Humidifier vs. Dehumidifier: What Are the Differences?

Christine Herrington

Christine is our Chief Editor and a contributing writer to the site.

Last Updated on January 19, 2022

What is a humidity level, and how does it affect us? Did you know that the humidity levels inside your home can impact your health? A home with high or too low humidity levels can suffer negative structural consequences and can negatively affect your body. Dry air exacerbates asthma and allergy symptoms, whereas moist air can cause airway constriction.  

In simple terms, a humidifier adds moisture into environments where there is not enough of it, and a dehumidifier removes water from areas where there is too much moisture in the air. Here are the main differences between the two and their primary uses.

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Table of Contents

How Does Humidity Affect Me?

You might be wondering why you need one of these devices and how the moisture in your environment impacts you and your home daily. Depending on whether your home has high or low humidity levels, there can be effects on you and the building.

If you find mold growing in your home or experience dampness, you may have a home with excess moisture in the air. Even small amounts of mold spores on the walls and ceilings lead to serious health problems, such as respiratory issues.

Over time, moisture causes damage to the structural elements of your home and becomes costly to repair. There are various ways to reduce moisture levels in your air, such as improving ventilation and not hang-drying clothes indoors. However, the most effective way to target excess moisture is by using a dehumidifier.

In contrast, if you experience dry or itchy skin or eyes and chapped lips, these may be signs that there is not enough moisture in your environment. If you live in these conditions, there can also be unpleasant consequences for your home and health.

Air that is too dry leads to cracks on furniture, plaster, and wooden beams. A humidifier is a device that helps in solving these issues by putting moisture back into the air inside your home.

Read More: Dehumidifier Buying Guide


What is the Optimum Level of Humidity for My Home?

Although telltale signs indicate that an environment is either too damp or too dry such as silverfish, mold, and spiders, you can test the moisture levels in your home before committing to purchasing either a dehumidifier or a humidifier.

Moisture in the air is measured by relative humidity and in most homes ranges between around 30% to 50%. Anything that is within this range is considered normal and a healthy level of humidity.

If the humidity levels in your home fall below these levels, there is a deficit of moisture in your air. In this case, a humidifier is the best option for your needs. However, if the moisture levels in your home read over 50%, then it may be time to start looking at purchasing a dehumidifier to reduce some of that excess.

To determine moisture levels in your home and get an accurate reading, you need to purchase a piece of equipment that can register humidity levels. This is known as a hygrometer. You can find a hygrometer in most home improvement stores for a reasonably low price. This helps you establish whether a humidifier vs. a dehumidifier is right for you.

Can You Put Essential Oils in a Humidifier without Ruining It

Humidifiers: What Are They and How Do They Work?

When looking at humidifiers to buy, you will notice two main types on the market. These are warm-mist humidifiers and cool-mist humidifiers. Warm-mist humidifiers are also sometimes referred to as steam vaporizers. When it comes to deciding between each of these two types, it is mainly a matter of personal preference, as both are effective at adding moisture back into the air.

Warm-mist humidifiers or steam vaporizers use electric energy to heat water to its boiling point. This water creates steam which is cooled before being put back into your air. This type of humidifier can be more effective for those who suffer from respiratory issues such as asthma or allergies.

Cool-mist humidifiers work by breaking up water into microscopic particles, which then re-enter the air in your environment as water vapor. In the summer, or if you live in a perpetually warm climate, this is often a better option as it can help cool the air in your environment, making you more comfortable.

Read More: High-Quality Humidifiers For Your Home


Dehumidifiers: What Are They and How do They Work?

On the other side of the humidifier vs. dehumidifier debate, you have dehumidifiers. There are also several types of devices that help to remove the moisture from your air to prevent dampness and mold.

The most common way a dehumidifier works is by using a fan to draw in warm air over a set of metal coils. A refrigerant that makes use of certain chemicals then works to reduce the overall temperature of these coils. This has the effect of shrinking the warm air, and tiny droplets will fall from the air as they shrink.

This is otherwise known as condensation, and it is taken and stored in a tank within the dehumidifier. On top of this, the air that’s cooled through the coils and had its moisture removed is then put back into your air by a fan. Over a short period, this effectively reduces the overall moisture levels in your indoor environment.

Humidifier vs. Dehumidifier: Which One Do I Need?

Humidity levels in the indoor air of your homes and workplace can significantly impact not only the buildings themselves but also your health and wellbeing. Spending a lot of time in an indoor environment with either extreme of moisture levels can have negative consequences.

There are easy ways to tell whether or not the moisture levels in your environment are optimal or not, and once you have these readings, you can explore your options to find the best solution for your home. If you’re dealing with a dry environment, various types of humidifiers can add moisture to your air. Conversely, if you’re dealing with mold spores and other classic indicators of excess moisture, a dehumidifier that works to remove water from your environment will be the best choice.


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