How to Recharge a Dehumidifier

Excess moisture lowers the quality of the air inside your home. It makes your home a haven for mold, mildew, pests, and other organisms. Mold, and even humidity itself, can also trigger respiratory conditions like allergies and asthma. Over time, excess moisture and its damaging effects will also ruin materials in your home. To keep moisture at bay and maintain healthy air, you need a good dehumidifier that runs well to handle the humidity in your home.

While dehumidifiers are a great investment overall, there may come a time where they do not function like they used to. It may take longer to do the same job it used to do with no problem, or keep running without collecting any water. This can be caused by a number of factors, one of which may be that you need to recharge your dehumidifier. However, depending on the type, this isn’t always as easy as plugging it in. Some dehumidifiers require special chemicals called refrigerants.

Below, we will look at the different types of portable dehumidifiers and how to determine if and when it needs a recharge. Then, we’ll have a brief look at what needs to be done and how the process works. Finally we’ll share some tips in maintaining your dehumidifier so you can use it for a longer time.

What Type of Dehumidifier Can You Recharge?

There are different types of dehumidifiers available for use at home depending on where you need it. You have a whole-house dehumidifier and stand-alone dehumidifiers for different purposes. The two main types are called desiccant and refrigerant. Both of these can effectively remove excess moisture from the air, but they work using two completely different methods of dehumidification. Recharging can also mean different things for each of these dehumidifiers.

Desiccant Dehumidifier

Desiccant dehumidifiers use some kind of hygroscopic chemical that moisture clings to, extracting water from the air molecules. This type of dehumidifier is further classified based on capacity and renewability. The most common desiccant dehumidifiers are either disposable or rechargeable. Disposable units, as you can guess, cannot be recharged. Once the desiccant is saturated with moisture, you can only throw it out or refill the container.

Eva-Dry E-333 Rechargeable Dehumidifier

Rechargeable desiccant dehumidifiers are very easy to use. You can also easily determine if the unit needs to be recharged. Most brands use silica gel beads to absorb moisture, then the silica gel will change color to indicate that they have reached their maximum moisture extraction capacity. 

How to Recharge a Desiccant Dehumidifier

Recharging a desiccant dehumidifier is also very easy. The silica gel will change color (typically from orange to green) after 20 to 30 days. Usually, you’ll only need to plug the dehumidifier into a power outlet for a few hours. Some brands allow you to put the entire unit inside the oven to heat it up more quickly.

Refrigerant Dehumidifier

A refrigerant-based dehumidifier works in a similar way to your air conditioner or refrigerator. This type uses refrigerants to keep the condensing coils cool. The dehumidifier pulls air laden with moisture through a fan. When the warm air comes into contact with the coils, the air loses its ability to hold moisture, resulting in condensation. This condensate is then collected in a tank or drained through a hose and fresh air is released.  A condensate dehumidifier works best in typical room temperatures.

Illustration of How Refrigerant Dehumidifiers Work

This type of dehumidifier can be recharged by replacing the refrigerant or coolant in the system. This task is typically done by an HVAC technician since it deals with toxic chemicals. However, most refrigerant dehumidifiers today cannot be recharged. If you have an older unit, you may determine if it can be recharged if you see a sticker or label on the unit that indicates this. If you cannot find any, you may need to ask the manufacturer or retailer or look up your dehumidifier model online to check.

When Should You Recharge a Dehumidifier?

In the case of refrigerant units, recharging your dehumidifier needs a lot of consideration. It is always best to consult with a professional since it can be a complicated process and improper handling can greatly impact the functioning and lifespan of the unit. To determine whether a dehumidifier needs a recharge, here are some factors you may need to check before contacting an HVAC technician:

No Dry Air

A properly functioning dehumidifier must release warm and dry air. If you notice that the exhaust is warmer but still moist, then your unit’s cooling function may be at fault here. One possibility is the unit needs a recharge.

No Condensation

Likewise, a properly functioning refrigerant dehumidifier collects condensate in its internal tank after a certain period of operation. If your unit has been running for a while and the tank is still empty, then your refrigerant may need a recharge.

Dehumidifier Control Panel Sample

No Change in Humidity Levels

Furthermore, if your dehumidifier has been running for a few hours but you do not feel any change in the humidity levels, you will have to check the unit’s functioning. Compare the humidity readout on the unit’s control panel with a separate humidity sensing device. If the unit’s humidistat doesn’t seem to be broken, then the problem may be with the refrigerant.

Fan and Motor Check

Some units have a light indicator to tell you when it needs a recharge. If not, check whether the fan and motor are functioning as usual. If there is no blockage or any obvious problem but your unit is still not operating as needed, it could be an indicator that it needs to be recharged. 

Types of Refrigerants

Refrigerant dehumidifiers use different types of coolant, a fluid or gaseous compound that absorbs heat from the environment to provide cooling. Old dehumidifier units used to work with the R-12 refrigerant. However, this type of refrigerant has been phased out due to its high Ozone Depletion Potential (ODP), its harmful effects on the environment, and on your health. If you’re still using a dehumidifier that needs R-12 refrigerant, it will be more cost-effective to purchase a new unit instead of looking for a recharge.

If you have a new dehumidifier, the two most common coolants today are the R-22 and the R-410A. Newer models up to around 2010 will usually use the R-22 refrigerant or what is commonly known as Freon. Along with dehumidifiers, most cooling appliances such as air conditioners and refrigerators may use R-22. However, it is a hydro-chlorofluorocarbon (HCFC), which also contributes to ozone exhaustion. 

