Best Basement & Crawl Space Dehumidifiers

Hot weather gets undeniably worse when the humidity goes up, and vice versa: you feel hotter, your skin gets clammy, and the air feels heavy and muggy. Humidity refers to the amount of water vapor in gas (or to put it simply, it’s the moisture in the air) and as an area gets more and more humid, a lot of other factors get affected within that particular area. Places that are closed off, near/have a source of water/moisture, do not get enough sun, and do not have proper ventilation are the ones that become too humid. Although any part of the house can get moisture/humidity problems, basements and crawl spaces are the areas that require extra attention in terms of humidity control.

Here’s a list of the best basement & crawl space dehumidifiers.

HOW CAN HUMIDITY BECOME A PROBLEM?

Why is moisture control so important? High humidity does not only make an area feel clammy and hot; it can also affect the structural integrity of the house negatively. If your basement or crawl space has been kept humid for too long, the carpet, wood, wall covering, and other fixtures within the area may get rusted and deteriorated, spurred on by the growth of mold and mildew. You have to understand that fungi exist in the air; their spores float around, which are relatively harmless in small quantities and if these spores are not given a chance to grow and thrive. Unfortunately, mold and mildew (or fungi in general) love damp, humid areas, and once they’ve found a favourable environment for them, their growth comes as easy as ABC.

The alarming thing is that fungi do not only cause an inconvenience in terms of rotting wood, carpet, etc., but these microorganisms can also cause a musty odor and worsen your health, especially if you have allergies because they have pollen that can act as allergens. Exposure or inhalation of pollen can lead to asthma, eye and skin irritation, allergic rhinitis, wheezing, and other upper respiratory tract infections. Worst case scenario, if people have had prolonged exposure to indoor mold, inhaling toxic (or non-toxic) pollens, they can develop chronic lung diseases due to mold infection within the lungs. Another worrying set of microorganisms that thrives in high humidity are dust mites, which can infest beddings, floorings, and furniture. These can also cause skin irritation and trigger allergic reactions.

To avoid such troubles, you must maintain a good level of humidity in your home, especially if you’re thinking of putting it up for a resale to allure potential buyers with pristine walls and perfectly- carpeted floors (just like how showers and bathtubs amp up resale value). Besides, early resolution of moisture problems is a lot cheaper than reupholstering your basement or changing your whole carpeting. But if you find yourself in need of remodeling your basement or crawl space, make sure to seek out and resolve all the roots of your moisture problems because remodeling a basement can get tricky, sometimes even way more troublesome than converting a half-bath into a full bath—a lot of factors get involved!

WHAT IS THE IDEAL INDOOR HUMIDITY?

For your home to be safe, comfortable, and retain its structural integrity, indoor humidity must be kept at a normal level. According to the National Asthma Council Australia, the recommended indoor humidity level that’s good for both your house and your health is between 30-50%. A low humidity level leads to dry air, which can dry out our skin, irritate our nasal passages, and cause floors to crack. On the other hand, high levels of humidity, as mentioned, support the growth of mold or dust mites and can trigger deterioration or rotting of wood, carpet, etc.

There are various ways to ensure that the humidity in your home stays within the optimum range; ensure that there are no leaks in and around your house, make use of exhaust fans in kitchens and bathrooms, and use moisture control appliances like humidifiers and dehumidifiers.

WHAT KIND OF DEHUMIDIFIER DO I NEED FOR MY BASEMENT?

To know what kind of humidifier one needs, you have to understand how a humidifier works first. At a certain temperature, the air can only hold a certain amount of water vapor; as temperature goes up, the amount of moisture the air can hold also rises. At 20°C, 1 m3 of air can hold around 6 ounces of water, maximum. With this amount of moisture in that certain amount of air, the relative humidity is at 100% (air is fully saturated), which is why it is called the state of saturation. If you recall, I mentioned previously that a relative humidity of 30-50% indoors is what’s good for both your home and your body. This is where dehumidifiers come in! A dehumidifier takes in air from its surroundings and removes excess moisture or water from it and blows out dehumidified air into the room, lowering the humidity to a certain level that is more suitable indoors.

There are two types of dehumidifiers, refrigerant and desiccant dehumidifiers, and these two operate differently. To gauge which one is perfect for your basement, we’ll have to briefly discuss how they work:

How does a refrigerant dehumidifier work?

A refrigerant dehumidifier (also known as a compressor dehumidifier) works by taking in damp air through a filter and passing it over a set of cold coils called the evaporator in order to dry the air. This dehumidifier, as the name implies, makes use of refrigerant, which is a fluid that is stored inside the coils that can absorb heat from the air and can transition from gas to liquid. In a nutshell, this process lowers humidity by cooling down damp air to the point that the moisture from it begins to condense (i.e., turning gaseous matter into liquid). The water that formed through this process is collected in a catch basin or water tank in the unit. Then, the resulting dried air is passed over a set of warm coils called the condenser, reheating the air to room temperature prior to releasing it back into the room through the fan.

