Question

How is the energy efficiency ratio (eef) related to the operating cost?

Answer 1

Energy Efficiency Ratio or EEF is inversely related to the operating cost whereby increased EEF means decreased OC (operating cost).

Say for instance:

Energy efficiency ratio (EER) of ACs:  The ratio between the cooling capacity and the power input of the Air Conditioners (ACs) .

For instance, if a 1 TR (3500 W) AC consumes 1000 watts, then the EER of the Air Conditioners is 3.5 W/W.  Air Conditioners (ACs) with high EER consume less power.

:)