Compressor Dehumidifier: What Is It & How It Works?

Dehumidifier Critic / Types / Compressor

A compressor dehumidifier is an appliance that reduces humidity levels in your house so that it feels cooler while also improving the health of indoor living spaces by lessening dust and mold build-up.

By removing moisture from the air, compressor dehumidifiers benefit people with allergies and asthma.

But more than that, what is it?

Compressor Dehumidifiers

If you have a problem with high levels of humid air in your home more than dust mites, these would be your best bet as they will help get it under control.

These compressor dehumidifiers are also effective at removing those musty smell that seems to come with relative humidity.

You can place these in rooms where the temperature is constant, which will allow these to run for longer periods without stopping. This means that they work well in dry areas, but not as effective in cold surface areas.

They are not thought to be as effective at lower temperatures, nor can they remove relative humidity from a cold surface space. But they do have their uses, and they seem to work better in some homes than others.

How Do Compressor Dehumidifiers Work?

They depend on a refrigeration process that heats gas until it reaches its boiling point. This hot gas is then used to heat warm air, which is drawn through a wick filter.

The wick filter can be dampened with a solution that will help it absorb the damp air water. It would give it time to dry back out before running into your compressor dehumidifier again. This helps to refrain from freezing up.

This process requires them to be able to reach the temperature of 32°F at least and up to for some models. They need this high temperature for the moisture to condense and go into a receptacle.

A Few Tips To Get The Most Out Of Your Compressor Dehumidifier:

Don’t Overload It – Don’t overload your compressor dehumidifier because it will cause it to work harder and may also break down quicker.

High Humidity – It is more difficult for this unit to control the desired relative humidity levels. This is because they are not designed for extremely humid environments.

You Need Good Ventilation – You need to make sure that you have good ventilation in the room or area they are in. This will help them work more effectively and efficiently remove humid air.

Key Features and Functionalities (Compressor Dehumidifiers)

Humidistat – Most models are equipped with this that can be programmed. This helps keep track of what the room’s relative humidity is and allows you to set it at your desired value.

Automatic Defrost Feature – They have this feature that allows them to still operate effectively. There are different degrees of how quickly they will defrost, but some are better than others.

Temperature Settings – Some also allow you to customize the temperature settings. This helps when the temperature environment that they are placed in fluctuates.

Fan Speed – They typically have this depending on the model that you get and can be placed in areas of your house where there is no temperature control. This includes garages, basements, and other places that are not climate controlled.

Indicators – Most models will also have indicators that will tell you when they are not at the optimal levels for humidity control. You will get a signal such as an alarm or flashing light.

Wheels and Handles – Some models are equipped with a slowly rotating wheel and handle to make moving them around easier. They can range from 12 lbs up to 110 lbs so depending on the model can be relatively easy to move.

Advantages of Compressor Dehumidifiers

Lower Price – Compressor dehumidifiers are the more popular type of unit. This is because they generally operate at a lower price and have proven to be very effective in removing moisture from the air.

Energy Efficiency – They don’t take much energy to run them and they are very quiet too.

Can Connect to HVAC System – It can be connected to your HVAC system, which all other types of humidity control systems.

Touch Screen – Many models are very user-friendly too with touch screen interfaces so you don’t have to worry about deciphering a manual.

Easier To Setup – It’s much easier to set up and install. As long as you have an existing ducting system in place or can run new through-wall ducts, then it will be easy to get this set up in your home.

Disadvantages of Compressor Dehumidifiers

Not as Effective – These dehumidifiers can only remove moisture if the temperature in the room is above 32°F. If it is below this, then they will not effectively remove relative humidity from the air.

High Noise Level – They are louder than other models and that means they will be noticeable when operating in your home or office. The only place that they can be placed is in an area where you don’t have to listen to them.

Placement – You will not want to place these in small rooms because of their noise level and also because the relative humidity may still be too high for them to effectively remove it.

Short Warranty Period – You will get a short warranty period with these units which is standard for all appliances. They run for about 5 years or up to 10,000 hours of use.

