May 2009- When it comes to staying cool, lighter is better. That's why tennis players wear white and why manufacturers usually refrain from using dark-colored coatings on roofs, car interiors or other surfaces exposed to extreme heat. The pressure from the heat can lead to failures and safety hazards.
But just as Andre Agassi's black headband, T-shirt and socks broke the mold, new pigments have burst onto the coil coating scene, shattering preconceived notions about what can and cannot be used.
Research and development
Over the past year, the National Coil Coating Association, Cleveland, has helped develop cool paints, or pigments that enable darker colors to withstand heat buildup. They can be applied to metal during the prefabrication process, then provide a specific color in the visible light range while reflecting incident light in the near-infrared range. Although only 5 percent of the total incident solar radiation gets reflected back into space with a standard black pigment, these tones produce something in the range of 30 percent to 45 percent. But they look the same to the naked eye.
"It really makes prepainting a more viable option in a lot of cases," says NCCA spokesman Alan Williamson. "And any business that works with sheet metal that's fabricated into parts that are post-painted for decorative or corrosion-protection purposes should really be considering [prepainting] anyway."
Not only do the cool paints help facilitate the prepainting process but they also neutralize a phenomenon construction workers, painters and roofers have been battling for years: the urban heat island effect. Typically, the heat island effect is evident on roofs, especially those that are black and made of asphalt. They absorb more heat than their surroundings and lead to smog, humidity and increased energy demands.
An expanding influence
Initially developed specifically for coatings and metal roofs, cool paints are being employed more often as more potential applications are discovered. Overseas shipping containers, building facades and just about any other metal product that faces substantial heat can employ the technology.
In addition to alleviating some environmental concerns, it's a practice that's beneficial to just about everyone involved.
"Any strategy that can play a role in reducing these heat effects is ultimately going to create a better, more comfortable environment," says Williamson. "Cool paints are a start, but the idea is to apply the concept to as many facets of our lives as possible."
The NCCA is developing and tweaking its offerings just as it has in the past with coil coatings, prepainted metals and corrosion-resistant products. The research continues in an effort to expend less energy and allow everyone to live more cheaply and comfortably. MM