Humidifier Vs Dehumidifier – Ideal Indoor Humidity For Sleep & Home

Humidifier Vs Dehumidifier Ideal Indoor Humidity For Sleep Home

Quick Answer

Both humidifiers and dehumidifiers are involved in controlling moisture within an environment to create ideal indoor humidity levels of around 40% – 50%. Learning the differences between a humidifier and dehumidifier will help you understand the benefits each provide to produce the optimal climate within your home. Humidifiers deliver additional moisture in the form of a mist, while dehumidifiers reduce existing moisture in the air. The decision of whether a humidifier or dehumidifier is for you will depend on the reason you require one, whether to assist with allergies and irritations or simply to control humidity levels within your surroundings. 

Humidifier Vs Dehumidifier: Improving Your Home & Sleep Environment

Setting the ideal indoor humidity for sleep and home requires three main things; a device to measure humidity, a device to remove humidity, and a device to add humidity. Before discussing the differences between a humidifier vs dehumidifier, it is important to first touch on what humidity is, what causes humidity to increase or decrease, and how you would go about measuring it.

Understanding Humidity

What Is Humidity?

Humidity can be calculated and expressed in two ways; relative humidity and absolute humidity.

Relative humidity is a measure of moisture in the air, as a percentage of the possible moisture that air can hold. Relative humidity takes the temperature of the air into account because the cooler air is, the less water it can absorb.

Absolute humidity, on the other hand, is the measure of water vapor in the air independent of temperature and is calculated as grams of moisture per cubic meter. What this means is a 77 percent day in winter and a 77 percent day in summer, as a measure of relative humidity, are going to have different absolute humidity levels because the temperatures are warmer in summer than winter.

Ideal Indoor Humidity Causes

What Causes Humidity To Increase In Your Home?

Managing ideal indoor humidity for your home can be a real challenge. The colder air is, the less moisture it can hold before condensation occurs (referred to a dew point). Increased humidity levels can come as a result of saturated ground, large bodies of water, or even nearby plants. Increased humidity in your home occurs as a result of your daily activities introducing moisture into your house. Some activities that introduce moisture into your home include;
  • Cooking
  • Showering
  • Running the washer & dryer
  • Some Plants
  • Dishwasher
  • Indoor drying

Variations in humidity, both high and low, will have different impacts on your daily comfort, sleep, home, and belongings.

Ideal Indoor Humidity

What is a good humidity level for your home? According to the environmental protection agency, the ideal home humidity levels are said to be between 30 percent and 50 percent, while ensuring it is kept below 60 percent. There are many reasons for this recommendation relating to health, sleep and comfort, also your home and belongings.

What Measures Humidity?

A hygrometer is used to measure relative humidity and is a useful tool if you intend on maintaining a normal humidity level in your home and bedroom. A hygrometer is often confused with a humidistat, which is usually built into appliances to measure and control the humidity output of that device. 

A hygrometer, on the other hand, is used only to provide a reading of moisture levels in a room. Humidifiers and dehumidifiers with an in-built humidistat are optimal for maintaining ideal indoor humidity, while a hygrometer will tell you whether you need to use a humidifier or dehumidifier. Hygrometers are relatively inexpensive, the iTronics TP65 is a good one that retails about $30, (you can check the latest prices here).

Humidifier Vs Dehumidifier: Exploring The Difference


What Does A Humidifier Do? 

A humidifier adds moisture to the air in an attempt to improve your home’s air quality. Humidifiers can deliver warm or cold outputs, producing mist in different forms to create an ideal indoor humidity level. 

What Problems Does Low Humidity Cause? 

Low humidity can make it difficult to sleep by the way of nose and throat irritation. Although not as extreme as high humidity, low humidity levels cause a range of problems around your home and even to your health.


  • Dry skin
  • Cracked lips or dry lips
  • Blood noses
  • Irritated nasal passages
  • Irritated throat
  • Itchy Eyes
  • Allergy flare-ups



  • Splitting wood, warped floors and furniture
  • Cracked paint
  • Caulks and glue weaken
  • Static electricity
Humidifier Vs Dehumidifier Low Humidity

How Does A Humidifier Work?

