The Dave Lennox Signature Collection is rated one of the most efficient central air conditioners rated at EnergyStar.gov, with a seasonal energy efficiency ratio (SEER) of up to 21.2. It's also quieter than most, with decibel ratings as low as 69. One unique feature of these air conditioners is that they're designed to work with solar cells, dropping their electricity use still lower. However, in terms of reliability, this brand gets mixed reviews.
Our greenest choice. The Dave Lennox Signature Collection isn't the most efficient air conditioner covered in our sources, but it's close. The top-of-the-line XC21 can achieve a seasonal energy efficiency ratio (SEER) of up to 21.2, and the more modestly priced XC17 will still achieve a SEER no lower than 16.5. Both models also have high overall energy efficiency ratios (EER), indicating how efficiently they will perform on the hottest days, when running full tilt.
These numbers are well above the level needed to qualify for an Energy Star rating; in fact, both models earn a Tier-3 rating from the Consortium for Energy Efficiency (CEE), which is the highest efficiency standard for central air conditioners. They can also save you anywhere from 28 to 38 percent on your power bill, when compared to a basic model that barely meets the minimum standards. What makes this collection especially green is it's compatibility with SunSource solar energy modules -- so the air conditioner can literally power itself.
Good overall value. Lennox, like other manufacturers, does not make its price list public. However, we found two contractor-run sites that provide cost estimates. QualitySmith.com put wholesale prices at anywhere from $2,400 to $3,400. WebHVAC.com gave slightly higher estimates: from $2,369 to $3,239 for the XC17 and from $3,129 to $3,779 for the XC21. These costs (which do not include installation) are about average for the central air conditioners that earn our highest rating.
Like all Energy Star-rated products, the Dave Lennox Signature Collection can get you a $300 income tax credit if installed by the end of 2013. Depending on where you live, these extra-efficient air conditioners may also qualify for additional rebates from your state government or your power company. In addition, if you choose the optional SunSource modules, the federal solar credit (good through 2016) will cover 30 percent of their cost --including installation.
Questionable reliability. The only reviews we found for specific models in the Dave Lennox Signature Collection were on the Lennox website. These are overwhelmingly positive, but they are mostly from new owners, so they give little information about reliability. We were able to find some information about Lennox air conditioners as a whole, however. A survey of more than 40,000 homeowners with central air conditioning found Lennox to be a reasonably reliable brand, with only 13 percent of units needing repairs in a given five-year period.
However, the feedback is less positive at FurnaceCompare.com. The vast majority of reviewers give the brand a 1-star rating with most complaints focusing on durability. On the other hand, even the highest-rated brands on this site get more negative reviews than positive ones, so this may not be a strike against the Lennox brand. As for the warranty, it's par for the course: All parts are covered for 10 years, but labor is excluded.
The Dave Lennox Signature Collection makes the list of the most efficient central air conditioners rated by the Energy Star program for 2013. All products bearing the Energy Star label must meet Environmental Protection Agency energy efficiency standards while still delivering the features and performance that consumers demand, but the products on this list are more efficient. In addition, the article notes that air conditioners in the Dave Lennox Signature Collection are unusually quiet and can be set up to run on solar power.
Review: Energy Star Most Efficient 2013 -- Central Air Conditioners and Air Source Heat Pumps, Editors of EnergyStar.gov, As of June 2013
Cecilia Harsch, a former big-box store manager, puts the Dave Lennox Signature Collection XC21 fourth on her list of the five best central air conditioners. Harsch says the models were selected based on their seasonal energy efficiency ratio (SEER) and "consistent cooling capabilities," though there's nothing to indicate hands-on testing. She also praises this unit's quiet operation and its durable steel outer cabinet.
Review: Best Air Conditioner, Cecilia Harsch, March 13, 2012
WebHVAC.com is a site run by a group of former HVAC contractors that "covers just about everything to do with HVAC equipment in your home, business, or environment." The editors award the Lennox Signature XC21 the sixth slot on their list of the 10 best central air conditioners, with particular praise for its high efficiency and optional solar power modules. However, its performance and reliability are not evaluated, and there's no mention of hands-on testing or consumer surveys.
Review: Top Rated Central Air Conditioners 2013, Editors of WebHVAC.com, As of June 2013
ConsumerReports.org does not test central air conditioners, but it does evaluate the reliability of different brands, including Lennox, based on a survey of its readers. In the latest survey, more than 40,000 readers who bought central air conditioning units between 2005 and mid-2011 reported on whether the units needed repairs. Of the 10 brands listed, most have repair frequencies between 11 and 13 percent. However, three brands perform significantly worse, with repair frequencies of 17 percent or higher.
Review: Central Air Conditioning Reliability, Editors of ConsumerReports.org, May 2012
FurnaceCompare.com has the largest collection of owner reviews of central air conditioners on the web. The Lennox brand as a whole gets worse reviews than most, with only 22 percent of owners recommending it. Most negative reviews focus on durability, and some complain about warranty service.
Review: Consumer Reviews of Lennox Central Air Conditioners, Contributors to FurnaceCompare.com, Not dated
QualitySmith.com is a site that helps connect homeowners with reliable contractors. While the site does not review or evaluate air conditioners, it does provide information about pricing. However, the site's editors caution that the prices do not come from the manufacturers; they're only estimates based on recent reports from contractors. QualitySmith.com estimates the wholesale prices of air conditioners in the Dave Lennox Signature Collection at anywhere from $2,400 for the smallest and least efficient unit to $3,400 for the largest and most efficient. The site also provides information about features, specs and warranty.
Review: Lennox Air Conditioner Prices: An Overview, Editors of QualitySmith.com, Not dated
The Dave Lennox Signature Collection is one of the few air conditioners for which we were able to find user reviews that mention models by name. Reviews on the Lennox website are overwhelmingly positive, praising the air conditioners' performance, efficiency and quietness. The only two negative reviews we found complain of a rattling or buzzing noise that other reviewers attribute to faulty installation.
Review: See What Other Customers Are Saying About the XC21 Air Conditioner, Contributors to Lennox.com, As of June 2013