Top 5 Best Crawl Space Dehumidifiers for Removing Moisture

crawl space dehumidifier reduced moisture

The last place in your home you want any moisture collecting is the crawlspace. That is because moisture in the basement or crawl space can create serious structural damage to your home if left unchecked. When moisture builds up in these areas, it can cause corrosion, warping, water damage, and the development of mold and mildew.

A serious concern from moisture in the basement or crawl space comes from something known as the stack effect. This is when moisture will climb inside walls and through the air to where it will contaminate the living space and increase humidity levels.

Fortunately, there is a simple solution – a crawl space dehumidifier.

Signs To Watch For

Water infiltration is easy to identify from the basement or crawl space if you know what to watch for. However, since crawl spaces are not somewhere where you might visit often, it’s good to know other signs to look for.

Here is a list of some of the most common signs that can tip you off to the need for the best crawl space dehumidifier to combat the problem:

  • high humidity levels from anywhere within the home
  • musty and dank odors
  • mold outbreaks on walls on the first floor
  • floorboards that creak or sag
  • attacks of asthma or allergies
  • wallpaper peeling
  • walls with water spots
  • sudden insect infestations in the bathroom or kitchen.

The Features of A Basement or Crawl Space Dehumidifier

There are a lot of bells and whistles that can be part of an under-house dehumidifier. Typically, the more you spend, the more features the unit will have. But what features are essential?

Aside from having a large capacity, there are several key features to look for when shopping for a crawl space dehumidifier.

Built-in Adjustable Humidistat

This is the setting tool that permits you to completely customize the level of humidity that your dehumidifier will work to keep. By setting the humidistat to reach a certain level of humidity, the dehumidifier will turn on and off when needed to maintain that level.


A hygrometer is a measuring device used to measure the current humidity level. This allows you to monitor and track levels as your dehumidifier works to maintain the level you have chosen for the area being serviced by the dehumidifier.

Automatic Shut-Off

Some dehumidifiers do not have continuous drainage… but rather have a collection tank to collect water extracted from the air. To prevent overflow, the water collection tank will have a sensor that will cause the dehumidifier to shut off when the tank is full. It also signals when the collection tank requires removal and emptying.

Continuous Gravity Drainage

An alternative to a collection tank is a hose hook up where water collected will be fed into a drain. This is particularly handy when using a small space dehumidifier. The hose is not always included and may need to be manually attached. With the dehumidifier located higher than the drain, it can work endlessly to discharge water as it is removed from the surrounding air.

Internal Condensate Pump

This is much the same idea as continuous gravity drainage only instead of relying on gravity to pull the water away from the under house dehumidifier, a pump manually pushes the water to a drain. This means that the dehumidifier does not need to be located above the drain.

Air Purification System

An attached air purification system with a filter that can be removed and cleaned is a feature that appears on many of the best crawl space dehumidifiers. This assists in providing good air quality as it is returned to the crawl space area after the moisture is removed.

Auto Defrosting System

For crawl spaces that get very cold in the winter, there is a risk of cold air freezing the condensed water collecting on the coils of the dehumidifier, which may cause damage to the unit or cause it to work less efficiently. A defrosting system keeps the temperature warm within the unit to prevent freezing.


PPD is the pints per day value of the dehumidifier. It means that a dehumidifier can remove a set volume of water per day. For example, a dehumidifier rated as 70 PPD means the unit can remove up to 70 pints of water from the air in a single day under specific conditions.


The conditions at which the PPD is measured are set by the AHAM, the Association of Home Appliance Manufacturers. The conditions used to rate all dehumidifiers are at 80 degrees Fahrenheit and 60 percent relative humidity.

Energy Star Listed

Energy Star is a symbol used to indicate a product is energy efficient.

The Different Types of Crawl Space Dehumidifiers

There are two main types of dehumidifiers for crawl spaces. They are desiccant and refrigerant.

  • A desiccant dehumidifier works on the principle of absorption. They use silica gel or bentonite clay as the desiccant which absorbs water molecules. Desiccant dehumidifiers are typically used to service smaller rooms.
  • Refrigerant-based dehumidifiers use cooling coils to encourage condensation. The typical design employs a fan to blow air across a refrigerated coil. Condensed air droplets form on the coil and drip into a collection reservoir or out through a drain hose.

