A crawl space dehumidifier lives in a place you rarely visit, so it has to run unattended for months. That rules out most portable bedroom and basement units. Crawl space units are built differently: they are low enough to fit between joists and the ground, they keep working in air in the 40s and 50s, they are designed to drain continuously (by gravity or a built-in pump), and many can be ducted.
Whether you call it a crawl space dehumidifier, a crawlspace dehumidifier or an under house dehumidifier, the best choice is usually a crawlspace dehumidifier with pump: a dehumidifier for crawl space with pump support can drain uphill and out of the crawl space without a floor drain. AlorAir dehumidifier models dominate this category, with Santa Fe and Aprilaire as the installer favorites.
One thing to know before you compare numbers: crawl space makers rate capacity on the AHAM test (80F, 60% humidity) or at "saturation" (90F, 90%), not on the 65F DOE test used for portable units. A 55 pint crawl space unit is not directly comparable with a 50 pint portable. Where ENERGY STAR has a DOE-test figure, we show it.
Crawl space dehumidifiers compared
| Pick | Capacity | Coverage | Pump | Noise | ENERGY STAR | Price tier | |
|---|---|---|---|---|---|---|---|
| Best overall AlorAir HDi65S | 55 pints/day (AHAM 80F) | Up to 1,300 sq ft (maker claim) | Yes | Max 52 dB (Sylvane listing) | Not stated | $$$$$ | Check price |
| Best value AlorAir HD55S | 55 pints/day (AHAM 80F) | Up to 1,300 sq ft (maker claim) | No | Not published for this SKU | Yes | $$$$ | Check price |
| Best for large crawl spaces AlorAir HDi90 | 90 pints/day (AHAM 80F) | Up to 2,600 sq ft (maker claim) | Yes | Max 58 dB (Sylvane listing) | Not stated | $$$$$ | Check price |
| Best Santa Fe Santa Fe Compact70 | 70 pints/day (AHAM 80F) | Crawl spaces about 1,800 to 2,600 sq ft (maker data sheet) | No | Not published | Not stated | $$$$$ | Check price |
| Best Aprilaire Aprilaire E070 | 70 pints/day (AHAM 80F) | Up to 2,800 sq ft (crawl space use; maker FAQ); Amazon listing says up to 2,200 sq ft | No | Not published | Not stated | $$$$$ | Check price |
| Most capacity Santa Fe Advance90 | 90 pints/day (AHAM 80F) | Not stated | No | Not published | Not stated | $$$$$ | Check price |
| Portable alternative Midea Cube 50 (pump) | 50 pints/day (DOE) | Up to 4,500 sq ft (maker claim) | Yes | Maker: as low as 42 dB(A). RTINGS measured 54.3 dBA (low fan) to 56.2 dBA (high fan) | Yes | $$$ | Check price |
Best crawl space dehumidifier with pump
AlorAir Sentinel HDi65S Crawl Space Dehumidifier with Pump
Best for: most crawl spaces without a gravity drain.
The AlorAir Sentinel HDi65S is our first choice for a typical crawl space with no drain. It is rated at 55 pints a day on the AHAM test (120 at saturation), AlorAir lists it for crawl spaces up to 1,300 sq ft, and it is rated to run from 33.8F to 104F. A built-in pump handles the water, and Wi-Fi lets you check humidity without crawling under the house. At 19.2 x 12.2 x 13.3 inches, it fits most crawl space clearances.
| Model number | HDi65S |
|---|---|
| Type | Compressor (crawl space / basement, low temp) |
| Capacity (AHAM test, 80F, 60% RH) | 55 pints/day |
| Coverage | Up to 1,300 sq ft (maker claim) |
| Built-in pump | Yes |
| Wi-Fi / app | Yes |
| ENERGY STAR | Not stated |
| Noise | Max 52 dB (Sylvane listing) |
| Low-temperature operation | 33.8F to 104F operating range (maker) |
| Capacity at saturation (90F, 90% RH) | 120 pints/day |
| Airflow | 130 CFM |
| Size / weight | 19.2 x 12.2 x 13.3 in, 44 lb |
| Warranty | 6-year limited (Amazon listing) |
| Price tier | Pro (about $900 and up) |
Pros
- Built-in pump
- Rated down to 33.8F
- Wi-Fi monitoring
- Compact
Cons
- Pro price tier
- Max 52 dB (fine under a floor, noticeable in a room)
Spec sources (checked 2026-11-11): AlorAir product page HDi65S; AlorAir HDi65S spec sheet; Sylvane listing (noise, low temp).
