I just bought 24 capacity gun safe that's 22 cubic feet. The dehumidifiers I am looking at cover 100-300 cubic feet. In this case is more better or worse.....?

I assume you are talking about a goldenrod. I have an 18" in mine, a 12" would probably work fine in yours but a bigger one won't hurt anything I don't believe.

I have an 18" Goldenrod in my 24gun safe and it does an awesome job.

I don't have one in either of my safes up here in Michigan and have never had a problem or noticed anything indicating I would need one.

One of my safes is 7yrs old & theres been a Goldenrod plugged into it since day one. My second safe is 2 months old & was put in my new farmhouse. Goldenrods will last for decades. (I always wipe the guns down before putting them into the safe as is common sense but also DON'T put a cold gun into a safe with a Goldenrod in it or condensation can occur on the gun & especially IN it! Let the gun sit for an hour or so to assume roomtemp then put it in the warm safe)

Here in Phoenix I have the opposite problem. My safe is in the garage and in the summer time the inside gets pretty warm. And no, I do not use a Goldenrod! A box of desiccant works just fine here.

lol Robert you're in that tenderbox/desert known as P-town. You don't need a DE-humidier, with your 4% day time humidity and 14% night time humidity you could probably put a pan of water in the bottom of your safe just to keep the stocks from drying out!

Actually HatchieLuvr I need to be careful with the lubricants - the heat makes the oil run. For the "Safe Queens" they barely have any oil or grease and need to have it re-applied before I take them shooting.

Funny you should mention this. My workbench has a butcher block top. Every 3 -4 weeks I slather mineral oil all over it to keep the wood from splitting due to dryness.

In both of my safes I have a ceramic light base and burn a 40 watt light bulb in them (25 watt when I can find them). The bulb gives off a little heat which is enough to drive any moisture out to the 'cooler' room. Plus it provides me with light when I am searching for a particular gun. Nothing wrong with the golden rods from what I've heard.