A:Answer Energy usage is copied below. As far as why they are all Energy Star, they fall within the Department of Energies specifications for energy savings in this product category.
50 pint Dehumidifier
Electrical Specifications
Voltage Rating: 115V, 60Hz
Amps (Cool): 6.6
Watts (Cool): 615
I've also copied the 30 and 70 pint below for refference
30 pint
Electrical Specifications
Voltage Rating: 115V, 60Hz
Amps (Cool): 4.8
Watts (Cool): 420
70 pint
Electrical Specifications
Voltage Rating: 115V, 60Hz
Amps (Cool): 7.5
Watts (Cool): 765
Thank You,
Frigidaire