Relative Humidity Distribution Research Articles

Relative Humidity Distribution along the Gas Flow Channel in a Wide Temperature Range

Relative humidity (RH) distribution is a crucial condition for proton exchange membranes in fuel cells. Estimation of the distribution in a cell by measuring RH at the cell outlet with varying the O2conversion was proposed. The O2 conversion is a function of the space time, a ratio of the active area from the inlet to the inlet volumetric gas flow rate. Varying the active area or the flow rate resulted in identical relation between the O2 conversion and the space time 60.5–90.5 oC with Nafion NR-212. Numerical simulation well reproduced the measured RH distribution, which was also closer to those estimated with assuming equal RH on the anode and cathode sides, i.e. sufficiently rapid water permeation. At higher temperature, more water generation or supply was required to attain RH equal to that at lower temperature. Increasing the inlet RH compensated the less RH increase at higher temperature.

Relative Humidity Distribution along the Gas Flow Channel in a Wide Temperature Range

Relative humidity (RH) distribution is a crucial condition for proton exchange membranes in fuel cells. Estimation of the distribution in a cell by measuring RH at the cell outlet with varying the O2conversion was proposed. The O2 conversion is a function of the space time, a ratio of the active area from the inlet to the inlet volumetric gas flow rate. Varying the active area or the flow rate resulted in identical relation between the O2 conversion and the space time 60.5–90.5 oC with Nafion NR-212. Numerical simulation well reproduced the measured RH distribution, which was also closer to those estimated with assuming equal RH on the anode and cathode sides, i.e. sufficiently rapid water permeation. At higher temperature, more water generation or supply was required to attain RH equal to that at lower temperature. Increasing the inlet RH compensated the less RH increase at higher temperature.

Simulation of ambient temperature and humidity distribution in eight-span greenhouse under different wind conditions and corn height

The greenhouse environment suitable for crop growth usually depends on reasonable ventilation, and outdoor air flow state and indoor crop height are important factors affecting the ventilation effect. This study conducted simulation and experimental research on corn cultivation in an eight-span plastic greenhouse, analyzing the effects of outdoor wind speed, wind direction, and indoor crop height variations on the uniformity of temperature and relative humidity distribution as well as the air flow dynamics within the greenhouse. The study shows that as outdoor wind speed increases from 0.5 m/s to 2.5 m/s, for every 1 m/s increment, temperatures decrease by 2.2 °C and 0.9 °C, respectively. The increase in outdoor wind speed resulted in uniformity of greenhouse temperature and humidity along the vertical height, but exacerbated the degree of inhomogeneity in the east-west direction. The change in outdoor wind direction leads to differences in airflow direction and ventilation volume. On the south side of the greenhouse, while temperature is lower, the relative humidity is higher, with maximum differences in temperature and humidity between the north and south sides being 0.6 °C and 1.5 %, respectively, when the northeast wind blows. The east wind has the best cooling effect. The uneven degree of temperature and humidity distribution in the east and west direction of the greenhouse is positively correlated with crop height. This study can provide valuable insights for adjusting and optimizing natural ventilation strategies in large multi-span greenhouses.

Deterioration modelling of GFRP-reinforced cement-based concrete infrastructure in service under the natural inland atmospheric environment

The aim of this paper is to develop an interdisciplinary methodology for modelling the deterioration of GFRP-reinforced concrete (G-RC) structures in service under natural atmosphere. The evolution of concrete carbonation was analyzed using a multiscale physico-chemo-mechanical coupling platform, which has been validated through numerous successful applications in practical concrete structures. The coupled heat transfer and mass transport in cement-based concrete, including temperature, relative humidity (RH) and pH distributions, were analyzed and simulated using the multiscale platform based on detailed information about the cement type, concrete mixture, and weather records. The resulting data were used to assess the degradation of GFRP reinforcements embedded in concrete through the gas-liquid state shift equation and the chemical etching model (CEM). The concrete carbonation and the degradation levels of GFRP reinforcements were validated by the field data after 15 years of service, demonstrating the effectiveness of the established deterioration model.

Effects of Shading Nets Color on the Internal Environmental Conditions, Light Spectral Distribution, and Strawberry Growth and Yield in Greenhouses.

