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5 Reasons Why Your Dehumidifier Is Blowing Cold Air

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Dehumidifiers have become popular appliances to have around the house. They are excellent devices for removing excess moisture in the air, which can cause allergies, respiratory issues, and even mold growth.

However, it can be a bit concerning if the unit starts blowing cold air.

In most cases, when your dehumidifying unit starts blowing cold air, it might indicate something is wrong.

There are several reasons for the issue. Some problems are easy to fix, and the appliance will be up and running in no time.

If your dehumidifier starts acting up, you are not alone. We have gathered some information about the common causes of the unit blowing cold air and what you can do to fix the problem.


Is your dehumidifier blowing cold air? Here are some of the reasons causing the issue:

  • Frozen coils
  • “Fan Mode” or “Defrost Mode” is on
  • Faulty Compressor
  • The target humidity level is reached
  • Low outside temperature

Has your dehumidifier stopped blowing hot air? Stick around to learn more about how the unit works, why it blows cold air, and how to fix them.

What Is a Dehumidifier?

If you are wondering what a dehumidifier is, it is a device used to take excess moisture out of the air in a room. The units are an excellent way to deal with damp problems around the kitchen, sitting room, laundry room, or basement.

Excessive moisture indoors can lead to some harmful effects on your health. It encourages mold growth that can cause respiratory illness and make your kid’s allergies start acting up.

Also, mold growth can destroy the walls and foundation of your house, making it unstable.

How Dehumidifiers Work

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Before identifying why your dehumidifier is blowing cold air, let us shed some light on how the appliance works. The units draw in air from the room using a fan.

As the air passes along the evaporator coil, the refrigerant removes heat, causing water to condense along its surface. The condensed water is then collected in a drain pan or pipe where it should be emptied.

The warm refrigerant then flows from the evaporator into the Compressor. The Compressor pumps the refrigerant to the condenser for the next heat transfer process.

During this time, the cold air from the evaporator passes next to the condenser, where it is heated before getting blown out of the dehumidifier.

Helpful Tip

The dehumidifier might blow cold air when it starts before the condenser heats up.

5 Reasons Why Your Dehumidifier Is Blowing Cold Air

Now that you have a firm grasp on how a dehumidifier works, you understand why it would be worrying when your device blows cold air.

Before embarking on a DIY project to fix the unit, it is vital to identify the cause of the issue.

Let us look at why the appliance is blowing cold air and how to fix it:

1. Frozen Coils

Dehumidifier With Touch Panel, Humidity Indicator, Uv Lamp, Air Ionizer, Water Container Works At Home On Kitchen. Air Dryer.

Frozen evaporator coils are a common reason why dehumidifiers blow cold air. The evaporator coils play a crucial role in cooling the excess moisture in the air.

As air is pulled in the device, it runs through the evaporator coils, where coolant removes heat, condensing water onto the coils.

However, clogged or dirty coils can easily freeze up and cause heat transfer problems. As the air travels through the coils, they are ineffective in condensing the excess water, leading to cold air being blown out.

Setting the dehumidifier to a low-temperature setting might also cause the coils to build up ice.

How To Defrost Frozen Evaporator Coils

If the coils are frozen, getting them functioning again is an easy task. You first need to check your manufacturer’s recommendations for the ideal temperature range for your unit.

If the setting is too low, raising the temperature should help get your unit working correctly.

If the coils are frozen, they might have a little dirt, dust, and debris clogging them. Before cleaning the coils, you must unplug the device and drain all the water in the pan.

Afterward, you will need to remove the dehumidifier’s back panel to access the coils.

When cleaning the coils, use a soft brush to remove any dust or debris gently. You can also use a toothbrush for those hard-to-reach areas.

Defrosting Evaporator Coils

Place a towel or rug under the unit or on the floor to avoid water damage caused by leaking when the coils defrost.

