10 Best Crawl Space Dehumidifiers For Better Air Quality

Crawl spaces are notorious for being chilly, wet spaces that can smell musty and have poor air quality. Since air rises, the dangers from below can filter up into your house.

Dehumidifiers are an excellent way to pull moisture from the air, reducing mold, insects, and other harmful contaminants that can affect allergies, asthma and cause breathing issues. This type of machine can also prevent structural damage to your home. In this review, we’ve found ten of the best crawl space dehumidifiers for better air quality. 

After the reviews, check out our detailed buyer’s guide that will help define the various factors you should consider when shopping for a crawl space dehumidifier. We also answer some frequently asked questions about the topic. 

The 10 Best Crawl Space Dehumidifier Options

We start our journey on picking the perfect crawl space dehumidifier by reviewing the ten best options for use in tight crawl spaces. Each of these models has features that make them ideal for the specific conditions of being under the house. We also provide the pros and cons of each option. 

1. Aprilaire Pro Dehumidifier

The Aprilaire Pro Dehumidifier comes in 70, 95, or 130-pint capacities and with a range of 2800, 3800, 5200, or 7200 square feet. You have the option of leveling feet or castors to keep this compact gray 25″ x 12.5″ x 12.5″ 56-pound dehumidifier stable in tight crawl spaces.

This dehumidifier helps keep the relative humidity below 60%, so there’s no issue with wood rot, termites, mold, or damp, musty odors. The Aprilaire Pro can remove up to nine gallons of water daily without the hassle of having to empty the collection tank repeatedly.

In a few simple steps, you can set this dehumidifier up to drain via the included hose or place it over a drain where the water can empty. You will need a 120 outlet plug for this unit to get power, drawing 5.8 amp while running at a consistent 60 Hz phase. 

Benefits

• Low maintenance care
• Easy one phase operation
• Compact size for small spaces
• Connects to drainage hose, so you don’t need to empty the water tank

Drawbacks

• Only one setting
• Noisy operation

The Aprilaire 1820 Pro Dehumidifier is a reasonable solution for homeowners who need a machine they can set up and leave operating without supervision in tight areas not close to living spaces, so you aren’t bothered by the noise. 

2. Alorair Basement Dehumidifier

The Alorair Basement dehumidifier has an Energy Star Certification that allows it to pull moisture from the air without raising your electric bill or your nerves due to <58dB(A) noise level. 

This 24.8″ x 13.78″ x 15.75″ crawl space dehumidifier can collect up to 198 pints of moisture daily in areas up to 2,600 square feet. A condensation pump (optional) allows this machine to pump continuously, while a built-in automatic defroster allows for operation in temperatures as low as 36℉ or as high as 104℉. 

The included hose is 15 feet wide, which transfers the collected water from the pump, so you don’t have to empty a tank. You do have to replace or clean the MERV-1 air filter every two to three months. There is also a separate remote control you can purchase to operate this machine. 

Benefits

• Quiet operation
• 198 pints of moisture daily
• Condensation pump optional
• Built-in automatic defroster

Drawbacks

• The filter requires frequent cleanings
• Heavyweight can make moving difficult

The Alorair basement dehumidifier is an energy-conserving, quiet operating dehumidifier with a high moisture retrieval rate of up to 198 pints daily in space up to 2,600 square feet. 

3. Waykar Dehumidifier for Basements

The Waykar dehumidifier features an easy-to-use control panel with multiple buttons to set the fan’s speed and operate the timer that controls the automatic start and stops. There’s also a rotatable side air vent, and a settings button to change the humidity level, and the power button to turn off and on.

When the tank gets full, there is a red indicator light that glows. This dehumidifier can handle spaces up to 2000 square feet, removing up to 34 pints of moisture daily while operating at 95°F,90%RH. 

You can set the humidity level from 30% to 85%, and the machine will automatically turn on when the humidity drops below your chosen setting. An auto-shutoff also allows this machine to cut off when it senses a full bucket.

Moving this dehumidifier around is easy due to 360° rotating wheels and lift handles. Attach the 6.56-foot drainage hose to drain the water manually if you don’t want to empty the 2.5L (0.66 gallons) water tank constantly. 

Benefits

• Custom humidity setting from 30% to 85%
• Auto on/off humidity setting and auto-shutoff when the tank is full
• Indicator light shows when the tank is full
• Easy to move around due to wheels and handles

Drawbacks

• A small tank will require frequent emptying if you don’t use the drainage hose
• Included drainage hose is short

For an easy-to-transport upright dehumidifier that can automatically detect and treat humidity in the air while using an auto-shutoff if the tank gets full, try the Waykar Dehumidifier. 

