Excess moisture and high humidity can often affect crawl spaces. This means they can be prone to such issues as mold and mildew and have unpleasant, musty smells. Damp crawl spaces are also more likely to attract pests like spiders, silverfish, and termites.
Even if you rarely visit your crawl space, you should still look at ways at reducing the humidity in your crawl space. This is because the humid air will rise up to the rest of your home. In one academic study from 2016, they found that for 19% of the homes they analyzed there was significant mold transmission from the crawl space to the rest of the house. An increase in allergy symptoms, respiratory problems, coughing, and sneezing are all unfortunate side effects of a damp crawl space. The good news is that with a crawl space dehumidifier you can significantly reduce these issues, and we’re here to help you find the right one.
Alongside each dehumidifier’s weight and tank size, we looked at special features like:
- Auto defrost
- Wi-Fi connectivity
- Auto-restart
- Antibacterial filter
Before purchasing your dehumidifier, it’s a good idea to consider the size of the crawl space and your budget. The Vacplus 1,500 Sq. Ft. 30 Pints Dehumidifier is our best budget buy. But if you’re looking for a more high-end model, the Aprilaire 1820 70 Pint Crawl Space Pro Dehumidifier is ideal and covers areas up to 2,800 sq. ft.
We used consumer reports analysis to remove any false reviews and ensure we found the best crawl space dehumidifiers. This meant that all our recommendations came from genuine people like you who have previously used these units.
Last update on 2023-03-30 / Affiliate links / Images from Amazon Product Advertising API
1. AlorAir Sentinel HD55 Dehumidifier
AlorAir brings you this fantastic crawl space dehumidifier that has the capability of extracting 55 pints per day (PPD) at 80°F, with 60% Relative Humidity and 120 PPD at 90°F, with 90% Relative Humidity (Saturation).
Operation of this unit is by way of a compact control panel that comprises: a power button, arrow buttons that are used to set the desired humidity level, a continuous operation mode button, plus indicator lights for power, continuous mode/auto-defrost, and a compressor.
There is also a digital display screen that shows the current humidity level in the crawlspace when the unit is first switched on and will briefly change to your desired humidity before reverting back to the current reading. If your crawlspace is not easily accessible on a regular basis, you can install the optional remote control unit to monitor the humidity levels.
It comes with a removable, washable “MERV 8” filter helping to keep the unit’s internal parts free from dust while it is operating. As there is no collection tank in the unit, the moisture is extracted and drained via gravity through a drain tube.
This dehumidifier measures 19.2 x 12.2 x13.3 inches, weighs just over 57lbs, and has adjustable feet so you can level it on an unfinished crawl space.
- Tank Size: N/A
- Room Size Availability: 1,300 sq. ft
- Weight: 57 lbs
- Special Features: Auto Defrost, Optional Remote Control
More like this: 10 dehumidifiers with a pump
What we love
- This unit comes with a 5-year manufacturer’s warranty
- Runs extremely quietly
- The filter is very easy to remove, clean, and reinstall
- It drains the water perfectly even without using a pump
We don't like this as much
- The drain hose that is supplied could be a little longer
- We wish the fan had more than one speed mode
2. Honeywell TP30WKN Energy Star Dehumidifier
This compact yet powerful dehumidifier from Honeywell can extract 20 pints of moisture per day from your damp crawlspace. Its small size, 13.2 x 10.5 x 20.1 inches, and weighing only 34lbs means it should fit in most spaces without any difficulty. It has a seven-pint capacity water tank, but if your crawl space is not easily accessible, there is the option to connect the included drain tube to the continuous drain outlet for automatic drainage, without having to think about emptying the tank. A washable filter is located at the back of the unit designed to protect the unit from dust.
A digital control panel located on the top of the unit allows you to set the desired humidity level, fan speed, timer, and sleep mode. The digital display screen shows the current humidity percentage when it is first switched on, and will change as you set your desired humidity level before it reverts back to the current level.
If your crawl space is particularly wet, you can run the unit continuously, draining through the drain tube. If at any time there is a buildup of frost on the internal coils, then the compressor will switch off, but the fan continues to run until the frost has melted before resuming dehumidifying.
This unit is fitted with casters, so it is important that it is positioned on a level surface for optimum performance.
