Informational Guide

Comparing Dehumidifiers Vs AC Units

We compare air conditioners and dehumidifiers to see which best suits your needs. See which appliance cools and cleans the air better.

by Josh M

Dehumidifiers and air conditioners work in a very similar way. They both help regulate the air in your home to help keep you comfortable and protect your belongings. They’re both very useful pieces of equipment with many similarities, but there are a few key differences.

In this guide, we’ll help explain the function of each and give you the full breakdown of the dehumidifier vs. air conditioner.

Condenser Unit of Aircon AC

Dehumidifiers are electrical devices that are designed to reduce the amount of moisture in your home, specifically by removing the excess moisture from your air. By filtering out this liquid, they help keep you comfortable and protect your home and belongings.

The first dehumidifier was invented by Willis Carrier, who coincidentally also developed the first modern air conditioner. He first designed a dehumidifier in 1902 to regulate the moisture levels in his printing plant in Brooklyn, and it worked well to protect the equipment. In the following decade, dehumidifiers became more popular, but it wasn’t until later in the 20th Century that home dehumidifiers became common. While the design and features have modernized, the key principle has remained the same over the years.

Most dehumidifiers work using a fan and some condenser coils. The air is blown over the coils, and the liquid is drawn from the air. This then drops down into a water storage tank, and the drier air is blown into the room. The device will run until the tank is full, and then it needs to be emptied before it runs a new cycle.

The other type of dehumidifier works using absorbent pads. These desiccant dehumidifiers blow the air through the warm pads, which gathers the excess moisture. This liquid gathers in the bottom of the dehumidifier, which can then be emptied.

You can get whole-house dehumidifiers, but most dehumidifiers are portable models. These can be moved into different rooms as needed and stored when not in use. This is particularly useful if you only need the device once a year.

Dehumidifiers help to protect your home from mold and mildew, which can build up in wet conditions. This can prevent damage to your belongings and your home, and they are often used in basements and garages where it can get quite damp. Dehumidifiers work well in humid or damp areas and are particularly effective in older houses.

Pros & Cons of Dehumidifying Your Home

What We Like
  • Prevents Mold And Mildew
  • Makes You More Comfortable
  • Protects Your Home And Belongings From Moisture Damage
  • Protects Those With Allergies
  • Works Well With AC
What We Don’t Like
  • High Running Cost
  • Creates Noise And Heat
  • Regular Emptying And Maintenance Needed

Home AC Units Explained

White and Gray Portable Fan

Air conditioners function to help you control the temperature in your home. They are similar to dehumidifiers because they do this by regulating the moisture levels in an area. By removing heat and some moisture from the air, it cools the area around you and leaves you feeling more comfortable in your home.

The first modern air conditioner was invented by the same man who invented the dehumidifier, Willis Carrier. In fact, he stated that the invention of the dehumidifier actually led to the creation of the air conditioner, and it all came from his desire to control the environment in an area. His first AC was designed in 1902, and air conditioners became commonly used commercially from the early 1900s. It was in the 1960s that home air conditioners became more common, and these days, the majority of homes in the US have them installed.

Air conditioners work similarly to dehumidifiers in that they use a fan and condenser coils. The fan draws air into the device, allows it to flow over the coils, which extract the heat and moisture, and then blows air into the room. The key difference is that most air conditioners draw air in from the outside, and it’s this cool air that impacts the temperature in your home.

There are several different types of AC used in residences. Portable air conditioners are popular now as they have a low up-front cost and require no installation. If you want or need AC throughout your home, you may opt for a central air conditioner that channels cool air through ducts around your home.

These are more expensive but are much more effective. Some other models like mini-splits or window ACs work well in a single room or area and don’t require too much effort to install. The choice of AC you go for will be determined by your home, climate, and budget.

Air conditioners are ideal for homeowners who want a cool, well-ventilated home. They work well in hot and humid climates, and the development of effective, modern, portable ACs means that homeowners can use an AC in the hot summer months and store it when it’s not in use. Every home will probably benefit from an AC at some point, and there’s a wide variety of models to meet every user’s need.

