If you want to find the best crawl space dehumidifier, you are in the right place!
In this guide, you'll learn:
- How crawl space dehumidifiers work
- Installation tips
- Top 7 dehumidifiers for crawl spaces
- And much more!
After being a home inspector for several years, I have seen so many crawl spaces with moisture problems and wood damage. High humidity in a crawlspace can cause mold issues, damaged insulation, pest intrusions, foundation problems, and other issues.
Dehumidifying a crawl space can help avoid a lot of problems, and that's why I made this list for the public! I want to help you pick the best crawlspace dehumidifier to keep your crawlspace dry, clean, termite-free, and mold-free.
Below is a shortlist of our top product picks, but keep reading to see our buyer's guide on how to pick the best one. Let's get started!
AprilAire E100 Energy Star Pro Dehumidifier
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AlorAir Sentinel HD55 Auto Defrosting Dehumidifier
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BaseAire AirWerx55 AirWerx55 Commercial Dehumidifier For Basements
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Dri-Eaz F413 Revolution LGR Industrial Dehumidifier With Pump
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Homelabs Energy Star Humidifier For Large Rooms And Basements
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Vremi 50-Pint Portable Dehumidifier For Large Spaces
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Waykar 155-Pints Industrial Dehumidifier For Crawl Spaces
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My Overall #1 Rated Pick
Updated On January 14, 2023
Our overall top pick for the best dehumidifier for crawl spaces goes to the AprilAire E100 because it can remove up to 12-gallons or 100-pints of water each day from under your house. The E100 features corrosion-resistant coils and a MERV 8 washable filter. It can even be programed to circulate air in order to even out temperature variations.
What Are The Best Crawl Space Dehumidifiers?
Only have a minute? Check out our top 7 crawl space dehumidifiers! Keep reading for our buyer's guide and the details of each top pick.
- AprilAire Dehumidifier Pro E100 Energy Star (Best Overall)
- AlorAir Sentinel HD55 Auto Defrosting Dehumidifier (Best Budget)
- BaseAire AirWerx55 Commercial Dehumidifier For Basements (Best Portable)
- Dri-Eaz Revolution LGR Industrial Dehumidifier With Pump (Best With Pump)
- Homelabs Energy Star Humidifier For Large Rooms And Basements (Best DIY Option)
- Vremi 50-Pint Portable Dehumidifier For Large Spaces
- Waykar 155-Pints Industrial Dehumidifier For Crawl Spaces
Top 7 Best Crawl Space Dehumidifiers Reviewed
Best Overall Pick
Our #1 top pick for crawl space dehumidifiers goes to the AprilAire E100 Pro because it is energy-efficient with the coveted Energy Star rating.
- Coverage Area: 5,200-sf
- Air Flow Capacity: ~200-cfm
- Pint Capacity: 12-gallons (100-pints)
AprilAire is actually the first manufacturer to get the Energy Star rating for their E-series line of professional dehumidifiers!
This AprilAire dehumidifier is made with rust-resistant aluminum coils, and it includes a washable filter that only needs to be cleaned or replaced once a year. There are other E-series models such as the E80, E70 or E130 if you want a lower or higher capacity and coverage area. The downside of the AprilAire E100 is that it doesn't come with a condensate pump so that will be extra if you can't do gravity drainage.
The Sentinel HD55 by AlorAir is a rugged high quality dehumidifier for crawlspaces, basements, garages, or other areas.
- Coverage Area: 1,300-sf
- Air Flow Capacity: 130-cfm
- Pint Capacity: 8-gallons (55-pints)
The Energy Star certified Sentinel has a special epoxy-coating that helps to minimize corrosion and maintain optimal dehumidification.
This unit comes with a defrosting system (and still runs while defrosting) so it can keep running even when it drops to 36°F. The downside of the Sentinel is that it is prone to breaking down for some users and it doesn't have as long a lifespan as the AprilAire E-series.
The AirWerx55 by BaseAir is our top pick for the best crawlspace dehumidifier that is the most portable.
- Coverage Area: 1,300-sf
- Air Flow Capacity: 130-cfm
- Pint Capacity: 15-gallons or 120-pints (saturation)
It comes with two handles and it is light enough that it can be easily moved to a different area for dehumidification.
