Danny as been writing about air purifiers for 10+ years. He is a major fan of home technology, which makes him the perfect person to test and evaluate products for HouseFresh
Excess moisture and high humidity can often infiltrate crawl spaces. This means they are prone to mold and mildew, not to mention unpleasant, musty smells. Damp crawl spaces are also more likely to attract pests like spiders, silverfish and termites.
Worryingly, these problems can impact your health, even if you rarely visit your crawl space. The humid air will rise to the rest of your home, causing allergy symptoms, respiratory problems, coughing and sneezing to increase.
The good news is that a crawl space dehumidifier can significantly reduce these issues, and we’re here to help you find the right one.
| Why You Can Trust Our Recommendations We’ve seen our fair share of dehumidifiers in action, including in our crawl space at HouseFresh HQ. All of the dehumidifiers on this list will fit in even the smallest of crawl spaces. Crawl spaces range in height from 39″ to 16″, so all of our product selections below are specially designed short, rugged dehumidifiers that we know can remove moisture. Alongside each dehumidifier’s weight and tank size, we looked at special features like: ✅ Auto defrost ✅ Auto restart ✅ Antibacterial filter ✅ Pump support ✅ Wi-Fi connectivity |
Top 3 Best Crawl Space Dehumidifiers
If you don’t have time to read through the full list, you can just focus on our top three recommended dehumidifiers for the crawl space:
Those are our top three picks but they are not the only good units to consider. If you haven’t found what you were looking for in the table above, you might want to keep scrolling down this page for all our recommended dehumidifiers.
1. Best Overall: Alorair Sentinel HD55
The Sentinel HD55 can extract 55 pints per day (PPD) at 80°F, with 60% Relative Humidity and 120 PPD at 90°F, with 90% Relative Humidity (Saturation).
It’s super simple to operate this thing; the compact control panel comprises:
- Power button
- Arrow buttons to set the desired humidity level
- Continuous Operation mode
- Indicator lights for power, continuous mode/auto-defrost
- Compressor.
A digital display screen 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 to the current reading. If your crawlspace is not easily accessible, 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 operating. The unit has no collection tank, so the moisture is extracted and drained via gravity through a drain tube.
The adjustable feet are a nice bonus, allowing you to level it on an unfinished crawl space.
What We Really Like:
👍 This unit comes with a 5-year manufacturer’s warranty
👍 Runs extremely quietly
👍 The filter is straightforward to remove, clean and reinstall
👍 It drains the water perfectly, even without using a pump
What We Think Could Be Better:
👎 The drain hose that is supplied could be a little longer
👎 We wish the fan had more than one-speed mode
SPECS & FEATURES
| Dehumidification Capacity | 113 PPD at saturation, 53 PPD at AHAM |
| Airflow Volume | 120 CFM (205 CMH) |
| Floor Area Coverage | Up to 1,200 sq ft |
| Dimensions | 19.2 x 12.2 x 13.3 inches (49 x 31 x 34 cm) |
| Weight | 57 lbs (26 kg) |
| Construction Material | Metal outer casing |
| Special Features | Built-in humidity sensor (can set humidity level between 36%-90%) + Adjustable feet and handle for easy transportation + Auto-diagnosis system that offers tips via error codes |
| Cord Length | 8 ft (2.43 m) |
| Filter | MERV-8 Filter |
| Max Noise Level | 52 dB |
| Warranty | 5 years |
2. Best Budget Option With Pump: Moiswell 145 with Pump
A new brand in the world of dehumidifiers, Moiswell brings commercial-grade features at a price that generally requires spending upwards of $800.
The Moisewell 145 includes a 6.5ft drain hose that can drain almost anywhere thanks to its internal pump that can force water vertically up to 16.5 ft.
The one stand-out feature of this crawl space dehumidifier is how small it is compared to the level of dehumidification power. It’s the shortest unit we have seen, yet it can still remove 145 pints per day.
What We Really Like:
👍 Great price for this level of capacity, airflow and floor coverage
👍 Small size compared to standard air purifiers with less dehumidification power
👍 Has access to keep the self-draining hose clean, so less maintenance required
👍 Quiet operation
What We Think Could Be Better:
👎 The brand is less well known
👎 Made in China, it might put some consumers off
SPECS & FEATURES
| Dehumidification Capacity | 145 Pints |
| Airflow Volume | 265 CFM |
| Floor Area Coverage | Up to 6,000 sq ft |
| Dimensions | 22.5 x 14 x 13.3 inches (57 x 36 x 34 cm) |
| Weight | 69 lbs (31kg) |
| Material | Alloy Steel |
| Special Features | Ductable + Auto drain by gravity + Auto defrost |
| Cord Length | 9.2 ft (2.8m) |
| Max Noise Level | 58 dB |
| Included Components | Drain Hose, Air Outlet Collar |
| Recommended Uses | Commercial Indoor Use |
| Warranty | 5 years |
3. Alorair HD55S
If you like our number one recommended unit, the Alorair HD55, but want an upgrade, the HD55S has more significant water removal — 120 pints, but comes at a higher cost.
