Do I Need a Humidifier or Dehumidifier in the Basement?

Do I Need a Humidifier or Dehumidifier in the Basement? | The humidity levels in your basement can significantly impact your home’s air quality, structure, and contents.

Maintaining proper humidity prevents mold, mildew, and damp-related issues.

However, deciding whether you need a humidifier or dehumidifier can sometimes be confusing. This guide will help you determine your basement’s best moisture control solution.

Do I Need a Humidifier or Dehumidifier in the Basement?

Understanding Basement Humidity

Most basements have higher humidity levels than the rest of the home due to their underground location. There are a few reasons for this:

• Foundation walls and concrete floors allow moisture to penetrate from the surrounding soil. As humidity levels fluctuate outside, water can seep through the structure’s cracks, joints, and pores.
• Pipes allow humid air and water vapor into the basement. Supply pipes bring in moist air, while drainpipes pull humid interior air out of the house and push it underground.
• Poor airflow and lack of ventilation trap moisture. Basements usually have fewer windows and air supply vents than upper floors, so humid air gets trapped inside.
• Furnaces, water heaters, sump pumps, and other appliances add moisture through evaporation and condensation.
• Interior moisture sources from laundry, bathrooms, cooking, and plant soils increase basement humidity.

So, without proper moisture control, basements are prone to having humidity levels between 50-70% on average, compared to the recommended 30-50% for indoor spaces.

Sustained high humidity creates an environment for mold, rot, and structural damage over time.

When to Use a Dehumidifier?

If your basement’s average relative humidity is above 50-55% for most of the year, then a dehumidifier is what you need.

Dehumidifiers actively reduce moisture levels in the air through condensation. Some signs that indicate a dehumidifier is necessary include:

• Visible mold or mildew growth on walls, floors, furniture, or stored items.
• Musty odor present even after cleaning.
• Wooden furniture, flooring, or framing showing signs of warping, buckling, or rotting.
• Condensation forms on basement windows, walls, or pipes.
• Dampness or water droplets on surfaces even when it’s not raining.
• Digital hygrometers consistently read above 55% humidity.

A dehumidifier will extract moisture from the air, keeping humidity levels between 30-50% to discourage mold growth.

Using one sized appropriately for the basement’s square footage is important.

Run it continuously during humid months and periodically during drier seasons for maintenance. Empty the collection bucket regularly.

When to Use a Humidifier?

On the other hand, if your basement’s average relative humidity drops below 30-35% for extended periods, then a humidifier should be considered. Signs that dry air could be an issue include:

• Static shocks from door knobs, carpet, or other objects.
• Dry nasal passages, skin, lips, or throat feeling parched.
• Wood furniture, trim, or floors appear cracked or shrunken.
• Collectibles like books, artwork, or musical instruments are at risk of damage from low humidity.
• Digital hygrometers consistently read below 30% humidity.

When air is too dry, it can cause health issues like nosebleeds, sore throats, eye irritation, and respiratory problems for some.

It also puts home contents and structures at higher risk of damage from cracking, shrinking, brittleness, and accelerated aging.

A humidifier adds moisture back into overly dry air, raising humidity levels to the recommended range of 30-50%.

Choose a model sized for the basement space and refill the water tank as needed to maintain humidity.

Humidifiers may need to run only periodically in non-heating months when humidity naturally rises.

Combination Humidifier/Dehumidifier Units

A combination humidifier/dehumidifier unit can work well for basements that experience wide humidity fluctuations throughout the year or areas that require different functions.

A combination humidifier/dehumidifier unit can work well. These all-in-one devices can switch between humidifying and dehumidifying modes as needed.

The hygrostat function automatically monitors humidity levels and activates the proper setting to maintain ideal indoor conditions between 30-50% relative humidity.

This provides continuous moisture regulation without manually operating separate units or measuring humidity manually.

Combination units take up less space than two separate appliances as well. However, they tend to be more expensive than basic humidifiers or dehumidifiers.

Consider your specific climate and humidity patterns to determine if the extra cost is worthwhile compared to using single-purpose models.

Other Humidity Control Methods

If the cost of an appliance is prohibitive, some lower-tech options still help improve basement humidity:

Ventilation – Installing bathroom exhaust fans, running laundry vents outside, and adding supply/return air vents helps circulate damp air.

Dehumidifying Paint – Special paints formulated to withstand moisture and buffer humidity swings on walls/ceilings.

Decor Choices – Avoid hanging fabrics that hold moisture, like curtains and area rugs prone to dampness storage.

Climate Control – Adjust thermostat settings and limit temperature differences between the basement and upstairs.

Drainage – Ensure proper grading/gutters to redirect surface water away from the foundation. Fix any drainage issues.

Sealing – Apply vapor barrier paint/sealant to cracks, seams and penetrations in walls and floors, allowing humidity entry.

Maintenance – Routinely clean gutters, sump pits, and de-scale water heaters to reduce indoor moisture sources.

Proper Storage

Whether you opt for a humidifier, dehumidifier or both, how contents are stored affects humidity control success.

Ensure items prone to dampness damage, like books, photos, and wood antiques, are stored in waterproof containers with drying agents if needed.

Avoid pile storage against exterior walls where moisture could penetrate uncovered.

Provide airflow around stored goods to allow them to fully dry out between humid periods.

Selecting a Location

For basements with high and low humidity areas, consider installing separate dehumidifiers and humidifiers in different zones rather than one central unit.

Mount appliances off the floor near the problem area for best access and efficiency.

Place dehumidifiers near windows where condensation forms or other damp spots. Mount humidifiers in drier interior areas.

Avoid sheltered spots directly under plumbing pipes or vents, which add more moisture.

Maintenance and Calibration

To keep moisture control appliances running effectively, follow the owner’s manual maintenance schedule for cleaning filters, changing pads, and emptying collection buckets.

Test and recalibrate any hygrometers and controls annually or as the manufacturer recommends for accuracy. Periodically inspect for leaks and damaged components.

Replace appliances as needed every 5-10 years, depending on usage and conditions.

Proper care helps maximise energy savings and humidity control benefits over the units’ lifespan.

Conclusion

With some assessment of factors like average humidity levels, contents stored, ventilation, and individual space needs – it’s usually clear whether a humidifier, dehumidifier or combination unit is best suited for basement humidity control.

Maintaining ideal moderate conditions between 30-50% relative humidity prevents structural damage mold growth and protects valuables long term.

Along with proper installation, location, calibration, and maintenance – moisture control appliances provide year-round protection for basements when humidity goes out of balance.

Monitor your specific conditions and adjust as seasons and needs change for optimal comfort and home preservation.

Frequently Asked Question