dehumidifier for gun safe

Best Dehumidifier For Gun Safe – Here’s What I Use…

Looking for a dehumidifier for your gun safe /cabinet? Or a dehumidifier for your regular safe? Well I can tell you what I have been using for many years, which I believe may be one of the best solutions for this issue.

Best is subjective. I have been using this particular dehumidifier (for gun safe – or any safe) for many years with great success. Here’s what I like about it, and why I think it’s one of the best for a medium size or larger gun safe (or any safe).

Dehumidifier For Gun Safe, Or Any Safe

Do you store firearms in a gun safe? Do you live in a humid climate? Even if you don’t, you need to keep your firearms dry (common sense!).

Do you keep cash in a personal safe? Important documents? Again, you need to keep them dry! If they’re sitting in there for a long time, they might get damp, or worse.

Eva-Dry Mini Dehumidifier

It is an incredibly popular ‘renewable’ dehumidifier. No power required (no cords) while it’s in service doing its job. Renew it (dry it out) when it needs it – by simply plugging into a conventional AC outlet for awhile.

“Works for areas up to 333 cubic feet”

This is their latest model, slightly different from my original purchase years ago:

Eva-Dry (E-333)
(view on amzn)

No Cords, No Batteries

You don’t have to plug in this dehumidifier while in use.

Simply place the dehumidifier inside your gun safe (or any safe). It has excellent capacity to absorb moisture, and will remain active for a long time before the silica beads become fully absorbed with moisture. After which you renew it (recharge it). I’ll explain in a minute…

TIP: You might also include a dial humidity gauge (hygrometer) for an accurate indication of relative humidity in your gun safe. I like the following choice:

Vault Hygrometer
(Lockdown storefront on amzn)

The Eva-Dry mini-Dehumidifier Moisture Gauge

The mini dehumidifier has the capacity to adsorb approximately 4 to 6 ounces of moisture out of the air.

It’s super easy to know when it’s time to renew the silica beads of this dehumidifier in your gun safe. Simply compare the color of the beads (viewable through a window) to that of the reference color gauge.

All you have to do is look at the color of the silica beads to know whether or not it needs to be renewed.

Eva-Dry has a newer model (pictured above) since my own purchase years ago. The following images below are slightly different from today’s product. The view port is different, and the bead colors are different.

Image: Shows color of silica beads in this example they’re dry (left), and the unit temporarily plugged-in while renewing (right).

How To Renew the Silica Beads

To renew the silica beads you just plug it in to any 120-volt AC outlet.

It does not need to be plugged in, or powered, during normal operation. Instead, when it’s time to renew, that’s when you plug it in – to dry out the silica beads. You simply remove it from your gun safe and plug the dehumidifier into an ordinary wall outlet.

When it’s plugged in, it heats up internally, which removes the moisture as the silica beads dry out. It takes about 10 hours.

Eva-Dry mini-Dehumidifier Dimensions

The ‘Eva-Dry’ dehumidifier is referred to as ‘mini’.

Latest model dimensions: 9 x 8.25 x 2.88 inches

Cubic Volume Absorption Of Moisture

What size dehumidifier? This dehumidifier is actually designed to work in closet size spaces.

The moisture absorption specification for this dehumidifier indicates 333 cubic feet, which is plenty for any gun safe!

A typical upright gun safe (volume – cubic feet) is much less than that. So this dehumidifier will last a long time in there before needing to be renewed.

For example, if your safe is about 5 feet tall, 2 feet wide, and a foot deep, that’s only 10 cubic feet. Even a very large gun safe might only be about 30 cubic feet inside.

Here’s their mini-dehumidifier which they rate at 500 cubic feet, and absorption up to 8 oz. of moisture. I don’t have this one, but if you’re looking for a bit more capacity:

Eva-Dry (E-500)

NOTE: It’s common sense to lightly coat the critical surfaces of one’s firearms with appropriate oil for long term storage. Taking them out once in awhile and cleaning them will likely avoid issues with humidity. However a dehumidifier provides extra insurance against such issues.

[ Read: Firearm Safety – Guns Kept For Home Security ]


  1. We use these same dehumidifiers in each of our gun safes. They work great. Good Christmas present….very affordable.

  2. Timely article as my Mauser’s butt plate has turned into a mass of rust. Barrel of my pellet rifle has also developed a blemish. Should I gasket the door opening before starting to use one of these?

    1. No need to gasket the door. The model I’ve reviewed here is more than capable of handling it.

  3. Well, thank you Ken. Since I have been reading MSB DH and DS have been receiving presents that they are thrilled with. I shall be ordering two of these for this year’s birthdays.

    Stay frosty.

  4. I’ve used these for years they do work good. I did end up putting a dehumidifier that self pumps in my safe room. I also have a electric dehumidifier rod in the safe as well. It got to a point I was not checking on the one shown here, and they were soaked. Now I’m off to go plug those back in…..

  5. Thanks, Ken, I ordered one through your site. What I’ve been looking for.

  6. Ken

    Not at home so can’t check the brand. Bought mine years ago at Costco. It was also listed as fire safe. Later I came to understand that many fire resistant safes are that way because of built-in humidity.

    Do you know if that’s the case? Would adding a dehumidifier make the safe less or non-fire resistant?

    PS Still not saving name and addresss

    1. Fire resistant safes are that because of the fire-resistant insulation built-in to their walls. Adding a dehumidifier won’t make a difference one way or the other regarding fire resistance.

  7. Good Article Ken.
    I live in an area that receives 7-8 inches of rain a year, and an average humidity of 15%.
    But at $15, why the help not drop one in each safe?
    VERY cheap insurance for many $k of firearms and documents

  8. I’ve also had some success partially renewing by leaving out in the hot sun in dry weather. In a grid down situation this might be helpful. I tried this because the outdoor outlets I wanted to use have hinged covers on them and these dehumidifiers would not fit to plug in. I had to use an outbuilding plug location and wanted to lessen the plug in time.

  9. I have two similar dehumidifiers in mine, safe is in a closet with a golden rod so moisture in safe seems to be much lower than when it was just out in the garage, i like the dehumidifiers we can plug in to dry, much better simple solution

  10. I have 4 of these and they have worked well over the years. It can get pretty humid in the summer where I live even with a dehumidifier and AC running so I swap them out in pairs.

  11. I have two of these. One is plugged in near the safe, and every time I get in the safe I swap it out with the one that was in the safe. The beads no longer change color at all in one of them, and they don’t change much in the other. I’m not sure they’re even working anymore, though the units do get warm when they’re plugged in. My safe has never seemed humid–I just figured they were a good idea. It might be a good idea to get new ones now. I see that they come with a five-year warranty, so I’ll check into whether my original ones have that, if I can find the contact info. BTW, I bought mine four years ago, and they were the same price then as the new model is now ($15).

    1. Well, you have to register the product within 30 days of buying for the warranty to be valid. I’m sure I didn’t register. I have sent an email to the company about this, and I’ll let you know if they stand by their product even though I didn’t do what they say had to be done.

    2. Wendy, you’re not supposed to leave the Eva-Dry plugged in all the time. Only to dry them out (renew) which takes approximately 10 hours.

    3. I’ve started having the same problem with the beads in the indicator window not changing colors anymore. The older units with the long narrow vertical window always worked fine, but in recent years the larger teardrop shaped windows never change colors. In one of my units the indicator beads even turned a constant black. So I don’t know what’s up with these units. I know they’re working because I also use a gauge, but I’m still trying to figure out what’s going on. As for their drying capability, they’re the best.

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