Recent advancements in deep dehumidification technology: A review

Comfort air conditioning systems generally provide supply air with a dew point temperature exceeding 5 °C and are widely used in building sectors. In industries and scientific research scenarios such as warehousing, pharmaceuticals, battery manufacturing, integrated circuit production, pneumatic equipment and certain laboratories, the demand for extremely dry air is rapidly increasing. The dew point of dry air may be required to be −40 °C or lower, consequently specific deep dehumidification technologies need to be applied to address the demand. This review summarizes the recent progress of deep dehumidification technologies. The principles of different dehumidification methods are initially introduced. Based on dehumidification and energy performance comparison, relevant deep dehumidification methods and the pros/cons are elaborated. Then, the characteristics and research status of different types of dehumidification materials are introduced, where several desiccants with great adsorption capacity and regeneration performance are reported. To achieve better dehumidification effect and energy efficiency, the study focuses on various deep dehumidification systems with an emphasis on multiple novel systems integrated with other refrigeration cycles or renewable energy. Finally, the limitations, key issues and research prospects of deep dehumidification are discussed. The study comprehensively reviews the research progress of deep dehumidification technologies in humidity demand, materials and system operation. This work aims to propose suggestions and recommendations for the development of deep dehumidification technologies with higher dehumidification efficiency and less energy consumption.