Search Results (893)

In Mediterranean countries such as Portugal, summer heatwaves increasingly threaten agricultural productivity by disrupting crop physiological processes. Greenhouse cultivation often exacerbates heat stress, while conventional cooling systems such as air conditioning and evaporative cooling impose unsustainable energy demands. This study investigates an Earth-to-Air Heat Exchanger (EAHE) system consisting of a five-tier helical PVC pipe configuration (29 m, buried at a depth of 3 m), installed in a prototype polycarbonate greenhouse in Covilhã, Portugal, and monitored under real summer conditions. Four ventilation scenarios were simulated in EnergyPlus 25.1, and a segmented NTU thermal model, implemented as a Python plugin via the pyenergyplus API, predicted the EAHE outlet temperature with CV(RMSE) values of 1.47% at 30 m³/h and 3.0% at 50 m³/h. The IPMA meteorological dataset provided the best simulation accuracy (RMSE = 2.31 °C, R² = 0.978). In simulations based on the experimentally calibrated models, EAHE preconditioning reduced accumulated heat stress degree-hours above 28 °C by 9.1 to 9.5% and lowered peak indoor temperature by up to 2.60 °C, at system COPs of 6.9 to 10.6, which are 2.3 to 3.5 times higher than conventional vapour-compression cooling; propagated measurement uncertainties confirm the robustness of this COP advantage. A model-based parametric scale analysis indicated that geometrically scaled circuits (DN200, DN400) achieve degree-hour reductions of 67 and 91%, supporting EAHE scalability through geometric proportioning, pending experimental validation at larger scales. Full article

Commercial plots in hot–humid tropical island cities require effective pedestrian-level ventilation; however, the extent to which different layout forms enhance wind-driven cooling potential under fixed development intensity remains insufficiently quantified. Taking Haikou as a representative tropical island case, this study examines how building count and spatial enclosure form affect the pedestrian-level wind environment of a commercial plot. A total of 63 layouts with one, two, and three building units were constructed under identical development constraints. ANSYS Fluent 2023 R1 (ANSYS, Inc., Canonsburg, PA, USA). was used to simulate pedestrian-level wind fields under representative summer southerly and east–northeasterly (ENE) wind conditions. Six ventilation-related indicators, including area-weighted mean wind speed, maximum wind speed, and the non-low-wind-speed area ratio in both seasons, were integrated into a Wind-Driven Cooling Potential Index (WDCPI). The weighting scheme combined climate-informed seasonal weights with entropy-based objective indicator weights. The results show that summer ventilation is more sensitive to layout form than winter ventilation. Although the average WDCPI decreases as building subdivision increases, layout B2 shows the highest WDCPI among the tested scenarios because its open inter-building space forms a continuous ventilation path aligned with the prevailing summer wind. The sensitivity analysis supports the relative stability of the ranking results. These findings highlight airflow connectivity and windward openness as important layout-screening principles for cooling-oriented commercial plot design in tropical island cities. Full article

Infrared thermography enables non-contact monitoring of induction motor thermal behavior, but absolute temperature alone may not distinguish faults with similar surface heating. This paper presents a proof-of-concept case study on the explainable thermographic diagnosis of three-phase induction motors using transient thermal signatures. Two faults were imposed on the same Siemens 1LA2080-4AA10 squirrel-cage motor: loss of forced ventilation (hereafter, cooling failure) and a resistive-bank-induced phase unbalance condition denoted in the test bench as 50% phase unbalance. The approach combines motor-specific regions of interest, transient thermal descriptors, hot area expansion, first-order thermal modeling, healthy baseline residuals, and two physically motivated indices: the Cooling Failure Index (CFI) and Phase Unbalance Thermal Index (PUTI). Cooling failure was analyzed from radiometric CSV data, whereas phase unbalance was evaluated from color-mapped thermal video through scale-based temperature reconstruction and is therefore interpreted as an estimated thermal signature. For the baseline self-reference consistency check, the residual-based fault flag remained false. Cooling failure increased the maximum radiometric temperature from 77.2 °C to 91.6 °C, with 43,399 pixels above 80 °C. Phase unbalance showed a localized stator-dominated rise without hot area expansion above 80 °C in the reconstructed sequence. The rule-based layer assigned high CFI to cooling failure and high PUTI to phase unbalance, supporting explainable case-study-based discrimination while avoiding claims of general classifier validation. Full article

