Most Efficient Room Air Conditioners in 2025

These are the top 10 most energy-efficient room air conditioners available today, ranked by the lowest annual energy cost. Choosing an efficient room air conditioner can save you hundreds of dollars over its lifetime. Energy efficiency matters because room air conditioners are typically used daily — even a small difference in wattage adds up over thousands of hours of use each year. The models below represent the best combination of low energy consumption and ENERGY STAR certification.