Compressor vs Desiccant Dehumidifier

Both these types of dehumidifiers are effective in removing excess moisture from the air, but it is important to understand that they have different functions and features. This makes them better suited for certain situations than others.

Compressor Dehumidifiers

These have more reliable humidity control and are better at removing moisture from the air. It can also connect to an HVAC system easier than desiccant models, but it is not suitable for small spaces with low temperatures because it requires a minimum of 32°F to function.

Desiccant Dehumidifiers

These are better at removing high humidity from the air in small spaces than compressor units, but they don’t have temperature requirements like other models.

They also have less reliable humidity control and may be affected by high temperatures outside that could make it work all summer long without getting rid of any moisture.

How to Tell if You Need a Desiccant or Compressor Dehumidifier?

Making your choice between desiccant and compressor dehumidifiers can be difficult, but you’ll need to consider how much you will be using your dehumidifier, as well as where you live.

Compressor Dehumidifiers are typically much less expensive to purchase. They are very energy efficient but also consume more energy than desiccant dehumidifiers.

Also, you have to buy a receptacle space or be willing to empty the water that has been collected daily. 

They work well in dry areas but don’t work well in humid areas. It can also freeze up if you run it too long in a cold room.

Desiccant Dehumidifiers work better in freezing conditions. They don’t require a receptacle space or to empty the water that has collected. But these can be much more expensive to purchase and run than compressor models. 

You don’t have to worry about these types of units freezing up as they run much cooler than compressor dehumidifiers with a desiccant wheel for portability. This means you can control the ambient air temperature of your home with them if you plan carefully.

How to Choose Between a Desiccant or Compressor Dehumidifier?

They both have their pluses and minuses and both can be very effective at removing moisture from the air. Depending on what your needs are, either desiccant or compressor can be the right choice for you.

It depends on your needs and what you are looking for from a dehumidifier. As always, it is recommended that you match airflow with the size of your appliance to get the most out of this process to have optimal performance. 

Homeowners need to keep their indoor air quality other than an air conditioner by keeping high humidity down. This is done by keeping moisture levels to a minimum, as well as having good ventilation systems and air filters.

Type of Dehumidifier That Is Right for Me (Compressor Dehumidifier)

Are You Trying to Warm the Space You Are Dehumidifying?

If you are trying to warm the space, you must get a compressor model with good ventilation. This will allow for more central heating to be transferred into the air while it also works on removing excess moisture from the air.

Using a compressor dehumidifier in a humid area, as mentioned above, will not work in this type of situation.

You do have an option though if you want to use your compressor dehumidifier in this way. You can add venting to the back of your unit to get some additional moisture out of the damp air.

Internal Air Temperature (Below 15°C / 59°F)

If you are trying to dehumidify a space where the air temperature is below 15°C / 59°F, it will cause your compressor dehumidifiers to be less efficient. You can keep this from happening in two ways with your selection though. 

First of all, you can only select a unit that has a continuous drain option. This will allow you to dispose of the water collected before it becomes a problem. Because your dehumidifier can’t heat enough air to keep up with the moisture being removed from that space. 

You also have the option of using an external condensing unit along with this dehumidifier. The condenser unit works exactly like mini-air conditioning, except it is placed on the outside of your house.

One thing about compressor dehumidifiers is that they require a lot more maintenance than desiccant dehumidifiers. They need to have the drain lines cleaned out regularly, which can cost you money if you don’t do it yourself.

Drying Washing Indoors

If you are drying your laundry indoors, you must have the right unit for the job. The two things to look at are whether or not you want compressor dehumidifiers and if one of these units will work with your venting system. 

Again, having this set up correctly is critical for getting the best performance out of your appliance.

If you are drying your laundry in the winter, the space must have good ventilation to get rid of moisture from the dehumidifier. This will help keep things as dry (like dry air) as possible in this area while also keeping indoor air quality.

Noise Levels

As was mentioned, compressor dehumidifiers make more noise than desiccants. If this noise level won’t bother you and you have the room around your unit to place it, then this is probably the best option for you. 

If you want a quieter dehumidifier, or you don’t have room to place the unit in the area where moisture needs to be removed from your space, then desiccant dehumidifiers are an option for you.