Pros & Cons of Air Conditioning Your Home

What We Like
  • Better Ventilation In Your Home
  • Cools Your Home
  • Reduces Humidity In Your Home
  • No Need To Open Doors Or Windows- Quieter And More Secure
  • Can Improve Sleep Quality
What We Don’t Like
  • Can Dry Skin Out
  • Costly To Run
  • Can Bring Bacteria/Spores In

Dehumidifier Vs Air Conditioner: Key Differences Explained

Ok, so you should hopefully know a bit more about dehumidifiers and air conditioners, but it’s still pretty obvious that these appliances are similar. To help you decide which you need, we’ve given a breakdown of the key differences so you can make an informed choice:

Cooling Capacity & Heat Removal

Air conditioners are literally designed to remove heat and cool your home. They do this by removing the hot moisture from your air and blowing cold air into your home. The coolant in the device helps to ensure that only cool air enters your home, and they’ll usually keep working until a specific temperature has been reached. Portable air conditioners are slightly different because they don’t have access to outside fresh air, but they still work by cooling and drying the air that comes into the machine.

Dehumidifiers work to remove moisture from the air in an area. This can have a cooling effect in your home, but dehumidifiers can actually add heat into an area because the device gives off a lot of warmth. The removal of humidity in an area can make your body feel cooler, but it generally won’t lower the actual temperature in your home.

If you want to cool your home, you need an AC because a dehumidifier just isn’t going to have the desired effect. The cooling effect of an AC is measured in British Thermal Units, and it’s important to get an air conditioner with enough BTUs to cool the space effectively.

Moisture Removal

Air conditioners remove heat, and part of the way they do this is by removing some moisture from the air. This isn’t their primary function, but you should notice the air getting dryer in your home. However, because they make a room colder if they’re operating in a damp room, they can actually make it even worse and lead to the spreading of bacteria, mold, and mildew.

Dehumidifiers are designed to remove moisture, and they’re very effective at it. They will filter the water from the air and leave a room noticeably less humid. In fact, you’ll need to empty the water collection tray from the dehumidifier quite regularly, so you’ll literally see how much moisture is being removed.

If you want to lower the humidity of a room, you need a dehumidifier.

Size of the Units

Air conditioners come in all shapes and sizes. You can buy central air conditioners, which are large units designed to cool a whole home, mini splits which will fit on a wall and cool a single zone, or portable ACs, which are generally intended to be small and lightweight. The physical dimensions of an AC do matter, but what really matters is the output that is measured in BTUs.

The higher the BTUs, the more cooling power it will provide and the larger an area it can cool. To cool a 100 square foot room, you need around 5000 BTUs, so it’s worthwhile measuring the area you want to cool. You can find an AC to meet your needs, but it will cost you more for larger units.

Dehumidifiers are generally portable, so they can be moved from area to area as needed, but they come in all different sizes too. The output from a dehumidifier is measured in its moisture removal capacity, given in pints or liters. This is an indication of how much moisture can be removed from the air in a 24-hour period. The size of dehumidifier you need will depend on the dimensions of the room and the current conditions.

For example, if you have a 300 square foot fairly damp room, you’ll want around 20-30 pints of moisture removal capacity. If you have a very wet room or a larger space, then you’ll need more.

Both air conditioners and dehumidifiers come in all sizes, but the important thing is finding something which works for your home. If they are too big, you’ll waste energy and potentially dry out a room too much. If they are too small, then they won’t work effectively. Make sure you measure the space and get the device which is the right size for the area.

Initial Purchase Cost

The upfront cost of an air conditioner varies massively depending on the size and type of the machine. You can usually get a fairly inexpensive portable AC that will work in a single area, but a full central air conditioner can cost over $5000. If you need ductwork to be installed, it can push the price up even higher, and you can end up spending a lot for a good AC.

The price of dehumidifiers also varies, but most dehumidifiers are portable. You can pick up a good dehumidifier for under $300, but it’s worth paying extra for a durable model because they will give you better long-term value.

Overall, dehumidifiers are cheaper, but you can get a great portable AC for less than a standard dehumidifier.