Greenhouses are used to create the appropriate environment for plant growth. Controlling the level of lighting using shading nets is one of the most commonly used methods for making suitable environmental modifications in greenhouses. The objective of this study was to examine the impact of three colored shading nets (green, black, and beige at shading rates of 50%) on inside air temperature, relative humidity, and spectral distribution of light in a greenhouse, as well as their effect on the growth and yield of strawberry plants. Data were collected during winter (December and January) and spring (March and April) months from shaded and unshaded blocks. The green net had the highest transmittance to solar radiation (τSR) during the two periods (38% and 35%, respectively) and the highest transmittance to photosynthetically active radiation (τPAR) of 34% during spring months, while the beige net had the highest τPAR of 27% during winter months. The black net had the smallest τPAR values during the two periods (22% and 29%, respectively). The lowest total light levels per season for solar radiation (SR) and photosynthetically active radiation (PAR) (746.8 and 293.7 MJ·m-2, respectively) were obtained under the black net, compared with (906.7 and 320.8 MJ·m-2, respectively) for the beige net, and (969.6 and 337.2 MJ·m-2, respectively) for the green net. The ratio of PAR to SR (PAR:SR) was 41% and 44% outside and inside the greenhouse for the control (without shade), respectively. The black net had the highest ratio of PAR:SR (39%) among the treatment nets. The green net transmitted more light in the blue-green region (400 to 570 nm) and transmitted the highest photon flux at 480 nm, while the beige net increased the infrared radiation flux from 730 nm and above and transmitted the highest photon flux at 604 nm. The study found that the green net increased the ratio of blue to red light (B/R), while the beige and green nets reduced the red to far-red light (R/FR) ratio. The photosynthetic rate, conductance to water, and transpiration were significantly higher for strawberries grown under the beige net. These results indicate that the beige net positively influenced leaf and stem characteristics, leading to improved strawberry yields. The best yields of strawberries were obtained under the beige net and the control group (no shade), surpassing the yields achieved under the black net by 26.3% and 21.4%, respectively.

Evaluation of plant canopy microclimates with realistic plants in plant factories with artificial light using a computational fluid dynamics model

Airflow parameters play a vital role in regulating the microclimate of the plant canopy and significantly affect plant development and growth in plant factories with artificial light (PFALs). A computational fluid dynamics (CFD) model with a realistic soybean canopy was developed to predict the distribution of radiation (W m−2), leaf temperature (°C), air velocity (m s−1), air temperature (°C), and relative humidity (%) within a plant canopy. The accuracy of the CFD model was confirmed by comparing mean absolute percentage errors of these variables which were 9.9 %, 1.4 %, 11.4 %, 0.8 %, and 1.8 %, respectively. The validated CFD model was used to simulate the lamp temperature and microclimate distribution of the soybean canopy under different inflow parameter levels on a cultivation shelf. The results revealed that the microclimate was primarily influenced by lamp radiation rather than convective heat when the inflow velocity was below 0.57 m s−1. Inflow velocity, air temperature, and relative humidity exerted more significant effects on air velocity, air temperature, and relative humidity, respectively, than the other variables in the plant canopy. The increase of inflow velocity significantly improved the uniformity of air velocity, temperature, and relative humidity in the plant canopy. However, note that this study investigated the lamp temperature and microclimate distribution in plant canopies under different airflow parameters using the CFD model without coupling plant transpiration to the surrounding climate. This provides valuable insights into the control of the plant canopy microclimate in general and more particularly on the shelves of PFALs.

Distribution Characteristics and Prediction of Temperature and Relative Humidity in a South China Greenhouse

South China has a climate characteristic of high temperature and high humidity, and the temperature and relative humidity inside a Venlo greenhouse are higher than those in the atmosphere. This paper studied the effect of ventilation conditions on the spatial and temporal distribution of temperature and relative humidity in a Venlo greenhouse. Two ventilation conditions, with and without a fan-pad system, were studied. A GA + BP neural network was applied to predict the temperature and relative humidity in fan-pad ventilation in the greenhouse. The results show that the temperature in the Venlo greenhouse ranged from 15.8 °C to 48.5 °C, and the relative humidity ranged from 24.9% to 100% during the tomato-planting cycle. The percentage of days when the temperature exceeded 35 °C was 67.3%, and the percentage of days when the average relative humidity exceeded 70% was 83.7%. The maximum temperature differences between the three heights under NV (Natural Ventilation) and FPV (Fan-pad Ventilation) conditions were 3.4 °C and 4.5 °C, respectively. The maximum relative humidity differences between the three heights under NV and FPV conditions were 8.4% and 21.7%, respectively. The maximum temperature difference in the longitudinal section under the FPV conditions was 3.2 °C, while the relative humidity was 11.4%. The cooling efficiency of the fan-pad system ranged from 16.6% to 70.2%. The non-uniform coefficients of the temperature under the FPV conditions were higher than those under the NV conditions, while the nonuniform coefficients of the relative humidity were the highest during the day. The R2, MAE, MAPE and RMSE of the temperature-testing model were 0.91, 0.94, 0.11, and 1.33, respectively, while those of relative humidity model were 0.93, 2.83, 0.10, and 3.86, respectively. The results provide a reference for the design and management of Venlo greenhouses in South China.

