If you have an older central air conditioner, you would do well to replace it with a high-efficiency unit. Considering recent changes in refrigerants and air conditioning designs, it is imperative that you replace the entire system.
To save energy and money, you should try to buy an energy-efficient air conditioner and reduce your central air conditioners energy use. Older air conditioners may consume more than 2000 kilowatt-hours of electricity per year, causing power plants to emit about 3500 pounds of carbon dioxide and 31 pounds of sulphur dioxide.
Today’s best air conditioners use 30% to 50% less energy to produce the same amount of cooling as air conditioners made in the mid-1970s. Even if your central air conditioner is only 10 years old, you may save 20% to 40% of your cooling energy costs by replacing it with a newer, more efficient model.
When buying a central air conditioner, look for a model with a high efficiency. Central air conditioners are rated according to their seasonal energy efficiency ratio (SEER). SEER indicates the relative amount of energy needed to provide a specific cooling output. Many older systems have SEER ratings of 6 or less. The minimum SEER allowed today is 13.
Look for the ENERGY STAR label for central air conditioners with SEER ratings of 13 or greater, but consider using air conditioning equipment with higher SEER ratings for greater savings.