Comparison of surface foil materials and dew collectors location in an arid area:a one-year field experiment in Kenya

This study characterized different polyethylene (PE) and polyvinyl chloride (PVC) plastic foil materials effectiveness for dew collection in arid field-conditions in Kenya. Dew yields were collected daily for one year. Ten dew collectors with four different plastic foils were setup in the experimental field. The cumulated dew yields ranged from 18.9 to 25.3 mm. The greatest cumulated dew yields were 25.3 mm (nightly mean 0.096 mm) and 24.3 mm (nightly mean 0.093) measured with PVC and OPUR coated collectors respectively. The lowest cumulated dew yields 18.9 mm (nightly mean 0.075 mm) and 19.1 mm (nightly mean 0.074 mm) were measured with PVC and PE coated collectors respectively. Dew provided a continuous water source during the dry season. The type of the surface material was not found to be a determining factor for the collected dew yield. The location of the collector at the experimental field had impact on the collected dew yields. We also compared harvested dew yields to measured meteorological parameters and calculated dew yields with the use of a diffusion model using the measured surface temperatures and coefficient of mass diffusion to evaluate the dew collecting potential under the prevailing conditions.