Capacity for dehumidifiers can be express in two ways: Capacity at AHAM, and Capacity at Saturation (or Max).
Capacity at AHAM
Capacity at AHAM lets you compare how different dehumidifiers will perform under the same conditions. The Capacity at AHAM rating is expressed in pints per 24 hour period at 80° F and 60% relative humidity.
Capacity at Saturation
Capacity at Saturation measures how much moisture the unit can extract while running continuously over a 24 hour period in an environment with unlimited moisture (i.e. a flooded basement).