I bought a whole storage locker filled with dive gear years ago. It was not a climate controlled facility and was in a local that gets over 100° in the summer and freezes every winter. The lady said the gear had been there over five years. All the plastic and rubber parts on the regs were still in what i'd call great condition (Conshelfs, various Sherwoods, lots of Dacors, and some nimrods; I dive with the ones I kept. The jet fins were toast (I don't know what they looked like before they were stored) but all the dacor, mares, wenoka, and some other fins were good. The masks that were clear silicone had yellowed bad. Bcd's looked terrible but all still held air. Nylon webbed plastic backplates were perfect. The hoses on the double hose regs were shot. Tanks were of course fine. Cheap rubber like knife sheath straps ect. didn't make it. From that experience I wouldn't and don't worry to much about how I store gear.