Low-cost air temperature and relative humidity sensors are increasingly deployed in dense urban monitoring networks for the characterization of urban heat islands and heat exposure. However, measurement accuracy strongly depends on the performance of the radiation shield protecting the sensor from solar heating. This study evaluates five low-cost radiation shield designs, including naturally ventilated, forced-ventilated, spherical, and chimney-type configurations, under tropical outdoor conditions on Reunion Island. Five calibrated SHT31 sensors were deployed simultaneously alongside a reference meteorological station over a five-week measurement campaign. Shield performance was assessed using standard metrological indicators, daytime–nighttime analyses, error distributions, and two-dimensional irradiance–wind diagnostics. Temperature RMSE values ranged from 0.68 to 1.18 °C, while relative humidity RMSE ranged from 2.65 to 7.39%. The forced-ventilated shield provided the best overall temperature performance, whereas the chimney-type design exhibited the largest errors. Combined irradiance–wind analyses showed that measurement errors were primarily governed by the balance between radiative forcing and convective cooling, with maximum temperature biases exceeding 2.5 °C under high-irradiance and low-wind-speed conditions. Based on these findings, several correction approaches were evaluated. A physically interpretable semi-empirical model reduced RMSE by 50%, while a Random Forest model achieved reductions of up to 66%. These results suggest that low-cost meteorological measurements can be substantially improved through appropriate shield design and meteorologically informed calibration procedures, particularly under tropical conditions characterized by strong solar radiation and limited precipitation. Full article

Increasingly stringent regulations regarding climate policy and the sustainable development paradigm determine the transformation of contemporary multi-family housing typology, manifested by a growing share of single-aspect micro-apartments (units with exterior exposure on only one facade). This article identifies the phenomenon of the energy-efficiency paradox, wherein highly insulated buildings successfully trap winter heat but inadvertently escalate summer cooling demands. Consequently, the primary operational challenge becomes limiting excessive solar heat gains in summer, which directly translates into high cooling energy demand, rather than solely mitigating heat losses in winter. Sustainable construction requires moving beyond the narrowly defined reduction of envelope thermal transmittance towards holistic adaptation to climate change and ensuring adequate indoor environmental quality. The methodology is based on a coupled energy-economic analysis, evaluating thermal balances and their direct financial implications for end-users. The variant analysis of solar heat gains conducted for a reference 30 m² dwelling in Warsaw proves that architectural optimization should not be determined solely by short-term investment profit maximization. Effective engineering optimization in construction requires the implementation of a full building life cycle perspective. Unfavorable glazing orientation and the lack of cross-ventilation necessitate the use of energy-intensive air-conditioning systems, which directly increases the building’s carbon footprint and generates hidden operating costs (differences reaching over 145 PLN annually for heating and approximately 70 PLN for cooling). The findings highlight the necessity for a critical reevaluation of design priorities for compact apartments, integrating social justice (by reducing information asymmetry in the real estate market, where buyers are often unaware of these future cooling burdens) with long-term economic rationality and the resilience of the built environment to extreme weather events. Full article

Wet cooling towers are widely used for low-energy thermal management and ventilation support; however, high-fidelity simulations are computationally expensive for large design studies. This work develops a physics-based static reduced-order model for a two-dimensional axisymmetric counterflow wet cooling tower derived from computational fluid dynamics (CFD) simulations coupled with a user-defined source-term formulation for heat and mass transfer in the fill region. A design of experiments based on advanced Latin hypercube sampling generated 210 configurations, of which 168 valid simulations were retained. The active inputs included tower diameter, fill height, inlet air mass flow rate, inlet air temperature, inlet humidity ratio, inlet water mass flow rate, and inlet water temperature, while the cooling range and evaporation rate were selected as target outputs. Five surrogate families were compared by cross-validation. Kriging was statistically most accurate, with $R_{CV}^2$ values of 0.9999 and 0.9998 for the cooling range and evaporation rate, respectively. Second-order quadratic polynomial models were selected as the engineering reduced order model (ROM) because they capture non-linear boundary curvatures with accuracy, achieving $R_{CV}^2\ge 0.9989$ and root mean square errors of 0.0426 K and 0.00042 kg/s while preserving an explicit, directly implementable algebraic form. Sensitivity analysis indicated that the inlet water temperature and air mass flow rate are dominant factors within the sampled domain. Full article

