Graphic of Air Controlling Devices VS Each Other

One of the great things about living in this modern world is the fact that there are so many different ways to improve the quality of air and comfort you feel inside your home.

No longer must you suffer from the effects of air pollution just because of where you live.

Indoor air can easily be cleaned using a simple air purifying device.

You also don’t have to put up with uncomfortable temperatures in your home during hot and cold seasons.

Portable air conditioners and humidifying products now exist to help keep you comfortable at all times.

While it’s definitely nice to have options to choose from for improving your quality of life at home, the problem is that many consumers don’t actually know which is the right product to buy.

For example, do you know what is the difference between a dehumidifier and an air conditioner?

Or, what the benefits of an air purifier vs humidifier are for your health?

If not, don’t worry.

Most people have no idea how to answer those types of questions and that’s exactly why we put together this post.

In this article, we’re going to explain what each of these devices below does and how each one compares to each other.

The details may surprise you!

  • Air purifiers
  • Air Conditioners
  • Humidifiers
  • Dehumidifiers

Air Purifier vs Air Conditioner vs Humidifier vs Dehumidifier

By the time you’re done reading this post, you’ll know exactly which product is the best for certain types of indoor conditions.

Getting Started: Some Brief Definitions

Before we launch into the comparisons it’s good for you to have a basic understanding of each air controlling device.

That way when we do compare each product, the explanations will make more sense.

What is an Air Purifier?

Air purifiers are used for health reasons.

Air purifiers remove pollutants and other particles from indoor air.

This includes particulates that have a negative impact on human health such as allergens, dust, smoke, animal dander, bacteria, mold spores, pollen and more.

There are two main types of air purifiers:

  • Those that use a dense filter to collect particulate matter. The official name is a “HEPA filter.”
  • Those that use electrostatic methods to remove contaminants from the air. These go by the name “ionic air purifiers” or “air ionizers.”

This page has the best rated air purifiers available that use HEPA filters. And this page has the top ionic air purifier reviews.

See all of Amazon's Best Selling Air Purifiers

What is an Air Conditioner?

Air conditioners are used for comfort reasons.

Air conditioners cool down a home by drawing hot air out of a room and pumping cold air back in. 

Air conditioners can change the temperature, humidity, and general quality of indoor air.

There are six main types of home cooling systems:

  • Central air conditioner that uses ductwork to deliver conditioned air throughout a house.
  • Ductless mini split air conditioner that includes an indoor evaporator unit and an outdoor compressor.
  • Portable air conditioner that stands next to a window and pumps hot air outside through a hose that’s connected to a window.
  • Packaged terminal air conditioner that’s a commercial-grade and self-contained unit commonly used in hotels.
  • Through the wall air conditioner that looks like a window unit, but is installed through the wall so it doesn’t take up any window space.
  • Window air conditioner that sits on a window sill and delivers cool air into a room while exhausting hot air outside.

What is a Humidifier?

Humidifiers are used for comfort and personal well-being reasons.

Humidifiers add water to indoor air as a way to increase the relative humidity.

When there’s more water in the air, the more ambient heat is retained, making a room feel warmer.

Sweat from the body also evaporates more slowly which adds to the warming effect.

Adding moisture to the air also helps prevent your skin from drying out and relieves irritation in parts of the body such as the nose, throat, and lips.

There are three main types of humidifiers:

  • Warm mist humidifier that works with boiling water.
  • Cool mist humidifier that works with cool water.
  • Ultrasonic humidifier that vibrates at an ultrasonic frequency and uses a fan to pump water into the air.

We tested the best small humidifiers on the market to save you the guess work and returns.

What is a Dehumidifier?

Dehumidifiers are used for comfort and health reasons.

Dehumidifiers reduce relative humidity levels by removing moisture from the air.

By stripping moisture from the air, a room will feel cooler because there is less water vapor to retain heat; however, the air is not directly cooled before being returned to the room.

