Some challenging technology is behind the highest current SEER equipment now available. Manufacturers are striving to make installation, service, and operation easier with onboard diagnostics, autoconfiguration, and even consumer-selectable dual-fuel systems.

Nordyne and the systems it markets in Tappan, Westinghouse, Maytag, and Frigidaire brand lines offer 23 SEER models now in two-ton capacity and, as part of the same product line, 21 SEER in three- and four-ton sizes. A five-ton unit will be available in the first quarter of 2007. The systems employ a Panasonic rotary compressor and an inverter board, "the brains of the iQ Drive system," according to company information.

"Interest in the 23 SEER product has been strong. We've trained over 75 distributor technical service advisors and we're back-ordered on the product," Drew Fitzgerald, vice president marketing, residential and light commercial at Nordyne, told The NEWS.

"Rotary compressors and inverter technologies are changing the industry today," he asserted. "What's really amazing is that our 23 SEER unit is no larger than our 13 SEER units. By using the inverter in a variable-capacity compressor, we're able to deliver ultra-high efficiencies but in a very reasonable size."

"Our use of inverter technology in standard unitary equipment is a big step for the industry. We're constantly working on improving efficiencies and, who knows, there may be improvements in the current technologies that will drive that efficiency even higher."

"We've been very successful implementing proven technology. But there are technologies that are proven outside of HVAC or outside of unitary HVAC that can be adopted into unitary products. As an industry, we need to be open to new and improved technologies," Fitzgerald added.

"When we started development of this (23 SEER) product we were targeting 18 to 20 SEER," noted Marc DeLaurent, Nordyne split system product manager.

Another attribute that consumers seek now is quiet operation. "We have a very quiet piece of equipment," DeLaurent said. The technology employed works like a dimmer switch, able to ratchet down to 40 percent power usage under favorable conditions such as at nighttime and its lower cooling demand, he explained.

Carrier, part of the United Technologies Corp. family, offers systems with SEER levels as high as 21, but hasn't yet introduced inverter technology in its North American product family, according to Johnny Johnson, Carrier brand manager.

"We have a design center in China. We have an Asia Pacific organization that is constantly working at that kind of technology and actually using that kind of technology, so yes, we're looking at that. We're looking at when do we think is the right time to bring some of this into the (U.S.) marketplace.

"We use inverter-driven technology in a lot of areas of the world," Johnson said. "We're always pushing the envelope on technologies being used in our product, but we also recognize that these have to be installed by people that are out in the marketplace today. The technologies have to be something we're comfortable with, that when they get into the marketplace they do work."

Look for future systems with SEER ratings in the "low 20s" from York Unitary Products Group, suggested Andy Armstrong, director of marketing.

"Our maximum efficiency today is in the 18 SEER range," Armstrong said. York is employing an aluminum blade-copper tube technology for the majority of its product line, "and we feel comfortable that will take us into the low 20s as we continue to use that technology effectively." Advancing beyond present SEER levels "is going to be driven for us by demand."

Microchannel coils have helped the group achieve smaller footprints and higher efficiency. One of the challenges of moving toward higher efficiency units is size. "We're demanding more and more of our consumers' backyards, which is creating major problems," Armstrong explained.

Trane and American Standard have systems ranging as high as 20 SEER. "I'm not sure what the theoretical limit is relative to pushing that efficiency envelope higher," said Dave Pannier, president of residential systems for the air conditioning business in both brands.

He noted that the ability to go higher than even 23 SEER lies in application of technologies already available, "perhaps in other industries or applications." He cited integration of controls to take systems from on-off switching to "infinitely variable capacity. You can take advantage of that from an operating efficiency perspective, varying the capacity of the machine with the call for cooling capacity from the space.

"There are other things too in terms of the aerodynamics of airflow, new technologies in airfoil design, and how you can make air-moving devices more efficient and quiet," Pannier added.

"Historically, our Amana brand products have sold a higher percentage of higher-efficiency product - or product that exceeds the current minimum efficiency requirements - than the rest of the industry, and that trend continues today," reported Al Knight at Goodman Manufacturing.

"When all the product introductions associated with our current development project are complete, Goodman will offer 13, 14, and 16 SEER air conditioners and heat pumps, and Amana will offer 13, 14, 16, and 18 SEER air conditioners and heat pumps," Knight added.