AlorAir Sentinel HD55
AlorAir Sentinel HD55S Crawl Space Dehumidifier (drain hose)
Best for: crawl spaces with a drain or an existing condensate pump.
The AlorAir Sentinel HD55 name covers a few versions. The original HD55 is listed at 53 pints (AHAM) for 1,200 sq ft; the newer HD55S is listed at 55 pints for 1,300 sq ft and drains by gravity hose. The HD55S is also on ENERGY STAR's certified list, where its DOE-test result is 36.33 pints a day at 2.08 L/kWh. That efficiency figure is higher than any 50 pint portable we track, and its estimated 379 kWh a year works out to about $69 at the 2026 U.S. average electricity price.
No pump means you need a drain or a separate condensate pump. If you have one, the HD55S is the best value here.
| Model number | HD55S |
|---|---|
| Type | Compressor (crawl space / basement, low temp) |
| Capacity (AHAM test, 80F, 60% RH) | 55 pints/day |
| Coverage | Up to 1,300 sq ft (maker claim) |
| Built-in pump | No |
| Wi-Fi / app | No |
| ENERGY STAR | Yes |
| Noise | Not published for this SKU |
| Low-temperature operation | Compressor rated down to 33.8F (retailer listing) |
| Capacity at saturation | Up to 120 pints/day |
| Note on the name | The original Sentinel HD55 is listed at 53 pints AHAM and 1,200 sq ft; HD55S and pump version HD55P are newer variants |
| Warranty | 6-year limited (Amazon listing) |
| ENERGY STAR test data | 36.33 pints/day, IEF 2.08 L/kWh, about 379 kWh/yr (record for Sentinel HD55S) |
| Price tier | Premium (about $400 to $900) |
Pros
- ENERGY STAR certified, IEF 2.08 L/kWh
- Rated to about 33.8F
- Lower price tier than the HDi65S
Cons
- No built-in pump
- Several similar model names: check for the S
Spec sources (checked 2026-11-11): Sylvane listing Sentinel 55 pint drain hose; AlorAir HD55 spec sheet; Sylvane listing original HD55 (53 pints, 1,200 sq ft); ENERGY STAR certified product record (Sentinel HD55S).
Best for large or wet crawl spaces
AlorAir Sentinel HDi90 Basement and Crawl Space Dehumidifier with Pump
For big crawl spaces, or ones that recently flooded, the HDi90 is rated at 90 pints a day (AHAM) and 198 at saturation, with 210 CFM of airflow and a built-in pump. AlorAir lists it for spaces up to 2,600 sq ft.
| Model number | HDi90 |
|---|---|
| Type | Compressor (crawl space / basement, low temp) |
| Capacity (AHAM test, 80F, 60% RH) | 90 pints/day |
| Coverage | Up to 2,600 sq ft (maker claim) |
| Built-in pump | Yes |
| Wi-Fi / app | Not stated |
| ENERGY STAR | Not stated |
| Noise | Max 58 dB (Sylvane listing) |
| Low-temperature operation | Down to 33.8F (retailer listing) |
| Capacity at saturation (90F, 90% RH) | 198 pints/day |
| Airflow | 210 CFM |
| Warranty | 6-year limited (Amazon listing) |
| Price tier | Pro (about $900 and up) |
Pros
- High capacity
- Built-in pump
- Low-temp rating
Cons
- Pro price tier
- Larger body; check clearance
Spec sources (checked 2026-11-11): Sylvane listing HDi90; AlorAir product spec PDF.
Santa Fe crawl space dehumidifier
Santa Fe Compact70 Crawl Space Dehumidifier
The Santa Fe crawl space dehumidifier most installers reach for is the Compact70 (formerly Compact2). It is rated at 70 pints a day on the AHAM test, moves 150 CFM, and Santa Fe's data sheet sizes it for crawl spaces of about 1,800 to 2,600 sq ft. Its rated operating range starts at 49F, which is higher than AlorAir's, so it suits crawl spaces that stay above the high 40s. It drains by gravity; add a condensate pump if needed.