2. “Fan Mode” or “Defrost Mode” Is On

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Additionally, the appliance might have the wrong mode setting. Most dehumidifiers nowadays have different modes for various functionalities. Two modes are “Fan Mode” and “Defrost Mode.”

When the Fan Mode is on, the Compressor turns off, and only the fan continues to circulate air around the room.

Because no refrigerant is pumped through the system, the air in the room will feel colder than usual.

The Defrost Mode was added to stop ice buildup on the evaporator coils. When the mode is turned on, the Compressor also stops working, leading to cooler air circulating in the room.

How To Fix a Wrong Mode Setting

The only thing you need to do is to switch back the Dehumidifying Mode on your unit. Some dehumidifiers automatically turn off the Defrost Mode after the ice in the coils has completely thawed.

3. Faulty Compressor

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The third culprit for the dehumidifier blowing cold air is a defective compressor. The Compressor is the heart of the unit. It is responsible for pumping refrigerant throughout its cooling system.

However, a faulty compressor can lead to heat transfer issues. If the refrigerant does not freely circulate in the system, the unit has a problem absorbing heat from the air and reheating it in the condenser. This can cause the dehumidifier to blow cold air.

How To Repair a Faulty Compressor

Unfortunately, there is little you can do to fix a defective compressor by yourself. The best thing to do is call an HVAC repair technician to look at the problem.

Additionally, if the Compressor is too damaged, the technician might advise you to replace the part with a new one.

Replacing A Compressor

A dehumidifier compressor must be replaced with an original equipment manufacturer (OEM) part. It will ensure better compatibility with the unit and improve its efficiency.

4. Target Humidity Level Is Reached

Air Purifier And Dehumidifier. Concept For Dehumidifying Room. Humidity Selection Button. Humidity Percentage Display. Close-Up Device.

The other reason that might cause your device to blow cold air is if it reaches its target humidity level. Dehumidifiers have a sensor that determines the room’s humidity levels.

Once the humidity reaches the desired level setting, the Compressor is automatically shut off.

However, in some appliances, though the Compressor is off, the fan continues to run and circulate air in the room.

This can be the reason why the dehumidifier is blowing cold air.

How To Fix Your Dehumidifier Reaching Target Humidity Levels

The only way to fix the issue is by turning up the target humidity level on the humidifier or setting it to Continuously Working Mode.

5. Low Outside Temperature

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Lastly, the low ambient temperature is also a problem. The ideal temperature for the dehumidifier’s optimum efficiency is 70-90°F.

Unless your unit is rated to operate in cold environments, most manufacturers recommend installing dehumidifiers in warm areas above 60°F.

Though the dehumidifier might still be working correctly, the unit might not have enough heat to warm the air as it gets blown out.

What To Do if the Temperature Is Too Low

The only option is to move the dehumidifier into another warmer room or use a heater before starting the appliance.

However, if your area is too cold, we recommend finding another unit capable of handling the extreme temperature.


Dehumidifiers are not meant to blow cold air like an air conditioner. If your unit has this issue, you might have a problem with frozen evaporator coils, wrong dehumidifier settings, a defective compressor, or low ambient temperature.

When the unit reaches its target humidity level, it can also start blowing cold air.

Helpful Titbit

Regular maintenance is crucial to ensure your dehumidifier works efficiently and for a longer duration.

Frequently Asked Questions

How Do I Stop My Dehumidifier From Freezing Up?

Clogged evaporator coils or air filters are the most common reason for your dehumidifier freezing up. When air circulation is insufficient, warm air cannot thaw the condensed water on the coils, leading to ice formation.

The best way to deal with the ice is to clean the air filter and evaporator coil.

Should My Dehumidifier Be Blowing Out Cold Air?

The short answer is no. When air is blown out of the unit, it is heated slightly above room temperature. If the dehumidifier is blowing cold air, it might have an issue with the following:

  • Frozen evaporator pipes
  • Wrong mode settings
  • Faulty Compressor
  • The target humidity level is reached
  • Low ambient temperature

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