Be sure to check out our hands-on review of the Honeywell TP30WKN.
- Tank Size: 7 pints
- Room Size Availability: 2,000 sq. ft
- Weight: 14 lbs
- Special Features: 24-hour timer, auto restart, auto-defrost
What we love
- Setup is easy with an intuitive design
- The low-temperature shut-off function helps to protect the unit
- There is a 24-hour, energy-saving timer built into the unit
- If you have a power outage it has an auto-restart function
We don't like this as much
- This particular model doesn’t have a built-in auto drain pump
- The water tank is tricky to clean without a “Q-Tip”
3. Vacplus 1,500 Sq. Ft. 30 Pints Dehumidifier
With a superior quality compressor, the 1,500 sq. ft. dehumidifier from Vacplus can quickly remove up to 30 pints of moisture from your crawl space every 24 hours. It features intelligent constant humidity control with automatic adjustment. Set your target humidity level and the unit will constantly sample moisture in the air and make the relevant adjustments to maintain that setting. The simple controls on the top of the unit have a power on/off button, fan speed, mode, timer, and humidity buttons, plus a digital readout screen.
A useful feature of this dehumidifier is its 2-way timing. It has a timed boot and shutdown function which allows you to program the 24-hour timer to take advantage of any cheap, off-peak electricity rates. If you choose to make use of the collection tank, then the unit will automatically shut off when the tank reaches capacity.
However, if your crawl space is typically difficult to reach, you may prefer to “set it and forget it.” To do this, you connect the included dehumidifier drain hose and the unit will drain via gravity. Both the collection tank and the drain hose connection are located at the rear of the unit, along with the washable, antibacterial filter.
Using a high-precision humidity sensor, the unit will sense when the humidity reaches your pre-set limit and go into standby mode. As soon as the humidity level rises the dehumidifier automatically starts again and continues extracting moisture until the level drops to the pre-set, helping to prevent issues such as mold and mildew from becoming a problem.
- Tank Size: 2.8 pints
- Room Size Availability: 1,500 sq. ft
- Weight: 20.9 lbs.
- Special Features: Intelligent humidity control, antibacterial filt
What we love
- The auto shut-off and dual drainage modes are a big plus
- Running it in continuous mode really pulls in the moisture
- Easy to set up and use, following the simple instructions
- Once you set the humidity level, it stays at that level
We don't like this as much
- We wish the unit came with a slightly longer drainage hose for easier placement
- The water collection tank could be a little bit bigger
4. ALORAIR Dehumidifier
This commercial-grade dehumidifier from Alorair has an airflow of 210 CFM and is capable of extracting up to 180 pints of moisture from the air. It measures 22.8 x 13.7 x 17.3 inches, weighs in at 78lbs, and is ideal for crawl spaces. When the unit is operating, this self-draining dehumidifier automatically expels the collected water, and knowing how cramped a crawl space can be, Alorair has included an extra-long power cord, and drain tube (both are 19.6 feet long), making it much easier to get power to the unit and to drain to the outside.
This crawlspace dehumidifier has a robust, internal pump that can push the water “uphill” to a maximum height of 15 feet. This is an advantage if the unit is situated on the crawlspace floor and the only way you can get the tube to the outside is to raise it up and out.
The included MERV-8 filter gives protection to the internal parts from dust damage and is easily removed by simply sliding it out of the housing for cleaning.
An easy-to-read display panel is located on the top of the unit. After setting the desired humidity level, the temperature and humidity at both the inlet and outlet are displayed, and the unit will turn off and on automatically to keep humidity at the chosen level. All in all, an ideal crawl space dehumidifier.
- Tank Size: N/A
- Room Size Availability: 2,300 sq. ft
- Weight: 78 lbs.
- Special Features: Internal condensate pump, alloy tube evaporator
What we love
- This dehumidifier is fool-proof, just set it and forget it
- It’s a powerful unit, but the noise level is relatively low
- The drain hose is longer and more flexible than other units
- Extremely easy to set up and very efficient in crawl space
We don't like this as much
- A remote device showing if the pump is working would be nice
- Users report this dehumidifier does its job well but can be a little noisy
5. Keystone 50 Pint Dehumidifier with Electronic Controls
A dehumidifier that can remove up to 50 pints every 24 hours from an area up to 4,500 sq. ft is something for you to consider if you have a damp crawl space. The HSTAD50D 50-pint model from Keystone does just that, improving the air quality while at the same time helping to prevent mold and mildew.
