Buyer's Guide & Information

Best Crawl Space Dehumidifiers

We have reviewed and compared the best crawl space dehumidifiers on the market. These brands keep the fresh air flowing in your home.

Among the most moisture-prone areas of our homes, laundry rooms, basements, and crawl spaces top the list. In our homes’ living areas, we can use our air conditioners or a dehumidifier to lower the humidity and get rid of moisture.

You can use a dehumidifier in a crawl space, too. The best crawl space dehumidifiers have proper draining, low maintenance, and easy to clean filters. But which one is right for you? Read on to find out how to determine exactly what you need in a dehumidifier and which one is ideal for your crawl space.

**Amazon models for Aprilaire products may vary slightly

Why a Crawl Space Needs a Dehumidifier

We don’t often think about our crawl spaces until they become a host to problems or issues. While they may be good for ducting access, water pipes, or even storage for your old decorations, they can also cause a lot of issues for homeowners. Dehumidifiers will solve a lot of those problems.

  • Mold and mildew.
    Humidity is a breeding ground for mold, and crawl spaces under the grade or prone to moisture will be a feast for those little spores. Reducing the humidity below 60% will prevent mold growth.
  • Pest infestations.
    Moisture attracts bugs and critters. The water they need to survive comes from the air, and when there is a lot of it, they will flock. Removing the moisture in the crawl space air will detract these pests from setting up home.
  • Structural issues.
    High humidity and moisture can also cause structural damage over time. This includes things like wood rot, foundation cracking, shifting, and sinking. Dehumidifiers will help prevent the moisture that causes these issues.
  • Other problems.
    There are many other problems associated with the moisture and humidity in a crawl space that are solved by dehumidifiers. Among the remaining list includes foul odors seeping up from the crawl space.

Crawl Space Dehumidifiers Compared

Model PPD Area Unit Size Price
Aprilaire 1870 XL Pro 130 7200 sq ft 30 x 19.5 x 18.75 inches Check Sylvane

Check Amazon

Alor Air HDi90 90 2600 sq ft 23.2 × 15.2 × 17.7 inches Check Amazon
Santa Fe Compact 70 70 2600 sq ft 12 x 12 x 21 inches Check Sylvane

Check Amazon

Dri-EAZ F413 Compact 80 2200 sq ft 17.6 x 12.5 x 21.5 inches Check Sylvane

Check Amazon

Ultra-Aire 70 1800 sq ft 12 x 28 x 12 inches Check Sylvane
ALOR AIR 85 2300 sq ft 22.8 × 13.7 × 17.3 inches Check Amazon
BaseAire Air Werx 90X 90 2600 sq ft 23.2 × 15.2 × 17.7 inches Check Amazon

PPD = Pints per day (Moisture Removal)

Choosing the Right Dehumidifier for Crawl Spaces

Buying the first dehumidifier you see may not be the best solution. There are several factors worthy of consideration before you make your purchase.

Dehumidifier Type

The type of dehumidifier will be a significant factor in your decision-making process. There are three basic types, and each one has it’s distinct advantages. Desiccant types use a silica gel membrane to pass air through, removing moisture. They are the most energy efficient types but remove the least amount of moisture.

Thermo-electric models use a Peltier pump for heat exchange, causing the air passing through to condensate. They are quiet when operating and remove a lot of humidity; however, they have more general maintenance than the other types.

Condenser models use a condenser and coils, much like an AC. The air condensates on the coils, removing the moisture. These are the models that remove the most water from the air, but they have the highest energy costs.

Temperature Requirements

The ambient temperature and relative humidity in your region will also play a factor in the dehumidifier you choose. Some models are not capable of working well in low temperatures. Freezing, frost, and ineffective airflow are major problems.

If you live in an area (or have a crawlspace) that sees averages below 41 degrees (Fahrenheit), you need to ensure you get a model with low temp capabilities. These will generally also include frost detection and defrost cycles.

Humidity Removal Vs. Coverage Area

Dehumidifiers are measured in two ratings: humidity removal and coverage area. The humidity removal rating is a measurement in pints per day (PPD) of the maximum amount of moisture that can be pulled in a 24 hour period with a temperature of 65 degrees and a humidity level of 60%.