Online Monitoring of the Temperature and Relative Humidity of Recycled Bedding for Dairy Cows on Dairy Farms

In large-scale dairy farming, the use of high-temperature-fermented dairy manure bedding instead of rice husk-based bedding and other commercial types of bedding is widely favored. Strip-stacking aerobic fermentation is the main production method of dairy manure bedding, but it has problems including unstable fermentation and the secondary breeding of pathogens. In this work, a multi-probe, integrated, online monitoring system for temperature and relative humidity was used for fermentation process optimization. The effects of the temporal and spatial distribution of fermentation temperature and relative humidity on the nutrient content curve and the moisture and ash content of manure bedding materials were systematically studied. The effect of the fermentation process on the retention rate of effective bedding materials (cellulose, hemicellulose, and lignin) was analyzed. The experiments proved that high-quality bedding material can be obtained through reasonable stacking fermentation. The fabricated bedding material has a total dry base content consisting of cellulose, hemicellulose, and lignin of 78%, an ash content of 6%, and a nutrient content of 17%. The obtained bedding material was produced to increase the bed rest rate and continuously inhibit the bedding bacteria content, keeping it at a low level for 5 days. This study proves that temperature and humidity monitoring can guide the optimization of the strip-stacking fermentation process of dairy manure and that it can be applied to large-scale farms to improve fermentation parameters.

Spatial Distributions of AQI, PM2.5, Relative Humidity, Speed, and Temperature in Twenty-Two Towns in Nigeria

Spatial Distributions of AQI, PM2.5, Relative Humidity, Speed, and Temperature in Twenty-Two Towns in Nigeria

Experimental study of ambient temperature and humidity distribution in large multi-span greenhouse based on different crop heights and ventilation conditions

Analyzing the distribution of temperature and humidity within a greenhouse is essential for optimizing ventilation strategies and improving crop quality and yield. The temperature and humidity distribution of eight-span greenhouse under natural ventilation and mechanical ventilation is studied experimentally. The influence of different crop height on temperature and humidity distribution in greenhouse and the influence of different mechanical ventilation strategies on temperature regulation were discussed. The results showed that the temperature difference between inside and outside the greenhouse decreased with the increase of crop height. Under natural ventilation conditions, the soil surface temperature is the highest, and the temperature at 0.5 m above the surface is the lowest, with the maximum temperature difference of 0.9 ℃. The temperature in the greenhouse was higher in the west and lower in the east, and the temperature difference decreased with the increase of crop height. In the east–west direction, the maximum temperature difference between tall crops, short crops and non-planted crops was 0.7 ℃, 0.9 ℃ and 1.0 ℃, respectively. High crops increase the relative humidity in the greenhouse and increase the uneven distribution of relative humidity. When growing tall crops, the difference between indoor and outdoor relative humidity is only 2.3 %. When the external shade and fan are turned on at the same time, the cooling effect is the best, the energy consumption is lower, and the temperature distribution is the most uniform. The results provide a valuable reference for optimizing greenhouse structure, formulating ventilation strategy and reducing agricultural energy consumption.

