The growing demand for hydrogen production using electrolysis systems requires the development of efficient and sustainable technologies for high-purity water production. At the same time, increasing global energy consumption and climate change intensify the need for environmentally friendly cooling and desalination technologies driven by low-temperature heat sources. One of the promising solutions is the application of adsorption chillers, which can simultaneously provide cooling and desalination processes while utilizing low-grade thermal energy, including waste heat and renewable energy sources. This paper presents experimental investigations of a three-bed adsorption chiller with a desalination function operating in an open-cycle configuration, where saline water circulates as the working medium. The experimental studies were carried out at the AGH University of Science and Technology Energy Center. The adsorption chiller can operate in both cooling and desalination modes as well as in two-bed and three-bed cycle configurations. The research focused on the application of the adsorption desalination system for the preparation of process water intended for supplying electrolyzers used in hydrogen production systems. The performed investigations included a multi-variant analysis of the desalination process under different adsorption and desorption cycle times as well as varying operating parameters of the supplied water and thermal driving conditions. The study evaluated the operational performance of the system, desalination efficiency, freshwater production capacity, and the quality parameters of the obtained water in the context of its suitability for electrolysis applications. The obtained results indicate that adsorption desalination technology can constitute an effective and environmentally friendly solution for the simultaneous production of cooling and desalinated water using low-temperature heat sources. The proposed system demonstrates significant potential for integration with renewable energy systems and hydrogen production technologies, contributing to the development of sustainable and energy-efficient industrial processes.