Former service manager here. If your job is protecting these repair parts, then you don't get to shrug off your local climate being what it is. It is your job to maintain climate control in the storeroom 24x7, both temperature and humidity. If you can't do that, then you need to date stock and redline it past a certain number of months.
Mind you, you don't have to clmate control a whole room or building. Just the stock. If you can get it done with an old refrigerator rigged to keep things at 25C, with an incandescent bulb to heat when ambient temperature falls below 15C (and gosh, most refrigerators have a light bulb socket already in them), and manual dessicant packs to remove humidity... good enough.
Good way to store welding rods, too.
Intentionally having the refrigeration coils and the light bulb fight each other is a good way to dry out the air. You wouldn't want to do that continuously, just turn the light bulb on anytime the humidity is too high and let the thermostat turn on the compressor.