HVAC Installation Cost

If you opt for a whole-home dehumidifier or an AC, you’ll need to factor in the installation costs. HVAC professionals will generally charge based on the size of your home and how much work is involved. If you pay to have a whole-home dehumidifier installed, it will cost between $1250 and $4000. If you’re getting a whole-home AC installed, it will cost between $1500 and $5000. Bear in mind that if you need ducts installed, it will cost you more.

Of course, if you go for portable dehumidifiers or air conditioners, then there are no installation costs, so it can save you a fortune.

Power Consumption, Energy Use, and Efficiency

Neither air conditioners nor dehumidifiers are particularly efficient, and you will notice the rise in your energy bills. On average, an AC will cost between $0.06 and $0.75 to run per hour, so the cost can really rack up if you have an inefficient unit. Dehumidifiers will cost between $0.04 and $0.16 per hour on average, so they are significantly cheaper, but you will normally need to run them for longer. In fact, many dehumidifiers are designed to be used 24/7, whereas your AC may only run for a few hours a day.

Overall, dehumidifiers are cheaper to run, but whether you’re getting an AC or dehumidifier, it pays to go for a modern, energy efficient model. Look at the BTUs of the model and consider the SEER rating (the higher the rating, the more efficient the device) before making a purchase.

Ease of Maintenance & Cleaning

Air conditioners need to be adequately maintained, or it can impact the performance. You should have your AC checked by an HVAC professional annually to ensure it’s all functioning properly. You should also look to clean your filters every 3-6 months, depending on how often you are using the device. Other than that, you should look to examine and clean your filter if you think there are any issues.

Your dehumidifier takes a bit more active maintenance because you usually need to empty the water storage tank. As soon as it fills up, you’ll have to pour out the water, or the dehumidifier won’t work. You’ll also need to replace the filter every 2-3 months to ensure that clean air is being circulated in your home.

It pays to stay on top of both appliances so you can avoid any issues, but generally, a dehumidifier will take a bit more active management.

Climate in Your Region

Black & White Digital Clock

The climate in your area, particularly the temperature and humidity, will impact whether an AC or dehumidifier will be more beneficial. Mississippi, Florida, and Louisiana are some of the most humid states in the US and would all benefit from a dehumidifier, but an AC will help to reduce humidity and make you cool. Whereas Texas has a very dry heat, and an AC is more beneficial than a dehumidifier. Areas like New York have hot summers but cold winters, so portable ACs work well so they can be stored when not in use.

It may be that you need a dehumidifier and an AC in some regions to help deal with the temperature and humidity separately.

Can You Use Dehumidifiers as an Alternative To an AC?

The short answer to this is no, these two appliances are different and should be used differently. Dehumidifiers can take some of the moisture out of the air but generate heat which can actually warm the surrounding area. This gives you the opposite effect of an AC.

Air conditioners can help to reduce the moisture in a room, but not in very damp conditions. If you use an AC in a very damp room, it can actually help bacteria, mold, and mildew spread and cause damage to your home.

You can’t use dehumidifiers as an alternative to ACs, and they are designed to do a different job. However, you can use an AC and dehumidifier in the same space, and it might be beneficial for you to have both set up.

People Also Ask (FAQ)

Can I use the dehumidifier and air conditioner at the same time?

Yes, you can use both simultaneously, and an AC can make your dehumidifier more effective. Be careful with the running costs though as using both appliances will take a bit of electricity.

Do dehumidifiers reduce temperature?

No, but removing moisture from an area can make it feel colder. In most cases, dehumidifiers will add heat to the room and make it warmer.

Should I run my dehumidifier in the summer?

Yes, moisture and humidity levels will get highest in summer, so your dehumidifier will work well.

Do dehumidifiers get rid of mold?

No, dehumidifiers will not kill bacteria or get rid of mold. However, mold is formed by damp conditions, and your dehumidifier will help remove this moisture and prevent mold from forming in the first place.


Dehumidifiers help to reduce the humidity in your home but can add to the temperature. Air conditioners will help reduce the temperature in your home and remove some humidity, but it won’t be as effective as a dehumidifier. You can’t use them interchangeably, so hopefully, this guide has helped you understand the similarities and differences, and you now know which one will benefit you the most.

Last Updated on December 9, 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.