Our Top 5 Picks Crawl Space Dehumidifiers

Here is our list of the best crawl space dehumidifiers:

MIDEA 4,500 Sq. Ft. Energy Star Certified Dehumidifier

MIDEA 4,500 Sq. Ft. Energy Star Certified Dehumidifier

This dehumidifier has a 50-pint AHAM rating and will service an area measuring up to 500 square feet. It comes complete with an auto-restart function which means that if the unit shuts down during a power outage, it will automatically restart and engage the settings that you added before the power went off.

The continuous dehumidification mode keeps your basement. crawlspace, bathroom, or other small space at the correct humidity level. The quiet operation – measured at a maximum volume of 51 decibels – allows this small space dehumidifier to be used in several different applications.


The collection tank is easy to remove and empty
Has the option of attaching a hose for continuous drainage


Some users found this product to be noisier than expected
The reusable filter requires manual cleaning
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ALORAIR 55 Pint Basement/Crawl Space Dehumidifier

ALORAIR 55 Pint Basement/Crawl Space Dehumidifier

This energy star-certified dehumidifier will remove 55 pints (AHAM) / 120 PPD (Saturation) and will service an area of up to 1,300 square feet. It is the ideal dehumidifier for rooms in cold environments as it comes with an automatic defrost system protecting the unit from freezing up in cold weather.

Plus, this model has something called internal corrosion protection which will reduce the possibility of corrosion that can lead to freon leakage. This feature also extends the life of the coils used to condensate moisture from the air.

This under house dehumidifier also has a five-year warranty and access to local customer support.


A well-designed, energy-efficient dehumidifier
Comes with a remote
MERV-8 filter is removable for cleaning


Some users have had issues with this model that sometimes does not drain properly
Other users report that this unit will just stop operating for no reason
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Aprilaire 70 Pint Commercial Dehumidifier for Crawl Spaces

Aprilaire 70 int Commercial Dehumidifier for Crawl Space

The Aprilaire E070 is rated to remove up to 70 pints per day of water from the air and uses a hose which is included for continuous gravity drainage. This is one of the best crawl space dehumidifier choices as it has a compact design that permits it to fit through small crawl space doors and between joists and tight spaces.

The corrosion-resistant aluminum coils are built to last and provide years of quality service. The unit is also very simple to operate. All you have to do is attach the hose, level the dehumidifier, plug it into a power source, set the desired humidity level, and let it do the rest of the work.


Provides coverage of areas up to 2,800 square feet
Easy to set up and operate
Small enough to fit almost anywhere


The design only permits front-mounting
This unit runs loud for some users
Customer support may not be as helpful as hoped for
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ALORAIR 90 Pint Basement/Crawl Space Dehumidifier

ALORAIR 90 Pint Basement/Crawl Space Dehumidifier

This is an updated version of the 55-pint model. In addition to being another energy star-certified crawl space dehumidifier, this model is rated at 90 pints AHAM / 198 PPD (Saturation) and will service an area up to 2,600 square feet.

The unit has a heavy-duty condensate pump that will effectively push water to the drain without the need for a gravity feed. This model also has the auto defrost featured the five-year warranty which includes access to a local customer support team.

The manufacturer suggests this small space dehumidifier is perfect for the basement, crawl space, storage areas, garage, large rooms, or for commercial use.


Unit is well packaged to prevent damage
Easy to install and operate
Automatic defrost allows operating at low temperatures
5-year warranty


The controller may not be as accurate as it could be
The internal pump has caused problems for some users
The warranty contains clauses that must be followed to the letter to prevent voiding the coverage
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Dri Eaz F413 Revolution LGR Compact Dehumidifier

Dri Eaz F413 Revolution LGR Compact Dehumidifier

Rated at a capacity of up to 12 gallons (96 pints) per day (AHAM) / 17.3 gallons (138 pints)/day (saturation), this compact under house dehumidifier has recessed feet. The control panel displays many functions ranging from the inlet/outlet temperature, relative humidity, and job hours.

The package includes the dehumidifier, a 40-foot drain hose, a 25-foot electrical cord, a 3M brand HAF High Airflow Filter, and an owner’s manual.

This unit has a compact design making it a perfect choice for small spaces such as a crawl space, basement, or pantry.


Simple design that is easy to set up and operate
Display shows all the pertinent data
Includes a long drain hose


Does not have a collection tray
Runs loud for some users
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The crawl space is one place where the humidity level must be controlled to prevent damage to your home. With many different crawl space dehumidifiers available on the market, it should not be difficult finding the right one for your specific needs.

By choosing the best crawl space dehumidifier suited to your conditions, it will mean that you don’t have to worry about moisture causing damage to your home or your health. Just because your crawl space is out of sight, don’t ignore the fact that moisture build-up in this area can have destructive effects on your home.

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