| Model number | Compact70 (4044110, formerly Compact2) |
|---|---|
| Type | Compressor (crawl space / basement, low temp) |
| Capacity (AHAM test, 80F, 60% RH) | 70 pints/day |
| Coverage | Crawl spaces about 1,800 to 2,600 sq ft (maker data sheet) |
| Built-in pump | No |
| Wi-Fi / app | No |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Low-temperature operation | 49F to 95F operating range (maker data sheet) |
| Airflow | 150 CFM |
| ENERGY STAR status | Not on ENERGY STAR's current certified list (checked Nov 2026); older listings may describe an earlier certification. |
| Price tier | Pro (about $900 and up) |
Pros
- Installer favorite, built for continuous duty
- 70 pints/day (AHAM)
- Large crawl space sizing
Cons
- No built-in pump
- 49F minimum operating temperature
- Pro price tier
Spec sources (checked 2026-11-11): Santa Fe Compact70 data sheet; Santa Fe 4044110 submittal sheet; Sylvane listing Compact70.
Aprilaire crawl space dehumidifier
Aprilaire E070 Whole-Home Dehumidifier
The Aprilaire crawl space dehumidifier is the E070, rated at 70 pints a day. Aprilaire's FAQ lists it for up to 2,800 sq ft and notes that this maximum applies to crawl space use, not whole-home use. Aprilaire units are normally sold and installed by HVAC contractors, so price and warranty depend on the installer.
Heads up: Sold on Amazon as well as through HVAC contractors. Ducted installs should be done by a pro.
| Model number | E070 |
|---|---|
| Type | Whole-house (ducted or ventilating) |
| Capacity (AHAM test, 80F, 60% RH) | 70 pints/day |
| Coverage | Up to 2,800 sq ft (crawl space use; maker FAQ); Amazon listing says up to 2,200 sq ft |
| Built-in pump | No |
| Wi-Fi / app | No |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Airflow | 200 CFM (Amazon listing) |
| Weight | 56 lb |
| Sizing note | Aprilaire sizes by climate region and how airtight the home is; ask the installer to run its Dehumidifier Selection Assistant |
| Price tier | Pro (about $900 and up) |
Pros
- 70 pints/day
- Sized specifically for crawl spaces
- Contractor support
Cons
- Usually needs a contractor
- Pro price tier
Spec sources (checked 2026-11-12): Aprilaire dehumidifier FAQ (ppd and sq ft); Aprilaire E-series guide, Nov 2025 (ppd, weights); Amazon listing B094PR3HQ1 (AprilAire E070 Pro).
Most capacity
Santa Fe Advance90 Dehumidifier
Santa Fe's Advance90 is listed at up to 90 pints a day at standard rating conditions (11.25 gallons). It is a good fit for large, damp crawl spaces where the Compact70 would run nonstop.
| Model number | Advance90 |
|---|---|
| Type | Compressor (crawl space / basement, low temp) |
| Capacity (AHAM test, 80F, 60% RH) | 90 pints/day |
| Coverage | Not stated by maker |
| Built-in pump | No |
| Wi-Fi / app | No |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Capacity in gallons | 11.25 gal/day at rating conditions (Santa Fe catalog) |
| Price tier | Pro (about $900 and up) |
Pros
- 90 pints/day
- Santa Fe build quality
Cons
- Few published specs beyond capacity
- Pro price tier
Spec sources (checked 2026-11-11): Santa Fe catalog.
Portable alternative (conditioned crawl spaces only)
Midea Cube 50 Pint Smart Dehumidifier with Pump
If your crawl space is encapsulated, conditioned and stays warm (mid 60s or higher), a portable 50 pint pump model like the Midea Cube can work and costs far less. ENERGY STAR notes that compressor units are tested at 65F and that you should consider a low-temperature model if the space usually falls below that. Most crawl spaces do, so treat this as the exception.
Heads up: Midea sells several SKUs (MAD50PS1QWT, gray MAD50PS1QGR, MAD50S1QWT without pump). Check the exact model number.