It is also equipped with epoxy-coated coils to help prevent corrosion and freon leakage (a common problem in dehumidifiers).
The AirWerx55 includes a MERV-8 filter to catch larger airborne particles to prevent contamination. One cool feature of this dehumidifier is that it has an auto-restart function so that you don't have to go into the crawl space just to restart it if there is a power out. A downside with the AirWerx55 is that the framing is prone to rust, and it also has a shorter lifespan compared to AprilAire.
The F413 by Dri-Eaz is an ultra compact and portable dehumidifier that can be placed in your crawlspace, garage, or other tight area.
- Coverage Area: unrated
- Air Flow Capacity: 120-180 cfm
- Pint Capacity: 12-gallons or 96-pints (AHEM)
It will remove 12-gallons of water per day out of your ambient crawl space air. The F413 includes a 4-stage filtration system to remove harmful particles like mold spores.
It also features automatic restart in case of a power outage so you don't have to go into your crawl space. The housing is extremely durable because its rotomolded and it's made in the USA for quality. The F413 includes a 40-ft drain hose to remove the condensate. Some home depots also allow rentals of the Dri-Eaz if you just need a temporary fix.
If you are looking for a less permanent or temporary solution, the HomeLabs dehumidifier is our top pick.
- Coverage Area: 3000-sf
- Air Flow Capacity: 165 cfm
- Pint Capacity: 5-gallons or 35-pints
This ultra-portable dehumidifier will remove up to 35-pints of water each day, and it has a coverage area of 3,000-sf.
Homeowners can hook up a 5/8" diameter garden hose to the drain nipple for continuous draining. And this under house dehumidifier is very quiet compared to commercial dehumidifiers.
If you want a portable dehumidifier for your crawl space or large space, the Vremi is a nice choice.
- Coverage Area: 4,500-sf
- Air Flow Capacity: unrated
- Pint Capacity: 7.5-gallons or 50-pints
This quiet and portable dehumidifier is perfect for a temporary solution or if there isn't that much moisture to deal with.
It can remove up to 50-pints of water each day and it can handle an area up to 4,500-sf. And like the other dehumidifiers, homeowners can install a drain hose for continuous draining.
The Waykar can remove up to an astounding 155-pints of water each day from your crawl space. It can also operate in cold temperatures up to 41°F and includes a defrosting system.
What Are Dehumidifiers For Crawlspaces?
A crawl space dehumidifier is a home appliance that automatically controls humidity levels and drains water to the outside.
Besides crawlspaces, it can also be installed in garages, basements, or other areas where dehumidification is desired. Crawl space dehumidifiers tend to be more rugged than your average dehumidifier and can remove up to around 7-14 gallons of water per day.
Crawl space dehumidifiers are also designed to be hung by the floor joists with straps but they can also be installed on the floor with wood or masonry blocks.
Read Also >> How To Get Rid of Black Mold In The Basement?
How To Pick The Best Crawl Space Dehumidifier?
When choosing the top crawl space dehumidifier, homeowners should consider the coverage area, moisture removal capacity, ease of installation, and other factors...
Coverage Area | What Size Dehumidifier?
The coverage area of a crawl space dehumidifier will tell homeowners how large of a space it can handle.
Typical coverage areas for these dehumidifiers are in the 3,000-sf to 7,500-sf range.
It is essential to make sure that the dehumidifier can handle your crawl space size so you should have a rough idea of the floor area dimensions.
PPD Rating Under The AHAM Standard
The PPD rating for crawl space dehumidifiers stands for pints per day and it will tell you how much water it can remove in a 24-hour period.
The most trustworthy PPD rating falls under the AHAM standard. AHAM stands for the Association of Home Appliance Manufacturers and this rating requires that the dehumidifier is tested with 80°F temperature and 60% relative humidity.
Most dehumidifiers for crawlspaces are rated at 50-PPD and all the way up to 150-PPD.
PPD Rating Under Saturation
The Saturated PPD Rating will also tell you how many pints per day of water the dehumidifier but under saturation conditions.