Measuring 15.39 x 10.83 x 23.23 inches this dehumidifier weighs 40lbs but does have casters for easier mobility. The unit has dual drainage methods, either manually handling the water tank or by gravity drainage through a garden hose.
Depending on how accessible your crawlspace is, you could opt for the tank to collect the moisture. When the tank reaches its capacity, the “full bucket” alert will be activated and the unit will automatically switch off until the bucket is emptied. If, however, the crawlspace is not easily accessed, then the continuous gravity drainage method might be the way to go.
Being drained by gravity, the hose outlet must be at a level lower than that of the hose adapter (included) connection, so positioning the unit to achieve the gravity drainage is important.
The easy-to-use controls allow you to adjust the dehumidifier and the LED display shows the current humidity level. The settings include control pads for Power, Continuous mode, Filter Alert, Fan Speed, and Timer plus lights to show the various settings.
- Tank Size: 12.8 pints
- Room Size Availability: 4,500 sq. ft
- Weight: 40 lbs
- Special Features: Auto-defrost, auto-restart, garden hose drain connection
What we love
- Has an auto-shutoff/turn-on feature to match the humidity setting
- This dehumidifier does a great job and is easy to program
- The filter is very easy to access, remove, and clean
- Effectively tackles musty odors
We don't like this as much
- It doesn’t come with a hose, only the hose adapter
- The water bucket can be tricky to get back in when removed
6. Yaufey 1750 Sq. Ft Dehumidifier
The Yaufey PD161D dehumidifier is one of the quietest models on the market today, with an operating noise level of between 43dB and 46dB thanks to its ultra-quiet technology.
If you have any standing water, signs of mold, or mildew, your crawl space will benefit from a unit capable of removing up to 32.7 pints of moisture every 24 hours in an area of up to 1,750 sq. ft. With a continuous dehumidification function, you can swiftly get the humidity down to an acceptable level, by setting the humidity to 30%RH, then set the unit to your chosen level to maintain by switching off and on when the humidity goes above it.
With dual drainage options, you can choose to use the water collection tank that holds 3.8 pints, and allow the unit to switch off when it gets full, or you can connect the included drainage pipe to the continuous drain port. This pipe is just over six feet long and must be kept on a downward slope to keep the water flowing via gravity.
The PD161D dehumidifier measures 11.4 x 7.1 x 17 inches and has casters for mobility, which can be very helpful when lifting the unit in a crawl space is not possible. A washable filter is located at the front of the unit and is easily removed for periodic cleaning using warm water and mild detergent.
The easy-to-operate control panel has only four buttons, power, fan speed, timer, settings, a digital display screen, plus a full bucket indicator warning light.
- Tank Size: 3.8 pints
- Room Size Availability: 1,750 sq. ft
- Weight: 23.8 lbs
- Special Features: Ultra-quiet Peltier technology, dual drainage methods, auto-defrost
What we love
- Easy to use operation, controls, and nice digital humidity display
- You can hear the fan but otherwise, this unit’s very quiet
- The automatic drain feature is a plus if you’re away
- This is a powerful dehumidifier really pulling in the humidity
We don't like this as much
- We wish the tank capacity was a little larger
- We’d like it if you could lock the casters in place to prevent the unit from moving
7. Aprilaire E130 Pro
Removing up to 130 pints per day, the Aprilaire E130 Pro dehumidifier is the perfect choice for a crawlspace up to 7,200 sq. ft. Its compact size, 12.5 x 12.5 x 25 inches, and a ten-foot power cord, means you can install it in most cramped areas.
With corrosion-resistant aluminum coils, this unit is built to last, reducing and helping to control the humidity in your crawl space, and thereby going a long way to prevent mold and mildew. There is no water collection tank, so you don’t have to keep remembering to empty one. A ten-foot, ¾ inch diameter drain hose is included along with the necessary connectors to have continuous drainage.
