Humidifiers vs Dehumidifiers. What’s the Difference?

This article aims to illustrate the differences between humidifiers and dehumidifiers. 

If you aren’t sure which of the two you need for your home, office, or any other space, leave it to us. We will take you through all of their features, the mechanisms that make them work, and the scenarios each one is best suited for. 

Put simply, humidifiers and dehumidifiers are polar opposites. Humidifiers increase the amount of water vapor in your surroundings, while dehumidifiers decrease it. 

That means humidifiers and dehumidifiers are used in different scenarios. Which one you choose will depend on factors such as your geographic location, the average relative humidity, and a couple other things that we’ll get into below. 

Keep reading for a head-to-head comparison between humidifiers and dehumidifiers.

Should I Buy A Humidifier Or Dehumidifier? 

If you aren’t super familiar with how humidity works, then you’re probably scratching your head trying to figure out which of the two to buy. 

Obviously, if you are trying to counter the effects of high humidity, you should be looking at dehumidifiers. Conversely, if the relative humidity in your home tends to be a bit lower, a humidifier is what you need. 

But what is ‘relative humidity’? What constitutes ‘low’ or ‘high’ humidity? And what are the signs for each?

Relative Humidity

Relative humidity is a measure of how much water vapor a given amount of air at standard temperature is holding, compared to how much it COULD hold. So if a given amount of air COULD hold 22 ml of water vapor, but is currently holding 11 ml, we say relative humidity is at 50%. 

Low or High Humidity

The consensus is that most people feel most comfortable between 30%-50% relative humidity. Anything above 60% is usually considered very high humidity. 

If you’ve ever used a weather app, the percentage in the ‘Humidity’ section is actually relative humidity. But that’s more of a general estimate for your city or town. 

The humidity in indoor spaces can vary significantly. Here, you can get a device called a hygrometer that tells you the relative humidity of a space. 

Humidity and Weather

Weather and climate directly affect humidity. This is because when the temperature of air increases, it allows the air to be able to hold more water vapor. Similarly, when temperature goes down, the air’s ability to hold water vapor also takes a hit. 

That means the relative humidity of an area increases in the summer, and goes down in colder months. 

If you’ve experienced that hot, sticky feeling in the rainy season, it’s  because the relative humidity is higher in summer months and the rain increases water vapor content in the air. Dehumidifiers help relieve some of that discomfort. 

Conversely, winter months can feel dry due to the lower temperature which causes air to become less dense in water vapor. This is where humidifiers shine. 

Signs Of Low Or High Humidity

There are other ways to tell if you’re experiencing low or high humidity. Low humidity may cause excessive coughing, snoring, and dry skin. Looking around the house you might notice that wooden fixtures, doors, and drawers don’t seal perfectly. 

On the other hand, high humidity may cause breathlessness, allergic reactions, and increased ambient temperature. Your house will suffer as well, as wooden doors, floors, and the like may become waterlogged. Paint may start peeling, which poses the risk of respiratory problems if paint particles are released into the atmosphere. 

So if you experience excessive coughing, your skin feels dry, lips get chapped or cracked, a humidifier may be in order. Alternatively, relative humidity below 30% also necessitates a humidifier. 

On the other end of the spectrum, relative humidity higher than 60% might cause discomfort. It may feel too warm and you might experience breathlessness. High humidity can also cause mold, so definitely keep an eye out for that. If you experience any of this, getting a dehumidifier might be a good idea.


  • Boost relative humidity of a space
  • Increase ambient temperature
  • Great for dry throats
  • Great for dealing with dry/cracked skin and lips
  • Can help with excessive coughing
  • Available in different sizes and water tank capacities
  • Can be used for various room sizes
  • Compact and easy to store
  • Most commonly used in winter/low temperature
  • Come in unique, fun designs
  • Some cheap options have low quality builds


  • Lower the relative humidity of an area
  • Have a slight cooling effect
  • Available in different sizes and capacities
  • Can be used in different-sized areas
  • Most commonly used in summer and hotter climates
  • Usually larger in size
  • The design is often a bit basic



Starting with the design and build of these two appliances, you’ll notice that while both are offered in more reserved, utilitarian designs, humidifiers also offer options that are a bit more fun and playful. 