4. BaseAire Dehumidifier for Crawl Space Basement

This dehumidifier by BaseAire weighs 77.1 pounds and has a 23.2″ x 15.2″ x 17.7″ compact size that fits most crawl spaces and basements up to 2600 square feet. Dual handles make this device portable, while 58 dB(A) allows for quiet operation. 

You can set the humidity level between 45% and 55% to auto-sense and withdraw up to 90 pints of moisture daily while operating under 60%RH @ 80°F. A built-in condensation pump offers a 14.7′ distance, allowing you to drain the water anywhere. 

An auto defroster ensures the coils don’t freeze, allowing for operation in temperatures from 33.8°F to 104°F. A Rare Earth Alloy Tube Evaporator protects the coils for more extended longevity. And the operation is as simple as setting the humidity using the easy control panel, which also displays the real-time humidity. 

Benefits

• Compact size and easy portability
• Built-in condensation pump provides 14.7-foot distance
• Automatic on/off based on humidity levels
• Quiet operation

Drawbacks

• Heavy weight
• Limited humidity level options

The BaseAire AirWerx90x is an energy-efficient, intelligent dehumidifier that automatically removes moisture and humidity from areas up to 2600 square feet. 

5. Alorair Crawl Space Dehumidifiers

The Alorair Energy Star Certified dehumidifier can remove up to 55 pints a day of moisture using AHAM conditions or 120 pints during saturation for areas up to 1300 square feet at <52 dB(A) noise level. 

A built-in automatic defroster allows this dehumidifier to operate at temperatures as low as 36°F (up to 104°F) that will turn on if the coils start to build up frost. 

A washable, reusable MERV-8 filter keeps your air quality pure and healthy (changed or washed every three to four months), while the small dimensions of 19.2″ x 12.2″ x 13.3″ make this device ideal for small areas like crawl spaces.

Benefits

• Compact size for small areas
• MERV-8 air filter
• Built-in defroster
• Auto-sensing and eliminating of humidity in the room

Drawbacks

• It only covers 1300 square feet of space
• Low moisture removal quantity

Users who need a smaller dehumidifier for spaces up to 1300 square feet with a built-in defroster and automatic detection and humidity removal would do well with an Alorair Dehumidifier. 

6. DRI EAZ Commercial Dehumidifier with Pump

The DRI EAZ commercial dehumidifier features an automatic pump out that allows water to drain continuously, so there’s no emptying of a tank or concerns about water overrun. You can attach the drainage hose to a drain or sink, so long as it’s not higher than three feet.

You can set the Dri Eaz dehumidifier to relative humidity between 40% to 90% to remove moisture and help dry paints or finishes in workshops or basements. Once you set your RH, this machine will automatically turn on and off to remove moisture from spaces up to 15,000 cubic feet.

At 12.5″ x 12.5″ x 17.63″ and 63.20 pounds, this equipment is easy to transport, stores easily, and fits in compact places, making it perfect for crawl spaces, basements, and other damp areas. In cases of a power outage, the machine will resume its previous settings upon power restoration. 

Benefits

• Continuous operation via drainage pump
• Custom relative humidity setting form 40% to 90% 
• Automatic detection and removal of moisture
• Compact size is easy to transport and store

Drawbacks

• It only covers 1,500 cubic feet of space
• It can’t drain if the hose is higher than three feet

For a space-saving commercial answer to removing moisture and humidity from small spaces automatically based on your RH setting, try the Dri Eaz dehumidifier. 

7. Santa Fe Compact Dehumidifier

The Santa Fe compact dehumidifier has a horizontal configuration with a flow-through design ideal for low-clearance spaces like basements or crawl spaces. 

An auto-restart allows this dehumidifier to resume operation after a power outage. And you have the option to hook up ductwork for coverage in divided spaces. 

This compact dehumidifier can filter up to 70 pints (8.75 gallons) of moisture from the air while running at 60% RH and 80°F at 580 watts. At normal mode, it handles 47 pints. It operates in temperatures between 49°F-95°F, so it’s not ideal for freezing temperatures. 

This humidifier can handle up to 3,000 sq ft in tightly sealed spaces. For moderately sealed – 2,200 sq ft; and for rooms with drafts, leaks, or other issues that allow moisture in, up to 1,800 sq ft. 