This is truly a “set it and forget it” dehumidifier. The front-mounted control panel with its digital display screen has only two buttons, on/off, and mode (used for an optional ventilation feature), plus an up and a down arrow to control the humidity setting. After switching on, the humidity is measured, and if higher than your setting, the compressor will turn on and start dehumidifying.
- Tank Size: N/A
- Room Size Availability: 7,200 sq. ft
- Weight: 98 lbs
- Special Features: Energy-efficient, corrosion-resistant aluminum coils
What we love
- Being able to connect ductwork to get good air circulation
- Effectively tackles musty odors
- Features thermostat/humidistat monitoring
- Arrives with a 5-year warranty
We don't like this as much
- The included drain hose has a tendency to kink
- We’d like to see carrying handles on the unit to aid with portability
FAQs about Dehumidifiers for Crawl Spaces
Anyone living in a home that has a crawl space knows the problems that can stem from excess moisture and humidity build-up in the space.
Crawl spaces are characterized by poor ventilation due to the enclosed nature of these areas. Moisture build-up in the crawl space, coupled with the warmth and darkness in the space can lead to mold and mildew growth. This, in turn, can attract pests and lead to allergic sensitivities.
The good news; all these problems can be avoided by using a crawl space dehumidifier.
A dehumidifier can fix these issues by absorbing the moisture in the crawl space, preventing mold and mildew growth. But there are a few things to consider before buying a dehumidifier for the crawl space, which will be the focus of this article.
What Is a Dehumidifier for the Crawl Space?
A crawl space dehumidifier is a home air conditioning device that absorbs moisture from the air in the crawl space, allowing you to maintain optimal humidity levels in your home. A crawl space dehumidifier protects your health by filtering the excess moisture from your home.
Besides the crawl space, a dehumidifier can also be installed in other areas, such as the bathroom, basement, and garage, where dehumidification is required.
Since these units are usually placed in rugged places, they also tend to be more rugged than the typical dehumidifiers and can filter around 7 – 14 gallons of water per day. Crawl space dehumidifiers can be installed on the floor or hung by the floor joints with straps.
What Size Dehumidifier Do I Need for My Crawl Space?
Many factors come into play when deciding the perfect dehumidifier size for your crawl space.
If you don’t intend to encapsulate your crawl space, you’ll need a larger capacity dehumidifier. But if your crawl space is partitioned or cut up by foundational walls or HVAC ducts, you may need at least two smaller capacity dehumidifiers.
When it comes to dehumidifiers for the crawl space, there’s no one size fits all solution. You don’t want to invest in a unit that takes up too much of your crawl space. So, before you even start looking, we recommend taking measurements of the coverage area first.
Factors to Look for When Buying a Dehumidifier for Your Crawl Space
Without further ado, here are the things to look for when shopping for a crawl space dehumidifier.
- Coverage Area
The area of coverage is a critical consideration because it determines how well the dehumidifier will perform. Most, if not all, brands mention the area of coverage in square feet, so getting this figure right shouldn’t be a problem.
The area of coverage defines the area the dehumidifier can clean.
For example, if you buy a dehumidifier with a coverage area of 1,000 sq. feet but use it in a 2,000 square feet area, it will not work. That’s why you should always determine the size of your crawl space before buying a dehumidifier.
- Defrosting System
Defrosting system is a critical consideration for those living in regions where temperatures get extremely low. Leaving your dehumidifier exposed to frigid temperatures can freeze the condensation coils and destroy the device.
The defrosting system maintains a warmer temperature, preventing the dehumidifier coils from freezing. This also allows the machine to run much longer.
- Tank Capacity
Depending on your area’s humidity level, your dehumidifier might get full pretty fast.
Hence, if you live in an area where moisture is above average, you’ll need a dehumidifier with a large tank capacity. This ensures it doesn’t get full every day, requiring emptying now and then.
The tank size indicates the amount of water the dehumidifier can hold at any given time. Most dehumidifiers’ tank capacity ranges from 10 to 90 pints. If you’re buying a dehumidifier for a larger space, try to get a unit with a larger capacity.
- Humidistat
The best dehumidifiers for crawl spaces should have a humidistat.
A humidistat allows the device to measure relative humidity and turn itself ON and OFF as needed. You can set the ideal humidity level and leave the system to do the rest.