"While we have not researched the actual or theoretical limits of SEER, we focus on what is practical in the market and what will be of the most benefit to the largest number of consumers," he continued. "Rather than have a very high SEER on a very limited number of tonnages and ARI-rated systems, as some of our competitors do, we have chosen to deliver solid 16 and 18 SEER performance at all tonnages in the specific product family."

"Higher SEER does sell," asserted Bill McCullough, director for cooling product management, Lennox International . "The ultra-high SEER - we make a product called the XC 21 that gets up to 20.5 SEER, is meeting our expectations for sales volume. It's an early adopter for consumers that just want to have the best."

He expects Lennox to develop units with higher SEER numbers, but the company is moving cautiously to make sure the size and weight of equipment isn't a problem. "We would like to have a lowest energy use product." With ultra-high SEER units, "the outdoor units have gotten quite large. I think we're at the edge in size of what a consumer will accept.

"None of our products are over 35 inches in width because the gates on many (residential) fences have a 36-inch opening." McCullough said that some outdoor units are not only big but very heavy. "I think we're at a limit as to what the market will bear in physical weight."

Variable-speed technology is "the best trick in the bag" for compressor manufacturers to boost efficiency levels, said Jim Rutz, director of marketing, Tecumseh Cool Products. In Japan, he noted, between 90 and 95 percent of units employ AC inverter technology, but he says AC inverters are relatively inefficient.

"The next development, which isn't brand new but is catching on as price points drop and things cascade, is the DC technology. That's probably where the largest efficiency gains are going to come, in the application of brushless DC motors to compressor mechanisms." That is already employed in some specialty applications such as for the U.S. armed forces and golf carts.

"Variable-speed drives and integrated systems are probably going to be the one-two punch for any really significant improvements in true energy consumption," Rutz said, but integrated systems get beyond the realm of SEER ratings.

Some manufacturers such as Carrier, Lennox, and Rheem are making more integrated systems that use waste heat from the air conditioning system to preheat domestic hot water, he said, but there are no formulas to rate the energy efficiency of an integrated system. "SEER was developed to describe in a single function what an air conditioner does. There is no magic formula for saying that an integrated system has some specific energy savings."

The Copeland Scroll Ultratech compressor used in the 15 to 16 SEER space is also used in systems rated at over 20 SEER, noted John Schneider, director of residential marketing, Emerson Climate Technologies. "We think that platform is optimal both for the emerging 15 to 16 SEER segment and then very high-end, high-SEER solutions."

"We're seeing significant growth in the 15 to 16 SEER segment of the market, and we expect that to significantly expand during the next five-year period," Schneider said. "The reason is that contractors and homeowners want to have the next level up in energy savings (beyond 13 SEER)." It's important to note, he said, that "contractors are also offering not just a more efficient system but one that can improve the comfort of the home as well."

The other factor driving that growth "is that those systems are becoming significantly easier to install. Instead of having to run extra wires and only have certain service crews capable of installing that equipment, now these products can actually communicate and autoconfigure," Schneider observed.

Sidebar: Searching for Technology

New approaches are being studied, both in company labs in the United States and abroad and in industry-wide research:

The Air-Conditioning and Refrigeration Technology Institute (ARTI) identifies itself as the HVACR industry's fundamental research organization and is part of the Air-Conditioning and Refrigeration Institute (ARI).

"Our work tends to be longer term (than the immediate future) and it's hard to quantify the benefits directly into SEER ratings," Mark Menzer, ARI's vice president, engineering and research, said. One of its key goals, however, is achieving a 50 percent reduction in HVACR annual energy consumption and peak electric energy demand in new residential buildings by 2020. That suggests higher SEER levels than what now prevails in the residential market.

Another ARTI goal is the review and monitoring both within the HVACR arena "and elsewhere" for breakthroughs that could contribute to achieving the ARTI roadmap goals.

The 11th International Refrigeration and Air Conditioning Conference and the 18th International Compressor Engineering Conference were held recently at Purdue University. Presentations dealt with such matters as installing thermoelectric elements on the heat exchangers of air conditioning units to reduce the electricity they consume, bowtie compressor research, and more accurate performance simulation of packaged air conditioning equipment.

The ASHRAE (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) Research Strategic Plan for 2005-2010 lays out goals that seem to reach even beyond those outlined by ARTI. Among those, "Produce by 2015 new residential and light commercial buildings that have 70 percent less energy use than buildings built at the turn of the millennium."

Publication date: 08/07/2006