How has the efficiency of air conditioners changed in the past 10 years, if at all?

Question

How has the efficiency of air conditioners changed in the past 10 years, if at all?

Answer 1

One of the bigger changes has been the coolant.  I have 2 new units at the house using Puron (R-410a).  Both replaced units using R-22.  Puron systems operate at approximately 50% higher pressure than the R-22, which means more thermal energy can be transfered in the fluid.  And since it does not require 50% more energy to obtain the same delta-T (change in temperature), the unit is much more efficient.

Answer 2

Becuase of the low current consumption applications used into today's newest technology such as using smaller motors that have less current but still do the same amount of cooling though.......