Since this whole process relies on the coils of the evaporator being cooler than the air outside, this type of dehumidifier is sensitive to cold seasons. In general, refrigerant dehumidifiers can operate well in areas with a temperature range of 5-30°C, though they work best at 20-30°C. So, if the area is not well-heated during cold seasons, the refrigerant inside the coils of the dehumidifier may freeze over, and it won’t work efficiently until the system gets to defrost properly. However, the advantage of this dehumidifier’s use of cold coils is that it is relatively cheaper and consumes less energy compared to a desiccant dehumidifier, which uses heat.

How does a desiccant dehumidifier work?

On the other hand, a desiccant dehumidifier, as the name implies, uses a desiccant instead of refrigerants stored in coils. What sets this type of dehumidifier from compressor ones is that it does not heavily rely on the temperature of the surroundings. Thus, even at low temperatures, a desiccant dehumidifier can work just as well as it does during the summer. The reason why this dehumidifier can work optimally in both hot and cold areas is due to the presence of the desiccant. It is a hygroscopic substance, which absorbs moisture from the air. Thus, the desiccant itself takes out the moisture from the air. This substance is widely used to remove humidity from areas/packages that must not be exposed to too much moisture (e.g., silica gel packs in bags of crispy snacks).

Basically, a desiccant dehumidifier works by taking in damp air through a filter and passing it through a rotor or rotating wheel that holds the desiccant. In this area, the excess moisture gets extracted from the air, absorbed by the desiccant. Then, heat is applied to extract the moisture from the desiccant. Like refrigerant dehumidifiers, some models have catch basins or water tanks to collect this moisture, while some units are equipped with drainage systems.

The downside of this heating feature is that it consumes more energy and might add heat to the room. However, unlike refrigerant dehumidifiers, desiccant dehumidifiers can remove the same amount of moisture from the air irrespective of the environment’s (external) temperature. Furthermore, desiccants have a long lifespan, as these materials do not expire and do not require replacement. These two features add to the durability and effectiveness of the dehumidifier. On the other hand, some refrigerant dehumidifiers might need maintenance or replacement of components if the refrigerant gets frozen over multiple times and if the compressor unit becomes faulty. This adds to the durability and effectiveness of desiccant dehumidifiers.

To sum it all up, here’s my recommended dehumidifier based on your home’s conditions:

  • A refrigerant dehumidifier is a great choice if you…
    • want less energy consumption/cost
    • want a relatively cheap dehumidifier
    • have a heated basement or great overall heating system
    • live in a relatively warm area or tropical area
  • A desiccant dehumidifier is a great choice if you…
    • want stable and efficient performance regardless of external temperature
    • want a long lasting, sturdy dehumidifier
    • have an unheated basement or overall poor heating system
    • live in areas that suffer harsh winters

WHAT SIZE OF DEHUMIDIFIER DO YOU NEED FOR YOUR BASEMENT OR CRAWL SPACE?

Not all dehumidifiers are capable of lowering the relative humidity in huge percentages; dehumidifiers have their own capacities and limits, too, just like air conditioners (you can link any AC BTU articles here). So, just like how it’s important to choose the right wire size when you’re shopping for a meter socket, circuit breaker, or an extension cord, it’s also important to check the dehumidifier’s size and capacity, regardless of its type, which is usually measured in liters or pint.

Most dehumidifiers come in three basic sizes/capacities: a small-capacity 30-pint, a medium-capacity 50-pint, and a large-capacity 70-pint. These capacities denote the maximum amount of water that the dehumidifier can remove from the air in a day. One pint equates to almost half of a liter or ⅛ of a gallon.

The main determinants involved in choosing the right size of a dehumidifier are relative humidity (RH) and room size. Naturally, you’d need a dehumidifier with medium to large capacity if you have a large basement with a high RH so that the dehumidifier can accommodate the amount of moisture in the air. In line with this, the bigger the room, the higher the capacity is needed because larger rooms would contain more air that would need dehumidifying. However, if you have a small crawl space with relatively low humidity, a small dehumidifier would suffice. With the use of this chart made by the Association of Home Appliance Manufacturers (AHAM), you can easily determine the proper capacity (pints/day) of dehumidifier for your home depending on these two factors:

Source: Energy Star

For a more reliable measurement, you can use a hygrometer to measure the actual relative humidity in your basement or crawl space. I recommend this, especially if you cannot properly observe the basement or crawl space for signs of moisture problems. Once you have a certain RH measurement, you can associate this with the signs of dampness mentioned in the table above. Here are the corresponding levels of relative humidity based on the new testing standards for modern dehumidifiers by the Department of Energy (DOE) last 2019:

  • Moderately Damp: 50-60% RH
  • Very Damp: 60-70% RH
  • Wet: 70-80% RH
  • Extremely Wet: 80-100% RH

WILL A DEHUMIDIFIER DRY OUT MY BASEMENT?

