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Humidifier vs. Dehumidifier: Which One Do I Need?

why you need the best dehumidifiers and humidifiers

Why you need to know the difference and why you need one

We can often be meticulous about maintaining the perfect temperature in our homes - constantly adjusting the thermostat to find that sweet spot between too warm and too cold. But one area of a home’s climate often overlooked is the humidity level, or relative humidity (RH).

Humidity refers to the amount of moisture in the air, which can often become too high in warmer weather and too low in colder conditions. An unhealthy RH can lead to exacerbated allergy or sinus issues, so it is essential to combat this with either a humidifier or dehumidifier.

But which one is right for the job? Below is everything you need to know about humidifiers and dehumidifiers, including their differing purposes and capabilities.

What’s the Difference?

Humidifiers and dehumidifiers are often confused for each other, but they are very different products. Their main similarity stems from the fact that they both work to regulate the amount of moisture in the air, but they do this in different ways. A humidifier increases the amount of moisture in the air (the humidity), and is commonly used in the winter months when the air is dry. It helps keep skin from drying out, as well as limits the effects of allergies and nasal congestion. On the other hand, dehumidifiers decrease the amount of moisture in the air, preventing mold and mildew from accumulating during the humid summer months; this fends off allergies and headaches that pop up in the summer.

Which One Should I Get?

The type of product you need depends on the humidity levels within your home. Humidity can be measured with a digital humidity reader, also known as a hygrometer, which can be found online or in stores for under $10. For the average home, a healthy humidity level spans from 30 to 50 percent, but some sources prefer 35 to 45 percent. Hence, if your home (or a specific room) is above 45 or 50% humidity, you should consider purchasing a dehumidifier. Similarly, if an area of your house is below 30 or 35% humidity, think about buying a humidifier.

What Are Different Types of Humidifiers And How Do They Work?

Winter can be brutal, so having a humidifier that effectively regulates your home’s humidity levels is essential. You have several options when choosing what type of humidifier is best for your needs; the results between the different models are often the same, but the process by which they add moisture to the air can differ greatly.

Warm Mist Humidifiers

Often called steam vaporizers, warm mist humidifiers boil water and disperse the resultant steam into the air; this means there is a risk of scalding or burning yourself if you do not properly utilize a steam vaporizer. One advantage is that the boiling water inhibits harmful bacteria from growing in the humidifier and being dispersed into the air. Households with children or pets may want to avoid warm mist humidifiers, since knocking over the device and spilling the boiling contents can lead to burns. Warm mist models can often be augmented with essential oils to add fresh scents or aromatherapy to the air around you.

Warm mist humidifiers usually work in these ways:

  • The humidifier is plugged into an electrical outlet.
  • The humidifier uses this energy to heat water in a container until the water is boiling.
  • The boiling water emits steam that is then cooled before being released into the air

Cool Mist Humidifiers

As the name suggests, these increase humidity levels by dispensing cool water droplets into the air of a house or room. They are often considered safer options than warm mist humidifiers, since they do not involve any hot or boiling water. However, there is an increased risk of bacteria building up in cool mist humidifiers and being dispersed into the air, since these types do not boil the water like warm mist models. Hence, cool mist humidifiers provide added safety but also a need for more frequent cleaning.

Some of the types of cool mist humidifiers are:


In these devices, a fan blows cool air through a wet belt or filter, which moisturizes the air. This is one of the most common types of humidifiers, and capitalizes on the benefits of evaporation (which is how moisture is naturally added to the air) by speeding up the process with a fan. An evaporative humidifier is typically larger than other types of cool mist humidifiers, due to the need for a fan and filter. Also, keep in mind that you will have to replace the filter occasionally on these models.


These models feature two spinning, wet plates whose vibration produces an extra-fine water mist, which is then dispersed into the room. Ultrasonic humidifiers are often quieter than other types and can save you money in the long run because they do not have a filter that requires routine replacement. These humidifiers come in several different shapes and sizes, with arguably the most popular being the raindrop-shaped model with mist ejected from the top. In addition, ultrasonic models can be found with aromatherapy features, USB power, or color-changing LED lights, making them quite the stylish choice.


These models employ a rapidly spinning disc or ceramic plate, which breaks water down into tiny droplets to be dispersed into the air. They are often cheaper yet louder than the aforementioned models, and also require routine maintenance to prevent bacteria buildup.

What Are Different Types of Dehumidifiers and How Do They Work?

Dehumidifiers remove moisture from the air to keep your house dry and less humid, and are a staple technology for many households during the summer months. As with humidifiers, there are a couple different types of dehumidifiers to choose from.

Refrigerative Dehumidifier

This is perhaps the most common type of dehumidifier, especially for everyday household use. They do not possess as much cooling power as other models, but they will still help maintain a healthy humidity level for your home (around 45% humidity).

Refrigerative dehumidifiers work in the following ways:

  • The dehumidifier uses a fan to capture and contain warm air, where it is cooled down by metal coils. These metal coils employ a chemical-based refrigerant to keep themselves cool and reduce the air temperature within the system.
  • As the warm air cools down, it also shrinks and produces small, warm water droplets that are then stored as condensation in the tank of the dehumidifier.
  • Free of the warm water droplets, the cold air is now blown back out into your house by another fan, thereby decreasing the amount of moisture in your surroundings.

Desiccant Dehumidifier

This is a much more powerful dehumidifier, but it is mainly only necessary for commercial storage, such as for pharmaceuticals, food, and chemicals. It can reduce humidity levels anywhere from 45% to 1%, but often utilizes power from thermal energy (natural gas or steam) instead of electrical outlets. Instead of condensation, desiccant dehumidifiers use chemical attraction to decrease humidity levels.

If you are looking for a dehumidifier for a lower ground level, then check out of review of the best basement dehumidifiers you can buy.

What Are the Benefits of Humidifiers and Dehumidifiers?

Humidifiers combat dry air, in turn preventing airway infections and other issues such as colds, nosebleeds, and bronchitis. They are a solid option for people in cold, dry climates that suffer from asthma or allergies, serving as a compact, inexpensive way to promote a healthier home environment.

Dehumidifiers decrease RH levels in the air, limiting the risk of mold and dust mites invading your home. Like humidifiers, they are also helpful for people with significant asthma or allergy issues, except that these devices are used during the warm, muggy months.

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