Humidifier vs Dehumidifier for Cough

Humidifiers and dehumidifiers both work to control indoor humidity and make the air more breathable. When used properly, they can help alleviate symptoms of upper respiratory infection and other health problems. However, they are completely different products with different purposes. 

First of all, humidity refers to the amount of water vapor in the air. The ideal indoor humidity level is between 40 to 60 percent. Some products that aim to help you control indoor humidity are the humidifier and dehumidifier. Some people may need either one of these at a time, and some may need both, depending on your weather and indoor air conditions in your home. 

For relief of respiratory conditions due to dry air, the best solution is to add moisture using a humidifier. However, there are other factors that must be considered, such as the cause of your cough. If there are airborne allergens present such as mold spores and dust mites, then a dehumidifier will be useful. How do these two appliances differ and how can you benefit from them? We’ll answer these questions below.

What Triggers a Cough?

Breathing dry air irritates your airways, causing them to inflame and become clogged with mucus. When your airways are filled with mucus or you inhale airborne allergens such as smoke or dust, a cough is a reflex reaction that attempts to protect the airways from irritation. When irritants enter the airways, whether it’s dry air, allergens, or even some medication, your throat forces you to cough to try and clear the particles and make breathing easier. 

When you cough in a low humidity environment, you produce air that can further spread the dust, pet dander, spores, and other airborne pollutants, which can only make your cough worse. Whether it’s dry air or allergens that’s causing irritation, balanced humidity can help relieve your condition. This can be easily achieved with a good humidifier or dehumidifier.

How Does A Humidifier Work?

How Does A Humidifier Work for cough featured photo

There are different types of humidifiers depending on the process used for humidification and the type of mist produced.

Evaporative vs. Ultrasonic

The most common type of humidifier is called an evaporative humidifier. It uses a wick filter or evaporator pad to absorb water from the tank. A fan then blows air through the filter so the water evaporates into the air with almost no visible mist. An evaporative humidifier regulates itself to prevent adding too much moisture to the air. It also filters the water from the reservoir, eliminating impurities that can leave white dust on surfaces around the unit. Since it has a fan, an evaporative humidifier is good for adding humidity to a large room.

On the other hand, an ultrasonic humidifier produces cool mist using a metal diaphragm vibrating at a high frequency. Built without a fan, an ultrasonic humidifier is ideal for nighttime use because of its nearly soundless operation. 

Cool Mist vs. Warm Mist

Some ultrasonic humidifiers can provide both cool and warm mist. A cool mist humidifier releases cool mist to increase moisture levels. Some cool mist ultrasonic humidifiers can also diffuse essential oils for added aromatherapy.

Meanwhile, warm mist humidifiers have an internal heater that boils water before releasing the warm steam into the air. It’s best for the relief of cold and flu symptoms, especially during winter.

How Does a Humidifier Help With Cough?

Benefits of Humidifiers

A dry cough or nonproductive cough is often caused by irritation in the throat and it can take a while to completely go away. A humidifier can help for this type of cough by adding moisture to your throat and passageways. This will typically help the cough to clear up faster. If the manufacturer’s instructions allow it, you may also add some essential oils like eucalyptus or tea tree oil to the humidifier to further the relief for your symptoms.

A wet cough or productive cough may be caused by inflammation of the mucus membrane, producing fluid or phlegm. A humidifier can help break apart the mucus so you can cough it up and provide temporary relief to your throat.

Potential Side Effects of Humidifiers

While humidifiers work really well in providing relief of cough symptoms, they can also pose some harm if used incorrectly. Too much moisture can create an ideal environment for mold growth, which can worsen coughs and other respiratory issues.

Another common indoor allergen that thrives in high humidity environments is dust mites. These microscopic insects feed on dead skin cells in moisture-rich areas like the pillows and mattresses in your bedroom. When inhaled, dust mite wastes can cause allergic reactions similar to hay fever.