Humidifiers work by transforming water into cold or warm mist, depending on the type of humidifier being used. There are five main types of portable humidifiers; Evaporative, Impeller, Ultrasonic, Warm Mist and Steam Vaporizer, each with their strengths and weaknesses.

Do Humidifiers Work?

The short answer is yes, if by work you mean adding moisture to the air inside your home. The long answer is dependent on why you need one. Both humidifiers and dehumidifiers can create ideal indoor humidity levels that are conducive to health and sleep. Generally, humidifiers are a great solution to introducing humidity into environments where humidity is low, and irritation and allergies are making life and sleep difficult.

Types Of Humidifiers

In addition to learning the difference between a humidifier and dehumidifier, it is important to understand the various delivery systems each offer so you can create your ideal indoor humidity level. As mentioned above, there are five types of portable humidifiers; Evaporative, Impeller, Ultrasonic, Warm Mist and Steam Vaporizer, each providing a different solution for delivering moisture into the air. Some humidifiers produce cool mist, while others provide a warm mist as their humidification solution. 

What Is A Cool Mist Humidifier?

A cool-mist humidifier is structured to discharge a cool mist into the air, usually at room temperature. There are three types of cool mist humidifiers; Evaporative, Impeller, and Ultrasonic, which create cold mist in different ways. Impurities in the water stored within the tank will likely be present in the air, so it’s important to keep cool mist humidifiers clean.

Evaporative Cool Mist Humidifier

Evaporative cool mist humidifiers use a wick filter, fan and reservoir/basin to operate. The wick absorbs water from the basin which is then blown by the fan, producing a purified mist that is released into the air. If you’re looking to set your ideal indoor humidity, using an evaporative humidification unit such as the TaoTronics top fill humidifier is a popular solution.

Impeller Cool Mist Humidifier

A cool mist Impeller humidifier uses a fast-rotating disk, powered by an electric motor. Water is sent through a diffuser, breaking it into small droplets and sending them into the air in a fog-like mist. Although noisy, Impeller humidifiers are thought to be the cleanest method of humidification. 

Ultrasonic Cool Mist Humidifier

Ultrasonic cool mist humidifiers use a ceramic or metal diaphragm vibrating at an ultrasonic frequency to create small droplets of water that are released into the air. Usually, a small fan forces mist out of the unit, however, some ultrasonic humidifiers have no fan and also produce a warm mist. If you’re looking for a quality Ultrasonic cool mist humidifier, I suggest the very quiet Everlasting Comfort 6L model, with a built-in essential oil diffuser, auto shutoff, and night light.

What Is A Warm Mist Humidifier?

Both warm mist and cool mist humidifiers are equally effective when it comes to humidifying the air. Warm mist humidifiers retain more minerals without releasing them into the air, reducing the formation of white dust and meaning you breathe in fewer impurities. Warm mist humidifiers do not require filter replacements, are quieter to operate, but are generally more expensive to run as a result of the heating process.

Warm Mist Humidifier

The upside to using a warm mist humidifier is they tend to build up less bacteria and mold as a result of water boiling. Once the water is boiled, steam is slightly cooled and introduced into the air, likely increasing the room temperature. Using a warm mist humidifier to set your ideal indoor humidity might not be beneficial, especially at night, as it could create a tropical-like environment, making it difficult to sleep.

Steam Vaporizer

A vaporizer is used to add medication and alternative remedies into the air in addition to humidity. Steam vaporizers release moisture into the air through a boiling process involving electrodes. The steam cools before leaving the vaporizing unit, however, the reservoir reaches boiling point, so these products are not recommended for homes with small children.

Humidifier Vs Dehumidifier Steam Vaporizer

Furnace Humidifier

A little outside the scope of this post, furnace humidifiers are a great solution to creating the ideal indoor humidity for your entire house. There are three types of furnace humidifiers; Steam, Flow-Through, and Reservoir, which are installed in conjunction with your home central cooling or heating system. These systems are more complex solutions than simply choosing a portable unit. 

