Passive and continuous moisture pump for humidity regulation via simultaneous water adsorption and desorption

Humidity control plays an essential role in various settings, such as in residential buildings and greenhouses. However, conventional dehumidification technologies fail to achieve continuous dehumidification with low up-front costs and energy consumption. Here, we present a passive continuous moisture pump characterized by a three-dimensional structural design incorporating a salt-impregnated composite sorbent. The moisture pump can conduct the adsorption and desorption processes simultaneously by spatially separating the adsorption and desorption surfaces. With chemical potential differences, the captured water is transferred outside to achieve continuous dehumidification without an active driving mechanism. In a stable high-humidity environment, the pump operates with an average dehumidification rate of 256.20 g m−2 h−1. For a scale-down greenhouse prototype, the moisture pump controlled indoor humidity in an appropriate range for horticultural crops during the day, which lasted an additional 5.5 h compared to a traditional passive dehumidification technology.