Average PPD ratings come in three primary ranges. Personal or smaller spaces fall between 20 and 30 PPD, the residential heavy duty falls between 40 and 60 PPD and commercial grade, high moisture removal with 70+ PPD.

The coverage area is a near-direct correlation between moisture removal and the square foot size of the room or home. Smaller units (20 PPD) can remove moisture in areas up to about 300 square feet. Larger units that reach 60 to 70 PPD (or more) can effectively remove moisture in spaces over 4500 square feet.

Drainage & Ducting

Just as there are various types of dehumidifiers, there are also multiple types of draining. The most common type of draining involves the reservoir tank that some models come with. The water collected drains into this tank or bucket that must be manually removed and emptied.

For crawl spaces, this may be more trouble than it is worth. Instead, automatic draining is recommended. This uses an internal pump to move water through a hose to an external drain. The drain can be a sink, toilet, water overflow line, etc.

If your model doesn’t have a pump but claims automatic draining, the answer is a gravity draining system. It works the same as the pump, except gravity does all the work. The water hose must be downhill from the machine to the drain so that the water can flow freely.

Other Dehumidifier Features

There are various other technological and ease-of-use features that may help make the sale. While not all of them are required, they can help your dehumidifier run better or make care and maintenance easier on you.

Filter Indicator Light

Changing the filter on a dehumidifier is easy. Remembering the exact number of operating hours to know when to change the filter is not so easy. If your model comes with a filter indicator light, though, you can tell, at a glance, if the filter needs to be cleaned or changed.

Built-In Auto-Humidistat

Auto-humidistats make the machines more efficient. Instead of running until you turn them off, you can set a humidity level on the control panel. When the humidistat reads the humidity is higher than the setting, the dehumidifier will turn on and run. Once the humidity level drops to the set level, the unit will shut off.

Auto Reset

If your power goes out, dehumidifiers equipped with auto-reset (also called auto-restart) functionality will turn back on when power is restored and load all the previous settings. This helps you not have to run to the machine to reset the humidity level or temperature settings every time the power flickers.

Frost Sensor

Frost sensors detect when the coils or pump has developed frost or has become frozen over. When this happens, the machine will shut down the operation and enter a defrost cycle. During the cycle, the frost is removed and drained away, and the machine will then resume working as intended.

Digital Controls

Digital controls and LED or LCD screens will help you ensure your settings are accurate. Unlike variable turn dials or analog controls, digital screens and LED indicators let you know exactly what’s going on. While they don’t add a lot to the price tag, digital controls can make a world of difference for user-friendly operation.

Noise levels

All dehumidifiers are going to make noise. Some will make more than others, and many models will include noise dampening controls around their pumps or motors—however, some models will not. You also need to consider where and how the machine will be installed. With vibration and reverberation from the crawl space a possibility, there may be more noise created.


All dehumidifier brands will offer different warranties. Some will be short-lived, with only a year or two of coverage, and others will have 5 years or more. What is important, though, is what is covered and what is not.

You should also understand what is required of you when making a claim. If you need to ship the unit back, you should know who is responsible for shipping costs and how long the turn


Finally, the price may be the biggest factor of them all. You need to stay within your budget while getting a dehumidifier that meets all of your needs and performs how you want it to. Higher capacity units will cost more, on average. Ensure you get the best dehumidifier you can that will cover the space you need and remove the amount of moisture in the air your home has.

For smaller models, you can expect to pay between $200 and $600, depending on actual capacity and features. Larger models and commercial grade dehumidifiers that range over 70 PPD can cost over $1000, with some industrial models reaching $3500 or more.

7 Best Crawl Space Dehumidifiers Reviewed

1. Aprilaire 1870 XL Pro

Our Top Pick
Moisture Removal 130 pints per day (PPD)
Coverage Area 7200 square feet
Dimensions 30 x 19.5 x 18.75 inches
Air CFM Range 310 CFM
Drainage System Continuous gravity drain

If you have a large crawl space or one with a lot of standing water, then you need the best large crawl space dehumidifier there is. The Aprilaire 1870 XL Pro is that model. It is our top pick for a reason, and that reason is this beast simply works.

