Best Crawl Space Dehumidifiers (2021 Review)

Are you looking for a dehumidifier to take care of the moisture in your crawl space?

You’re in the right place!

In this proHVACinfo guide, you’ll learn:

  • What are crawl space dehumidifiers? (and why you might need one)
  • What are the different types of crawl space dehumidifier? (learn which are most effective)
  • How do crawl space dehumidifiers work?
  • What do you look for in the best crawl space dehumidifiers? (keep an eye out for these things!)
  • Our reviews of the best crawl space dehumidifiers
  • And much more!
proHVACinfo | Crawl Space Dehumidifiers

In a rush? Below is a quick roundup of our top crawl space dehumidifiers!

ImageProduct
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Aprilaire 1820 Pro Dehumidifier
  • Simple Setup
  • Direct Drain
  • Compact Size
  • Excellent Moisture Removal for Most Crawl Spaces
  • Direct Drain
  • Compact Size
View on Amazon
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Dri-Eaz Revolution LGR Dehumidifier
  • Continuous Operation
  • Huge Daily Water Removal
  • 40' Drain Hose
  • Continuous Operation
  • Huge Daily Water Removal
  • 40' Drain Hose
View on Amazon
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AC Infinity AIRTIAN T8 Crawlspace Ventilator Fan
  • Heavy Duty Stainless Frame
  • Digital Display
  • Affordable Price
  • Heavy Duty Stainless Frame
  • Digital Display
  • Affordable Price
View on Amazon
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AlorAir LGR Compact Dehumidifier
  • Waterproof Design
  • Efficient Operation
  • 5-Year Warranty
  • Waterproof Design
  • Efficient Operation
  • 5-Year Warranty
View on Amazon
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Waykar Dehumidifier
  • Excellent Safety Features
  • Great Design
  • Child Lock Setting
  • Excellent Safety Features
  • Great Design
  • Child Lock Setting
View on Amazon

What Are Crawl Space Dehumidifiers?

If your home has a crawl space, chances are you’re aware of their pitfalls.

While cost-effective for housing builders and well-intentioned for the homeowner, sometimes crawl spaces result in a hassle for those living in the home.

However, by their very nature, crawl spaces are prone to moisture-related issues including mold and wood rot.

Crawl space dehumidifiers are electrical appliances designed to absorb water from the atmosphere in a crawl space in order to prevent the above problems by reducing the overall humidity in the crawl space and maintaining the humidity at a desired level.

By reducing the humidity, they prevent the development of stale and musty odors, and can stop mold and mildew from growing.

Generally speaking, your crawl space should be at a humidity level less than 70%, ideally around 55%.

proHVACinfo | Crawl Space Dehumidifiers

What size crawl space dehumidifier do I need?

This is one of the most common questions about crawl space dehumidifiers.

Like dehumidifiers for other parts of the home, the capacity for crawl space dehumidifiers is sized in pints per day.

The needed pints per day are determined by the square footage of the area needed to dehumidify, and the condition of the room without dehumidification.

Check out this table below to get an idea of how many pints per day you need!

EnergyStar Dehumidification Needs
Source: Energystar.gov

What are the Different Types Of Crawl Space Dehumidifier?

There are two main types of crawl space dehumidifier.

Some are more common than others, but all are designed to do the same job.

Heat Pump Style

This is the most common style, mainly because they are typically capable of removing the most water from the air.

They actually work using much of the same technology as an air conditioning unit.

They feature a heat pump and heat exchange coils, and use a fan to blow humid air from the room over the coils.

As the coils are extremely cold, when warm, humid air passes over them, the airborne moisture immediately condenses on them.

This moisture is now in the form of water and can drip into the collection tank, or, out through a hose to a drain.

Ventilator Style

These are a lower tech option, but are reliable and cost-effective ways to reduce crawl space humidity.

Rather than removing moisture from the air, these dehumidifiers work to expel the damp air to the outside.

These dehumidifiers are usually mounted directly in an outside wall.

How Do Crawl Space Dehumidifiers Work?

