Dehumidifiers can be highly effective in preventing mold growth by reducing indoor humidity levels but they will not remove or kill mold already growing in your home or business.
Mold requires moisture to grow and reproduce. It typically thrives in environments with relative humidity levels above 60%. This is why controlling indoor humidity is crucial in the fight against mold.
By removing excess moisture from the air, dehumidifiers create an environment that is less hospitable to mold growth. They can help protect your home and belongings from water damage and mold-related deterioration.
The Environmental Protection Agency (EPA) recommends maintaining indoor humidity levels between 30% and 50% to prevent mold growth.
Lower humidity levels not only deter mold but also reduce the growth of dust mites and other allergens, leading to better overall air quality.
While dehumidifiers are excellent tools for mold prevention, it’s important to understand their limitations:
- They Don’t Kill Existing Mold: Dehumidifiers can prevent mold growth, but they cannot eliminate existing mold.
- They Can’t Fix Underlying Issues: If there’s a persistent source of moisture, such as a leak, a dehumidifier alone won’t solve the problem.
- They Require Proper Maintenance: Dehumidifiers need regular cleaning and emptying to function effectively and prevent mold growth within the unit itself.
How Dehumidifiers Work
Dehumidifiers are devices designed to remove excess moisture from the air. They work by drawing in humid air, removing the moisture, and then releasing drier air back into the room. There are two main types of dehumidifiers:
- Refrigerant Dehumidifiers: These work similarly to air conditioners. They draw in air over cold coils, causing moisture to condense and collect in a water tank1.
- Desiccant Dehumidifiers: These use a moisture-absorbing material to extract water from the air.
Scientific Evidence
Research supports the use of dehumidifiers in mold prevention. A study from the University of Cincinnati found that using dehumidifiers in conjunction with HEPA filters could effectively control indoor relative humidity and reduce airborne fungal spores in certain environments.
Best Practices for Using Dehumidifiers
To maximize the effectiveness of a dehumidifier in mold prevention:
- Maintain Optimal Humidity: Set your dehumidifier to maintain humidity levels between 30% and 50%.
- Run Continuously: In high-humidity areas, it’s often beneficial to run the dehumidifier continuously.
- Regular Maintenance: Clean and empty your dehumidifier regularly to prevent mold growth within the unit.
- Strategic Placement: Place dehumidifiers in areas prone to high humidity, such as basements, bathrooms, and kitchens.
Combining Dehumidifiers with Other Mold Prevention Strategies
While dehumidifiers are effective, they work best as part of a comprehensive mold prevention strategy. Consider combining them with:
- Air Purifiers: These can help remove mold spores from the air, complementing the moisture-reducing effects of dehumidifiers.
- Proper Ventilation: Ensure good air circulation in your home, especially in high-moisture areas.
- Regular Cleaning: Keep surfaces clean and dry to prevent mold growth.
- Addressing Water Issues: Fix any leaks or water damage promptly.
Conclusion
In conclusion, dehumidifiers can indeed help with mold by creating an environment that is less conducive to mold growth. They are particularly effective in preventing mold in areas prone to high humidity.
However, it’s important to remember that while dehumidifiers are excellent tools for mold prevention, they are not a cure-all solution. They work best when used in conjunction with other mold prevention strategies and proper home maintenance.
If you’re dealing with an existing mold problem, it’s crucial to address the root cause and consider professional mold remediation services.

Moe is the CEO and chief mold inspector for Mold Safe Solutions – a Southern California mold inspection and remediation company serving all of San Diego, Riverside and Orange Counties.
Call or text direct for a FREE quote @ 760-818-6830
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