If we’re talking about damp walls and carpets due to condensation brought upon by excessive humidity, a powerful dehumidifier with a large capacity can help you solve that problem. However, this is only true if the root of the problem has been resolved. If you have extensive water damage or a continuous leak, this dampness and excessive humidity could come back once the leak occurs yet again. But otherwise, a dehumidifier can definitely help keep your walls and carpeting dry and safe from mold.

In some cases, some people become reluctant to buy dehumidifiers because they’re afraid that the dehumidifier would work too well and dry out the area too much. However, that’s not the case at all! As long as you know the right settings, your basement is safe from being too dry or too damp with the help of a dehumidifier. And if you’re still having some doubts, you can look for dehumidifiers that have built-in humidistat, which allows you to set a certain RH level. This way, you can always be sure that the RH in your basement stays at a normal range.

DEHUMIDIFIER SETTINGS FOR YOUR BASEMENT

As mentioned, dehumidifiers have built-in humidistats that allow users to set the resulting RH to the level that they want the room’s air to be in. Since the ideal level of humidity indoors is between 30-50%, most units can be set into the following fixed RH levels: 30%, 40%, and 50%. Other dehumidifiers, however, have more flexible settings, where you can set the RH into a more specific level (i.e., 32%, 45%, 48%, etc.) or beyond 30% or 50%. Now, some people actually find the recommended RH range of 30-50% confusing, unsure whether which RH level is the best for a certain part of the house.

For basements, many HVAC engineers and technicians claim that the perfect RH level is 40%. Some people would argue that 50% is better because the air is more comfortable to breathe in, but some cases show that when the weather gets hotter, especially during the summers, mold growth is more likely to happen if it gets humid in the basement. Thus, a 40% dehumidifier setting is much better during this time to counter the possibility of mold growth. For tropical areas that get extremely humid during rainy and hot seasons, you might want to lower it to 30%, if needed.

BEST DEHUMIDIFIER FOR BASEMENT:

Just like how garden tractors and air conditioners come in different types, there are also different types of dehumidifiers on the market. Dehumidifiers have different drainage systems, air discharge placements, smart features, and many more. After our long search, we’ve determined that hOmeLabs HME020031N is one of the top dehumidifiers that you can get for your basement or crawl space. Homelabs, stylized as hOmeLabs, is a renowned brand, famous for the top quality and performance of their dehumidifiers. Here are some of the noteworthy features of HME020031N:

  • Capacity: 70 pints
    • 45 pints if based on DOE 2019 standards
  • Gravity drainage
    • 1.8 gallon water storage with water level indicator
  • Area of coverage: 4,500 sq. ft.
  • Adjustable humidity level
    • RH level range: 35-85%
    • 5% increments
  • Two different fan speeds and modes
    • normal or turbo
    • continuous or timer mode (24-hr timer)
  • Washable filter
    • with filter state indicator and filter change reminder
  • Automatic shut-off, restart, and defrost
  • With built-in humidistat, handles, wheels, and drain hose outlet
  • Energy Star Certified

But if you want to check out other brands, I recommend GE Appliances. This brand also offers some of the best dehumidifiers and other home appliances out there in the market.

OTHER FACTORS TO CONSIDER WHEN BUYING A DEHUMIDIFIER:

To further refine your search for the best basement & crawl space dehumidifier, here are some features that you should look out for:

  • Energy Efficiency – Look for a dehumidifier that has an Energy Star rating. This indicates that the unit is energy-efficient, producing quality results while consuming the lowest energy possible.
  • Draining Method – The common drainage systems that dehumidifiers have are the following: manual drain, gravity drain, and condensate pump. Pick the one that you find to be the most convenient.
    • Manual drainage system – PROS: no need for installation of drain hose; CONS: periodic manual removal of water
    • Gravity drainage system – PROS: no need for periodic manual removal of water; CONS: dehumidifier must be placed at an elevated area relative to the drainage hose
    • Condensate pump – PROS: no need for periodic manual removal of water; CONS: setting up a drainage hose
  • Noise Level – Look for a dehumidifier with a low-noise operation. Most units are quiet, producing only a humming noise when at a low or medium fan speed. So, you have to test it at high/max speed to see how noisy it can get.

IF IT’S TOO LATE…

and you find out that your basement is in a state that cannot be rescued by a dehumidifier, a small-scale renovation might be your only saving grace. If this is the case, you might want to check out these tools that can make your work so much easier: best welding glasses, goggles, and helmets; and best welding gas for TIG and MIG welders. This SAE to metric conversion chart may also come in handy during your renovation project to ensure that everything is carefully measured and calculated.

I hope that this article had successfully shed some light on how to find the best dehumidifier for your basement and crawl space! If you’re planning on buying other home appliances, you might want to check out this buying guide for air conditioners, casement air conditioners, and home lawn/garden tractors.

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