Improvement in Forecasting Short-Term Tropical Cyclone Intensity Change and Their Rapid Intensification Using Deep Learning

Abstract Forecasting the intensity of a tropical cyclone (TC) remains challenging, particularly when it undergoes rapid changes in intensity. This study aims to develop a convolutional neural network (CNN) for 24-h forecasts of the TC intensity changes and their rapid intensifications over the western Pacific. The CNN model, the DeepTC, is trained using a unique loss function, an amplitude focal loss, to better capture large intensity changes, such as those during rapid intensification (RI) events. We showed that the DeepTC outperforms operational forecasts, with a lower mean absolute error (8.9%–10.2%) and a higher coefficient of determination (31.7%–35%). In addition, the DeepTC exhibits a substantially better skill at capturing RI events than operational forecasts. To understand the superior performance of the DeepTC in RI forecasts, we conduct an occlusion sensitivity analysis to quantify the relative importance of each predictor. Results revealed that scalar quantities such as latitude, previous intensity change, initial intensity, and vertical wind shear play critical roles in successful RI prediction. Additionally, the DeepTC utilizes the three-dimensional distribution of relative humidity to distinguish RI cases from non-RI cases, with higher dry–moist moisture gradients in the mid-to-low troposphere and steeper radial moisture gradients in the upper troposphere showed during RI events. These relationships between the identified key variables and intensity change were successfully simulated by the DeepTC, implying that the relationship is physically reasonable. Our study demonstrates that the DeepTC can be a powerful tool for improving RI understanding and enhancing the reliability of TC intensity forecasts.

Spatial distribution characteristics in segmented PEM fuel cells: Three-dimensional full-morphology simulation

Segmented proton exchange membrane (PEM) fuel cells are widely implemented in measuring their internal spatially distributed variables (e.g. current density and temperature). However, the difference between the segmented and ordinary fuel cells in spatial distribution characteristics has not been fully understood. In this work, we studied the spatial distribution characteristics in segmented fuel cells (cell area: 366.6 cm2) utilizing a three-dimensional (3D) large-scale fuel cell model that considers the full morphologies of metallic bipolar plates (BPs) and dot-matrix hydrogen, air and coolant flow distribution zones, including the current density, temperature, water content, etc., and compared with those in ordinary fuel cells. It is found that placing a segmented print circuit board (PCB) next to the bipolar plate (BP) component has little influence on fuel cell performance and internal distribution characteristics, whereas the measured current density distribution in the PCB still has inconsistency with that in the ordinary fuel cell, indicating that the influence of segmentation on electron conduction cannot be neglected. In the fuel cell with segmented BP and PCB, the fuel cell performance decreases significantly mainly due to increased electrical and ionic ohmic loss. In addition, the BP's segmentation significantly influences on the water and thermal state inside the whole fuel cell, leading to inconsistency in the measured temperature, relative humidity (RH) and current density distributions with ordinary fuel cells.

The moist halo region around shallow cumulus clouds in large eddy simulations

AbstractIn this study, the moist buffering halo region of shallow maritime cumulus clouds is systematically investigated using large eddy simulations with various grid resolutions and numerical choices. Autocorrelation analyses of cloud liquid water and relative humidity suggest a converged size of 200–300 m for moist patches outside clouds when the model resolution is below 50 m, but may overestimate this size due to noncloudy moist regions. Based on a composite analysis, the structure of the moist halo immediately outside individual clouds is examined. It is found that, regardless of model resolution, the distribution of relative humidity in the halo region does not depend on cloud size, but on the real distance away from the cloud boundary, indicating some size‐independent length scales are responsible for the halo formation. The relative humidity decays with distance more quickly with finer horizontal resolution, which is possibly related to the model resolution dependence of the cloud spectrum. The halo size near the cloud base is larger than that within the cloud layer and this feature is robust across all simulations. Further analyses of backward and forward Lagrangian trajectories originating from the moist halo region reveal the possible role for subcloud coherent structures in cloud‐base halo formation. Possible mechanisms explaining cloud halo sizes and associated length scales are discussed.

Analysis of microclimate temperature and relative humidity distribution of local poultry house in a subtropical area of Nigeria

The design of the ventilation system to ensure microclimate condition are optimum in poultry houses in the Nigerian context requires knowledge of the microclimate parameter distribution, which is lacking in the literature. This study investigated the patterns of temperature and RH distributions in a typical local poultry house. The specific objectives were to (i) analyse the vertical and horizontal distributions of the microclimate parameters in battery cage poultry housing and deep litter poultry housing, (ii) identify whether the distribution is homogenous or heterogeneous, and (iii) identify the data spread of parameters. An experimental intensive naturally ventilated local poultry house was used for this study. It consisted of deep litter (DL) and battery cage (BC) poultry housing systems partitioned by an air wall. Daytime, nighttime, rainy, and dry season temperature and RH distributions in the BC and DL poultry housing were analysed. Approximately 1.2 °C temperature difference was recorded between the poultry house and the ambient environment during the day and night. The temperature and RH distributions in the poultry housing were heterogeneous. Approximately 5% and 67%–73% of the daytime and nighttime temperature data, respectively, and 37%–41% of daytime RH fell within the optimum values.

