Development and performance evaluation of a double chamber evaporative cooling system for storage of vegetables

Abstract

The object of research is a double chamber evaporative cooling system for the storage of vegetables with one chamber filled River sand, the other Sawdust as absorbents and Ambient chamber storage conditions being the third treatment (control). Amaranthus was used as the test crop. The structure was developed both internally and externally using six (6) inches concrete blocks and plastered with cemented mortar. 460 g each of Garden fresh vegetables (Amaranthus) were collected and kept chambers of the evaporative cooling system and ambient chamber conditions (control), then, replicated twice respectively. Change in quality (weight reduction, withering, change in colour), temperature change, relative humility and cooling effectiveness were the parameter assessed during the experiment and were subjected to analysis of variance (ANOVA) using Duncan’s Multiply Test at 5 % level of significance. The experiment was conducted and analyzed at Crop Production Department of the Federal College of Forestry (Jericho Ibadan, Nigeria). The study revealed there were no significant difference between relative humidity (%), absorbent cooling efficiency (%) for absorbent materials in the evaporative cooling chambers were (89.90 %, 89.30 % and 75.80 %) and (88.50 %, 82.50 % and 80.40 %) for day 10 and 15 River Sand (RS), sawdust (SD) and Control (Cont.) respectively. While, Control had moderately highest temperature reading at day 13 (30 °C), followed by Sawdust (28.90 °C) and River Sand (27.80 °C). However, vegetables kept in the ambient chamber were observed to rot faster than those in the double chamber of the evaporative cooling system. Complete deterioration occurred at day 5 for ambient chamber conditions. The quality of the vegetables kept in double evaporative cooling chamber using river sand performed best in the storage of Amaranthus. This research hereby recommended that evaporative cooling chambers filled with river sand and constant water supplied to keep the absorbent moist should be utilized for storage of Amaranths and other vegetables in an evaporative cooling system. Further studies should vary the use of different porous absorbent. Also, cooling fans should also be incorporated to the storage system to enhance cooling efficiency.