This dehumidifier from Hydrosorbent comes with an inbuilt recharge indicator. The indicator is at first orange in colour, but it really turns by itself very clear when it demands a reactivation. They absorb extra humidity in the ambiance by extracting water molecules into a desiccant materials which attracts h2o. Also, https://funny-lists.com/story22100646/5-essential-elements-for-dehumidification-in-cold-stores