How Big of a Dehumidifier Do I Need for My Home?
Choosing the right size dehumidifier depends on how much moisture is in the air, not just the size of the room.
A unit that is too small will run constantly and still struggle. A unit that is slightly oversized usually performs better and lasts longer.
What Dehumidifier Size Means
Dehumidifiers are rated by how many pints of moisture they can remove from the air in a 24-hour period.
Higher numbers mean the unit can handle more moisture.
Common residential sizes include:
- 30 pint
- 40 to 50 pint
- 50 to 70 pint
The goal is steady moisture control, not nonstop operation.
Start With the Size of the Space
Use the square footage of the area where humidity is noticeable.
As a general starting point:
- Small rooms and enclosed areas often work with 30 to 40 pint units
- Medium-sized spaces usually need 40 to 50 pint units
- Large or open areas often require 50 to 70 pint units
Ceiling height matters. Taller spaces behave like larger rooms.
Adjust for How Damp It Feels
Square footage alone is not enough.
Consider:
- Whether the space feels slightly damp or consistently wet
- Whether musty smells are present
- Whether condensation is visible
General guidance:
- Mild humidity: choose the lower end of the size range
- Noticeable dampness: move up one size
- Persistent moisture: choose the larger option
Undersizing is the most common mistake homeowners make.
Open vs Divided Spaces
Open layouts allow air to circulate more easily.
Divided spaces, storage rooms, or areas with closed doors restrict airflow and may require:
- A larger unit
- Multiple units
- Careful placement
Do not assume one small unit can manage multiple separate rooms.
Drainage Matters More Than Size
How water is removed affects usability.
Consider:
- Gravity drain if a floor drain is available
- Built-in pump if water must move upward or across distance
Units that rely only on buckets often get ignored once they fill too quickly.
Practical Recommendation
If you are between two sizes, choose the larger one.
A dehumidifier that cycles on and off is generally healthier for the unit than one that runs nonstop.
You can view common residential dehumidifier sizes here:
– Small spaces (30–40 pint dehumidifier units)
– Medium spaces (40–50 pint dehumidifier units)
– Large spaces (50–70 pint dehumidifier units)
In larger homes or open floor plans, a single portable unit may struggle to control humidity evenly. In those cases, homeowners sometimes consider whole-house dehumidifiers that connect to existing ductwork. These systems are designed for broader coverage but involve higher cost and installation considerations. We’ll cover the differences separately.