VC-21A-C023 - Design, Fabrication and Evaluation of Integrated Evaporative Cooling System for the Storage of Fruits and Vegetables ✓ Most Recent

In developing countries, over 50% of horticultural crops are lost after harvesting due to absense of or poor postharvest cold storage facilities. Cold storage facility is a critical component of the food supply chain and food security because it can extend the storage period of the perishable products; avoid glut and post-harvest losses, reducing transport bottlenecks. The objective of the study was to design and construct an evaporative cooling system to store horticultural products in a wide range of climatic conditions in Ethiopia. The design integrates direct evaporative cooling system and indirect evaporative cooling system with technical improvements and re-arrangements for continuous operation and handling purpose. After the design and construction work of the cooler was completed, its performance was tested and evaluated without product load at maximum mean annual temperature for five days. Finally, the performance and effect of the cooler on tomato shelf life and quality was evaluated by storing fresh tomatoes inside the cooler shelves. For comparison (control group), randomly selected fresh tomatoes were stored in a basket, which is a standard method that retailer display tomatoes in the market in the study area. A portable evaporative cooler was constructed from locally available and used materials and integrated with new temperature and relative humidity sensors. It had a capacity of 260 Kg (573.2 lb). The evaporative cooler resulted in a reduction in the maximum ambient temperature from 32.8°C (91.6°F) to 23.5°C (74.3°F) in the cooler. As the ambient temperature drops to 21.8°C (71.4°F), the temperature in the cooler reduced to 15°C (59°F). The cooler stabilized the relative humidity between 77- 88%. The newly designed and constructed evaporative cooler reduced the postharvest loss of tomato from 80 % in a traditional basket to 5% in the evaporative cooler. The cooler reduced the postharvest loss of tomato by 94%. It maintained the quality of the fresh tomatoes. In conclusion what we showed in this study was that we have refined the design and constructed a low cost and effective cooling system that can be used by poor retailers of vegetables and fruits. Evaporative cooler is an old and forgotten technology, if the design and construction are refined, it can be used to regulate temperature and relative humidity and used in different purposes especially for those who cannot afford to buy modern thermal regulation technologies.  See more