Abstract
This study presents a combined experimental and modeling investigation of cellulose-based evaporative cooling pads, focusing on the synergistic effects of inlet air psychrometric conditions and air velocity on cooling performance. Unlike conventional studies that examine temperature, humidity, and airflow separately, this work systematically analyzes their interactions and impact on air cooling and humidification. Experiments were conducted under controlled variations of dry-bulb temperature, relative humidity, water temperature, air velocity, and water flow rate. The results show that the maximum cooling efficiency (up to 90–95%) is achieved under moderate air temperature conditions (28–34 °C), inlet water temperature ranging from 22 to 25 °C, low to medium relative humidity (30–50%), and within the studied air velocity range of 0.27–0.53 m/s. where coupled sensible and latent heat transfer mechanisms are optimized. Air velocity enhances mass transfer by renewing the air boundary layer, while favorable psychrometric conditions drive efficient evaporation. Both humidification and temperature drop are highly sensitive to the interplay of these parameters, highlighting the importance of coordinated optimization. A one-dimensional heat and mass transfer model was developed using experimentally identified heat and mass transfer coefficients. The model demonstrates reliable performance prediction under the investigated inlet humidity conditions, with MAE and RMSE values below 7% for cooling efficiency, and shows excellent agreement with measured outlet air temperatures, with MAE and RMSE values below 1 °C, indicating very low pointwise errors. Overall, the model accurately reproduces the system behavior within the studied operating range. These findings provide practical guidance for designing and operating high-efficiency evaporative cooling systems, emphasizing the importance of simultaneously optimizing air psychrometric conditions and airflow to maximize cooling and humidity control in hot and dry climates.