Towards indoor hydroponic fodder sustainability with a low-cost atmospheric water generator

This paper introduces a low-cost electronic circuit to control and monitor an Atmospheric Water Generator (AWG) system based on thermoelectric cooling. The study evaluates water collection by a specific AWG device in a Hydroponic Green Fodder (HGF) production environment to explore the feasibility of using this technology as a supplementary method for crop irrigation. The proposed circuit measures key parameters of an AWG prototype, including temperature in the cold and hot zones of the Peltier cell, relative humidity, and ambient temperature. Based on this data, a control algorithm enhances water collection and reduces energy consumption for moisture condensation by regulating energy delivered to the Peltier cell and heat sink subsystems. The control and monitor circuit is programmable and adaptable for different AWG prototypes. Tests showed variable water collection rates from 3.01 mL/h to 4.93 mL/h. Under conditions of 84.1% relative humidity and 19.5 °C ambient temperature, the system produced 4.93 mL/h with a power consumption of 34.6 W. Conversely, at 68.3% relative humidity and 19.6 °C ambient temperature, the collection rate decreased to 3.01 mL/h, with a power consumption of 34.7 W. This water volume represents a significant proportion, ranging from 16% to 55%, of the irrigation needed to produce one kilogram of hydroponically grown fodder, assuming HGF cultivation requires between 1.5 to 3.0 liters of water per kilogram of forage produced.