Assessing potential indicators of aerosol wet scavenging during long-range transport

Abstract. As one of the dominant sinks of aerosol particles, wet scavenging greatly influences aerosol lifetime and interactions with clouds, precipitation, and radiation. However, wet scavenging remains highly uncertain in models, hindering accurate predictions of aerosol spatiotemporal distributions and downstream interactions. In this study, we present a flexible, computationally inexpensive method to identify meteorological variables relevant for estimating wet scavenging using a combination of aircraft, satellite, and reanalysis data augmented by trajectory modeling to account for air mass history. We assess the capabilities of an array of meteorological variables to predict the transport efficiency of black carbon (TEBC) using a combination of nonlinear regression, curve fitting, and k-fold cross-validation. We find that accumulated precipitation along trajectories (APT) – treated as a wet scavenging indicator across multiple studies – does poorly when predicting TEBC. Among different precipitation characteristics (amount, frequency, intensity), precipitation intensity was the most effective at estimating TEBC but required longer trajectories (>48 h) and including only intensely precipitating grid cells. This points to the contribution of intense precipitation to aerosol scavenging and the importance of accounting for air mass history. Predictors that were most able to predict TEBC were related to the distribution of relative humidity (RH) or the frequency of humid conditions along trajectories, suggesting that RH is a more robust way to estimate TEBC than APT. We recommend the following alternatives to APT when estimating aerosol scavenging: (1) the 90th percentile of RH along trajectories, (2) the fraction of hours along trajectories with either water vapor mixing ratios >15 g kg−1 or RH >95 %, and (3) precipitation intensity along trajectories at least 48 h along and filtered for grid cells with precipitation >0.2 mm h−1. Future scavenging parameterizations should consider these meteorological variables along air mass histories. This method can be repeated for different regions to identify region-specific factors influencing wet scavenging.

Measurement and modelling of the moisture distribution in early-age concrete in the joint of composite beam and hollow core slab

The building moisture in concrete can damage the surface material if applied too early before the excess moisture has dried out. The composite beam forms an abnormal structure at the joint of the hollow-core slab, in which the thickness of the structural concrete is almost the thickness of the entire slab. For this reason, the joint of the beam and hollow core slab must be taken into account when assessing the adequate drying of concrete structures. The considered composite beams are steel casing beams, which are casted full of concrete. To achieve a composite structure, there are holes in the sides of the casing, through which moisture from the concrete transfers to the surrounding structure. However, the drying of the concrete inside the beam is significantly limited. The level of relative humidity of the concrete inside the beam remains moderately high for a long time, depending on the quality of the concrete and, consequently, the self-desiccation of the concrete. When using concrete with a low water binder ratio, drying occurs at a level of about 85%RH as a result of self-desiccation. In the study, relative humidity in the joint was measured continuously and with instantaneous measurements. The relative humidity in the joint concrete was also monitored after the surface structure layers were installed. In addition, humidity was measured from below the surface material and continued until equilibrium was reached. The structure was simulated as a 3D model and studied using a concrete material model which takes into account the self-desiccation and the thermal dependence of the sorption. A good agreement was found to describe the effect of temperature changes on the relative humidity of concrete that can be observed in continuous measurement. In addition, a suitable prediction of relative humidity below the surface material can be achieved based on modelled relative humidity distribution before the installation of the surface structure.

Comprehensive analysis of structural and thermal performance for the concrete and steel joints used in the assembled building

The structure joints and connection type of buildings play a decisive role in their safety and reliability. Therefore, most studies have focused on the structural performance, ignoring their thermal performance. Three common assembled concrete joints and four steel joints usually used in the assembled building were selected to study their bearing capacity, seismic performance and stiffness degradation. In addition, the temperature and relative humidity distribution of six types of envelopes were evaluated within a year and the effect of different envelope options on the linear thermal transmittance of each joint was investigated. The results show that the best structural performance of concrete joints and steel joints are the grouting sleeve joint and the cantilever section bolt connection respectively. The seismic performance of steel joints is generally stronger. Furthermore, for every 25 mm increase in AAC thickness, the overall linear thermal transmittance of the component increases by 0.02–0.04 W·m−1·K−1. On balance, the grouting sleeve joint is the optimal concrete joint in terms of both structural and thermal performance, but better damp proofing measures are necessary outside of it. Moreover, the cantilever section bolt connection is the optimal steel joint and requires better insulation measures. Interestingly, the building envelope construction of “75 mm autoclaved aerated concrete + 90 mm mineral wool + 75 mm autoclaved aerated concrete” is the best choice for matching joints.