These older refrigerants can also be harmful to your health. On the other hand, R-410A, also known as Puron, is a better alternative to Freon. It is a hydro-fluorocarbon (HFC), which does not contribute to ozone destruction. R-410A also performs more efficiently than Freon.

How to Recharge a Dehumidifier

While recharging a desiccant dehumidifier is as easy as plugging the unit into a wall outlet, refrigerant units are a different conversation. Before, the older dehumidifiers could be recharged with readily available recharging kits from hardware stores or online. However, you will not find these recharge kits in stores anymore. This is because of environmental regulations regarding the hazards of handling a toxic chemical like a refrigerant. 

It is highly commended that you ask for professional help if you need to replace your coolant or recharge your unit because these coolants produce chemicals and gases that may be dangerous. Contact a reliable HVAC agency to get your unit checked beforehand. 

Once the HVAC technician has determined that your dehumidifier needs a recharge, these will be the main steps to get the job done. First, they will remove the valve cover, then the excess air inside. They will tighten the connection then open the valve to check the level of the refrigerant on the gauge. They will carefully refill the refrigerant, then close the valve. 

Safety Precautions When Recharging a Dehumidifier

As we have reiterated, recharging a dehumidifier involves dangerous chemicals, and whether you hire a professional for the job or not, there are some precautions you must take for the safety of everyone in your home. 

Firstly, keep any of the items you’ll be using away from children. This includes the dehumidifier itself and especially the refrigerant. Keep them away from children and pets before and during the recharging process.

Before you recharge the unit, it’s important to find the best location. During recharge, the unit may release some excess air, moisture, or chemicals. To protect yourself from any harmful effects, place the unit in an open or well-ventilated area. If needed, wear a mask, gloves, or other protective garments.

Additionally, it’s best to put the dehumidifier on a heat-resistant surface since it can get very hot during recharge. Also remove any blockage and keep a distance from the unit to prevent overheating.

What To Do When Recharging Doesn’t Work

Even if you’ve done the process perfectly, there’s a chance your dehumidifier might still not work. If your unit is still covered by its warranty, the first thing you must do is to contact the manufacturer to find the best solution. In fact, you should do this even before recharging since they’ll know best what to do. This could save you a lot of money too. Instead of going through the trouble of recharging, they might simply replace the unit itself or some of its components.

On the other hand, if your dehumidifier warranty has expired, you may still contact your manufacturer and explain your unit’s problems. They should be able to provide the appropriate customer service and repair depending on your needs.

Meanwhile, you can also do the following maintenance on your own: Clean the coils with a vacuum to remove any dust and debris. Check whether the motor and the fan are running. If there’s a rattling sound, check for any loose screws.

If everything looks well but your dehumidifier is still not working, there might be a fault with the compressor. If you’ve performed proper maintenance and checked all components for proper functioning but your unit hasn’t responded to recharging, then the compressor could be the issue. This can be hard to tell so it’s still best to get a professional to check your unit and assess where the problem is coming from.

How To Avoid Recharging Your Dehumidifier

In the case of refrigerant dehumidifiers, recharging your unit must be one of your last resort. Whether you’ve successfully recharged your dehumidifier, you’ll want to avoid repeating the process again after a few years. Even better if you never need to do it. To ensure your dehumidifier never needs a recharge again and help it function properly for a longer period, it takes a lot of care on your part.

Most importantly, you need to use the right dehumidifier unit for your space and find the best location for it. Keep your unit away from walls, furniture, or any obstruction so that the air can flow properly to and from the unit. Place the unit on a level surface to avoid any leaks, be it from the condensate or the refrigerant. 

When operating, keep the doors and windows closed so that the unit will only need to cover the area inside the room. The more outside air gets in, the harder the unit will have to work. 

After turning off, do not turn on the unit immediately. Give it about 10 minutes before switching on again to stabilize the pressure buildup in the unit. 

If using the tank, make sure to empty the water as soon as possible. Rinse the tank and dry it before replacing it in the unit. Even if the tank looks clean, disinfect it at least every two weeks to avoid mold and mildew growth inside the machine. Use soap and water or a vinegar solution, then dry it out completely.

You also need to clean the air filter and grilles regularly. A lot of modern dehumidifiers have a filter indicator that lights up after a set time to remind you to check the filter. Check your manual for instructions on filter cleaning or replacement.

Lastly, turn off the unit and check the internal coils for frost when temperatures drop very low. Most refrigerant models today have auto defrost function for this. Frost buildup can damage the components and ultimately the unit itself.

These are only some basic guidelines you can follow to properly maintain your dehumidifier and avoid having to recharge it, to begin with.


Can all dehumidifiers be recharged?

Not all dehumidifiers can be recharged. It will be indicated on the unit if it is rechargeable. Some mini desiccant units can be recharged and reused every few weeks. Refrigerant dehumidifiers, however, will need more work. Look up the manufacturer and the unit model. Then, the unit must be assessed by a certified HVAC technician whether it needs a recharge. 

Can I recharge a refrigerant dehumidifier myself?

Unlike the desiccant dehumidifier, you cannot recharge a refrigerant or condensate dehumidifier yourself. While it was possible before, today this task must be performed by a professional because refrigerants are toxic chemicals.

How much does it cost to recharge a dehumidifier?

Usually, recharging a dehumidifier will cost between $50 and $200 depending on the amount of work that your HVAC technician must perform and the type of refrigerant your unit requires. 

How long does a dehumidifier last?

It depends on the type and to a certain degree, the brand. With proper care and maintenance, most modern dehumidifiers can last up to ten years without needing a recharge.

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