Saturation conditions mean an environment of 90°F temperature and 90% relative humidity— a very extreme environment.
The vast majority of dehumidifiers for crawl spaces will never experience these conditions but it is a useful rating to tell you the maximum amount of moisture it can handle.
Defrosting System And Temperature Rating
A defrosting system built into a dehumidifier is a great feature if your area experiences freezing temperatures.
If the crawl space gets very cold, the condensing coils can freeze over and damage the unit. For dehumidifiers with defrost systems, they can usually handle temperatures as low as 20°F to 35°F but you should check with the manufacturer.
Some crawl space dehumidifiers will even keep running while the defrost system is activated so you don't lose performance. Other dehumidifiers will shutoff automatically once the defrost cycle has begun.
Noise Level of Dehumidifier
The noise level of your crawl space dehumidifier can be an issue since it is close to the first floor of the home.
Small dehumidifiers tend to run at only 30-45 decibels, but larger units can be much louder at 55-100 decibels. If you are concerned about noise, we recommend checking with the manufacturer for a decibel rating as well as reading customer reviews.
How you install the dehumidifier can also impact the noise level.
Make sure that the platform is solid and level and you may also want to add some platform padding.
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Cost To Run And Longevity
Homeowners should consider the energy efficiency of their dehumidifier of choice and how much it will cost to run.
Energy Star rated dehumidifiers will use at least 15% less energy than comparable units. But the longevity or lifespan of the dehumidifier can have a bigger impact on your wallet.
Since crawl spaces tend to be harsh environments, dehumidifiers breaking down is a common issue among homeowners. For cheaper models, dehumidifiers frequently only last 12-24 months. A high quality dehumidifier should last much longer than that, and that is why I usually recommend AprilAire.
How Do Commercial Crawl Space Dehumidifiers Work?
A crawl space dehumidifier humidistat will automatically turn the dehumidifier on and off in order to reach a target humidity level.
Typically there is a control panel on the side of the unit with up and down arrows so you can pick which humidity level you prefer.
Most homeowners should set the humidistat to between 50% and 60% in order to minimize the chances for mold growth and wood damage. Some crawl space dehumidifiers even have optional remote controls so that you can adjust the humidity level without having to go into the crawl space.
The condensate pump of a dehumidifier will mechanically pump the water to the exterior of the home.
Most crawl space dehumidifiers don't come with condensate pumps and they are drained by gravity. If you need a pump, it will need to be installed separately onto the side of the machine. A hose or pipe will need to be routed to the outside of the home or to a floor drain.
Virtually all crawl space dehumidifiers have a filtration system to prevent damage to the unit. The filter system may be just one filter, or it may have a 2-3 filter layer.
We recommend that homeowners find out if the filter is washable or if it will have to be replaced regularly.
Also, how often do you have to clean or replace the filter?
Since most crawl spaces are a hassle to get into, homeowners shouldn't buy a dehumidifier that has to have regular filter changes. A once a year filter change or cleaning is best.
Crawl space dehumidifiers will have some type of digital or analog control panel on the side of the unit. It will allow you to at minimum control the set humidity level of the crawl space.
You simply push the buttons to reach your desired humidity such as 55%, and then the dehumidifier will turn on and off in order to reach that humidity level.
Some under house dehumidifiers also have remote control systems (usually purchased separately) so you can control the unit without going into the crawl space.
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How To Install Crawl Space Dehumidifiers?
Installing a crawl space dehumidifier isn't that difficult depending on how much room there is to work.
If your crawl space is very tight or if there are hazards like electrical wiring, pests, or other problems—calling in a contractor to install it is recommended.
Here are few installation tips...
Where To Place Crawl Space Dehumidifier?
Ideally, an under house dehumidifier should be located in the center of the crawl space.
It is essential to keep the dehumidifier away from the crawl space door or any other area that may bring in exterior air.
If a central location doesn't work, then the dehumidifier should be placed so that the intake is closer to the foundation wall — and so it exhausts to the center of the crawlspace.
Hanging From Joists
One common installation of crawl space dehumidifiers is to hang it by straps from the joists. If your crawl space has room, hanging it by straps is a great option.