What We Really Like:
👍 5-year warranty
👍 Made in the USA
👍 Affordable price for commercial features
👍 It uses a rare earth alloy tube evaporator
What We Think Could Be Better:
👎 No pump, just a gravity drain hose
👎 You will save money with HD55 if you prefer to spend less for a slightly less powerful dehumidifier
SPECS & FEATURES
| Dehumidification Capacity | Up to 120 pints of water per day (55 Pints/Day @ AHAM) |
| Airflow Volume | 130 CFM (230 CMH) |
| Floor Area Coverage | Up to 1,300 sq ft |
| Dimensions | 19.2 x 12.2 x 13.3 inches (49 x 31 x 34 cm) |
| Weight | 44 lbs (20 kg) |
| Material | Alloy Steel |
| Special Features | Automatic defrost + Internal corrosion protection + Memory restart + Remote control system |
| Cord Length | 10 ft (3 m) |
| Max Noise Level | 52 dB |
| Filter | MERV-1 Filter (Optional MERV-8 Filter) |
| Warranty | 1 year (parts and labor), 3 years (parts and labor on refrigeration system ONLY) and 5 years (parts on refrigeration system ONLY. |
4. Best for Very Large Crawl Spaces: AprilAire E130
It’s not cheap, but the AprilAire E130 is one of the most powerful crawl space dehumidifiers on the market. It can remove 130 pints and even works in crawl spaces as large as 7200 square feet.
All AprilAire units are designed and built in the United States by a brand that has been in the market for decades. This is an Energy Star-certified dehumidifier so it’s energy efficient.
What We Really Like:
👍 Made in the USA
👍 Affordable price for commercial features
👍 It uses a rare earth alloy tube evaporator
What We Think Could Be Better:
👎 Higher price than Chinese-made options
👎 Better value with the HD55 if you prefer to spend less
SPECS & FEATURES
| Dehumidification Capacity | Up to 130 pints |
| Airflow Volume | 310 CFM |
| Floor Area Coverage | Up to 7,200 sq ft |
| Dimensions | 19.5 x 30 x 18.75 inches (49 x 76 x 48 cm) |
| Weight | 113 lbs (51 kg) |
| Material | Galvanized Steel, Plastic |
| Special Features | Smart sensor + Continuous draining + Adjustable humidity control + Digital display + Automatic defrost + Automatic moisture removal + Overheat protection + Automatic shutoff + Washable filter. |
| Included Components | 10-inch Outlet Duct Collar, 10-inch Inlet Duct Collar, Backdraft Damper, Torx Bit (T20), Leveling Feet, Screws, Barbed Drain Fitting, 8-foot Power Cord |
| Filter | Washable MERV-8 Filter |
| Cord Length | 8 ft (2.4 m) |
| Max Noise Level | 50 dB |
| Warranty | 5-year warranty |
5. Best Commercial Crawl Space Dehumidifier: Alorair Storm LGR Commercial
This commercial-grade dehumidifier from Alorair can extract up to 180 pints of moisture from the air and is an ideal size and weight for crawl spaces.
This self-draining dehumidifier automatically expels the collected water. 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 drain to the outside.
Its robust internal pump can push the water “uphill” to a maximum height of 15 feet. This helps if the unit is on the crawlspace floor, and you can only get the tube to the outside to raise it up and out.
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 the inlet and outlet are displayed. The unit will turn off and on automatically to keep humidity at the chosen level — an ideal crawl space dehumidifier.
What We Really Like:
👍 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
What We Think Could Be Better:
👎 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
SPECS & FEATURES
| Dehumidification Capacity | 180 PPD at Saturation, 85 PPD (AHAM) |
| Airflow Volume | 310 CFM |
| Floor Area Coverage | Up to 2,300 sq ft |
| Dimensions | 22.8 x 13.7 x 17.3 inches (58 x 35 x 44 cm) |
| Weight | 78 lbs (35 kg) |
| Material | Polyethylene (PE) |
| Special Features | Self-draining thanks to its pump + Automatic defrosting + Auto ON/OFF operation + Memory restart + Display temperature and humidity |
| Included Components | Drain hose |
| Filter | MERV-8 Filter |
| Cord Length | 19.6 ft (5.9 m) |
| Max Noise Level | 58 dB |
| Warranty | 5-year warranty |
6. Aprilaire 1820 70 Pint Crawl Space Pro
Removing up to 70 pints per day, the Aprilaire 1820 dehumidifier is the perfect choice for a crawlspace up to 2,800 sq. ft. Its compact size 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, thereby preventing mold and mildew. There is no water collection tank, so you don’t have to remember to empty it. A ten-foot ¾ inch diameter drain hose is included along with the necessary connectors to have continuous drainage.