While it only has a single fan speed, it will move through 310 CFM of air, removing up to 16 gallons of water per day. That means all those puddles and that inch of standing water in the corner will be gone before you know it.

One of the best features of this particular model (aside from the enormous moisture removal) is that it can accommodate up to 7200 square feet of crawl space. Smaller spaces will still do well, of course, but this guy was made for big areas.

It also is quite easy to install. It comes with leveling feet so you can mount it just about anywhere, as long as it is higher than the drain. If you need to pump water up and out, this may not be the best model for you. But you can place this unit directly over a drain or attach a hose and run it to the drain down the line.

Because it doesn’t use caster wheels, it can get awkward to get into position, especially if your crawl space is an actual crawling space. At 113 pounds, you aren’t going to just sling it around where you need it.

Once installed, you have the option of placing the control panel on the top or front of the unit, giving you a better installation range. It also has simple to use digital controls that let you set your space’s desired humidity level.

Once set, that’s all there is. Turn it on and let it work. It will shut off when humidity levels are reached and come on when they get high again. With a 5-year warranty, your investment is protected, and your crawl space will be dry as a bone.


  • 5-year warranty parts and labor
  • Filter lasts 12 months
  • Leveling feet instead of casters
  • Auto-humidistat installed
  • Front or top-mount control panel
  • Easily ducts into HVAC system


  • Can be heavy and awkward to move
  • Only 1 fan speed

2. AlorAir HDi90

Best Crawl Space Dehumidifier With Pump
Moisture Removal 90 pints per day (PPD)
Coverage Area 2600 square feet
Dimensions 23.2 × 15.2 × 17.7 inches
Air CFM Range 210 CFM
Drainage System Continuous pump drain

If you have a large crawl space but need to pump the water up and out, then you want the best crawl space dehumidifier with a pump. That is the AlorAir HDi90. Moving a lot of air and removing up to 90 PPD of moisture, you can’t go wrong. And it has a lot of features to offer, too.

Starting with the capacity, this machine will work well in spaces up to 2600 square feet, moving at least 210 CFM of air. When needed, the internal condensate pump works to move the collected water up to a drain height of 15 feet.

Unlike our top pick, this device has caster wheels to easier portability. However, when leveling is needed, the wheels are adjustable, just don’t expect inches of travel. You also don’t need ducting for this one to work, and you can set it and forget it, or move it where it is needed the most.

In your crawl space, the humidity controls will allow the dehumidifier to turn on and off, helping to save on your energy bill. It also features low temp operation, with a range that falls down to 35 degrees (Fahrenheit) and can maintain humidity levels between 36 and 90%.

There’s more. When the temperature drops in your crawl space, the AlorAir model features a frost sensor and defrost cycle that will happen automatically. As long as the unit stays above 35 degrees, it will stay running, frost or not.

With a 5-year warranty, the machine, pump, motor, and housing are all covered. You truly have nothing to lose except a lot of humid air in your crawl space.


  • 5-year warranty
  • Adjustable caster wheels
  • Low temp operation
  • Heat Gas Valve defrosting
  • Internal pump drain height of 15 feet
  • Auto-humidistat controls


  • May be difficult to level
  • Can get loud during operation

3. Santa Fe Compact70

Best 70 Pint Dehumidifier For Wet Crawl Space
Moisture Removal 70 pints per day (PPD)
Coverage Area 2600 square feet
Dimensions 12 x 12 x 21 inches
Air CFM Range 150 CFM
Drainage System Continuous gravity drain

If your crawl space is wet, you need the water gone right now. There is no better dehumidifier for wet crawl spaces than the Santa Fe Compact70. It will remove moisture from the air as fast as it can suck it in. It has a lot of features to consider, as well.

The Compact70 is a relatively small unit, which makes the hang kit more alluring. Because it is small, you can purchase the hanging kit and suspend the dehumidifier between joists to conserve the storage space.