Field measurements undertaken in six paired primary school classrooms in Anambra State, Nigeria, previously demonstrated that interlocking compressed earth block (ICEB) classrooms maintained significantly lower occupied-hour temperatures than adjacent sandcrete block (SCB) classrooms. This study applies DesignBuilder/EnergyPlus simulation, evaluated against field measurements, to investigate the physical mechanisms underlying this observed thermal advantage and to explore seasonal performance beyond the period accessible through field monitoring. Simulation models were developed using literature-derived thermophysical properties and validated against field measurements collected at Awkuzu Primary School on 2 July 2024. Model accuracy was assessed using ASHRAE Guideline 14 metrics. The ICEB model achieved NMBE of −6.4% and CV(RMSE) of 6.8%, satisfying both recommended thresholds. The SCB model achieved CV(RMSE) of 15.6%, while NMBE of −14.0% marginally exceeded the recommended threshold because of conservative TMYx boundary conditions. Results indicate that the superior wet-season performance of ICEB classrooms is attributable to the interaction between high thermal mass (μ = 0.31; φ = 9.1 h) and continuous cross-ventilation. Parametric crossover simulations demonstrated that ventilation was the dominant cooling mechanism, while ICEB wall thermal mass provided an additional independent thermal benefit of approximately 0.31 °C. This material contribution is secondary in magnitude to the ventilation effect and is not presented as a standalone practical advantage. Dry-season simulations suggested a possible reversal of performance under near-calm harmattan conditions; however, the magnitude and direction of this effect remain uncertain because of EPW boundary-condition limitations. The findings suggest that classroom thermal performance depends on the interaction between envelope thermal mass and ventilation configuration rather than material properties alone and highlight the potential importance of controllable ventilation in naturally ventilated educational buildings in tropical climates. Full article

Traditional windcatchers are often discussed as passive cooling devices for hot–arid climates, yet their sustainability performance under contemporary comfort-controlled operation remains insufficiently understood. This study evaluates the energy and load-based carbon implications of integrating a windcatcher into a high-thermal-mass courtyard house in Şanlıurfa, Türkiye. A combined DesignBuilder v6.1/EnergyPlus v8.2 and CFD-based assessment was used: annual heating and cooling loads were calculated through EnergyPlus-based building energy simulation, while CFD analyses were used to interpret representative airflow behavior and localized thermal effects within the semi-open iwan. Scenarios varied operational schedule, geometry, material configuration, ventilation openings, and water pool integration. The results show strongly context-dependent performance rather than uniform energy or carbon benefit. Continuous operation weakened annual performance, whereas seasonal operation produced more balanced outcomes. The P.1 configuration produced the lowest total annual energy demand among the tested scenarios, decreasing total demand from 70,929.99 to 70,806.65 kWh/a, corresponding to a reduction of 123.34 kWh/a or 0.17% relative to the baseline. However, this limited reduction was accompanied by a 6.02% increase in cooling demand and a 2.52% decrease in heating demand. Consequently, the total load-based carbon indicator increased from 18.32 to 18.60 tCO₂/year, corresponding to an increase of 0.28 tCO₂/year or 1.53%. CFD results indicate that the semi-open iwan geometry and its orientation relative to prevailing winds constrained airflow effectiveness and limited the transfer of local cooling effects to conditioned zones. This study demonstrates that vernacular passive systems should be evaluated through integrated annual energy, airflow, and load-based carbon analyses before being adopted in sustainable renovation or climate-responsive design. Full article

Under extreme high-temperature conditions, heat accumulation in rooftop photovoltaic (PV) arrays can substantially reduce PV conversion efficiency and output power. To improve the thermal and power-generation performance of rooftop PV systems, this study developed a computational fluid dynamics (CFD) model for a rooftop PV array and validated it using field measurements from Chongqing, China. The relative root mean square errors (rRMSEs) between simulated and measured backsheet temperatures at the three measurement points were 6.31%, 7.52%, and 8.45%, respectively, indicating acceptable model accuracy. The effects of mounting height, tilt angle, and front-to-rear row spacing on PV backsheet temperature, conversion efficiency, and output power were then investigated. A central composite design (CCD) within response surface methodology (RSM) was used to establish regression models linking the design variables to the objective functions. Finally, an NSGA-III-based multi-objective optimization framework combined with TOPSIS was used to identify the optimal configuration. For the rooftop PV array studied under extreme summer conditions in Chongqing, the TOPSIS-selected compromise solution corresponded to a mounting height of 0.90 m, a tilt angle of 15.63°, and a front-to-rear row spacing of 2.96 m. Compared with the original configuration, the optimized passive installation geometry reduced the peak PV backsheet temperature by 2.3 °C without active cooling, water consumption, or additional energy input. Under the same meteorological and irradiance conditions, this temperature reduction increased conversion efficiency by 0.5% and output power by 0.4%. Detailed inter-row short-wave shading and electrical mismatch were not explicitly modeled. Therefore, the row-spacing effect mainly reflects changes in ventilation and module temperature under the same irradiance input. The proposed framework provides a practical reference for installing and optimizing rooftop PV arrays in hot-climate regions. Full article