Amazingly, you can control this dehumidifier over Wi-Fi. By adding a smart controller, you can use your smartphone to access settings, check that the unit is working, or see the humidity level from anywhere you happen to be. This is perfect for checking up on the unit without physically accessing it in your crawl space.
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 the unit on, the humidity is measured, and if it’s higher than your setting, the compressor will turn on and start dehumidifying.
What We Really Like:
👍 Being able to connect ductwork to get good air circulation
👍 Designed and made in the USA
👍 Features a Wi-Fi thermostat/humidistat monitoring connection
👍 Arrives with a 5-year warranty
What We Think Could Be Better:
👎 The included drain hose tends to kink
👎 We’d like to see carrying handles on the unit to aid with portability
SPECS & FEATURES
| Dehumidification Capacity | 70 PPD |
| Airflow Volume | 200 CFM |
| Floor Area Coverage | Up to 2,800 sq ft |
| Dimensions | 12.5 x 25 x 12.5 inches (32 x 63.5 x 32 cm) |
| Weight | 56 lbs (25.4 kg) |
| Material | Galvanized Steel, Plastic |
| Special Features | Continuous draining + Adjustable humidity control + Digital display + Automatic defrost + Automatic moisture removal + Overheat protection + Automatic shutoff + Washable Filter |
| Included Components | 8-inch Outlet Duct Collar, 8-inch Inlet Duct Collar, Torx Bit (T20), Leveling Feet, Screws, Barbed Drain Fitting, 8-foot Power Cord, 10-foot Drain Tubing, Washable Filter |
| Filter | MERV-8 Filter |
| Cord Length | 10 ft (3 m) |
| Max Noise Level | 53 dB |
| Warranty | 5-year warranty |
What to Look for When Buying a Dehumidifier for Your Crawl Space
Anyone living in a home with a crawl space knows the problems stemming from excess moisture and humidity build-up.
Crawl spaces are characterized by poor ventilation due to the enclosed nature of these areas. Moisture build-up in the crawl space, warmth and darkness 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 using a crawl space dehumidifier. A dehumidifier can fix these issues by absorbing the moisture in the crawl space, preventing mold and mildew growth.
Here are five things to consider before buying a dehumidifier for your crawl space:
1. Height of dehumidifier in the context of the size of the crawl space
Many big box dehumidifiers won’t fit in tiny crawl spaces, so you must look at those designed with low height in mind. Many crawl-space-designed dehumidifiers can be attached directly to floor joists.
2. Coverage area of the dehumidifier
The coverage area is critical 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 should be easy.
The area of coverage defines the area the dehumidifier can clean. For example, buying a dehumidifier with a coverage area of 1,000 sq. feet and using it in a 2,000 square feet area will not work.
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.
Regarding dehumidifiers for the crawl space, there’s no one size fits all solution. You want to invest in something other than a unit that takes up too much of your crawl space.
Before you even start looking, we recommend taking measurements of the coverage area first.
| 💡 Pro Tip: 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 and the amount of water that can be removed over 24 hours. For example, in a 1,300 sq. ft. slightly damp crawl space, a dehumidifier capable of extracting 20-30 pints per day (PPD) is adequate. A very damp crawl space would need a 30-40 PPD unit and a unit that can extract more than 50 PPD for a wet crawl space. |
3. Does it come with a defrosting system?
The defrosting system is critical 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.
| 💡 Pro Tip: Can’t afford a unit with a defrosting system? Not to worry, we have put together a step-by-step guide with tips on what to do if your dehumidifier ices up. |
4. Gravity drain vs. pump
Unlike household dehumidifiers, there is no tank to empty, as crawl spaces are usually hard to access. Most crawl-space units will either use a pump or a gravity hose to allow you to remove water from the air to a drain. If you need to move water upwards, you will want to look for a dehumidifier with an integrated pump.
5. Availability of a 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.
| 💡 Pro Tip: 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. |
Common Questions about Dehumidifiers for Crawl Spaces
🤔 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 are also more rugged than the typical dehumidifiers and can filter around 7 – 14 gallons of water daily. Crawl space dehumidifiers can be installed on the floor or hung by the floor joints with straps.
🤔 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.
Drying out a wet crawl space may take eight to ten hours. 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 relative humidity level. 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, this will prevent frost build-up on the coils.
Wrapping Up
Crawl spaces are known to be dark and dirty and the excess moisture can impact your health. Choosing the right dehumidifier is an essential line of defense against this.
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 essential because it will run the dehumidifier when the humidity exceeds the set level and switch off when it drops below it. An automatic defrost system could be sound if you suffer from wintery conditions.
In summary, choose a dehumidifier that will handle the crawlspace area, remove the most moisture daily and drain the water in the most beneficial way to suit your lifestyle.
Last update on 2023-09-12 / Affiliate links / Images from Amazon Product Advertising API