Review on dehumidification technology in low and extremely low humidity industrial environments

Many industrial environments have low-humidity requirements. However, most research focuses on dehumidification systems in civil buildings, while research on industrial low humidity environments is extremely limited. This paper aims to summarize the research of dehumidification systems in low-humidity industrial environments, and provide some suggestions for the selection and improvement of dehumidification systems. Firstly, the environmental control requirements of industrial plants are reviewed and categorized into low humidity and extremely low humidity based on a relative humidity of 45%. Then, the performance and applicability of condensation dehumidification systems, desiccant wheel (rotary dehumidifier) dehumidification systems and liquid desiccant dehumidification systems in typical industrial environments are summarized. Several preliminary system selection and configuration methods are presented. It is shown that the traditional condensation system is only suitable for low humidity plants. The desiccant wheel-based system is more capable of deep dehumidification, with a humidity ratio of less than 4 g/kg of supply air, while the liquid desiccant-based system can achieve high air volume operation of 10000 m3/h. Furthermore, their ranking under different scenarios is still outstanding issues. Evaluation indicators that weigh factors such as initial investment, operating costs, and control effectiveness need to be urgently proposed. Long term on-site testing is strongly recommended.