We recommend setting the humidistat to 55% in most cases. If the humidity in the space exceeds this setting, the dehumidifier will turn on and start working. If the humidity falls below that level, then it will stop working.
Wrapping Up
A crawl space dehumidifier is a home air conditioning device that absorbs moisture from the air in the crawl space, allowing you to maintain optimal humidity levels in your home. These units are usually kept in the crawl space and tend to be more rugged than the typical dehumidifier you’d find in a bathroom or garage.
When choosing a dehumidifier for your crawl space, it’s important to start by taking measurements of your crawl space. This ensures you get a unit powerful enough to cover your area. Other important factors to consider include the unit’s coverage area, tank capacity, defrosting system, and handy features like a humidistat.
Can you use a dehumidifier in a crawl space without encapsulation?
If possible you will want to seal up your crawlspace to increase how effective the dehumidifier will be at removing moisture. If it’s not sealed or encapsulated, the dehumidifier will have to deal with more and more air from the surrounding area.
We would still recommend using a dehumidifier in a non-sealed environment if the other option is to do nothing. A dehumidifier will still help to reduce humidity even in a nonsealed environment such as a room in the home. A crawl space is often more sealed than most areas of the house so you will still benefit from the use of a dehumidifier.
If you are concerned about performance go for a large dehumidifier that can deal with larger spaces or those that are naturally damper such as a crawl space.
How do you dehumidify a wet crawl space?
Remove all the standing water by using a wet vac or pump. Once the water is gone, remove any wet material and clean all the surfaces to prevent the spread of mold.
Now it’s time to use a portable dehumidifier. A large room dehumidifier will work for a small crawl space, but for a large space, then a commercial-grade unit will work best. Set the controls to between 30 and 45 percent and run it continually. It may take eight to ten hours to dry out a wet crawl space. Electric fans and a low source of heat will speed up the process.
What features usually come with a crawl space dehumidifier?
Modern crawl space dehumidifiers usually have the following features:
- A Hygrometer. This measures the humidity levels currently in the crawl space.
- An adjustable humidistat. This is used to set the desired level of relative humidity. The standard level is between 30 and 40 percent.
- Constant draining. Many units come with a drainage collection tank, which, when full, will shut the unit off. Other units have continuous drainage or a combination of both. The recommended method for a crawl space is continuous drainage.
- An auto-defrost system. If you live in the colder states, then this will prevent frost build-up on the coils.
How to find the best dehumidifier for my crawl space?
To find the best dehumidifier for your crawlspace, calculate the area to be treated, then look at the specifications of dehumidifiers. The critical numbers you are looking for are the maximum recommended square footage, coupled with the amount of water that can be removed over a 24-hour period.
For example, in a 1,300 sq. ft. slightly damp crawl space, a dehumidifier that is capable of extracting 20-30 pints per day (ppd), would be adequate. A very damp crawl space would need a 30-40 ppd unit, and for a wet crawl space a unit that can extract more than 50 ppd.
Which Dehumidifier is best for you?
Crawl spaces are known to be dark and dirty, and if your crawlspace is sealed, then the quality of the air is probably not the best. As the outside temperature rises, the humidity inside the crawlspace will also increase leading to problems such as mildew, mold, rot, and other issues. A crawlspace dehumidifier will go a long way to eliminating the root cause – unwanted moisture.
Almost every crawl space dehumidifier will state the amount of square footage it can handle. Select one that closely matches your crawlspace area. Too small a unit won’t remove enough humidity, and won’t have much effect on any mold or mildew that is present.
A built-in humidistat is important because it will run the dehumidifier when the humidity gets higher than the set level, and switch off when it drops below it. An automatic defrost system could be a critical feature if you suffer from wintery conditions, and having a condensate pump included means you don’t have to rely on gravity to drain the water out of the dehumidifier.
Choose a dehumidifier that will handle the area of the crawlspace, remove the most moisture per day, and will drain the water in the most beneficial way to suit your lifestyle. Check out our top picks for small, mid-range, and larger rooms below.
- Budget – Vacplus 1,500 Sq. Ft. Dehumidifier
- Mid-range – AlorAir Sentinel HD55 Commercial Dehumidifier
- High End – Aprilaire 1820 70 Pint Crawl Space Pro Dehumidifier