Humidifiers can also become a source of germs and bacteria if not cleaned and maintained properly. These organisms will be released into the air along with the water vapor. Basically, a humidifier that’s not clean and pumping dirty water into the room can make things worse.

How Does A Dehumidifier Work?

Humidifier vs. Dehumidifier featured photo

A dehumidifier does the total opposite of a humidifier as it reduces the amount of moisture in the air. This is done through different dehumidification methods.

Compressor Dehumidifier

Most people are familiar with the compressor-based or refrigerant dehumidifier, which works similar to an air conditioner. The compressor pumps the refrigerant to the condenser and evaporator coils to cool the air, pull the moisture, then reheat the air. A fan draws the humid air and passes it over the cooling coils. As the air temperature decreases, the moisture condenses. The condensate drips down into the internal tank or flows out through a drain hose.

Peltier Dehumidifier

Another method that mini dehumidifiers use is called thermoelectric cooling or the Peltier effect. It is based on the idea that a voltage of electricity creates a temperature difference between the two sides of a Peltier module. Humid air is drawn by a small fan through the cold side, where the moisture condenses and collects in the tank. The cold and dryer air passes through the hot side, then warmer, dryer air is released. 

Pro Breeze Mini Peltier Dehumidifier
Pro Breeze Peltier Dehumidifier

Desiccant Dehumidifier

The other type of dehumidifier is called a desiccant. It uses chemicals that absorb or adsorb moisture from the air it comes into contact with. A desiccant comes in a wide variety of capacity and renewability. The main difference from other types is that the desiccant doesn’t need to cool down the air to extract moisture. Instead, moisture is transferred to the desiccant until it is fully saturated. Some desiccant chemicals (e.g., calcium chloride) dissolve into the moisture while others (e.g., silica gel) can be renewed for repeated use.

How Does a Dehumidifier Help With Cough?

Benefits of Dehumidifiers

Reducing humidity with a dehumidifier eliminates mold and airborne spores that trigger allergies, bronchitis, and dry cough. By removing the excess moisture that can cause mold growth, you can also reduce your cough symptoms if caused by a stuffy nose.

A dehumidifier can help alleviate wheezing. When the airway is blocked by phlegm or mucus due to allergies, it makes a wheezing sound. A dehumidifier can help with this by reducing common airborne allergens like mold spores and dust mites.

Lower humidity also aids asthma control. Heavily moist air is hard to breathe, especially for asthmatic people. A dehumidifier reduces moisture in the air and brings the humidity level down to the ideal range. However, remember that dehumidifiers only provide temporary relief and are not a treatment for asthma or any respiratory illness.

Potential Side Effects of Dehumidifiers

While dehumidifiers help control indoor relative humidity, they can also make the air extremely dry. This can happen if you don’t monitor the humidity level or if you use the dehumidifier in the winter. You usually don’t need it in low-temperature conditions because the air is already dry.  When the air lacks moisture, it can irritate your airways and lead to coughs. In this case, a humidifier is your option.

Dry air can also worsen pneumonia. When running a dehumidifier, you should always keep the humidity within 40 to 50 percent, especially if you or anyone in your family has a compromised respiratory system. A dehumidifier with a built-in humidistat will be beneficial so it can adjust and maintain your humidity setting automatically.

Tips to Alleviate Coughing

Although humidifiers and dehumidifiers have some benefits, you must never rely on them alone to ease your cough. They are only helpful for temporary comfort, depending on the humidity levels in your home. If they’re not working effectively to relieve your symptoms, here are some tips we recommend:

First, make sure your home is clean. If you run a humidifier or dehumidifier in a room filled with dust and dirt, your cough will only become worse. Removing the allergens in the room is the first step to your recovery. You must also regularly clean your carpets and upholstery (vacuum and occasionally steam clean). Dust and dust mites typically hide in these areas, which can cause a dry cough and nasal congestion by impacting air quality in your home.

Consider medicine. There are over-the-counter treatments for coughs due to the common cold and flu. But if you have a persistent cough, it’s best to consult a doctor who can prescribe the right medication for you.