Moisture damage in buildings has traditionally been discussed primarily in relation to winter condensation in cold climates. In hot-humid regions, however, damage develops under different boundary conditions, including warm and humid outdoor air, frequent rainfall, air-conditioning operation, air leakage, and limited drying after wetting. Climate change is treated here as contextual background that can intensify these boundary conditions, not as the primary object of quantitative attribution. This structured narrative review synthesizes literature on climatic boundary conditions, envelope moisture response, moisture- and mold-risk assessment, microbial implications, and building adaptation. It is supplemented by illustrative climate-data analysis, global exposure mapping, and selected field examples; these components contextualize the proposed drying-deficit framework but do not constitute comprehensive validation or global risk prediction. Drying deficit is proposed as an interpretive framework for situations in which moisture supply, storage, and repeated wetting exceed available drying capacity over relevant time scales. The review identifies the need for assessment methods that account for cooling-driven gradients, airflow paths, material storage, microbial response, and occupant behavior. It also highlights adaptation strategies such as rain control, leakage reduction, vapor-open drying paths, humidity-controlled ventilation, dehumidification, moisture-tolerant materials, and integrated hygrothermal and microbial monitoring. The proposed framework requires further validation and should not be treated as a universal explanation for all moisture damage in hot-humid buildings. Full article

Amidst global carbon neutrality goals, China’s building energy consumption gains prominence, with heating and cooling exceeding 50% of the total. Underground structures leverage inherent geological thermal inertia to significantly reduce ventilation energy demands. This study employs combined field measurements and numerical simulations to investigate heat exchange mechanisms and performance in underground hydropower station air intake tunnels. Four representative tunnels (Sichuan, Fujian, Hebei, Yunnan) served as case studies, monitoring air temperature, humidity, velocity, and wall temperature. Field-monitored parameters informed a computational fluid dynamics (CFD) model, enabling quantitative analysis of rock thermal conductivity, inlet air velocity, and wall temperature effect on heat exchange efficiency. Research shows that: (1) significant seasonal adaptive characteristics exist, achieving peak cooling efficiency (69.04%, summer) and heating efficiency (78.86%, winter); (2) rock thermal conductivity is the primary efficiency determinant—quartzite tunnels exhibited 11.8% higher average efficiency than tuff tunnels; and (3) inlet air velocity negatively correlates with efficiency, exceeding 90% at 0.1 m/s but declining to 69% at 1.5 m/s. This work provides a theoretical basis for optimizing energy-efficient ventilation in underground engineering and validates the pivotal role of rock thermal inertia in reducing operational building energy consumption. Full article

Energy consumption in hot–arid and warm climates is driven by cooling demand during long, intense summers. In these contexts, the residential sector accounts for much of national electricity use, and cooling can exceed 70% of annual household consumption. Saudi Arabia exemplifies this pattern, with the residential sector consuming over half of the national electricity and cooling dominating demand in hot–arid cities like Riyadh. Against this background, this study explores the adaptation of the Passive House approach—originally developed in cold and temperate regions—for a cooling-dominated, hot–arid context. A detached villa in Riyadh was selected as a case study, and its energy performance was modeled in DesignBuilder using a baseline calibrated against 12 months of electricity bills. Passive House measures were then tested. The results showed that insulating walls and roofs provided the largest reductions in electricity use, at 21% and 15%, respectively, while high-performance glazing with external shading achieved an additional 3.4%. Improvements in airtightness and ventilation with heat recovery yielded only minor savings in a cooling-dominated climate. When all measures were implemented together, the villa’s annual electricity consumption was reduced by 48% compared with the baseline, and cooling demand was reduced by 72.3%. These findings demonstrate that Passive House measures can be effectively adapted to hot–arid conditions, with envelope insulation and solar-gain control delivering the most significant benefits. The Riyadh case underscores the potential of Passive House principles to reduce residential electricity use in cooling-dominated housing and to support energy-efficient design in hot–arid and warm-climate regions. Full article

