Central air conditioning systems go high efficiency, at higher cost

There's nothing like losing your central air conditioning during a heat wave to add urgency to your decision whether to fix the old or buy new. But the decision whether to buy is a bit more complicated this summer than usual.

That's because in January, the minimum energy efficiency standard for central air conditioners will increase by 30 percent, resulting in more energy-efficient systems but raising their cost to consumers. So for a limited time, consumers will get to choose: A lower-priced system with less energy efficiency or a higher-priced system with better energy efficiency?

Efficiency of central air conditioning systems is measured by the Seasonal Energy Efficiency Ratio. Often referred to by its acronym, SEER, the federal standard is similar to the miles per gallon rating for automobiles; the higher the number, the more energy efficient it is. The minimum SEER rating that can be sold today is 10, but it will be rising to 13.

The new systems are quieter, more reliable, and pollute less due to innovative scroll compressor technology that maintains precise temperature levels and lower relative humidity. While there is no way to calculate the savings on a homeowner's energy bill or the exact increase in price for the central air conditioning system, said Paul Stalknecht, president and CEO of the Air Conditioning Contractors of America, homeowners will save money over the lifetime of the new system, which is usually about 15 years.

''Homeowners can save anywhere from $10 to $20 a year up to hundreds a year. There are so many variables," he said, including the SEER rating of the system being replaced, how many hours per year the unit is used, the size of the home, and how well the home is insulated.

Homes between 1,600 and 2,200 square feet typically require a 2 1/2- to 3 1/2-ton air conditioner. According to Emerson Climate Technologies, 13 SEER systems will produce annual cost savings that could range from $35 for a 1-ton system to $180 for a 5-ton system at the New England average of 13 cents per kilowatt hour.

Tom Bettcher, head of Emerson Climate Technologies, said that it is still uncertain how much more the minimum SEER systems will cost after January because prices are still being finalized. Stalknecht estimated that a 13 SEER system will cost from hundreds to thousands of dollars more.

Although 10 SEER systems will stop being manufactured in January, they will still be available until inventory has been exhausted, leaving homeowners the short opportunity to choose a lower-priced and lower-energy-efficiency system. Bettcher said it is an individual choice that depends on how much a consumer uses his air conditioning system. However, he said there is no need for homeowners with existing systems to update if theirs is properly operating.

After a survey revealed that 90 percent of homeowners with central air conditioning had not heard about the new federal regulations announced in April, Emerson started an effort, dubbed Get SEERious, to educate homeowners about the SEER rating and energy consumption.

For more information on the new regulations and the SEER rating, visit getSEERious.com, www.acca.org, or ari.org, the website of the Air Conditioning and Refrigeration Institute.