One great aspect of compressor dehumidifiers is how portable they are. Because you don’t have to worry about venting or taking water out of the space, these units can be moved around much easier.

If you need to take your dehumidifier from one part of your home, such as a basement, to another location in that same space. This portability can be extremely helpful both for removing moisture and also for storing it when you aren’t using it.

Running Costs

Compressor models do require a bit more electricity to run than desiccant units. This may make the monthly cost for your dehumidifier higher if you run it often.

It is also important that you clean out these drain lines regularly otherwise, they could freeze and cause damage to your unit or even have to be replaced. 

This cost can build up if you don’t keep those drain lines clear. If it isn’t done regularly, it can cost you more money.

Best Way to Use a Dehumidifier (Compressor Dehumidifier)

Get Ready to Use Your Dehumidifier

It is important to prepare and protect the space you are going to be running your unit. If you have any carpeting, it will absorb moisture from the air as well as any airborne dust particles.

If there is a lot of airborne dust, it is best to use a vacuum cleaner with a high-powered setting to get rid of as much of this dust as possible. These particles can also be harmful to the coils within your unit if they become clogged up.

Removing all carpeting and cleaning the area will help prevent any damage from occurring when you are running the unit.

Operate Your Dehumidifier Correctly

Once you are sure that the area is safe to run your dehumidifier in, you must operate the unit correctly. The machine needs to be placed so it has a good air supply as well as an adequate drain line.

It makes sense to place this unit in a corner or along an outside wall where there will be good airflow through the machine. This will help get rid of moisture content faster and make sure the unit is operating at maximum efficiency.

Maintaining Your Dehumidifier

You must perform regular maintenance on your dehumidifier. If you don’t, the unit will not work as well as it should and may even break down over time.

The first part of this maintenance includes checking the drain line each time you use it to clean out any particles that have built up inside the line. You should also check the fan for any particles that may be in the airflow as well. 

The coils should also be checked carefully to make sure they are clear of any debris or buildup that could cause damage. To ensure your dehumidifier is working at top efficiency, it is important to use filtered water with this machine.

It is also important to keep the air filter clean so it can help trap any airborne particles that may be in your air supply. Regularly changing out the filter is an effective way to make sure it does its job of protecting your machine and air supply.

Compressor Dehumidifier FAQ

Dehumidifier Compressor Does Not Turn On?

The first thing you should do is remove the power cord and check to see if it has been reset and turned off properly.

If that isn’t the issue, make sure there is power reaching your unit by checking all of the proper outlets and fuses. But once the problem is still not resolved, you may need to have your unit repaired or replaced.

Why Does a Dehumidifier Compressor Not Run For Hours While the Fan Still Runs?

If you are having an issue with the compressor and fan running separately, it is important to make sure there isn’t any damage to your coils. 

If your coils are not damaged, you likely have a bad thermal protection switch. When the temperature reaches too high, this switch will automatically turn off to prevent damage from occurring to the unit.

This can happen if you are trying to run your dehumidifier in an area that is too hot or cold for the machine.

Why There’s No Water Collected While Dehumidifier Fan and Compressor Runs?

If your dehumidifier is running but it isn’t collecting any moisture, there could be a problem with the drain line. It may need to be cleaned or there might have debris clogging up the line.

It can also mean that there is too much airflow within your dehumidifier causing the water from being pulled out of the air. This can be fixed by placing it against an outside wall so the warm air will collect along the wall and then escape through a window or door.

Why Does Dehumidifier Compressor Is Buzzing?

If you notice that your unit is making a buzzing noise when it is running, there are usually two possible problems to look for.

The first is if the coils have collected too much dust and need to be cleaned. The second problem could mean there is a loose wire or something in the way of the fan blade. If this still hasn’t solved the problem, you may have a bad compressor.

How to Tell if a Dehumidifier Compressor Is Working?

The best way to test this is by weighing down a piece of paper on your coils. If it starts to get damp, then the compressor is working properly.

It is also important to not run the machine for too long. Once the coils have reached an optimum level, turn off your machine and wait for a few hours to let it dry back out.