Drinking lots of water can be really beneficial as it can help thin mucus in your throat to lessen cough sympotoms. Avoid drinking sweet beverages as these can make your throat dry and itchy and potentially trigger coughing.

Inhale warm steam. If you don’t have warm mist humidifiers, you can simply inhale the steam from a basin. Pour hot water into the basin, then cover your head with a towel to trap steam. Stop if the steam gets too hot or if the heat makes you uncomfortable.

Have some warm soup. This will help break up the mucus clogged in your throat and open up your airways. Make sure to add soothing spices like lemongrass, ginger, thyme, turmeric, and rosemary if possible.

Lastly, you can gargle saltwater. Salt kills some mouth and throat bacteria so you can spit it out with the water. Saltwater can also help loosen the mucus blocking your airway and reduce inflammation in the throat.

Best Humidifiers for Cough

If you’re looking for a humidifier to help relieve coughing due to dry air, we recommend the following warm and cool mist humidifiers. 

Vicks Warm Mist Humidifier

Vicks V745A Warm Mist Humidifier

This Vicks warm mist humidifier is specifically designed to release warm, soothing vapor to help relieve congestion from the common colds and cough. It can also reduce respiratory discomfort to help you breathe and sleep better. 

You can add Vicks VapoSteam to moisten dry, irritated nose and airways. The medicated steam helps alleviate coughs due to minor throat and bronchial irritation associated with colds and allergies.

The Vicks humidifier features a one-gallon tank with a wide opening to make it easy to fill and clean your humidifier. You can easily turn on and off the unit and select the mist output level with the knob. The humidifier will shut off automatically when the tank is empty. This model doesn’t have a filter, so that’s one less thing to worry about. 

Levoit Warm Mist and Cool Mist Humidifier

Levoit LV600HH Warm Mist Humidifier

Levoit is a top choice for portable humidifier units for homes. The LV600HH model is both a warm and cool mist humidifier that helps relieve congestion, coughs, allergies, and other respiratory symptoms. It delivers moisture up to 500 mL/hr to humidify spaces as large as 753 square feet or 70 square meters. The large 1.5-gallon (six-liter) water tank can last up to 60 hours at the lowest mist setting.

This humidifier features an onboard humidistat that automatically adjusts the mist level to maintain your relative humidity setting. The water tank needs to be filled to 480ml for the humidifier to operate. You can easily adjust the settings on the front panel or use the included remote control.

Pure Guardian Warm Mist and Cool Mist Humidifier

PureGuardian H4810AR Warm Mist Humidifier

The Pure Guardian H4810AR Ultrasonic Humidifier also provides warm and cool mist options to help alleviate symptoms of cough and colds. The easy-to-fill, wide 2-gallon tank can last up to 120 hours to add moisture to large rooms up to 600 square feet.

The convenient control buttons allow you to choose from low, medium, and high mist levels. Simply press the Warm Mist button to get warm mist and set a timer for four, eight, or 12 hours. Pure Guardian features Silver Clean protection to guard against mold, mildew, and bacteria on the surface of the tank.


Both a humidifier and dehumidifier can help alleviate cough. However, the right choice for you depends on the current state of your home, specifically the indoor humidity levels. A humidifier adds moisture while dehumidifiers pull moisture from the air. If you have a cough triggered by an allergic reaction to organisms in high humidity levels, then you need a dehumidifier to keep the humidity down and remove the allergens. On the other hand, if you have a dry, itchy throat made worse by the dry air, then you can run a humidifier to moisten your airway. 

It’s essential to keep the humidity levels in control to maintain your comfort. Either device can be helpful for relieving coughs, but make sure to take proper care of the unit. You must also remember that humidifiers and dehumidifiers can only provide temporary relief and aren’t a cure for coughs. If your cough isn’t going away for more than a week or so, you may need more than a humidifier or dehumidifier so consult a physician as soon as you can.

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