In the most downstairs portion of our house we have a waterproof fire safe with standard important documents in it. For some reason, during the summer only, it seems like humidity builds up within the safe and specifically causes the passports to start curling. We don't see any kind of curling with any of the other documents stored in the safe, just the passports.
I am unsure what kind of coating is used on the passports, but I'm sure it's got a bajillion security features. Regardless, I'm not sure if those same features are contributing to the curling.
Thus far, we have tried collecting silicon packets from new pairs of shoes and putting them in the safe. That has not fully alleviated the problem and I want to know if just going for a full bowl of rice will solve the problem? My concern with this latter solution is that the space inside the safe isn't very big, I'd like to avoid eating up a bunch of it with a rice bowl.
In case it's relevant, we have a smart thermostat that strives to maintain a temperature inside the house of around 82 F during the day when nobody's in the house and keep the humidity levels between 40-55%. Depending on how bad the outside humidity is, this isn't always feasible, but I'd say the humidity in the house never exceeds 60%.
Does anyone have any ideas for how to dramatically lower the humidity within a small, enclosed space like this? Or should I just fully commit to rice?