In this section we will focus primarily on how heat pump style dehumidifiers work.

Heat pump style dehumidifiers work on the refrigeration cycle.

First, the humid air from the crawl space is drawn into the dehumidifier through the louvers on the side of the unit by an internal fan.

The moist air then passes over the supercooled evaporator coils.

The rapid cooling causes the moisture in the air to condense and return to its liquid form.

There won’t be streams of water here, but a noticeable amount will begin to bead up on the coils.

This water will start dripping off the coils and into either the collection tank, or out of the unit through a hose led to a drain.

Now that the moisture is removed from the air that has entered the dehumidifier, another fan blows the dry air back out into the room.

This process continues in a cycle, continuously lowering the average humidity in the crawl space.

If your crawl space dehumidifier has a collection tank, there will be a float that activates a cut off when the tank is full.

This type will need to be emptied regularly. If it is hooked up to a hose, it can run continuously with no intervention.

What Do You Look For In The Best Crawl Space Dehumidifiers?

No matter which technology you’re considering for a crawl space dehumidifier, you should know about the factors that separate the average from the great.

Reputable manufacturers should quote these specifications, and that should make it easy for you to compare them and make the most informed decision.

Dehumidifying Footprint

This is typically measured in square feet, and gives a rough indication as to the maximum area that the unit will be effective on.

For example, if your crawl space is 1500 square feet, but your dehumidifier is rated for 1000 square feet, it will constantly be working at maximum load, and will likely never catch up and take control of the humidity in the space

Tank Size

This is particularly important for anybody who does not have a run off or drain to have their dehumidifier empty to.

The tank size denotes how long the unit will run for without needing to be emptied.

So, if you have a unit with a 7 gallon per day tank, and a 10 gallon tank, you may end up having to empty it daily as most dehumidifiers have an auto shut off when the tank is full.

The larger the capacity, the better, but remember, a large tank full of water is heavy and potentially difficult to get out of the crawl space.

If you don’t want to intervene regularly, consider setting up arrangements for a hose and drain.

Unit Dimensions

As many of the industrial type crawl space dehumidifiers are extremely heavy given their size, this should be considered before purchase.

This about how you will get it into and positioned within the crawl space. If the unit is tall, you will need to think about whether it will actually fit inside the space.

Safety Features

As we mentioned above, good crawl space dehumidifiers should have safety features like auto shut offs for instances when collection tanks are full.

This makes sense, because having water overflowing into your crawl space is likely worse than having the humid atmosphere you were trying to get rid of.

Timers are another great safety feature that allow you to run the unit only for certain portions of the day, not only does this reduce the risk of overheating and potential fire, but it also helps to conserve electricity.

Finally, we suggest looking for a unit that has an easy-to-read display.

By definition, you’re probably in a dark, tight spot when working with your dehumidifier so a straightforward display can really make a difference!

Warranty

It’s definitely worth taking the time to find crawl space dehumidifiers from brands that clearly stand behind their products.

What better way for a manufacturer to show trust in their product than to offer a generous warranty?

This will give you the peace of mind you need, especially if you’re considering one of the more expensive industrial style dehumidifiers.

Best Crawl Space Dehumidifiers Reviewed

Final Thoughts On Crawl Space Dehumidifiers

Dehumidifiers are a vital appliance in any home with a crawl space.

You may not even feel that the air needs to be dehumidified in your crawl space, but run any of these 5 units down in yours for 48 hours or more and you will be amazed at how much moisture they can draw out of the atmosphere.

Controlling the humidity can prevent serious damage to your home, and even reduce the possibility of viral transmission as drier air does not provide the right kind of environment for viruses and bacteria to breed, grow and spread.

In this day and age, that’s a benefit everybody can use.

Stephen Marks

Stephen Marks

Stephen is an HVAC and home-repair enthusiast. He's here to answer any of your questions about HVAC!

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Stephen Marks

Stephen Marks

Stephen is an HVAC and home-repair enthusiast. He's here to answer any of your questions about HVAC!

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