Results of experimental testing of the hybrid active fog-water harvesting device HygroCatch operated in the HV DC field ionization mode

The fog water collection results describe a series of 18 experiments conducted with the HygroCatch harvester between 23 and 26 November 2025. Fog water collection is based on the ionization of fog droplets using a 13 kV direct-current high-voltage electrostatic field (HV DC) under variable fog liquid water content (LWC) conditions. HygroCatch operates in the HV DC field ionization mode. The electrode chamber consists of three rows of parallel, vertically oriented cylindrical aluminum electrodes, with 10 electrodes in each row. The central row comprises discharge electrodes with a diameter of 2 mm. The outer rows form the collector electrodes, each with a diameter of 5 mm. The air gap between the electrode rows is 25 mm, while the spacing between adjacent electrodes within each row is 15 mm. The fog droplet size ranges from 2 to over 50 µm. The active electrode area is 0.053 m². The average fog water yield achieved through active collection using an HV DC field is 2.37 kg/m²/h, while the maximum recorded yield is 3.17 kg/m²/h. The reliability of the results was assessed using the Shapiro–Wilk test, yielding W(18) = 0.92 with p = 0.11.