Several Day & Night central air conditioner models are certified by the Air Conditioning, Heating & Refrigeration Institute as energy-efficient models. These models also meet the standards for Energy Star certification from the Department of Energy.
Most Energy Star-certified Day & Night air conditioner units in production as of 2015 achieve Seasonal Energy Efficiency Rankings of 14.5, including models from the CSA, CXA and NXA outdoor units when paired with select ENA-series or END-series interior units. CCA model units can achieve even higher SEER ratings of 16.7 or more, qualifying them for the Consortium for Energy Efficiency's Tier 2 and Tier 3 designations. These tier ratings are given to products that are even more efficient than the minimum Energy Star standard.