It also features a ducting kit that allows you to use forced air circulation. There is also an external condensate pump kit available if you have problems finding a drain downhill from the install spot. However, both of these, like the hang kit, are additional purchases.

The good news is that you only pay for what you need, and not a lot of extra things you won’t ever use. However, it does come with many features that you don’t have to pay extra for. Automatic defrost, for example, is already installed.

While not a low temp operating dehumidifier (low operational temp is 49 degrees), it will eliminate any frost that collects on the coils. It also has an auto-humidistat for humidity control and energy savings. This model is also Energy Star qualified.

The machine comes with a 6-year warranty that protects the housing, motor, sealed condenser unit, and control panel. It doesn’t cover normal wear and tear, the 2-stage filter, or the wheels, though.


  • 6-year warranty
  • External drain pump and ducting kits available
  • Optional hang kit for suspended humidity control
  • Humidistat included
  • Energy Star qualified
  • 2-stage filter


  • Drain hose is fairly short
  • Most features are additional purchases
  • Recommend installing drain trap

4. Dri-EAZ F413 Compact

Best Portable Dehumidifier For Crawl Space
Moisture Removal 80 pints per day (PPD)
Coverage Area 2200 square feet
Dimensions 17.6 x 12.5 x 21.5 inches
Air CFM Range 121 – 180 CFM
Drainage System Automatic pump drain

If you find yourself in the position where you need a dehumidifier in your crawl space, just not all the time, you might look for a portable solution. That solution is the Dri-EAZ F413 Compact. Small, lightweight, and portable, you can take this unit wherever it suits your needs the most.

It has enough features included to make the investment highly worthwhile, without giving you a lot of things you don’t need or won’t use. For example, the digital display lets you set a humidity level and displays the inlet and output temperatures, as well as humidity level and running hours.

The internal pump is automatic and doesn’t just run to run. It will only kick on when needed to save you energy consumption, but unlike many dehumidifiers, this one comes with its own drain hose. In fact, you get 40-foot of drain hose so you can route it just about anywhere.

The drain height on the pump is about 14 feet, giving you enough power to get upstairs or out a window. The main issues here are that the feet aren’t adjustable, so leveling may be tricky. It also has a detachable power cord, which is great for portability, but it has been known to wiggle lose due to the vibrations.

It does offer you a 3-speed fan, though, so you don’t have to run it at full bore the entire time. You can make a selection as to the best speed for your current needs and go with what works best. The 6 year warranty covers everything inside the shell and the lifetime portion covers the housing itself.


  • 6-year warranty parts/ Lifetime housing
  • Pump only works when needed
  • Digital control panel shows temp, humidity and hours run
  • Auto-restart feature
  • Included 40-foot drain hose


  • Customer service isn’t the best
  • Power cord can come loose

5. Ultra-Aire

Best Rated Dehumidifier For Crawl Space
Moisture Removal 70 pints per day (PPD)
Coverage Area 1800 square feet
Dimensions 12 x 28 x 12 inches
Air CFM Range 150 CFM
Drainage System Continuous gravity drain

If you are looking to others to help you make your decision, you will be pleased with the highest rated and best reviewed crawl space dehumidifier out there. The Ultra-Aire is almost a work of art and features add-ons that make it one of the most versatile dehumidifiers on the market.

This single speed fan-driven device is capable or commercial-grade levels of moisture removal, reaching 70 PPD with 150 CFM airflow. This means that your crawl space will stay dry, see a reduction in mold and mildew, and lower humidity.

The dehumidifier has a lot of accessories, all of which are additional purchases. However, because of this, you can basically build the system to your exact needs. The one thing to keep in mind, though, is that all Ultra-Aire dehumidifiers require professional installation.

That isn’t to say you can’t do it yourself, but if you do, you will have no warranty. When it is professionally installed, you get a 6-year warranty on all parts and a 2-year warranty on the labor.

But let’s talk about what it does come with. The gravity drain feature means you need to install it uphill from the drain. It has an automatic defrost cycle, even though it isn’t rated below 49 degrees, no frost or frozen coils will occur.