Removing excess moisture also helps prevent mold, bacteria and other particulates from growing indoors that thrive on wet conditions.

There are three common methods for the process of dehumidification:

  • Refrigerant process that collects moisture into a water tank.
  • Dessicant material that absorbs water from the air.
  • Electronic heat pump that condenses water vapor and drains outside.

We tested the best small dehumidifiers on the market to save you the guess work and returns.

Applying What You Learned: Product Comparisons

Air Purifier vs Air Conditioner (or Air Conditioning)

Air purifiers don’t remove heat or humidity from the air like air conditioners do.

Instead, these devices clean the air around you by filtering contaminants (dust, pollen, bacteria, etc.) that cause respiratory and other health-related issues.

Some air purifiers use a fan to draw air into the unit in order to trap particulate matter and this same fan blows fresh air back into the room.

This process can create a cool breeze like you would feel from a rotary fan, but it’s just a side effect and not designed to cool down a room.

Air conditioners work to remove heat and humidity from a room, and some do have a slight air purifying effect.

These devices lower the temperature in a room by drawing hot air out and exhausting it to the outdoors.

Cold air is then pumped back into the space.

During the air conditioning process, air travels through a grille that’s outfitted with an air filter.

The purpose of this filter is to prevent airborne particles from damaging the internal air conditioner parts.

Some pollutants (dust, pollen, bacteria, etc.) are trapped in the filter and air purification does happen; however, the efficiency is nowhere near that of an air purifier.

Air conditioner filters can’t capture fine particles like an air purifier filter can.

For more details visit our dedicated post on Air Purifier vs Air Conditioner.

See all of Amazon's Best Selling Portable AC Units

Air Purifier vs Humidifier

Air purifiers and humidifiers have completely different functions, but you’ll find that both aide in your well-being.

Air purifiers are used to clean the air that you breathe indoors and have no impact on the humidity levels.

These devices reduce airborne toxins and allergen substances such as dust, mold, bacteria, pet dander, chemical vapors, smoke particles, gaseous pollutants, and more.

The less amount of these particles that are in the air, the less chance they have to enter your lungs, which helps you stay healthier and feel more energized.

If you’re interested, we have a whole section about air purifiers and how they work.

Humidifiers have a direct effect on relative humidity. These devices add water to the air, but don’t clean it like air purifiers do.

Instead, humidifiers help provide relief for health issues that are a result of dry air inside the home.

Low humidity levels are known to cause irritation of the eyes, throat, and lungs and sometimes even headaches, sickness and fatigue.

Having the proper balance of humidity (35-50%) inside the home is essential for your overall health and comfort.

For more details visit our dediated post on Air Purifier vs Humidifier.

Air Purifier vs Dehumidifier

Air purifiers and dehumidifiers are not designed to do the same thing, but you’ll find that both can help minimize certain types of allergens inside the home.

Air purifiers operate in one of two ways:

  1. By circulating air inside a room and passing it through a filter which traps airborne pollutants like dust, pollen, pet dander, smoke, mold, etc.,
  2. By sending out an electrostatic charge which pulls pollutants out of the air and causes them to drop to the ground.

Both of those processes can prevent the multiplication of mold spores and bacteria by removing these particles from the air, but neither can control the humidity levels like a dehumidifier.

If excessive moisture persists inside a room, then those types of pollutants can continue coming back.

Air purifiers are best used for cleaning the air of the widest variety of toxins so that the environment around you is more sterile.

Here are some of the top ways air purifiers can help.

Dehumidifiers suck moisture out of the air and reduce the humidity inside a room.

This process doesn’t clean or filter the air like an air purifier, but it does help remove allergens that thrive off of moist conditions.

This includes mold, bacteria, dust mites, and other microbes.

When the humidity level indoors is less than 50%, those organisms cannot survive.

Dehumidifiers are best used in damp interior locations in order to fix heavy moisture issues.