Benefits

• Compact size for small areas
• Auto-restart if the power goes out
• Collects up to 70 pints per day
• Multiple modes including econ to save power

Drawbacks

• It doesn’t cover large areas
• It won’t work in cold temperatures

If you’re interested in a crawl space dehumidifier that can allow for connection with multiple ducts for divided rooms, the Santa Fe might be the one for you.

8. BaseAire Dehumidifier for Crawl Space Basement

The BaseAire dehumidifier AirWerx55 features a front-facing control panel with an RH display. And it has a capacity of up to 55 pints of moisture daily in spaces up to 1,300 square feet to maintain a 45% to 55% relative humidity. 

Once you plug this dehumidifier up and set the RH, the machine will automatically switch on and off to keep the humidity within range. This machine runs at 120 PPD, 55 PPD at AHAM, or 34.53 PPD when running at 60°F, 60% RH. 

An included 6.5′ drain hose eliminates the need to drain a reservoir repeatedly. Gravity will make the hose self-drain. To protect your coils from freezing, this dehumidifier has a built-in defroster that allows for operation in temperatures as low as 33.8°F with a noise level at 52 dB(A). 

Benefits

• Drainage hose makes it easier to drain without manual labor
• Built-in defroster
• Low dB(A) operation
• Compact size for storage, transporting and setting up in tight spaces

Disadvantages

• Limited to spaces smaller than 1,300 feet
• Max of 55 pints per day

The BaseAire dehumidifier is perfect for anyone looking for a quiet, compact dehumidifier for small crawl spaces that experience low temperatures.

9. DRI EAZ Compact Dehumidifier

For a pop of color, try this rugged blue and gray compact and portable dehumidifier by Dri Eaz. Despite its small size of 17.6″ x 12.” x 21.5″, the Revolution can draw out up to 17 gallons of moisture a day. 

The display shows real-time temperatures for outlet and inlet plus relative humidity with a built-in pump that automatically drains water through the included 40 ft long hose that can pump up to 20 feet higher than the machine. 

This dehumidifier has excellent performance for restorative drying by pulling out water from floods, leaks, or condensation. There is no built-in defroster, meaning this machine won’t operate in cold temperatures.

Benefits

• Works as a restorative dryer and dehumidifier
• Can pump water up to 20 feet above machine
• 17 gallons moisture retrieval per day
• Detailed display for easy tracking of progress

Disadvantages

• It doesn’t have a built-in defroster
• Loud operation

For a durable, rugged dehumidifier that can handle the extreme hazards of worksites, disaster areas, or significant water collections, you need the Dri Eaz compact dehumidifier. 

10. Alorair Commercial Dehumidifier with Pump

This commercial dehumidifier with pump by Alorair comes in a flashy red and gray color combo with a withdrawal capacity of up to 180 pints daily while only taking up 22.8″ x 13.7″ x 17.3″ of space. These features make it perfect for tight horizontal areas like crawl spaces that require continuous dehumidification. 

As a heavy-duty water damage restoration dehumidifier, this option features a condensate pump that pulls 13.4 gallons of water a day using 5.62 amps and a 115V outlet. It turns off and on automatically based on your chosen humidity settings. 

It also features auto defrost, preventing coils from freezing and letting It operate between 33.8°F and 104°F. It can even work underwater due to a rubber seal surrounding the circuit board. 

Benefits

• Commercial duty for spaces up to 2,300 sq ft
• Pumps up to 13.4 gallons of water daily
• Operates in cold temperatures
• Waterproof

Drawbacks

• Heavy 
• Loud operation

The Alorair Commercial dehumidifier with pump is the perfect solution for large areas with standing water, such as flooded basements or worksites, due to its waterproof abilities.

What Is a Crawl Space Dehumidifier?

A crawl space dehumidifier is self-explanatory by name. It is a dehumidifier that goes into the crawl space (empty space underneath your house foundation) to remove humidity.

A dehumidifier is a machine that pulls moisture out of the air. As the damp, musty, cold air of crawl spaces mixes with warmer, moist air that blows in through vents, the air becomes hot and damp – humid. 

If the relative humidity (RH) gets higher than 50%+, the conditions become perfect for wood rot, mold, and insects like termites. As the air circulates from the crawl space into your home, tiny particles come with it that can be dangerous for your health.

Possible contaminants that can hide in the air include dust mites, rodent decay and wastes, mold, mildew, radon gas, funguses, and rot. 

For people with allergies, asthma, or breathing problems, breathing in mold and other small particles can exacerbate the symptoms. 