The auto-humidistat allows you to set a humidity level to maintain the unit will get to work. You can also use it as a truly portable device, or add it to a ducting kit for a more permanent install. Either way, the maintenance is low, with a MERV-13 filter that needs to be cleaned only once a year.


  • 6/2-year warranty parts/labor
  • MERV 13 filtration
  • Automatic defrost cycle
  • Auto-humidistat installed
  • Stand alone or ducting options


  • Must be professionally installed
  • Additional kits can get expensive

6. ALORAIR Commercial

Best Compact Crawl Space Dehumidifier
Moisture Removal 85 pints per day (PPD)
Coverage Area 2300 square feet
Dimensions 22.8 × 13.7 × 17.3 inches
Air CFM Range 210 CFM
Drainage System Continuous pump drain

You would think that being a dehumidifier and working in wet basements and crawl spaces, that these units would be waterproof. The truth is, the electrical components and computer boards inside aren’t protected, except in the case of the best compact crawl space dehumidifier. AlorAir Commercial Storm has a rubber encased circuit board making it waterproof.

You can actually place this unit in a standing puddle of water with no ill effects. It will also dry that puddle in just a few hours and keep your crawl space less humid and completely dry. There isn’t another model out there right now with the same claim.

Aside from the bright, vivid colors of their Storm models, the 85 PPD capacity is quite impressive. While it is a single-speed fan, it does push a healthy 210 CFM of air around. Sometimes, and depending on location, the units do get pretty noisy.

This unit is rated for low temp operation. Using HGV defrosting, it is rated to 35 degrees. The coils are also coated with epoxy to prevent corrosion and improve longevity. The entire unit is built solid and rugged.

Among the best features is the included drain hose that features a snap-on quick connect fitting. The internal drain pump is a continuous pump that has a drain height of over 14 feet. No matter where the highest humidity levels or standing water are located, this portable, compact unit will get the job done.


  • 5-year warranty
  • Hot Gas Valve defrosting
  • Waterproof design can be placed directly in water
  • Drain hose quick-connect


  • Only compatible with MERV-8 filters
  • Can be loud during operation

7. BaseAire AirWerx90X

Best Value Crawl Space Dehumidifier
Moisture Removal 90 pints per day (PPD)
Coverage Area 2600 square feet
Dimensions 23.2 × 15.2 × 17.7 inches
Air CFM Range 210 CFM
Drainage System Continuous pump drain

The AirWerx90 from BaseAire is the best value for crawl space dehumidifiers you will find. It has a high capacity, sizeable operational space, and is packed with enough features to keep you excited. There are a few aspects which are obviously money-saving omissions, but it’s nothing you can’t deal with.

The worst part of the entire unit is the filtration. It is designed to use MERV filters up to MERV-8. The issue, though, is that the unit ships with a MERV-1. While the filters aren’t that expensive, it is a hassle to remember to order one when you make your initial purchase.

It has an incredible remote operation with a full remote control panel that can be installed or mounted just about anywhere. The problem, though? It isn’t included and must be purchased separately. You can operate the machine just fine without it, of course, but it is one of those purchases you may want to invest in.

Other than that, there isn’t anything bad to say about this dehumidifier. It has a single speed fan that pushes 210 CFM of air to remove up to 90 PPD of moisture. Say goodbye to humidity and standing water.

With a coverage area up to 2600 square feet, you won’t have much issue in your crawl space. Of course, it will work better if your basement or crawl space is encapsulated, but it isn’t a requirement.

The biggest draw is that it has a condensate pump, includes the drain hose, and offers an industry best 20-foot drain height. You could literally pump to your roof and into the gutters if you wanted to.

The 5-year warranty is also great, with customer service just a phone call away. If you can overlook the pricey remote and the need for a new filter right away, this deal is almost too good to pass up.


