This dehumidifier from Hydrosorbent comes with an inbuilt recharge indicator. The indicator is at first orange in color, but it turns by itself clear when it needs a reactivation. Though, bear in mind cold air may well not include lots of moisture to start with. Professional models are constructed with https://dstdehumidifiers.co.uk/case-studies/desiccant-dehumidifiers-in-cold-stores/