Assessing the Suitability of Plant Waste Materials as Alternatives to Sand in Zeer Pot Refrigerator

Abstract

Zeer pot refrigerator is a passive evaporative cooler used in developing countries to preserve perishables in domestic level. Introducing alternative insulating material by replacing sand will improve the cooling efficiency of zeer pot because irreversible heat and mass transfer process are influenced by the insulating material that is filled in the gap between two pots of this evaporative cooler. The main objective of the study is to evaluate the suitability of materials -such as coir dust, saw dust, and crushed com husk together with com hair to be used as absorbent materials in zeer pot refrigerator. The experiment was conducted as complete randomized design with 4 treatments and 3 replicates. Moisture content, bulk density and water holding capacity (WHC) of each material were determined. In addition, fungal growths in the saturated samples were observed visually. The moisture content (wb%) of sand, coir dust, saw dust and crushed corn husk with hair were 0.71, 11.96, 12.04 and 8.50 respectively. Bulk density (g/cm3) values were 1.46, 0.13, 0.17, and 0.18 respectively. WHC (g/g) values were 0.90, 10.97, 4.82, and 8.54, respectively. No fungal growth was observed in the materials even after 14 days. Hence, highest bulk density and lowest WHC were shown by sand. It can be concluded that all materials can be used as alternatives to sand in zeer pot refrigerator. Nevertheless, further experiments should be conducted to confirm and verify the results obtained from this experiment