Cracking Resistance of Steam-Cured Precast Concrete Using High Alite Cement with Modified Fly Ash

Cement with fly ash has rarely been used in Japan, mainly because its strength development is slower than ordinary Portland cement. In this research, the effect of the new type of fly ash (which was modified by the electrostatic belt separation method) with high alite (C3S) cement on cracking resistance of precast concrete prepared by steam curing was studied. The mechanical and shrinkage properties of the proposed fly ash concrete were compared with those of concrete made using OPC cement without fly ash. In order to study the cracking tendency of precast concrete with the proposed cement with fly ash, thermal stress analysis was conducted, taking into consideration the experimental data of concrete properties with the different concrete mix proportions. A standard precast concrete box culvert model was used in this 3D FEM analysis, and the distribution of temperature and relative humidity in the cross-section and induced restraint stress during and after steam curing were discussed. Steam-cured concrete with fly ash and high alite cement developed higher compressive strength on the first day of age than concrete with OPC. The proposed fly ash concrete developed high cracking resistance in the early days. On the other hand, the results showed that the drying shrinkage at later ages was the main cause of cracking.

Effects of different irrigation methods on regional climate in North China Plain: A modeling study

Agricultural irrigation is important in boosting crop yields in especially water-stressed regions, but little is known about the distinct climatic effects induced by different irrigation methods, particularly in the North China Plain (NCP) where irrigation is applied extensively. Here we examine the climatic effects of flood (FI), sprinkler (SI) and drip irrigation (DI) over NCP during the growing season using dynamic irrigation schemes implemented into a coupled land-atmosphere model. The model generally captures the spatial distribution of surface temperature, relative humidity and precipitation. The changes in regional average surface temperature induced by FI, SI and DI are –0.43, –0.53 and –0.19 °C, respectively. The relatively larger cooling effect for SI than that for FI is associated with enhanced cloud formation. By shifting the surface energy balance, FI and SI cause a wet, cool, cloudy and shallow planetary boundary layer, while DI exhibits the smallest effect and indeed inhibits cloud formation. The increases in convective available potential energy and precipitable water induced by FI and SI enhance convective precipitation over NCP by 0.8–1.2 mm d–1. In contrast, the reduced precipitation due to surface cooling within DI leads to a warmer and drier surface from June to August, which likely increases upper-level geopotential heights and in turn suppresses precipitation in a series of climate feedbacks. The distinct hydrometeorological interactions and feedbacks arising from different irrigation methods are likely related to different irrigation rates, frequencies and approaches of water application. While DI is recognized as the most water-saving method, it also generates the least surface cooling among the three methods and is thus less effective in safeguarding grain yields against rising temperatures. Our study emphasizes the need for more sustainable and adaptive irrigation methods to ensure food security, water conservation and climate stability in the face of climate change.

Optimizing the performance of cotton Bundle-based solar evaporative cooling system using a CFD Model: Model Development, Validation, and optimization

A Solar Evaporative cooling system is an energy-efficient, environmentally friendly, and low-cost air conditioning system. It is an economical air conditioning system for any type of cooling application, such as cold storage of horticulture products and ventilation systems. In this work, a computational fluid dynamics CFD-based model was used to study the parametric effect and to optimize the evaporative air cooler. The system used cotton bundles for the absorption and evaporation of water. Heat and mass transfer processes were coupled using user-defined functions. The accuracy of the model was validated by the experimental results. The predicted results well agreed with experimental results; with average errors of 13.39% (pressure drop), 2.347% (supply air temperature), and 2.22% (supply air relative humidity). The effects of airspeed, porosity, and thickness of the bundle on the cooling performance of evaporative cooling were studied. The incoming air had a dry-bulb temperature of 33 °C and a relative humidity of 28.4%. The study assessed the velocity, temperature, and relative humidity distribution in a cooling chamber. The optimum cooling system reduced the air temperature by up to 12℃ and increased relative humidity to 94% at 1.69 m/s inlet air velocity, 20 cm bundle thickness, and 30.23% porosity.