Performance Evaluation of a Medium Size Charcoal Cooler Installed in the Field for Temporary Storage of Horticultural Produce
Abstract
<!-- /* Font Definitions */ @font-face {font-family:"MS Mincho"; panose-1:2 2 6 9 4 2 5 8 3 4; mso-font-alt:"MS 明朝"; mso-font-charset:128; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:fixed; mso-font-signature:1 134676480 16 0 131072 0;} @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:1; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:0 0 0 0 0 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} @font-face {font-family:"\@MS Mincho"; panose-1:2 2 6 9 4 2 5 8 3 4; mso-font-charset:128; mso-generic-font-family:modern; mso-font-pitch:fixed; mso-font-signature:-536870145 1791491579 18 0 131231 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"MS Mincho"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 72.0pt 72.0pt 72.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->Evaporative cooling has been used over time as effective method for controlling the environment in structures. However, documented scientific information on performance of commercial scale storage systems is limited. A medium size charcoal cooler with a volumetric capacity of about 27 m3 and wall thickness of 100 mm was constructed at Kikoo in Kibwezi district in the Easter Province of Kenya. The cooler had a sisal stem ceiling covered with 50 mm thick dry reeds. The area is known for irrigated horticultural farming under extreme environmental conditions. The cooler was constructed to provide temporary storage for fruits and vegetables destined main for export to international markets as a remedy to minimize loss of quality before collection. The performance of the charcoal cooler was evaluated on the basis of the temperature and the Relative humidity with three scheduled watering regimes at 8:00, 12:00 and 4:00 hours due to the scarcity of water. Measurements were taken in the cooler, adjacent grading room and outside the structure to give the ambient conditions. The cooler had the lowest temperature and the highest relative humidity irrespective of time and watering schedule. Triple watering of the cooler showed the highest temperature and relative humidity difference reaching 11˚ C and 38% respectively. Triple watering also maintained the relative humidity in the cooler relative within the recommended range of 80 to 95% for horticultural produce despite the fluctuations shown within the watering schedules. The cooler temperature however remained above the recommended range of 0 to 10˚ C for fruits and vegetables. A watering interval of 2 hours from 8:00 hours was determined as more appropriated considering the extreme environmental conditions and scarcity of water.
