Informational Guide

Comparing Humidifier Vs Dehumidifiers

What are the key differences between humidifiers & dehumidifiers? This guide covers all about these appliances and which one you should choose for your home.

by Josh M

Humidifiers and dehumidifiers are both great tools to have around if you want the utmost comfort and healthy humidity levels in your home. However, many are unsure about how the two vary.

So, what is the difference between a humidifier and a dehumidifier? You’re about to find out, because this guide covers all that and which one you should choose for your home.

Simply put, humidifiers add moisture to the air around them to boost the humidity in your home, office, or any other indoor space it’s placed in. There are different types of humidifiers, which use different methods in order to create the moisture and extra humidity.

Cool Mist Humidifiers

Cool mist humidifiers use either a disc spinning at high speeds or a plate vibrating at high speeds to create tiny droplets of water. Others use air blown over a wet wick to push out moisturized air. In all cases, the water starts and stays cold, to keep your air cold yet perfectly humid.

Warm Mist Humidifiers

Warm mist humidifiers boil water, producing steam that is slightly cooled before exiting the humidifier. As they produce a warm mist, this can be particularly soothing to the breathing passages.

Ultrasonic models are a bit more modern, creating mist through super-fast vibrations. The mist can be either warm or cool, depending on the model and operating mode.

Evaporative humidifiers heat water, producing steam as well. These are a type of warm mist humidifier. As they evaporate the water, it rises, sending it out into the air. The best models move this water first through a filter of some kind which can help with allergies.

Pros & Cons of Humidifiers

What We Like
  • Reduced risk of contracting cold and flu viruses
  • Healthier plants and furniture
  • Less dry skin, chapped lips, nosebleeds, etc.
  • Can save money and energy during colder seasons
  • Reduced static electricity, which can make you more comfortable and help eliminate the risk of damage to electronics
What We Don’t Like
  • Requires regular cleaning to avoid harmful bacteria
  • Produces noise which can be potentially annoying
  • If unregulated, can produce too much moisture
Allergies and Congestion

What Does a Dehumidifier Do?

As you can probably guess by the name, dehumidifiers actually reduce moisture in the air. If your home is feeling a bit musty, these are great for clearing things up.

Most models are able to reduce indoor humidity levels all the way to the ideal 30-50%. These can function in different ways and come in varying sizes from small, portable units to large whole-house models.

Compressor dehumidifier

Compressor dehumidifiers are typically the more popular of the two, using a condensation method to take water from the environment around it. Once the damp air is taken in, it travels over a cold coil, where water is separated from the air.

This condensed moisture is then moved into a tank, and dry hair is warmed to room temperature and released into the area around it. You may need to manually empty the tank each time it fills.

Desiccant dehumidifier

Desiccant dehumidifiers have a compressor and cold surface as well but operate more like a sponge to absorb moisture with a desiccant wheel. The wheel is powered by an internal heater, so you can use it consistently with little-to-no sound.

These are more compact as well, making them more convenient for many users.

Pros & Cons of Dehumidifiers

What We Like
  • Helps with allergies by reducing the risk of mold growth and fewer dust mites
  • Comfort levels increased
  • Helps minimize skin irritation or respiratory issues
  • Clothes dry quicker, stored food less likely to mold
What We Don’t Like
  • Some are quite noisy
  • Can increase energy bill
  • Requires regular maintenance as the storage tanks must be emptied and cleaned out often

Comparing Humidifiers vs Dehumidifiers – Which is Best for You?

Now that you’ve read a bit about both, you may be wondering, “do I need a humidifier or dehumidifier?”. Below, we’ve compared both to make it a more straightforward selection for you.

For Allergies & Congestion

One of the most common reasons people look to purchase a humidifier or even dehumidifier is for allergies. What’s really cool about both of these machines is that they both are capable of helping reduce allergy symptoms, including congestion.

If your home contains dust mites or even mold spores, dehumidifiers are going to be effective in reducing your symptoms. Mold is oftentimes caused due to overly humid spaces, and dust mites love the moist air too.

However, humidifiers for allergies exist because they add moisture to overly dry air, which can hold allergens as well. Not only that, dry air can inflame the sinuses and cause nasal passages to become blocked.

For Asthma

Humidity can be a major contributor to asthma attacks, so if you suffer from the condition, it’s important to keep levels in check. Humidifiers for asthma are usually the go-to as dry air can cause your nose and throat to become irritated and spark asthma attacks.

We generally recommend humidifiers for most of these cases.

On the other end of the spectrum, too much humidity can also be challenging. As we have mentioned before, moisture can hold mold spores and dust mites which are massive asthma triggers.

For a Stuffy Nose & Cough

In most situations, if you have a stuffy nose and cough, it’s aggravated due to too-dry air. If you’re also experiencing dry skin, cracked lips, etc., then that’s likely your case.

Humidifiers for coughs will absolutely help here, adding just the right amount of moisture so that your breathing passages are no longer negatively affected.

For Baby/Nursery

So what is best when talking about a humidifier or dehumidifier for baby nurseries? Once again, you’ll want to opt for a humidifier here. Unless your baby is sleeping in a basement or your home doesn’t have air conditioning/is too humid, you likely aren’t going to need a dehumidifier.

However, air that’s too dry can make them more susceptible to cold viruses and other illnesses, so you need a humidifier to combat that risk.

Many people try to make comparisons between an air purifier vs a humidifier vs a dehumidifier. You don’t have to use only one or two, either. Technically, you could use them all!

If you’re worried about allergies, asthma, or simply getting a cold, you can use an air purifier in conjunction with a dehumidifier or humidifier to help you breathe easier with cleaner air.

Learn where to place your humidifier by following this guide.

People Also Ask (FAQ)

Can you run a humidifier and a dehumidifier at the same time?

You absolutely can! While at first glance, it may sound a bit counterproductive or even silly, the two products operate in different ways. Just make sure you’re using them strategically.

Can a dehumidifier be used as a humidifier?

Nope. They both serve completely different purposes – exactly the opposite of one another. Dehumidifiers remove moisture from the air, making the air dryer. Humidifiers add moisture to the air, improving the humidity level.

How do you know if you need a humidifier in your room?

There are quite a few different signs:

  • Static shock
  • Dry or itchy skin
  • Nose bleeds
  • Chapped/cracked lips
  • Frequent coughing
  • Allergies/Worsened allergy symptoms
  • Congestion
  • Gaps in wood flooring/cracks in wooden furniture

Do dehumidifiers kill viruses?

They can if your home already has excess humidity. However, you need to be careful that you aren’t drying out your home too much, as this can also make you more susceptible to acquiring a cold, flu, or other viruses.

Dehumidifiers can help kill airborne pathogens, however, as these tend to cling to moisture in the air. Of course, this is juts one barrier in protecting yourself follow other hygienic recommendations as well.

Clean with Sanitizers


Now that you know pretty much everything there is to know about the differences between humidifiers and dehumidifiers, have you decided which one is right for you and your needs?

We hope that our guide was able to make that an easy decision for you. Thanks for tuning in, and we’ll see you again shortly! You’re well on your way to breathing easier and living more comfortably!

Last Updated on July 16, 2021

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.