Solar energy has become one of the most important renewable energy sources for reducing dependence on conventional fossil-based energy systems. Rooftop photovoltaic (PV) installations play a key role in the expansion of solar energy, particularly in tropical countries such as Vietnam. This study experimentally investigates the effects of roof material, rear ventilation gap, PV technology, solar irradiance, and wind speed on the power conversion efficiency (PCE) of rooftop PV modules under tropical climatic conditions in Ho Chi Minh City, Vietnam. Three roof types (concrete, tiled, and corrugated metal), three rear ventilation gaps (10, 30, and 50 cm), and two PV technologies (monocrystalline and polycrystalline) were evaluated under real operating conditions. The results indicate that increased module temperature significantly reduces power output and PCE, even under high solar irradiance. PV modules installed on corrugated metal roofs exhibited the highest operating temperatures and the lowest efficiencies, whereas concrete and tiled roofs provided more favorable thermal conditions. Increasing the rear ventilation gap enhanced convective cooling, with the 30–50 cm configurations showing superior heat dissipation compared with the 10 cm configuration, particularly for corrugated metal roofs. The experimentally determined heat transfer coefficient ranged from 23.48 to 67.64 W m⁻² K⁻¹, exceeding the theoretical wind-based coefficient (16.86–17.22 W m⁻² K⁻¹), thereby indicating the contribution of mixed convection, radiative exchange, and roof–module thermal interactions. Monocrystalline modules consistently achieved slightly higher efficiencies than polycrystalline modules. The findings provide practical guidance for optimizing rooftop PV installations and improving energy yield in tropical climates. Full article

Accurate prediction of the internal temperature of mushroom bags is essential but remains challenging owing to the complex nonlinear coupling between ambient conditions and the bag’s thermal state. This study proposes a physics-guided machine learning framework that translates thermodynamic prior knowledge into a set of interpretable engineered features. Specifically, we construct features that capture temporal thermal lags via cross-correlation optimal lag analysis, represent integrative thermal memory through cumulative moving averages and exponentially weighted moving averages (EWMAs) with a physically calibrated half-life, and quantify the interaction between evaporative cooling and ventilation using a vapor pressure deficit-gated temperature gradient. The engineered features are combined with standard environmental variables and supplied to several machine learning algorithms. Four paradigms—a physics model, a one-step physics model, a purely data-driven model, and the proposed physics-guided model—are systematically compared across four representative cultivation scenarios. The physics-guided XGBoost achieves the highest predictive accuracy, with R² values of 0.996, 0.993, 0.997, and 0.973 for the four datasets, significantly outperforming all baselines. SHAP and Accumulated Local Effects analyses reveal that EWMA dominates predictions and that the learned feature–response relationships align with established thermodynamic principles, confirming physical consistency. The framework provides a practical, interpretable solution for feedforward environmental control in edible mushroom cultivation. Full article

Rising cooling demand in hot-arid climates requires passive, low-energy building strategies that can be compared across heterogeneous evidence. This study develops a PRISMA-informed systematic mapping review and an evidence-based energy-efficiency decision matrix for building-scale passive cooling strategies in hot-arid climates, while comparing evidence from both traditional and contemporary building contexts. Scopus and Web of Science Core Collection were searched for English-language journal articles and reviews published between 2010 and 2026. Rather than conducting statistical meta-analysis, the review uses qualitative and evidence-based synthesis to map, classify, and interpret heterogeneous performance evidence. After duplicate removal, 844 records were screened. A completed prioritized full-text synthesis assessed 92 reports and produced a core analytical evidence base of 78 studies, supported by 11 borderline or contextual studies, giving 89 mapped studies. The studies were coded by strategy cluster, climatic context, building typology, evidence type, performance metric, energy relevance, water dependency, implementation complexity, maintenance sensitivity, and evidence strength. Seven strategy clusters were identified: evaporative/windcatcher/solar-chimney systems; envelope/façade/shading strategies; courtyard/microclimate strategies; roof-based cooling; earth-to-air or ground-coupled cooling; natural ventilation/night flushing; and integrated passive cooling packages. The results show that passive cooling decisions require more than a thermal performance comparison. The proposed matrix distinguishes performance potential from implementation suitability and provides a structured design-support framework for low-energy hot-arid buildings. Full article