For more details visit our dediated post on Air Purifier vs Dehumidifier.

Air Conditioner vs Humidifier

Air conditioners and humidifiers don’t often get compared to each other because they do completely opposite things; however, here’s an explanation of how each works.

Air conditioners are used to lower the temperature inside a home.

These machines do this by pulling hot air and humidity out of a room and expelling it outside.

After the hot air has been filtered, what’s left is cooled and then returned back into the room.

Most air conditioners decrease the amount of moisture in the air through dehumidification. However, some small room coolers do exist that use the process of water evaporation as a way to cool the air. It’s called “evaporative cooling”.

But for the most part, the less water vapor in the air, the cooler it feels and the more your body can regulate its own temperature by releasing sweat.

You may be interested in how a window air conditioner works or how a portable air conditioner works.

Or you can go right to our buying guides to find the best deals: portable air conditioner reviews and window air conditioner reviews.

Humidifiers increase the amount of moisture inside a room and are primarily used for health reasons.

Higher levels of relative humidity help nourish the skin and other body parts and prevent them from drying out.

Regulating temperature is just a side-effect of humidifiers. With more water vapor in the air, a room will feel warmer because it retains more heat. Adding humidity to the air also reduces the amount of sweat that can evaporate from your skin, which decreases your body’s ability to cool itself.

Now, if you live in a dry environment, then adding a mist of cool water vapor to the air can make it feel cooler on your skin. And there are air conditioner and humidifier combo units available.

To learn more about how these AC units can work for you, check out our best ventless portable air conditioner guide.

Air Conditioner vs Dehumidifier

Air conditioners and dehumidifiers have similar mechanical functions, but each produces a different result.

Both devices reduce the relative humidity in a room; however, air conditioners return air that has been chilled to the room whereas dehumidifiers return air that has been reheated.

Therefore, air conditioners are used for comfort (and cooling) while dehumidifiers are used to protect a room from dampness and remove musty odors (not changing the temperature).

Depending on what your specific needs are for an air controlling device in your home should determine which of these two products would be a better choice.

It’s also important to point out that you can pair an air conditioner with a dehumidifier in order to help the air conditioner operate more efficiently.

The less moisture there is in the air, the less work an air conditioner has to do to cool it.

However, there are some air conditioners that can operate as a continuous dehumidifier, such as a mini split AC unit. These systems constantly remove indoor moisture even when the cold effect of air conditioning is not running.

For related information, check out how humidity affects air conditioning. And visit our best affordable portable air conditioner page for inexpensive options that don’t take up a lot of space.

Humidifier vs Dehumidifier

Humidifiers and dehumidifiers do the exact opposite of each other.

Humidifiers increase the level of humidity in the air while dehumidifiers decrease it.

The deciding factor on which product to use is the relative humidity of the space you intend to place it in.

You can measure this with a device called a hygrometer.

You can pick a hygrometer up for less than $10 online or from your local home improvement store.

A relative humidity of 35-50% is recommended for a comfortable and healthy environment while also protecting your home from damage caused by excessive dryness or humidity.

If the humidity in the space is lower than 35% then a humidifier is the right choice (it adds moisture).

If humidity is above 50% then a dehumidifier is what you’ll need (it removes moisture).

Many people use a humidifier in the winter months when the air is dry in order to keep their skin from drying out.

Increasing relative humidity is also a great way to help reduce allergies and nasal congestion.

Dehumidifiers are used most often in the summer months when the air is hot and humid.

Decreasing relative humidity helps a room feel cooler while also preventing the growth of things like mold and mildew.

Avatar for Katherine Dyson

About Katherine Dyson

Katherine is the lead Staff Writer. She conducts in-depth research and interviews with industry experts in order to produce a wide range of content for the site. Her main role is to write helpful articles that aid people who are seeking to improve their indoor air quality and comfort. (See Full Bio)