with green roofs, considering large potential of roof greening. This study provides insight into the interplay between urban morphology, realistic roof greening potential, and the UHI effect on local microclimate, improving our understanding of microclimate regulation with green roofs.

Evaluating Urban Heat Island Mitigation Strategies in Rajshahi, Using ENVI-Met: A Remote Sensing Approach

The Urban Heat Island (UHI) effect is a critical environmental challenge in the 21st century, intensified by rapid urbanization and industrialization. This study focuses on Rajshahi, a rapidly urbanizing city in Bangladesh, where the UHI effect has already begun to manifest significantly. Utilizing ENVI-met software, a comprehensive analysis was conducted to evaluate the effectiveness of urban vegetation strategies, such as green roofs and street planting, in mitigating local temperatures and improving outdoor thermal comfort in Rajshahi's Central Business District. The findings reveal that these mitigation strategies can reduce air temperatures by up to 10 Kelvin, providing substantial cooling benefits. This research highlights the importance of integrating green infrastructure into urban planning to combat the UHI effect, enhance sustainability, and improve the overall livability of urban environments. The study offers valuable insights and practical recommendations for urban planners and policymakers, aiming to foster resilient and sustainable urban development in rapidly growing cities like Rajshahi.

Thermal Environments of Residential Areas: Sunlight and Building Shadow in a Chinese City with Hot and Humid Summers

With a primary focus on sunlight and building shadows, we studied the impact of residential building orientation angles, building heights, and area combinations, as well as the underlying surface materials, on the outdoor thermal environment in Changsha, a city located north of the Tropic of Cancer. On the basis of Changsha’s regulations, the research results indicate that building orientation angles of 15–45° and 315–345° can generate more building-shadow areas and have a better effect on improving the outdoor thermal environment. Based on the study of many common residential block building layouts in Changsha, we believe that, for point-pattern residential blocks, an increase in building lengths can be very effective for increasing building-shadow areas and thermal comfort. For row-pattern residential blocks, an increase in building heights can be regarded as more effective for increasing building-shadow areas and reducing air temperatures. Shadow areas formed on impervious surface material areas, such as concrete pavements, reduce the air temperature more than shadow areas formed on natural surfaces, such as grasslands. For the planning and regeneration of residential areas, urban planners should focus on placing more green spaces in areas which are seldom or never covered by building shadows; they should also focus on installing more impervious surfaces in areas covered by building shadows. These strategies are beneficial for making full use of building shadows to reduce air temperatures in residential areas.

Experimental and numerical study on the integration of solar-driven desiccant and thermoelectric Systems for Sustainable Thermal Comfort

Global reliance on traditional cooling systems is a pressing concern, especially given their substantial energy demands and refrigerant-related greenhouse gas emissions. The need for sustainable cooling solutions is especially urgent in hot and humid regions. This study presents an innovative solution by introducing a compact, solar-driven cooling system that integrates a Desiccant Wheel (DW) and a Thermoelectric Cooler (TEC). This novel combination leverages solar energy to enhance cooling efficiency while reducing environmental impact. The system's performance was tested through experimental methods and non-dimensional analysis, which served to validate the TRNSYS simulation. The simulation included custom components representing the DW and TEC's physical characteristics. Results demonstrated that the system effectively reduces air temperature and humidity to maintain thermal comfort, achieving Coefficients of Performance (COP) of 0.94 and 1.13in Toronto and Vancouver, respectively. A key feature of the system is the heat recovery design, which uses waste heat from the TEC to regenerate the desiccant material, enhancing COP by 68%. Further analysis through TRNSYS simulation explored the system's adaptability to various climate conditions by testing a range of temperatures (26–43°C) and relative humidity levels (30–100%). This analysis identified three operational regions, optimizing the system's application based on environmental conditions. A life cycle assessment determined a Global Warming Potential (GWP) of 0.0172 kg CO2 per kW of cooling capacity and an Energy Payback Time (EPBT) of 3.34 years. The economic analysis indicated a total system cost of $2719, predominantly due to the DW and TEC components. In conclusion, this research offers a sustainable and efficient cooling system that provides thermal comfort in hot and humid climates, marking a significant advancement in climate control technology.

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.

Impacts of ash tree removals on summer daytime temperatures in Madison, Wisconsin

Maintaining and increasing canopy cover is frequently promoted as a strategy for mitigating excess heat in cities. However, the impact of changing tree cover on surrounding air temperatures is often unpredictable and can depend on tree species, size, shape, and location. In this study, we explore whether the removal of ash trees in one downtown neighborhood in Madison, Wisconsin affected surrounding air temperatures at small spatial scales (15 to 35 m). We used a bicycle-mounted temperature and radiation sensor to repeatedly record high-frequency observations along four transects. We observed no discernible difference between daytime air temperatures near locations surrounded by tree removals and temperatures at locations without any nearby tree removals. Overall, across the four clusters of streets that were monitored, proximity to mature ash trees did not correlate to reduced air temperatures. Attempts to model temperature as a function of surrounding land cover and street tree characteristics all had poor predictive power (R2 ranged from 0.01 to 0.54), and explanatory variables related to tree cover were never statistically significant. The finding that the removal of ash trees did not impact daytime air temperatures patterns at the neighborhood scale suggests that the most densely developed streets in Madison may not easily support sufficient canopy cover to experience tree-induced cooling, underscoring the importance of pursuing a variety of strategies to mitigate urban warming.

