In the tug-of-war between copper-brass and aluminum radiator technology, analysts agree that aluminum has clearly won the battle in the light, on-road vehicle sector. The focus is now on the off-road, heavy-vehicle market.
Although aluminum holds the edge in the near term, the emerging CuproBraze technology stands out as a bright alternative to aluminum in the heavy-vehicle sector in the long term. CuproBraze produces thinner, lighter copper radiators with good corrosion resistance and repairability, greater flexibility and tensile strength, easier cleaning and lower material costs, according to those familiar with the product.
Currently, emerging challenges favor aluminum's lighter weight over copper-based products, according to Sandeep Kar, program manager of heavy truck technologies at San Antonio-based market research firm Frost & Sullivan. Record-high diesel fuel prices—$4.76 a gallon in mid-July—and ever-tougher Environmental Protection Agency (EPA) emissions rules are steering heavy vehicle makers toward aluminum as the best solution to weight-savings problems.
"Truck makers, fleet operators and end-users are doing all they can to reduce the weight of the truck so they can save diesel fuel costs," Kar said. "We are in an environment of very incredible fuel prices, and that is impacting the heavy truck design."
Most North American medium- to heavy-duty trucks used copper radiators before early 2000, according to Kar. The major shift to aluminum came after a series of EPA diesel-emissions regulations were implemented in early 2000, including an EPA mandate of a 90-percent reduction in diesel emissions in all new heavy trucks by 2010.
Aluminum radiator manufacturers are investing in research and development to meet customer needs. "Aluminum radiators can now support that kind of aggressive heat management," he said. "There are greater heat-dissipation benefits from aluminum over copper. And because you can get aluminum for a lower price and at a lighter weight, the choice becomes obvious."
With the focus on fuel efficiency, future aerodynamic advances seem likely to further swing the vote in favor of aluminum, according to Kar. He said that designing a truck with a longer and narrower nose for increased fuel efficiency will favor aluminum, given the smaller radiator size necessary to fit the nose.
Kar expects the changes to occur most rapidly in off-highway heavy vocational trucks used in mining and forestry because more power is needed to propel them. He predicted that this section of the market will favor aluminum radiators by 2010.
However, the one technological development that might change the flow back to copper in the heavy-vehicle market is the emerging CuproBraze heat-exchanger technology that produces thinner, lighter copper radiators. "It's definitely something to watch out for in the long term," Kar said, because it marries the best qualities of copper and aluminum. However, it likely will take the market until at least 2012 to accept the product and begin implementing it on a large scale, he added.
When copper radiator suppliers begin losing their market share in the short- to medium-term, they might promote CuproBraze more aggressively to catch up to aluminum. But the product will be relatively expensive compared with aluminum and traditional copper-brass radiators until producers start to recoup their research and development costs. It also will take a while before consumers overcome the stigma attached to the original copper-brass radiators, which contained lead and could be toxic.
Robert Weed, vice president of automotive and original equipment manufacturing at the New York-based Copper Development Association, touted copper radiators for their strong thermal transfer capabilities, durability and operating efficiency that give the technology an advantage over aluminum in heavy-duty applications.
These qualities are particularly important for heavy vehicles because they often have large turbo-charged diesel engines, which require more-powerful cooling systems and tend to run for long distances, sometimes under extreme conditions, before they are serviced or replaced.
Weed believes that although copper-based radiators will continue to hold onto a good portion of the heavy-vehicle market, the CuproBraze technology won't necessarily allow the red metal to recapture market share in heavy-duty vehicles. The main barrier is the large push to similar aluminum-brazing technology advocated by leading auto parts suppliers like Kariya, Japan-based Denso Corp., whose customers include Toyota Motor Corp., which has plants in China, South Korea and North America.
While small in number, these large heat-exchanger companies wield a lot of clout, and—given the millions of dollars they've invested in the technology—are unlikely to switch back to a copper-based product, even for CuproBraze.
"I think we are going to see a much greater gain in market share on the global scale than we will in North America," Weed said.
While the die seemingly has already been cast in North America, things are far less firm in developing countries like China, where new radiator plants—some using CuproBraze technology—are still being built, he said.
Tim Strelitz, president of California Metal-X Inc., a Los Angeles-based brass ingot manufacturer dealing heavily in radiators, agrees. He sees the potential for original equipment manufacturers to gravitate to the new copper radiators, but as long as aluminum is roughly one-third the cost and density of copper the industry will continue to turn to the light metal.
"Life is always about choices, and those choices in business are always about cost," he said. "It's always a tug-of-war. But copper as a radiator is much better than aluminum over the greater course of time."