With the return of hot weather, and with electricity rates set to jump sharply this summer, Marylanders are becoming painfully aware of how expensive it will be to cool their homes from now on.
If their old central air-conditioning systems have been limping for years, many are likely to be ogling the new, high-efficiency systems that promise to cool their homes with up to 30 percent less electricity.
Not so fast.
Industry experts say the new, more-efficient models mandated by the federal government since January might indeed deliver the promised energy savings.
But they also come with a list of caveats.
The new systems are not only 20 percent to 25 percent more expensive, manufacturers say - they're also physically larger. And that, in turn, can make them more difficult and costly to install properly on those pads outdoors, as well as in the closets and furnace rooms indoors where the old components hummed happily for years.
"My air conditioner space is constrained. I can't put [a larger unit] in unless I take out a wall, and my wife doesn't want to take out the bathroom," said Glenn C. Hourahan, vice president of research and technology at the Air Conditioning Contractors of America, an industry group based in Arlington, Va.
The issue has prompted an industry campaign urging homeowners not to cut corners, lest they cancel out the higher efficiency they're paying for, or even worse, condemn their new system to early failure.
"Consumers should be cognizant, if they need to buy a system, of what they are being offered," said Raymond A. Granderson, training manager for Rheem Heating and Cooling Co., in Fort Smith, Ark.
"It doesn't take much, if [the system] isn't matched properly or put in properly, to see the SEER rating drop dramatically."
And with it, your energy savings.
SEER stands for seasonal energy efficiency ratio. It's a measure of the unit's cooling output (in British thermal units) for each unit of energy input (in watt-hours).
On Jan. 23, the U.S. Department of Energy imposed a new minimum SEER efficiency standard - first proposed by the Clinton administration - on residential central air conditioners and heat pumps. (Window units are not affected.)
The new rule raises the minimum SEER from 10 to 13. For equivalent systems, the change should provide a 30 percent savings in power consumption.
It's the AC equivalent of the government's 1.6-gallon flush rule - which lowered water usage in new toilets by an even greater margin.
Eighty percent to 85 percent of the residential central-air systems installed since 1992 are rated at 10 SEER. Systems older than that could be rated at 8 SEER or lower.
That's because most builders keep costs down by using the cheapest systems available, and few homebuyers ask to spend more for a more efficient system - even if they're available. Central air systems typically cost $2,500 to $6,000.
By 2030, the government believes, the installation of 13-SEER systems will save the equivalent of a year's electricity consumption by 26 million U.S. households. The changeover could also result in reduced power plant carbon dioxide emissions equal to the annual output of 3 million cars.
The impact on manufacturers has been huge.
Carrier Corp., the world's largest manufacturer of heating and cooling equipment, has spent $250 million to redesign its product line and retool its Tennessee factory to meet the new standard.
Texas-based Lennox International took 18 months to find ways to squeeze greater efficiency out of its old 10-SEER line.
"We certainly had units that could meet the [new] minimum," said Bill McCullough, director for Lennox's cooling product management. The company sells systems as high as 19 SEER, he said, "but they weren't designed for the entry-level market."
So, company engineers designed bigger heat-transfer coils and added higher-efficiency condensers and motors to achieve 13-SEER efficiency.
Homeowners can continue to operate their old equipment. And dealers can keep selling their remaining stockpiles of 10-SEER systems, manufactured before Jan. 23. Industry observers say some dealers are boosting prices on their diminishing stock of the smaller, cheaper units.
After the old units sell out, however, all homeowners faced with replacing an old or worn-out central air conditioning or heat pump system will have to grapple with the complexities imposed by the new regulations.
Costs and savings
On the surface, it seems cut and dried. In theory, if you're paying $100 a month to cool your home now with a 10-SEER unit, replacing it with a 13-SEER system should cut your bill to as little as $70.
Manufacturers say the higher-efficiency equipment might cost more than a 10-SEER model - say, $6,000 instead of $5,000. But some observers say prices won't be that high.
"Last year, SEER 13 was a premium product. ... This year, SEER 13 is your basic commodity," said Harvey Sachs, director of the buildings program at the American Council for an Energy-Efficient Economy. "Everybody's got to try to meet the commodity producer's price."
By all accounts, consumers should recover the cost difference between 10-SEER and 13-SEER systems in four or five years of more efficient operation - less where temperatures and electricity rates are high.
But price isn't the only bump in the road. Bigger and better coils - the components that actually absorb heat from the home's interior and transfer it to the outdoor environment - make many of the new units up to 20 percent larger than comparable 10-SEER systems.
The outdoor portion of the "split-system" equipment, which contains the compressor and fan, could prove too big for the old concrete pad, or too close to the house or other structures for proper air circulation. So the unit, along with the tubes and wires that connect it to the indoor components, might have to be relocated.
Even more problematic are the evaporator coils and circulating motor. They sit indoors, on top of the air-handling system, usually in the basement or a closet somewhere.
"The larger equipment has to be accommodated somewhere within the structure, and the homeowner may be giving up something, [such as] a closet," Rheem's Granderson said. "I think it [size] is going to be a significant issue for a great percentage of the applications."
Cramming a big new coil into a tight space can raise other issues.
"It's not so much how to get the box to fit in the space, as how to transition the ductwork," Hourahan said.
When bends in the ducts are too abrupt, the system might have to work harder to move the cool air, he said, "And all of a sudden a 13-SEER works no better than the 10-SEER box you had before."
But the industry has an even bigger concern: installers who might try to save money, undercut the competition or save the expense of enlarging a closet by persuading homeowners not to replace the indoor coils at all.
"In the long term you'll make the situation worse," Granderson said. "Systems are designed for matching indoor coils, and if you don't put in the right coil, you'll get a lot of performance issues, refrigerant issues and [premature] compressor failures."
On the other hand, it's possible to do even better than 13 SEER if you're willing to spend the money. Manufacturers offer more costly systems with ratings as high as 21.
Terry Townsend, a consulting engineer in Chattanooga, Tenn., and president-elect of the American Society of Heating, Refrigeration and Air Conditioning Engineers, cautioned that high-SEER systems can also raise a new set of problems for homeowners.
"When you're increasing the SEER rating, you're reducing the moisture-removing capability," he said. That's because high-efficiency systems don't run as much and have less time to dehumidify the air, possibly leaving the house cool but clammy.
It might take separate dehumidifying equipment to solve that problem, Townsend said.
Achieving SEER ratings higher than 13 or 14 usually requires more sophisticated controls, as well as variable-speed compressors and motors - the equivalent of a dimmer switch on a light fixture.
"If somebody is a real greenie," they might want such a system, Hourahan said. "My concern is it's too sophisticated and complicated, and probably only a handful of people can work on it."
Replacing a 10-SEER system with 13-SEER should produce a sizable energy savings, he said. "It's much more important to have the equipment, whatever it is, properly installed."
He suggests that consumers pick a 13-SEER system, with a matched indoor coil, and use the money they don't spend on higher SEER ratings to have their ductwork inspected and sealed.
"Studies have shown that brand-new houses leak 20 to 40 percent of their air-conditioned air into the attic," Hourahan said, comparing it to a Toyota Prius hybrid with a leaky gas tank.
"I'd much rather spend less money on SEER and use it ... to make sure the cold air gets where it's supposed to go."