August 10, 2024 | Journal of Agriculture and Food Research |
Researchers from King Mongkut's Institute of Technology Ladkrabang, Thailand, and Université Paris-Saclay, France, conducted a study to evaluate the performance of evaporative cooling (EC) as a cost-effective alternative to mechanical refrigeration for small-scale farmers in developing countries. The study focused on using a wet fabric blanket in a real-scale cargo chamber to enhance temperature control during short-distance transportation.
The experiment involved constructing a cargo chamber commonly used in Thailand and equipping it with axial fans to simulate airflow conditions during transport. Test products (hollow plastic balls) were loaded into the chamber, covered with a wet blanket, and subjected to varying inlet air velocities (0.8–3.6 m/s) under controlled environmental conditions (29–30 °C and 70–73% RH). Measurements of air temperature, product temperature, and relative humidity were taken every minute for three hours using thermocouples and hygrometers.
The results showed that the EC system reduced air temperature by 3–4 °C, with higher cooling efficiency observed at greater air velocities. Simplified heat and mass transfer models developed for the study matched experimental data with a maximum mean relative error of 1.2%. The system also reduced lettuce mass loss to less than 6%, compared to 8–10% outside the chamber. The findings suggest that a wet blanket-based EC system can improve cold chain performance for short-distance transport in tropical climates.
