The most energy-efficient ducted air conditioner will vary depending on various factors such as the size of the home or building, climate, and individual needs. However, air conditioning units with high Seasonal Energy Efficiency Ratio (SEER) and Energy Efficiency Ratio (EER) ratings are generally considered more energy-efficient than those with lower ratings.
SEER ratings measure the unit's cooling efficiency throughout a typical cooling season, while EER ratings measure efficiency at a specific operating temperature. The higher the SEER and EER ratings, the more energy-efficient the air conditioner is.
There are several brands and models of ducted air conditioners with high SEER and EER ratings, including Carrier Infinity, Lennox XC25, Trane XV20i, and Daikin DX20VC. However, the best option for your needs will depend on various factors, including your budget, climate, and the size of your home or building. You should consult a licensed HVAC professional to assess your needs and recommend the most energy-efficient
ducted ac.