Check moisture content of the air vs temp and relative humidity
This simple tool allows you to determine the moisture content of the air. The ability of air to hold moisture varies exponentially with temperature. As the temperature increases the amount of moisture it can hold before saturation (100% relative humidity) increases dramatically. Figure 1 shows this saturation moisture content.
The tool will tell you the amount of moisture in your space in g/m3. Given the dimensions of your sealed space and its volume you can determine the total moisture present. If you wish to adsorb this moisture with desiccants you can head over to the silica gel, or molecular sieve, adsorption tools page to determine how much desiccant you should use.