What Is A Dehumidifier?

What Does A Dehumidifier Do?

A dehumidifier is the opposite of a humidifier; it is used to remove moisture from the air, rather than add it. High levels of humidity can cause damage to your home, make sleep difficult and make your home a breeding ground for mold and bacteria. Dehumidifiers work well in maintaining ideal indoor humidity levels and reducing the growth of allergens throughout your home.  

What Problems Does High Humidity Cause? 

In addition to making sleep very uncomfortable, high humidity levels cause a range of problems around your home, health, and comfort.

Home: Effects

  • Condensation on walls floors and surfaces
  • Rot from condensation runs down on wood
  • Peeling wallpaper
  • Damage to electronic devices
  • Increased power usage
  • Stains walls and ceilings
  • Slow drying laundry


Home: Environment

  • Algae grow on surfaces
  • Bacteria, mold, and mildew rapidly multiply
  • Dust mites in bedding, upholstery, pillows and soft fabric proliferate
  • Allergens bloom
  • Cause bad odors


Health: Effects

  • Heightened allergy symptoms
  • Asthma flare-ups 
  • Stuffy feeling – feel hotter than it is


How Do Dehumidifiers Work?

Dehumidifiers operate by drawing in warmer moist air and cooling the air within the unit before blowing the air back into the room. The humidity levels are controlled by a humidistat or control board with a sensor.

Do Dehumidifiers Work?

Dehumidifiers work well in reducing the amount of moisture in the air and creating ideal home humidity levels if high humidity is an issue. The question you should ask is how much moisture do I need to be removed, and how big is the space it needs to be removed from? 

Small, cheaper, portable dehumidifiers such as the Pro Breeze Electric Mini Dehumidifier, remove a lower volume of moisture from the air and are generally suited to smaller spaces. Larger dehumidifiers, like the Frigidaire, can remove up to 70 pints of water a day, and come with a hose, meaning it can run all day and night without the need to empty the tank.

Types Of Dehumidifiers

The three main types of dehumidifiers are; Refrigerant Dehumidifiers, Desiccant Dehumidifiers, and Thermo-Electric Dehumidifiers. Each provides a different solution to removing moisture from the air with varying volumes of reduction. Choosing a dehumidifier that is specific to your needs is an important part of maintaining ideal indoor humidity.

Refrigerant Dehumidifier (Compressor)

Refrigerant, or Compressor Dehumidifiers, are the most common type of dehumidifier requiring a fan, compressor, condenser, and evaporator (in the form of a heat coil, fin and tube, or microchannel) to operate. They work by drawing air over a cooled coil using the fan to create condensation, which then falls into a container or is diverted to a drain. Refrigerant dehumidifiers work best in warmer conditions, but will also increase room temperature by 1-2 degrees. A great, mid-sized, portable option is the Inofia 30 pints dehumidifier, which is capable of draining 4 gallons per day (at 86 F). The Inofia is suitable for bedrooms, bathrooms, basements and motor homes.

Desiccant Dehumidifier (Chemical Absorbent)

Chemical Absorbent, or Desiccant Dehumidifiers, use a desiccant wheel to absorb moisture from the air. Desiccant material not being used goes through a drying process that collects water in a container after evaporation. These systems are a better option than Refrigerant Dehumidifiers when the humidity is high, but temperatures are low. During Summer, either option is fine, as you will be able to create ideal indoor humidity levels and have a comfortable night’s sleep.

Thermo-Electric Dehumidifier (Peltier)

Thermo-Electric, or Peltier Dehumidifiers, require three parts to function; a Peltier module, heat sinks, and a fan. The fan pulls air into the front cold heat sink where condensation occurs and the water is collected in a reservoir below. The cold air then passes through a hot heat sink, warming the dry air and releasing it back into the room. Thermo-Electric Dehumidifiers are best suited to very small spaces such as laundry, bathroom, and closets, as their capacity to remove moisture is limited. 