If the humidity stays high enough to allow wood rot or termite infestations, the wood structures that support your house can become compromised, leading to structural instability. 

Benefits Of Using a Crawl Space Dehumidifier

Many people are unaware that the air quality under the house can affect the quality of air inside. This issue is because air rises from the ground up – referred to as a stack effect. 

As the air comes out of the basement or crawl space, it circulates through the rest of your home. If there are any problems under your house, the dangers could come indoors. 

A humidifier helps dry and clean the air to remove any particles lingering in the air from dust, mold, or other debris. For people with allergies, a dehumidifier is essential for healthy air quality. 

Using dehumidifiers can also make your home feel more comfortable. High humidity levels can cause the air to feel damp with condensation, making you feel hot and sticky. 

Dehumidifiers under the crawl space can also help protect your house’s structural integrity. When there’s too much humidity in the air, the excess moisture can lead to rotting wood. Anything higher than 28% is harmful to your house structure.

Reducing the humidity under a house can also reduce the probability of pest infestations attracted to moist settings. Termites are the most significant concern.

Signs You Need a Dehumidifier In Your Crawl Space

How do you know if you need a dehumidifier in the crawl space of your home? Start by checking your area for these signs. If you notice any of these problems, check out our top ten recommendations for the best dehumidifiers for your crawl space.

If you notice cracks in your drywall, gaps between the baseboards and the floors, or your floors sag, slope, or creak while in use or not, you could benefit from a dehumidifier in your crawl space. Moisture collecting on the inside of your windows is another sign. Some of these issues may require immediate treatment by professionals. Other evidence includes:

Damp, Moldy Odor

The most significant sign that you should invest in a dehumidifier to place under your house is if you detect the presence of a foul, moldy smell throughout your home. This smell could be coming up from beneath the house. If so, it might be a warning sign that your crawl space has too much moisture in the air. 

Pipes in the Crawl Space

If your crawl space provides access to your home’s ductwork, HVAC system, water pipes, or vents, there’s a significant chance you will have too much humidity under your house. These systems produce condensation, which increases humidity. 

Signs of Structural Damage

High humidity and excess moisture can lead to multiple problems that could cause your home’s structure issues. Prolonged exposure to dampness in the air can cause wood to rot. These damp conditions also invite damaging pests like termites. Other issues that damp crawl spaces can cause are swollen floors, window frames, doors, or rust along metal pieces.

Breathing Discomfort

If you start to experience breathing problems indoors, multiple headaches, or severe allergy attacks, it could be due to poor air quality as the air from below moves around the inside. 

Considerations When Choosing the Best Crawl Space Dehumidifier

At this point, you’re probably sold on the idea of placing a dehumidifier in your crawl space. But now the real work begins – picking the perfect one. To help you on your shopping trip, consider these factors. Each home has unique needs that you should consider to make sure you pick a dehumidifier that will work for your home.

Coverage

To get the best use out of your product, you have to be sure and pick one powerful enough to manage the entire space. You’ll need to factor in the size of the area and how much humidity is present. 

The best models will allow you to dry out the air, despite above-average moisture. Most crawl spaces do not have insulation or proper sealing to block out humidity, so there are higher moisture levels. 

Size

You’ll also want to consider the size of the dehumidifier itself when comparing different options. While a larger one may require less emptying, you may struggle with the task if the machine is larger than you can comfortably maneuver. 

You’ll also need to consider how the size of the dehumidifier will relate to the available room in the crawlspace. If it’s a compact area, using a larger device can take up too much space, be a hassle to move around, and possibly not work correctly. 

Safety Features

Finding a machine with additional safety features helps you physically and gives you peace of mind that nothing dangerous will happen. Most newer model dehumidifiers feature crucial safety features such as automatic shut-offs, tank full alarms, and low power alerts. 

You want safety features and any additional options that can make your life easier, like a timer, remote controls, or touch screens.

Tank Size

You’ll also need to consider the size of the tank capacity. Dehumidifiers can fill up fast if there’s a ton of moisture in the air. Once full, you’ll have to empty the tank before the machine can resume working. 

If you don’t want to be constantly running back and forth into the musty under space of your home, consider getting a larger capacity dehumidifier.

How to Install a Dehumidifier In Your Crawl Space

Installing a dehumidifier in your crawl space is a simple, relatively painless process that does not require many steps.

Determine Placement

Once you’ve done your research and purchased a dehumidifier that has all the features you need, including being the appropriate size to fit in your area, it’s time to decide on placement.

