The EPA publishes every certified dehumidifier in a downloadable file: 535 models, 511 of them portable. Each row carries the measured capacity in pints per day, the efficiency as an Integrated Energy Factor in liters per kilowatt hour, and the annual energy in kilowatt hours. Every certified brand reports into that file in the same units, which is not true of the capacity and coverage numbers on the listings themselves.
Certification is a floor, not a ranking. Of the 511 portable models, 199 sit at exactly 2.01 L/kWh, so that value is a cluster rather than a differentiator. All four machines on this page sit at 2.01, and their annual energy runs from 507 to 526 kWh, a spread of 19 kWh. On efficiency alone, these products are the same machine.
There is a stricter tier called ENERGY STAR Most Efficient 2025, and it is worth knowing where it lives. Of the 107 portable models that hold it, 59 are under 20 pints a day and 41 are between 20 and 29. Five are in the 50 pint class, and they are branded Vellgoo, Waykar, MegaLight and ZAFRO. Waykar holds two of them, CTH150D and CTH150PD at 2.2 L/kWh and 471 kWh a year, and neither is the machine it sells on Amazon as a 150 pint dehumidifier.