Exploring Thermal Discomfort during Mediterranean Heatwaves through Softscape and Hardscape ENVI-Met Simulation Scenarios

The study examines the effectiveness of various design strategies in alleviating the impacts of heatwaves in the Mediterranean region, focusing on a densely populated post-refugee urban area in Greece. By analyzing five different design scenarios, the study aims to identify the most efficient approach to mitigate thermal stress outdoors. The five design scenarios include changes in albedo values and coatings and alterations in the number and type of trees. The methodology includes a literature review, field work and microclimate simulations with the use of ENVI-met 5.6.1. The study evaluates ENVI-met data through potential air temperature, PET and UTCI analysis. The experimental results indicate that the most effective strategy is associated with urban greening. In particular, increasing tree cover considerably reduces air temperature, PET and UTCI values by 4 to 10 degrees Celsius. This finding highlights the potential of urban greening to enhance thermal comfort and combat heatwave effects. The research findings may be useful to landscape architects and urban designers, in light of a more climate-responsive urban design in the Mediterranean region. Future research may also assess the combined impact of multiple mitigation strategies on a larger scale, informing evidence-based policies for heatwave resilience.

Enhancing Thermal and Daylight Performance of Historic Buildings with Passive Modifications; A Tropical Case Study

Historical buildings worldwide hold immense potential for adaptive reuse within the framework of the circular economy, a concept gaining traction in the building construction industry for its role in reducing carbon emissions. Many of these structures boast passive building design strategies, which inherently lower energy demands. Among these, thermal mass and daylight harvesting emerge as pivotal strategies for achieving indoor thermal and visual comfort, respectively. However, with the advent of significant climate change and evolving built environments, the efficacy of these historical passive strategies is subject to debate. This study focuses on a residential building constructed in the 17th century by Dutch settlers in Galle, Sri Lanka, serving as a case study. The research targets improvements in both thermal and visual comfort. Thermal performance analysis was conducted through air temperature measurements, revealing a notable 3-hour time lag and a 2.5°C reduction in peak air temperature during the day. Conversely, nighttime measurements indicated a rise in indoor temperature compared to ambient conditions. Using Design Builder software, the building was modelled to assess its daylighting conditions. Drawing upon thermodynamic principles and daylight harvesting techniques, the study proposes building envelope interventions and ventilation strategies to address nighttime overheating and enhance daylight utilization. The results demonstrate that these modifications can potentially reduce nighttime heat by 2-3°C, while also decreasing the energy requirement for lighting comfort from 51.10 kWh/m² per annum to 44.84 kWh/m² per annum. This research showcases the effectiveness of judiciously implemented interventions in historical buildings, illustrating tangible improvements in both thermal/visual performance and energy efficiency. Leveraging inherent qualities of historical structures and integrating modern design strategies to these buildings can play a vital role in sustainable urban development and energy conservation efforts.

Strategic tree placement for urban cooling: A novel optimisation approach for desired microclimate outcomes

Trees are crucial elements for improving urban microclimates by providing cooling through shading, evapotranspiration, and windbreaks. To maximise their cooling effects, it is essential to strategically position the trees in optimal locations. However, research on optimising tree location and its impact on microclimates is limited owing to computational challenges and costs. This study introduces a novel method that employs three optimisation algorithms—i.e., Non-dominated Sorting Genetic Algorithm II (NSGA-II), Particle Swarm Optimisation (PSO), and Ant Colony Optimisation (ACO)—to identify the optimal locations for trees in urban environments to enhance urban thermal comfort. The research methodology involves simulating microclimate responses to tree placements optimised by each algorithm and assessing the results based on urban thermal comfort. The results underscore the efficacy of optimised tree locations, demonstrating that optimising tree locations can significantly reduce the Universal Thermal Comfort Index (UTCI) in urban areas. Furthermore, the findings suggest that the clustering of tree canopies has a compounding impact on these cooling benefits in urban areas. Notably, all three algorithms significantly improved UTCI. PSO demonstrated the rapid identification of effective tree configurations. However, ACO provided the most substantial reduction in air temperature, highlighting its potential as an effective tool for urban cooling. While efficient, NSGA-II plateaued earlier, suggesting its utility in scenarios where timely solutions are crucial.

The impact of local microclimates and Urban Greening Factor on schools’ thermal conditions during summer: A study in Coventry, UK

Thermal comfort in schools affects children's wellbeing and educational outcomes. Global warming and frequent heatwaves have worsened the overheating issue in schools, especially in Western European countries, like the UK. While previous studies have mainly focused on residential and commercial buildings, school-related research often emphasised indoor thermal conditions, neglecting the broader influence of microclimates on the overall thermal conditions. Therefore, this research explores the thermal conditions in schools, during the summer of 2023, with a specific focus on the impact of greenery and materials. Urban Greening Factor (UGF) and its relationship with indoor and outdoor air temperatures were explored for the first time.Field studies were conducted in four primary schools in Coventry, UK, measuring indoor air temperatures and micrometeorological parameters. Tree shade demonstrated a substantial cooling effect, reducing air temperature and mean radiant temperature by up to 6.4 °C and 22.9 °C, respectively. Considerable difference between measured air temperatures in sunlight and official meteorological records highlights the need for microclimatic studies in schools. Thermal imagery identified high surface temperatures on artificial grass (67 °C) and asphalt (55 °C). Urban Greening Factor showed a strong correlation with classroom temperatures but failed to account for spatial greenery distribution and subsequently outdoor thermal conditions. The study concludes that optimising tree shade and replacing dark and artificial materials, are necessary for effective heat mitigation, offering valuable insights for policymakers and urban planners to create thermally comfortable and sustainable school environments.