Consider your dehumidifier’s requirements for the length of the power cord – this will limit how far the cord will stretch from a power outlet. 

Suppose your machine doesn’t have a memory power that allows the dehumidifier to resume operation after a power outage. In that case, you may want to install a remote control that will enable you to control the settings without crawling below. If not, you’ll want your machine in a location that you can access easily. 

You’ll also need to consider drainage – with a hose drain, the length of the hose will affect placement. The hose has to be able to empty the water into a drain, sink, outside, or some other safe outlet. 

If your dehumidifier uses a water collection tank, you’ll want to place your machine somewhere easily accessible that’s close to a dumping location. The ground also needs to be flat and even to prevent water from spilling out of the pan.

Dehumidifiers also blow out air, so a wall or other solid object mustn’t block the airflow vent. Some models have a continuous pump and censoring of the area’s RH for auto on and off. 

You’ll also want to consider the noise level of the dehumidifier during operation when trying to determine placement. If it’s loud, you wouldn’t want it under the home’s main living areas, such as family rooms or bedrooms. 

For U-shaped crawl spaces, the humidifier would do well in the middle of the space. Position the dehumidifier on either end for rectangular-shaped crawl spaces. You’ll need to run flexible ducting for all options to split the exhaust air from the intake air. Flexible ducting can also help channel the exhaust from one half of the space to the other is divided crawl spaces.

Set Your Desired RH Level

Once you’ve got your dehumidifier placed in the preferred location, plugged up, and powered on, your next step is to set your preferred relative humidity level. 

Crawl spaces should maintain an RH of 50% to 60% to prevent foul odors, rotting wood, insects, mold, and harmful particle circulation throughout the home. Some dehumidifiers allow you to set your optimal range, while others may automatically operate within the preferred RH level. 

The first few days after you’ve set your machine up, it’s a good idea to do frequent monitoring to track the dehumidifier’s effectiveness. Some devices display the room’s real-time RH level. But you can also use a wireless hygrometer to test the air quality of the space.

Best Crawl Space Dehumidifier FAQ

Here are a few commonly asked questions customers have about using a dehumidifier in tight, compact areas like crawl spaces. We hope these answers will help you complete everything you need to know when comparing and shopping for a new crawl space dehumidifier. 

Will a dehumidifier work in a crawl space?

Dehumidifiers are excellent tools to use in crawl spaces to improve the air quality and reduce moisture, which can cause a host of health problems for your home and family. Most areas under the house will be musty, dank, and damp due to the empty space between the ground and the house’s frame. 

However, you might see an increase in your electric bill due to constantly operating. Choosing an option with energy efficiency can help reduce your heating and cooling bills. You will need to ensure there’s a way for the machine to drain effectively. And you’ll have to remember to do maintenance to keep your dehumidifier working correctly. 

What is the best dehumidifier for a crawl space? 

This review covered ten of the best dehumidifiers for a crawl space, giving you a range of options to meet different needs, such as square footage, moisture retrieval amount, and drainage. 

The best overall dehumidifier is the Aprilaire Pro Dehumidifier (#1), while the Alorair Commercial Dehumidifier with Pump (#10) works best for locations with standing water.

How much does a dehumidifier cost for a crawl space?

Because crawl space dehumidifiers will cover more area than options you’d use for small spaces like bedrooms, bathrooms, or living spaces, they have a higher price tag. A durable dehumidifier to go under the house can range from $1,500 – $2,000.

What is the best way to keep a crawl space dry?

Crawl spaces can retain water due to various reasons. Leaks, ineffective drainage around the house, cracked foundations, and floods are common culprits of standing water in a crawl space. 

Adding a vapor barrier to your crawl space can reduce the chances of moisture getting into the space. Insulation blocks water while lowering your energy bills. And covering any vents that lead outdoors can also minimize water collection. 

Outside your home, you can improve drainage, so water can’t pool around your foundation. You may need to reposition or relocate gutters and downspouts. And treat any leaks that may be adding to water buildup. A dehumidifier with a pump can help pull out standing water.

Conclusion

Dehumidifiers are an excellent way to reduce moisture and humidity in your home caused by having a crawl space under your house. When choosing a dehumidifier to place in compact locations like a crawl space, you’ll need to consider the machine’s drainage, water retrieval capacity, energy consumption, and size. We’ve given you all the tools necessary to make your shopping trip easy and productive. Any of the ten options we’ve provided for the best crawl space dehumidifiers would be ideal for your needs.