Other Forms Of Dehumidification

Ventilating Dehumidifier

Ventilating dehumidifiers are units that remove moisture from your entire house. They work by introducing air from outside through a filter, dehumidifying and cycling air back out for improved circulation.

Air Conditioner

Although not on this list as a dehumidifier per se, air conditioners also provide a level of dehumidification. Air conditioning units often have a “dry mode”  that helps reduce relative humidity levels, but not completely dehumidifying your home.


Having a good ventilation system will help reduce humidity by sucking moist air out of a room. Ventilation systems work best in areas where you are introducing humidity through the use of appliances, such as when cooking and showering.

Humidifier Vs. Dehumidifier: Which Do You Need?

In this section, we explore whether you require a humidifier or dehumidifier, based on health conditions and purpose.

For Conditions

Humidifier or dehumidifier: For Coughs, Colds And Stuffy Noses

Trying to sleep with a cough or a cold can be extremely frustrating, and many people claim to find relief by using a humidifier. This may be because making the air moist helps clear mucus out of your nose and throat, although more research is required before this scientific claim can be made.

Humidifier Or Dehumidifier: Allergies

Both humidifiers and dehumidifiers can be used to bring you allergy relief. Bacteria, mold and dust mites thrive in overly humid environments, which increases the prevalence of potential allergens. When humidity levels are low, these allergens die off and dry out, making it easier for them to become airborne. Using both a humidifier or dehumidifier can help you set ideal home humidity levels, decreasing allergens and helping you get a good night’s sleep. As mentioned above, a hygrometer can be used to measure relative humidity levels, providing you an indication of whether you need to use a humidifier or dehumidifier (or neither).

Humidifier Or Dehumidifier: Asthma

Using either a dehumidifier or humidifier for asthma can help prevent symptoms since the triggers for asthma widely vary. Using a dehumidifier for asthma will reduce occurrences if the trigger is too much humidity, whereas using a humidifier for asthma will reduce occurrences if the trigger is not enough humidity. When it comes to potentially serious conditions such as asthma, your best solution is to seek the guidance of a medical professional, who can better advise whe

Humidifier Or Dehumidifier: Bronchitis

Cold temperatures and low humidity levels have been scientifically linked to increased occurrences of respiratory tract infections. In the instance of bronchitis, maintaining an ideal indoor humidity of about 50 percent will aid loosening mucus and make breathing easier. If your bronchitis occurred during cold and dry Winter months, use a humidifier to increase your home humidity levels.

Humidifier Or Dehumidifier: Eczema

Low humidity levels can draw moisture from your skin, worsening symptoms of eczema. Using a humidifier will increase humidity in the home, limiting the amount of moisture air takes from its surroundings. 

Humidifier Or Dehumidifier: Dry Skin, Hair And Lips

Similar to eczema, it is best to use a humidifier to help reduce dry skin, hair and lips. Maintaining an ideal indoor humidity level of around 50 percent will reduce the occurrence of dry skin, hair and lips, if low humidity is the issue.

For Seasons

Humidifier Vs Dehumidifier: Summer

Humidifier Vs Dehumidifier Ideal Indoor Humidity Summer

During sticky Summer months, dehumidifiers will draw moisture from the air, increasing the overall comfort of your home. When researching the right type of mechanism and model, you should consider the following;

How Much Moisture Do You Need To Remove?

Maintaining ideal indoor humidity levels when reducing humidity, requires an estimation of the overall space in order to establish the size of the unit required. Lowering the humidity in your closet will require a different solution to lowering humidity levels within your bedroom or living area.

What Features Should I Look For?

Ultimately, the features you require are entirely up to you, however, some features to take note of are: 

  • Digital humidistat that offers ‘set and forget’ automation
  • Programmable timer
  • Lightweight
  • Water capacity
  • Drainage pumps and hoses
  • Washable filters
  • Quiet operation
  • Energy efficiency

How Much Does A Dehumidifier Cost?

