How to Choose the Right Dehumidifier Size
Dehumidifier capacity is rated in pints (or liters) of water removed per day. The right size depends on your room's square footage and how damp the space is. A unit that is too small will run constantly without achieving the target humidity; one that is too large cycles on and off rapidly, reducing efficiency. AHAM guidelines provide a standard reference for matching capacity to space.
Capacity Guidelines by Humidity Level
For moderately damp spaces (50–60% humidity): 10 pints per 500 sq ft (50 m²). For damp spaces (60–70%): 12–14 pints per 500 sq ft. For very damp (70%+): 16–22 pints per 500 sq ft. Wet spaces with visible mold or standing water may require 25–50+ pints per day. When in doubt, size up — running a larger unit at a lower fan speed is quieter and more efficient.
Key Features to Look For
Check the water tank capacity — a small tank means more frequent emptying. If you plan to leave the unit unattended for long periods, choose a model with a continuous drain hose connection. Look at the noise level (dB rating), auto-restart after power outages, and whether the unit includes an air filter. Energy Star certified models use about 15% less energy than non-certified units.
Placement and Maintenance Tips
Place the dehumidifier in the center of the room or in the dampest area, away from walls and furniture so air can circulate freely around it. Clean the air filter every two weeks and rinse the water tank regularly to prevent mold growth inside the unit. Before storing for the season, run the unit in fan-only mode for a few hours to dry the interior components.
Frequently Asked Questions
It's the maximum amount of moisture the unit removes from the air per day under standard test conditions. A 30-pint unit removes up to 30 pints (14L) daily.
40–60% is the comfortable range. Above 60%, mold and dust mites thrive; below 40%, skin and airways become dry and irritated.