How to Choose the Best Basement Dehumidifier
Moisture problems and mold caused by water leaks in the basement walls can be prevented with proper waterproofing and dehumidification.
Learn how a dehumidifier can help prevent mold and mildew problems caused by excess moisture in the basement - and how you can choose the best unit for your space.
Moisture in the basement can lead to mold growth and cause rot. High humidity in the basement can also cause hidden damage in the basement and upper floors of the home. A dehumidifier, when combined with proper drainage, can prevent moisture damage and improve indoor air quality and comfort.
This post will help you understand whether you need a dehumidifier, how a dehumidifier works, the types of dehumidifiers,
and features to look for when buying a basement dehumidifier. We've included an infographic below summarizing everything you need to know when buying the best dehumidifier for your basement.
Click on one of the topics below to jump to the information you're looking for.
- Do I Need a Dehumidifier in My Basement?
- How a Dehumidifier Works
- Types of Dehumidifiers
- Factors to Consider When Selecting a Basement Dehumidifier
- More Ways to Reduce Basement Humidity
Do I Need a Dehumidifier in My Basement?
In spaces that are naturally more damp, such as basements and crawl spaces, a dehumidifier will help dry the air, reducing musty odors and preventing mold growth and other issues caused by excess moisture.
A basement dehumidifier helps maintain an ideal indoor relative humidity (RH) level in the space. The Environmental Protection Agency suggests that the indoor relative humidity be kept between 30-60% to help prevent mold growth. A home with relative humidity above 60% can also be a breeding ground for pests and wood rot.
Read more about indoor relative humidity and why it's important to understand.
How a Dehumidifier Works
A dehumidifier ranges in size from a portable, room-size unit to a whole-house system that’s added on to the home’s HVAC system. Both types of dehumidifiers work the same way. The unit is set to the desired humidity level. When the humidistat measures a humidity level that’s higher than the set level, the dehumidifier turns on. A fan moves the humid air over a cold metal coil. The moisture condenses into water, which drains into a bucket or through a drain hose.
Types of Dehumidifiers
There are two main types of dehumidifiers: portable units and whole-house systems. Unless you need to dehumidify an entire floor of the home, or the whole home, a portable dehumidifier is the most common type of dehumidifier used to control basement humidity. A commercial or industrial-strength portable dehumidifier is an efficient option for damp basements, crawl spaces, and any space that's prone to high humidity, such as an indoor pool area.
Factors to Consider When Buying a Basement Dehumidifier
In addition to choosing the type of dehumidifier to install, there are several other factors to consider when choosing the right dehumidifier for your basement.
1. Size of the basement and the right-size dehumidifier
It’s important to choose a dehumidifier with a capacity that’s right for the basement area’s square footage. BobVila.com suggests selecting a dehumidifier that holds ten pints of water for a 500-square-foot-space and four pints for every additional 500 square feet. So a 1,500-square-foot basement would need a dehumidifier with about an 18-pint capacity. And if the basement is very damp, they recommend a dehumidifier that holds 12 pints of water for a 500-square-foot space and five pints for every additional 500 square feet. So a very damp 1,500-square-foot basement would need a dehumidifier with at least a 22-pint capacity.
Some portable dehumidifiers have manual drainage. This means that water collects in a bucket. The water bucket needs to be regularly removed and emptied, especially in a basement that’s very damp or wet. It’s also important to note that the unit turns off when the water bucket is full - and stops removing moisture from the air - until the bucket is emptied and replaced.
A more convenient option is to install a dehumidifier with automatic draining. There are two ways water can be drained automatically from a dehumidifier: Using gravity and a drain hose or a condensate pump.
The most effortless way to drain a basement dehumidifier is with a condensate pump. The water can be pumped into a sink or to a sump pump system that collects the water and pumps it out of the basement.
3. Features of the basement dehumidifier
While it’s necessary to select the right dehumidifier for the basement’s size and conditions, it’s also a good idea to look for other features that can make the unit easier to operate and solve other needs, such as air filtration.
Popular basement dehumidifier features:
- Automatic Humidistat - A humidistat automatically turns the dehumidifier on and off to maintain the desired humidity level and save energy.
- Automatic Restart - An automatic restart feature automatically restarts the dehumidifier in the event of a power failure.
- Low-Temperature Operation - A dehumidifier that operates and performs in low temperatures is ideal for use in a basement or crawl space.
- Automatic Defrost - An automatic defrost feature defrosts ice buildup on the unit to keep the dehumidifier operating in cold temperatures.
- Air Filter - Some basement dehumidifiers have an air filter that traps allergens and particles, helping reduce allergy symptoms and protect the unit's components from damage caused by dust and debris.
A basement dehumidifier can prevent mold growth and rot caused by excess moisture in the basement. Adding a dehumidifier in the basement can also improve indoor air quality in the home.
The SaniDry Sedona dehumidifier and the SaniDry XP dehumidifier from Basement Systems are large-capacity, low-temperature dehumidifiers that are capable of easily drying a large, very damp basement. They have internal pumps and feature automatic draining. For more information about dehumidifying your basement, visit our Dehumidification Learning Center or contact your local Basement Systems dealer.
More Ways to Reduce Basement Humidity
Even the best basement dehumidifier won’t work effectively if there are issues with water seepage and standing water in the basement.
There are simple ways to improve drainage around the foundation and reduce excess humidity at the source, such as:
- Extend downspouts from your gutters away from the foundation of your home
- Keep gutters and downspouts clean
- Make sure the soil slopes away from the home to avoid pooling of water around the foundation
- Avoid over-watering of landscaping near the foundation
- Ensure that clothes dryers are properly vented to the outside
- Use vent fans in bathrooms and kitchens to remove humidity
If you need help controlling the humidity in your basement, schedule a Free Consultation with a Basement Systems dehumidifier installer near you. Your local dealer can help you decide on the best SaniDry dehumidifier unit for the size and condition of your basement.