How efficient is a Carrier air conditioner with Puron refrigerant?

Carrier air conditioner systems using Puron refrigerants are very efficient, though precise efficiency ratings vary from model to model. The highest-efficiency residential Carrier air conditioning model as of 2015 achieves a Seasonal Energy Efficiency Rating of 21, comparable to the 23 rating of the most efficient models.

Puron is the Carrier brand name for R410A, a non-ozone-depleting refrigerant that consists of a mixture of the chemicals difluoromethane and pentafluoroethane . Air conditioning systems using Puron operate at a higher pressure than those using older refrigerants such as R22, so it is necessary to take additional care when servicing such units.