  • 5-year warranty
  • 20-foot drain height
  • Ducting optional for forced air focus
  • All digital LED control panel
  • Low temp rated


  • Remote control operation is additional purchase
  • Rated for MERV-8 filter but comes with MERV-1

Why Crawl Spaces Are Prone to Moisture

Crawl spaces are prone to moisture primarily because of their location. Being at or below ground level makes moisture a problem. Most of the moisture comes from the air, with cooler, heavier air resting in lower parts of our homes.

As the heat of the day or other sources cause the air temp to rise, the moisture is released as condensation causing mold, mildew, or even wood rot. Moisture comes from the ground, too. Water seepage from the dirt can make the area look and feel dry, but the moisture evaporates into the air, raising the humidity.

The most efficient method of controlling this excess moisture is to use a dehumidifier. A few other methods (see below) help curtail humidity, but a dehumidifier is one of the easiest and most effective moisture removal methods.

How to Install a Dehumidifier in a Crawl Space

Installing a dehumidifier isn’t a difficult task in most cases. Installing in a crawl space can add to the difficulty and frustration, though. If you are uncomfortable working in the space or need an electrical outlet installed, you may wish to call in a professional.

If you are more into the DIY style, that isn’t a problem. You need to make sure you have a place for the unit to drain and get power. Beyond this, your only concern is if it is a stand-alone unit or needs ducting to work for a whole home dehumidifier.

Once everything, such as power, draining, and location, is figured out, you need to place the unit and make sure it is level. Some models come with leveling legs, while others will use caster wheels. If your model has wheels, you may want to put it on blocks or a level piece of plywood.

After the machine is in place, you need to connect the drain hose and run it to the drain. After you connect the power, you should run through all the settings and make sure it is set up how you want it. Turn the unit on and test run to ensure the noise level and vibrations are minimal and the pump or drain work as expected.

More Ways to Maintain a Damp-Free Crawl Space

There are a few methods to help combat humidity and moisture in a crawl space. The most common method is to use air supply from the home’s HVAC system. While this can work, it can also create a positive pressure in your crawl space, resulting in negative pressure in your home.

The second most used method is called encapsulation. This is a process of drying out the crawl space and then covering the ground, walls, and exterior vents with a waterproof moisture barrier. This will keep the moisture from coming in from outside, up through the ground, or in through the wall.

Of course, the easiest and best method is to install a dehumidifier. Only a dehumidifier can effectively maintain negative pressure in the crawl space, repel mold and mildew and remove excess humidity and moisture.

People Also Ask (FAQ)

Can I use a regular household dehumidifier in a crawl space?

You can use a regular portable household dehumidifier in a crawl space; you just may not want to. Most of these units do not have automatic draining or auto-humidistats. Without these two simple features, you will need to get in the crawl space daily to empty the draining tank and ensure your unit is on or off as needed.

How do I know what size dehumidifier to get for a crawl space?

The best way to know what size dehumidifier you need in a crawl space is to take measurements. You need the square footage of the area, which only requires multiplying the room’s width by the length. Once you have this number, you can compare it to the humidifiers’ PPD rating and their associated charts to find the right size and capacity for your needs.

What are the average running costs of a dehumidifier for crawl spaces?

Crawl space dehumidifiers have a few specialties that most other types don’t offer. Because of their durability, capability and ruggedness, they will cost more than your average in-home style. You can expect to pay between $950 and $1200 for good quality, mid-tier models, and between $1300 and $2000 for higher-end or more capable units.

Where is a good place to buy these units?

Some of the best places to purchase a crawl space dehumidifier are online through Amazon or Sylvane. These two online retailers offer great deals on models and styles that aren’t available in most big box stores due to age, newer styles, or lack of warehouse storage space. However, you can also find decent models in those big box outlets like Home Depot and Lowe’s, but you will most likely pay a little bit more.


Dehumidifying your crawl space can be a hassle and an on-going battle. With the best crawl space dehumidifier, though, the job becomes a lot easier. This article showed you what to look for when shopping for a new dehumidifier and which models were the best for your crawl space.

If you are still undecided, take a closer look at our top pick. The Aprilaire 1870 XL Pro is a model that has high capacity, low noise, and simple maintenance. Once it is installed, you can basically forget about it until it is time to change the filter.

Ian Haynes