According to experts, a central air conditioner's performance depends at least as much on how well it's installed and maintained as on the equipment itself. Moreover, because every home is different, there's no all-purpose standard for comparing how well units work. Thus, we weren't able to compare either specific models or brands of central air conditioners in terms of performance.
One factor that can be measured, based on feedback from users, is reliability. We didn't find any sources that evaluate the durability of specific air conditioner models, but we did find a couple of sources that compare the reliability of air conditioner brands as a whole. The major manufacturers of central air conditioners include:
A major survey of homeowners with central air conditioning found that most of these brands are about equally reliable. Between 11 and 13 percent of homeowners reported that their air conditioners broke down during a five-year period for most brands. However, three brands -- Goodman, Amana and York -- had significantly worse ratings, with 17 to 18 percent needing repairs.
Goodman and York also get poor overall ratings at FurnaceCompare.com, a major clearinghouse for user reviews of central air conditioners. Interestingly, Amana is actually one of the highest-rated brands on the site.
The editors of FurnaceCompare.com suggest that Goodman's low ratings have less to do with the company's products than with the quality of the contractors who install them. As the editors explain, "other manufacturers, such as Trane and Bryant, establish stringent requirements for technicians who install their equipment, while Goodman will let anyone install one of their air conditioners."
Contractors who have contributed to the website say the problems they find with Goodman units are usually due to faulty installation, rather than defective parts concluding, "If you buy a Goodman air conditioner from a skilled contractor... it will be as reliable as any other brand."
So, if most brands are equally reliable for the most part, how can you choose among all the central air conditioners out there? When we consulted sites run by contractors and other experts in the home-appliance field, we generally found that they recommended central air conditioners based on factors that are simple to measure: efficiency, quietness and warranty length. Based on these criteria, several products were clear standouts.
One model that pops up on several lists is the Maytag M1200 PSA4BI iQ Drive. This model has two major selling points: efficiency and quietness. With SEER ratings of up to 24.5, this model earns a spot on the EnergyStar.gov's 2013 list of most efficient air conditioners, and Home-Tech.com dubs it "the industry's elite." Maytag also touts it as "the quietest air conditioner available," running at as little as 59 decibels (about as loud as normal conversation). Designed and built in the U.S., this air conditioner is backed by a 12-year warranty.
The Dave Lennox Signature Collection also earns a spot on Energy Star's list. The top model in this line, the XC21, has a SEER of up to 21.2, while the less expensive XC17 can still achieve a SEER as high as 18. Both models run at around 69 decibels -- not nearly as quiet as the Maytag, but still quieter than many standard air conditioners. Its warranty covers all parts, including the compressor, for 10 years.
Several different sites recommended air conditioners from the Carrier Infinity Series, including the 24ANA1 and 24ANB1. This line combines SEERs of up to 21 with quiet operation, as low as 65 decibels. Home-Tech.com says this model's two-stage compressor excels at removing humidity from indoor air. The editors of WebHVAC.com also praise Carrier's durability, saying, the brand "has one of the best service records in the industry." The warranty covers all parts for 10 years, but only if the unit is registered within 90 days of purchase; otherwise, it lasts only five years.
We also saw lots of recommendations for the Trane XL20i. Though not quite as efficient as others, it still boasts an impressive SEER of up to 20. Editors at FurnaceCompare.com say this model "receives frequent rave reviews." It earns recommendations from Bestcovery.com, WebHVAC.com and Home-Tech.com. The warranty for this Trane unit covers the compressor for 12 years and other parts for 10. The manufacturer also has a good reputation for reliability; the editors of WebHVAC.com say the brand is known for "lasting the longest and being built the toughest."
The Rheem Prestige RASL-JEC (also known as Ruud Ultra UASL-JEC) is included on the Energy Star list despite the fact that, with a SEER of up to 19.5, it is not as efficient as the Trane XL20i or the Carrier Infinity Series. The editors of WebHVAC.com call this model "durable and very reliable," and it's backed by a 10-year parts warranty plus a 10-year conditional replacement warranty (which requires registration). Ruud, a subsidiary of Rheem, sells an identical model under the name, Ruud Ultra UASL-JEC.
Although Amana gets poor ratings for reliability in the customer-satisfaction survey cited above, one particular model gets multiple recommendations. The Amana ASXC18 is declared a best value at HomeTech.com, offering a good balance of quality, price and warranty coverage. Though it's not as efficient or quiet as others on this list, it's well above average for both, with a SEER of up to 18 and a sound rating of 71 decibels. The warranty is another big plus. In addition to a 10-year limited warranty on parts, Amana offers a lifetime limited warranty, which promises to replace the entire condensing unit if the compressor ever fails.