Desiccant (a moisture absorbing compound), can be a good thing to use if your PCB is at risk for condensation.

Recharging Desiccant

Desiccant can be re-used, just by drying it in the oven.

Put in on an oven tray.

dessicant-on-oven-tray Desiccant about to be dried on an oven tray.

Set the temperature to 125°C.

dessicant-setting-oven-temp Setting the oven temp (125C) to dry the desiccant.

Set the timer to 5 hours.

dessicant-oven-timer-5-hours Dry the desiccant for a good few hours (I chose 5).

Be warned though, some packs of desiccant can’t handle the heat from re-drying! The packs which exploded/melted in the picture below where all the same brand, and the desiccant packet felt plastically rather than the other that felt more like paper.

dessicant-exploded-in-oven Desiccant that exploded/melted in an oven. The stuff that exploded was all the same brand, and the packaging felt plasticy while the stuff that survived felt more like paper.