Humidifiers come in unique, trendy designs that you can mix and match with your desk, living room, baby nursery, and wherever else you might need them.

Dehumidifiers, on the other hand, tend to have bland, straightforward designs. You’ll find most dehumidifiers in white, gray, or black, and it’s almost always a boxy, rectangular design. 

Meanwhile, humidifiers come in all shapes and sizes, from ones with the classic ‘refrigerator’ look, to ones that are shaped like children’s toys!


This is another major difference between humidifiers and dehumidifiers. Humidifiers, you can find in every shape and size out there. Small ones can fit on your nightstand, desk, or even a shelf. Sure, larger options exist, with higher capacities, better coverage, and more features, but that’s mostly because humidifiers have a pretty simple internal design.

The inside of a dehumidifier is a bit more complicated, however. It uses larger components, which necessitate a larger outer shell. So usually, dehumidifiers tend to have a bigger footprint than humidifiers. 


More components and larger components translate to higher prices for dehumidifiers. That’s not to say you can’t find high quality dehumidifiers at a reasonable price. But the fact remains that while smaller humidifiers can be had for under $25, even a decent dehumidifier will cost 3-5 times as much!

Health Benefits

Humidifiers and dehumidifiers are designed to combat different types of health concerns and medical symptoms. 

Humidifiers could be a great addition to the house if you suffer from dry throat, excessive coughing, and dry/cracked skin and lips. They also lessen allergies and make sleeping more comfortable. Heavy snorers (or rather their partners) should find humidifiers to be an absolute godsend! 

Dehumidifiers also have significant health benefits. Certain allergens and irritants thrive in damp conditions. A dehumidifier reduces dampness and moisture in the air, effectively making it harder for such microbes to grow. Dehumidifiers also reduce chances of disease-causing mold to develop in your home. 

And while we always recommend consulting your physician first and foremost, a lot of people find that dehumidifiers help with asthma and breathlessness in general. 

Heating/Cooling Effect

Both humidifiers and dehumidifiers have limited effects on the ambient temperature, though in opposite directions. 

Running a humidifier can make a room feel slightly warmer or cozier, though your furnace will still be doing the heavy lifting. Some humidifiers come with cool/warm mist modes, which can have a more pronounced effect on temperature. 

Dehumidifiers reduce relative humidity, which can feel cooler and more pleasant, but no dehumidifier will counter the Sun’s wrath on a hot summer day!


Modern designs and components mean both humidifiers and dehumidifiers can offer exceptional reliability. That said, both will need regular upkeep. Cleaning the unit, replacing filters, and keeping up with the maintenance are all essential if you want your humidifier or dehumidifier to last. 

Here, we do think humidifiers have a slight edge on the competition. Since they are so simple, and only have so many components, there’s just less stuff to go wrong. Dehumidifiers, owing to their more complex designs and higher-end componentry, may experience problems down the line, especially if you don’t maintain the unit properly. 

Again, we’re splitting hairs, and odds are, your dehumidifier won’t experience any major issues over its lifespan. But it’s something to keep in mind. 

Humidifiers vs Dehumidifiers: The Winner

There is no clear winner between humidifiers and dehumidifiers. Both are designed to do different tasks. In fact, they are designed for completely opposite functions. 

Sure, dehumidifiers are larger, more expensive, and more prone to issues down the line, but humidifiers have their fair share of problems as well. Humidifiers are so common these days that finding a high quality one that actually lasts can be a hassle. 

Plus, neither can do what the other one does, regardless of the price, build quality, or size. 

That is why we put together buying guides for humidifiers and dehumidifiers, where we recommend the best, highest performing models for you to choose from. 

And that’s really the best advice we can give: to do your research and choose the best humidifier or dehumidifier for your particular needs.


Shawn Willis is all about humidifiers. After working for some of the biggest names in the industry, he started HumidifierGuys with Scott Dawson. Now, the dynamic duo helps others figure out what they need in their next humidifier.

Shawn is an avid sports fan, motorcycle enthusiast, and has two dogs named Whiskey and Boba.