The cost of reducing home humidity will depend on the amount of moisture you are trying to reduce. Generally, the cheaper the dehumidifier, the lesser the volume the unit can hold, hence a lower time frame it can dehumidify in a given cycle. I have grouped some of the best dehumidifiers available based on price bracket, to help you achieve ideal indoor humidity, regardless of budget.

Best Dehumidifiers Under 50 Dollars

Humidifier Vs Dehumidifier: Winter

Humidifier Vs Dehumidifier Ideal Indoor Humidity Winter

It is common to use humidifiers during the Winter months, as air tends to be cooler and dryer, causing itching and irritations. When researching the ideal type and model, you should consider the following;

How Much Moisture Do You Need To Add?

Are you looking to set comfortable humidity levels in a large living room, or a smaller space such as your baby’s bedroom? Before deciding on a humidification unit, it is a good idea to consider the capacity of the unit to produce and monitor moisture over your desired time frame.

Do You Want To Spend Time Maintaining The Unit?

Warm mist and cool mist humidifiers have different maintenance requirements. If you want a solution that doesn’t require regular cleaning, you may be better off choosing a warm mist unit.

Do You Have Young Children?

Cool mist humidifiers are a safer option if you have young children, as they will not burn themselves if an accident happens. Since warm mist humidifiers require water to reach boiling point, these can become a potential hazard around small children.

How Much Does A Humidifier Cost?

Maintaining ideal home humidity may come at a price, but it doesn’t have to break the bank. If price is your primary concern, the following summary is a good guideline for selecting the best option based on your budget.

Best Humidifiers Under 50 Dollars

Best Humidifiers Under 100 Dollars

Best Humidifiers Under 200 Dollars

Best Humidifiers Over 200 Dollars

Drawbacks Of Humidifiers And Dehumidifiers

Potential Risks When Using A Humidifier

Dirty Air

Failing to properly clean and maintain your unit’s water tank can lead to the mist containing dirt, meaning you will be breathing impurities emitted. In addition to dirt, the humidifier can be a breeding ground for bacteria, so it is recommended to clean and replace water on a regular basis.

Too Much Humidity

Failing to monitor and regulate humidity levels can lead to less than ideal indoor humidity. As mentioned earlier, ideal home humidity should be between 40 and 50 percent, but definitely less than 60 percent. If your humidifier contains an in-built humidistat, this shouldn’t be a problem, however, if it does not, you could consider using a hygrometer.

Bacteria & Mold Growth

Not only can bacteria and mold be present in a dirty unit, but high humidity levels can cause them to breed within your home. This is another important reason to monitor and maintain optimum humidity levels in your home.

White Dust

White dust is a dried mineral deposit that can form as a result of using water that is full of minerals. The three types of humidifiers that can produce white dust as a byproduct of the steaming process are the Evaporative, Ultrasonic, and Impeller. White dust is generally not harmful, but if you suffer from allergies, asthma, or other breathing conditions, it may become problematic. If white dust is a problem, you can reduce its occurrence by using distilled water, using a demineralization cartridge, or purchasing a warm or cool mist humidifier instead.

Potential Risks When Using A DeHumidifier


Although dehumidifiers are used to prevent mold, if you don’t address an existing mold problem, dehumidification can make the problem worse. Dehumidifiers can push mold into other spaces around your home and exaggerate allergy symptoms by spreading dried allergens through the air. In addition to pushing mold around your house, your dehumidifier could grow mold in the water tank. For this reason, it is important to monitor and clean the water catchment periodically.

Final Word

Both humidifiers and dehumidifiers play a role in controlling the climate within your home, helping to eliminate allergies, irritations and allowing for a good night’s sleep. Humidifiers can deliver moisture in the form of cool or warm mist, using different methods of delivery, while dehumidifiers reduce moisture in the air, most commonly by refrigeration. Hydrometers are used to gauge whether you need to use a humidifier or dehumidifier, whereas humidistats are built into appliances, allowing you to control and monitor humidity levels. It is important to be able to monitor humidity to set the ideal indoor humidity level and create a comfortable environment for your family. 

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