Not only does this protect the dehumidifier from water damage and flooding events, but it will also create more efficient drainage of the condensate.
With the extra height, you may not even need a condensate pump, and it will also give you more room for storage or servicing.
Installed On Floor With Base
Crawl space dehumidifiers are commonly installed on the floor.
There should be a thick platform or two blocks for the dehumidifier to rest on such as 4-6" thick masonry blocks, bricks, or wood. It is important to make sure the base is secure and level.
There are also adjustable legs underneath the dehumidifier which you will have to adjust to make sure it is level.
The crawl space dehumidifiers drain line will automatically funnel the condensate collected to the outside of the home (or to a floor drain).
Depending on the type of drain line, your unit may require a p-trap or even a loop in the line.
Also, if gravity will not be able to drain the condensate to the exterior by itself, then you will need to install a condensate pump onto the side of the dehumidifier.
Must Have Closed Or Sealed Crawl Space
The crawl space needs to be closed or sealed when using a crawl space dehumidifier.
If the vents are open when using a dehumidifier, the humidity will still be brought in from the outside, making a dehumidifier pointless.
It would be equivalent to having the windows open inside your home when the A/C is running.
Read Also >> 7 Pictures Of Mold In Air Ducts
What Are The Risks Of Dehumidifiers For Crawlspaces?
The main risk of a crawl space dehumidifier is that homeowners don't address the actual cause of water in the crawl space.
As a home inspector, finding exterior defects that lead to water intrusion is a daily exercise.
Before even installing a crawl space dehumidifier, we recommend that homeowners fix the underlying moisture problems such as...
- Poor Grading: If any of the ground next to the home is sloping towards the home, or even if it is just flat, then it can lead to water problems. The ground next to the home should slope away from the foundation. The next time there is heavy rain, observe how the water reacts near the foundation.
- Gutters And Downspouts: Downspouts need to have extensions so that they don't drain right next to the house. Downspouts should drain several feet away from the foundation. Homeowners should also make sure that the gutters are working properly.
- Sprinkler Issues: If you have landscape sprinklers, they should not be discharging water right next to the foundation.
What Is The Purpose Of Crawl Space Dehumidifiers?
The purpose of a crawl space dehumidifier is to prevent hidden mold growth, wood deterioration, and insulation damage from high humidity.
High moisture can damage the wood subfloor, joists, band joists, and other wood framing. Moisture will also damage and lower the R-value of fiberglass insulation that is installed above the crawl space.
Are Dehumidifiers Effective In Crawl Spaces?
Industrial dehumidifiers are highly effective in crawl spaces and can remove 50 to 100 pints of water per day.
Crawl space dehumidifiers have attached drain lines so that the moisture removal is automatic and homeowners don't have to manually remove the water.
What Size Dehumidifier Do I Need For My Crawl Space?
The size of your dehumidifier depends on the floor space of your crawl space.
Homeowners will need to calculate the dimensions and match it up with the rated 'coverage area' of the crawl space dehumidifier.
And if there is a lot of moisture, homeowners should pick a dehumidifier with a higher PPD (pints per day) water removal capacity.
What Is The Best Way To Dehumidify A Crawl Space?
The best way to dehumidify a crawl space is to make sure that the ground around the house slopes away from the home.
It is also essential that homeowners verify that their gutters and downspouts are working properly. Downspouts should drain the water several feet away from the home's foundation.
After solving these basic problems, a crawl space dehumidifier can remove additional moisture.
Our #1 Top Pick: AprilAire E100 Energy Star Pro Dehumidifier
Our top pick for the best crawl space dehumidifier goes to the AprilAire E100. Here's why...
#1. Large Coverage
This dehumidifier can easily dry out your crawl space or basement, but it is also powerful enough to dehumidify your entire home. It is rated for up to 5,200-sf of coverage area.
#2. Corrosion Resistance
The coils in this AprilAire dehumidifer were designed to resist rust and corrosion which will help prevent freon leaks — one of the most common complaints among homeowners.
#3. High Capacity
The AprilAire dehumidifier can remove a large amount of moisture in a day—up to 12-gallons of water.