| Model number | MAD50PS1QWT |
|---|---|
| Type | Compressor (portable) |
| Capacity (current DOE test, 65F) | 50 pints/day |
| Coverage | Up to 4,500 sq ft (maker claim) |
| Built-in pump | Yes |
| Wi-Fi / app | Yes |
| ENERGY STAR | Yes |
| Noise | Maker: as low as 42 dB(A). RTINGS measured 54.3 dBA (low fan) to 56.2 dBA (high fan) |
| Bucket / capacity | Expandable bucket; listed as 3x more water capacity than a standard bucket |
| Humidity setting range | 35% to 85% |
| Rated power input | 480 W (Canadian MAD50PS1QGRC spec sheet) |
| Drain options | Bucket, gravity hose, or built-in pump that lifts water to a sink or window |
| Pump lift | Up to 16.4 ft vertical per Midea's spec sheet (a Midea support answer on Home Depot says 14 ft) |
| ENERGY STAR test data | 49.67 pints/day, IEF 2.01 L/kWh, about 515 kWh/yr (record for MAD50PS1QWT-A) |
| Price tier | Mid (about $200 to $400) |
Pros
- Much cheaper
- Pump and app
Cons
- Not built for cold, unattended crawl spaces
- Taller than crawl space units
Spec sources (checked 2026-11-11): Midea US product page (MAD50PS1QGR, 4,500 sq ft, pump); Midea Canada spec sheet MAD50PS1QGRC; Home Depot listing (42 dB(A), ENERGY STAR, 3X water capacity); RTINGS review MAD50PS1QWT (measured noise, efficiency); ENERGY STAR certified product record (MAD50PS1QWT-A).
Low-temp rating table
| Model | Rated minimum operating temperature | Source |
|---|---|---|
| AlorAir Sentinel HDi65S | 33.8F | AlorAir product page |
| AlorAir Sentinel HDi90 | 33.8F | Retailer listing |
| AlorAir Sentinel HD55S | 33.8F | Retailer listing |
| Santa Fe Compact70 | 49F | Santa Fe data sheet |
| Portable compressor units | Tested at 65F; ENERGY STAR suggests a low-temp model below that | ENERGY STAR |
Ideal crawl space humidity
There is no single official crawl space number, but the guidance lines up: keep relative humidity below 60% at all times, and aim for about 50 to 55% in an encapsulated crawl space. The EPA's general rule for buildings (below 60%, ideally 30 to 50%) applies, and mold and wood-decay risk climbs when crawl space air sits above 60% for long periods.
Is 60 humidity in crawl space air OK? It is the upper limit, not a target. If your crawl space reads 60% in summer, set the dehumidifier to 50 to 55% so it has room to handle humid spells.
Crawl space sq ft sizing chart
| Crawl space size | Typical choice |
|---|---|
| Up to about 1,300 sq ft | 55 pint (AHAM) class: AlorAir HD55S or HDi65S |
| About 1,300 to 2,600 sq ft | 70 to 90 pint (AHAM) class: Santa Fe Compact70, Aprilaire E070, AlorAir HDi90 |
| Over 2,600 sq ft or very wet | 90+ pint units, or two units; ask an installer |
Sealed, encapsulated crawl spaces need less capacity than vented ones because less humid outdoor air gets in. One reviewer notes that maker ratings assume open conditions, so a tightly sealed crawl space often needs less than the chart suggests.
Dehumidifier in crawl space without encapsulation
You can run a dehumidifier in a vented crawl space, but it is working against outdoor air coming in through the vents and moisture rising from bare soil. At minimum, lay a ground vapor barrier first. Building-science writers generally recommend sealing the crawl space and then drying it with a dedicated dehumidifier or conditioned air; Green Building Advisor describes a stand-alone dehumidifier as an effective, if more expensive, way to treat the air in a sealed crawl space.
If you are unsure whether to encapsulate, get an inspection. A dehumidifier is not a fix for standing water or drainage problems.
Buying-guide decision table
| If your crawl space... | Buy |
|---|---|
| Has no drain and gets cool | AlorAir HDi65S (pump, 33.8F) |
| Has a drain or sump | AlorAir HD55S |
| Is large or recently flooded | AlorAir HDi90 |
| Is being done by an HVAC contractor | Aprilaire E070 or Santa Fe Compact70 |
| Is encapsulated and stays warm | Midea Cube 50 (budget) |
Frequently asked questions
Do I need a dehumidifier in my crawl space?
Is 60 humidity in crawl space OK?
Can you use a regular dehumidifier in a crawl space?
How much does a crawl space dehumidifier cost to run?
Sources
- ENERGY STAR: Dehumidifiers buying guidance and sizing chart
- ENERGY STAR Certified Dehumidifiers dataset (data.energystar.gov)
- EPA Mold Course, Chapter 2: indoor humidity guidance
- Green Building Advisor: Five ways to deal with crawl space air
- Aprilaire: dehumidifier FAQ
- U.S. EIA Short-Term Energy Outlook: residential electricity prices