How Does a Dehumidifier Rod Work?

Dehumidifiers come in many different types and sizes or various purposes. Humidity is nearly impossible to avoid in small, enclosed storage spaces like safes or closets, especially if it contains moisture-prone items like paper and fabric. One type of dehumidifier designed for such spaces is the electric rod which heats up the air to stop moisture buildup.

Alternatively, to prevent too much moisture from accumulating inside, it’s common to use moisture-absorbing products like salt, baking soda, or rice in your kitchen, or you can buy calcium chloride or silica gel from hardware stores. There are many ways to remove moisture in a safe or any storage space. While these might work to a certain degree, a dehumidifier is often the most effective and efficient solution to control humidity. 

How Does a Dehumidifier Rod Work?

Unlike the other more common types of dehumidifiers, an electric dehumidifier rod actually works more like a heater. It does not directly lower the humidity levels by removing moisture from the air. Instead, it warms the air by heating up the rod itself at a surface temperature of about 100 to 125F. For large safes or cabinets with a built-in electrical outlet, a dehumidifier rod is the most efficient way to prevent condensation and protect your valuable items in storage. 

As we know, condensation occurs when the air temperature inside reaches its dew point or the temperature at which the relative humidity is at 100 percent. The heated rod circulates warm air within the safe and stabilizes the temperature inside so that it never reaches the dew point. And so, instead of eliminating humidity by pulling moisture from the air, a dehumidifier rod prevents condensation. The heated air forces the moist air out through small cracks in the safe. 

Because hot air rises and cold air sinks, it’s recommended to position a dehumidifier rod at the bottom of the safe or cabinet. These dehumidifiers come with mounting brackets for easy installation.

The main advantage of using an electric dehumidifier rod is it requires very little maintenance. All you have to do is install it and plug it in, then the space stays warm and dry. The most common downside to electric rods is the need to connect the plug and cord inside your safe. The rod can also get too hot to touch. Although it won’t be hot enough to burn your hand or other flammable materials, it can be uncomfortable to touch with your bare hands. Furthermore, some people might find it inconvenient to have an electric appliance plugged in all day. 

Applications of Dehumidifier Rods


Due to its size and design, a heating rod is suitable to use in a wardrobe, cabinet, closet, or any such storage space in your home. It protects clothes, fabrics, and other belongings from mold and mildew, and the musty odors that come with high humidity levels.

Mold and mildew are particularly damaging to clothes, shoes, bags, and other leather products. If you leave it unattended for long, you might notice black spots or white powder settling on the surface of these items. This is a sign of mold and mildew due to excess moisture, and the longer the exposure to these organisms, the greater the damage. 

Safe or vault

A safe is designed to keep your cash, jewelry, and important documents protected from theft and fire accidents. However, this sealed metal storage space cannot protect your valuables from condensation. Since it is tightly closed, cool air cannot circulate and the moisture from your items inside builds up and forms condensation on the walls of the safe. This can be particularly damaging to organic materials like paper and fabrics.

Gun Safe

A lot of gun equipment manufacturers also produce electric rod dehumidifiers to protect gun safes from moisture buildup. Gun owners often use gun safes to store firearms, ammunition, and gun accessories, as well as other valuables. Moisture buildup can cause metals to rust, fade, and corrode, which can also compromise the safety of firearms.

Musical instruments

Dehumidifier rods can also be used to control humidity for musical instruments such as pianos and guitars. Instruments with wooden frames or structures are especially prone to moisture. While the effects may be unnoticeable at first, over time it can damage parts of the instruments and ruin the sound quality. 

Cameras, telescopes and other digital equipment

Mold growth due to high humidity can cause serious damage to digital equipment, specifically the microscope lens, videotapes, and filmstrips. Once damaged, they can be extremely difficult to restore. Rod dehumidifiers are the perfect size for storage spaces to maintain the ideal humidity level to protect digital equipment.

Why You Need a Dehumidifier Rod

While you protect your belongings from theft and fires in storage, they’re not safe from potential damage due to condensation. In a tightly sealed space that you don’t frequently open, the warm, moist air gets trapped together with the moisture from the items inside. The moisture from organic materials like paper or fabric evaporates into the damp air with nowhere else to go. 

When the humid air hits a cooler surface, like the walls of the safe, the air also cools down until it reaches the dew point and forms condensation. When condensation builds up, it can cause wood to warp and rot, and metals to tarnish, rust, and corrode. This is unpleasant to look at and also weakens the material of metals or even the safe itself. 

Longer exposure to high humidity levels also creates an ideal environment for the growth of mold and mildew. This is particularly harmful to wood, fabrics, clothes, and paper. Furthermore, touching mold or inhaling mold spores can trigger allergy symptoms or cause asthma attacks and other respiratory conditions.

To prevent these problems, you need to find the right dehumidifier that can fit the space. Once installed, dehumidifier rods require little to no attention. They only consume a small amount of power that you’ll barely even notice when they’re running. 

Factors to Consider When Choosing a Dehumidifier Rod


Consider the size of your storage space and what rod length can fit inside. The smallest you can get is 12 inches long, while there are also options of 18 inches, 24 inches, and 36 inches. It’s always best to go with the longest rod that can fit inside for maximum coverage. Measure your safe or cabinet to make sure the rod fits and it can provide the required heat for all items inside. Manufacturers typically indicate the recommended area for each unit. If necessary, you can install multiple units; for example, one on the left and another on the right side. 

Temperature and Humidity Level

The ambient outside temperature and humidity in the room can also impact the amount of moisture that can accumulate inside the safe. If you live in a humid region and place the safe in a basement or the dampest area in the house, then you can expect higher humidity inside the safe. More than the humidity level itself, extreme changes in temperatures outside the safe lead to condensation inside. This is because when the temperature outside suddenly drops, the cold metal walls will cool down the warm air inside, resulting in condensation. 

Installation Requirements

Any dehumidifier requires certain steps for installation and maintenance. Dehumidifier rods for safes and other tiny spaces have only a few requirements that you must satisfy so they can work efficiently. Ensure that your safe has the space to accommodate the unit as well as the needed wirings. You will also need a constant power source nearby or it will not operate.


Dehumidifeir rods are the most effective humidity control solution in any closed space like a safe or vault. To truly keep your belongings safe, you also need to protect them from moisture levels inside the storage. There are many different types and sizes of dehumidifiers designed for various purposes. You can only maximize your benefits from these dehumidifiers if you know where and how to use them properly. 

Dehumidifier rods, in particular, are suitable for gun safes and most other types of safes, wardrobes or cabinets, musical instruments, and other storage spaces for expensive equipment. Unlike other types of dehumidifiers, its dehumidification process is actually more similar to that of a space heater. For optimum humidity control, you can use different types of dehumidifiers in a single area.

Related Articles