Basement Dehumidification 101: A Guide to Dehumidifiers for Basements

Excess moisture inside the house is never a good thing. It can cause respiratory problems and other health issues, damage wooden furniture, and even undermine the structural integrity of the home itself. 

The basement is one of the areas of the house that is prone to excessive humidity, thanks to its underground location, poor ventilation, and close proximity to the surrounding soil. Dehumidifying your basement is essential to maintaining a dry, healthy, and comfortable environment, and that’s what this guide is all about.

Why Basements Need Dehumidification

Basements often have higher humidity levels than other parts of the home due to the following factors:

Poor Ventilation: Limited airflow allows moisture to accumulate.

Concrete and Soil Moisture: Basement walls and floors can absorb moisture from the ground, increasing humidity.

Plumbing Leaks: Water leaks from pipes and sump pumps can introduce excess moisture.

Condensation: Temperature differences between basement air and cold surfaces cause moisture buildup.

Property Damage: Basements are often used to store household items. A cluttered basement may hide the signs of excessive moisture until the stored goods start showing damage, which may be too late by then.

What is the Ideal Basement Humidity Level?

According to the Center for Energy and Environment, the recommended basement humidity level is between 30% and 50%. Based on data from the US Environmental Protection Agency, humidity above 60% can encourage mold growth, while levels below 30% may result in dryness and discomfort for the household.

Signs Your Basement Needs a Dehumidifier

• Musty odors

• Visible mold or mildew growth

• Water stains on walls or floors

• Condensation on windows or pipes

• Peeling paint or wallpaper

• Increased allergy symptoms or respiratory issues

• Struggling AC unit, caused by the system being overwhelmed by water vapor

If more than one of these occurs at the same time, then it’s a definite effect of excess humidity and a sign that it’s time to dehumidify your basement.

How to Choose a Basement Dehumidifier

Dehumidifiers come in many sizes and capacities. When selecting one specifically for your basement, consider the following:

1. Capacity (Pints Per Day)

Dehumidifiers are sized by how many pints of moisture they can remove per day. The capacity you need depends on your basement’s humidity level and square footage:

• Moderate dampness (50-60% RH): 10-20 pints for small basements, 20-30 pints for larger basements

• High humidity (60-80% RH): 30-50 pints

• Severe moisture issues (>80% RH): We recommend going over 50 pints

2. Drainage Options

Dehumidifiers collect the excess moisture into a water tank. There are 3 ways to empty the tank:

• Manual Water Collection: Standard dehumidifiers collect water in a reservoir that needs periodic emptying.

• Continuous Drainage: A built-in drain hose allows the unit to empty water automatically into a floor drain.

• Pump-Activated Drainage: Some models include a pump to push water to a higher drainage point.

3. Energy Efficiency

Look for Energy Star-certified dehumidifiers, which use 15% less energy than standard models.

4. Operating Temperature

Basements can be cold, more so if you live up north. If you’re in a cold weather area, you may want to opt for a dehumidifier with low-temperature operation or an auto-defrost feature to prevent ice buildup.

5. Additional Features

These are nice-to-haves to make operation more efficient and convenient. 

• Digital Humidistat: This uses a sensor to automatically maintain a set humidity level

• Auto Restart: This feature automatically restarts the unit in case of a power outage

• Air Filtration: An added feature that purifies the air by removing dust and allergens in addition to excess moisture, effectively making it both an air cleaner and dehumidifier in one.

Also check out our guide on Choosing a Dehumidifier for other parts of the home.

Best Dehumidifiers for Basements

Small entry level with manual water tank:

GE ADYR22LC 22 Pint Portable Dehumidifier for Wet Spaces

This 22 Pint portable dehumidifier is Energy Star-certified. It uses the newer R32 refrigerant with low Global Warming Potential (GWP), more efficient than R410A.

The bucket will collect 7 pints before needing to be emptied, with an automatic shut-off as well as a bucket full light. If you choose to direct drain (floor drain required, as there is no pump on this unit), it can remove up to 22 pints per day.

The unit uses a Digital Humidistat that lets you set precise humidity levels. The electronic push pad control panel allows you to set your humidity level from 30% to 70% in 5% increments. It is perfect for use in cooler areas and will operate down to 41°F. 

Larger capacity with pump:

Friedrich D50B1B 50 Pint Portable Dehumidifier with Pump

This 50-pint Energy Star-certified dehumidifier is perfect for larger wet to very wet spaces from 1000 – 2000 sq. ft. Very wet spaces may include an area with standing water or always wet floors.

It includes three drainage options. The first is a removable 16-pint collection bucket or manual emptying; second is continuous drainage, and finally a drain pump. The drain pump allows for vertical or horizontal pumping up to 15 ft. from the unit.

You can set the humidity level from 30% – 90% RH. The D50B1A also includes a 2-speed fan, 24 hour ON/OFF timer, auto defrost and will operate in low ambient temperatures down to 41°F. The control panel includes a bucket full lamp, defrost lamp, current temperature/timer set and humidity displays as well as fan speed and °C / °F selector button.

Premium / whole home:

Aprilaire E080 80 Pint E-Series Professional Grade-Whole House Dehumidifier

Aprilaire’s E-Series delivers professional grade dehumidification for your entire home. This model is an Energy Star Rated dehumidifier that is perfect for use in basements, crawl spaces or as a whole house dehumidifier.

It will remove up to 80 pints of moisture per day for spaces that are up to 4400 sq. ft. – perfect for smaller homes and basements. Humidity control can be set between 40% and 80%. It comes with two duct options, flex duct or hard pipe, for flexible installation. This enables it to be placed in crawl spaces, attics, or basements, or in “freestanding” operation with dedicated targets for living spaces or ducted to your HVAC equipment.

This unit was recognized as the Most Efficient Dehumidifier in the ENERGY STAR 2021 list.

5 Ways to Reduce Basement Humidity

1. Improve Ventilation

Ventilation helps minimize moisture and allows excess humidity to be vented. Use exhaust fans or install vents to allow moisture to escape.

2. Seal Cracks and Leaks

Holes in the basement or foundation allow moisture to seep in, either from the soil or the water table below the ground. Apply waterproofing sealant to foundation walls and floors.

3. Insulate Pipes

This helps minimize condensation as well as the risk of leaks and burst or frozen pipes.

4. Run the AC

AC units produce cold dry air. This helps remove excess moisture during the warm season.

5. Use a Sump Pump

If you live in a flood-prone area, a sump pump helps prevent water accumulation in basements.

Conclusion

A properly dehumidified basement can prevent structural damage, improve air quality, and create a more comfortable living space. If you use your basement for storage, this also prevents damage to your stored belongings. Investing in the right dehumidifier will help keep your basement dry and mold-free. 
Need help finding the best basement dehumidifier? Check out our range of high-quality dehumidifiers that meet your basement size and budget.