Before the NASA alloy, there were two ways to meet these temperature requirements, says Hartlein. One method was to use existing aluminum to make a bigger fan that spins more slowly. The drawback to this approach was that a bigger fan requires more space. “If we use the NASA alloy, the fan is smaller relative to the competition, and the tunnel can be smaller as well. Even if you can take a foot out of the construction of a new tunnel, there are massive potential savings,” says Hartlein. “In addition, the properties of this material allow us to run even hotter, leading to safety smoke exhaust at temperatures beyond what tunnel designers anticipated.”
The other solution, Hartlein says, was to make the fan blades out of steel, but this required a specialized motor to turn and reverse the fan. “Steel weighs roughly three times more than aluminum. If it is three times as heavy on the rotating parts, the bearings are heavier, the shaft is heavier, and the motor is heavier—a lot comes with it. The motivation and opportunity for us to use aluminum, where in the past we would have had to use steel, is quite attractive to us. We can lower the cost of the overall product and provide better performance through the use of this alloy. We are just beginning to find applications that will provide value to our industry using this alloy.”
While Twin City Fan Company has purchased the tools to produce 3 sizes of the fan, it plans to manufacture 12 different sizes in total. In 2011, Clarage sold the first of its fans made with the NASA alloy to a company testing the fans to certify them to European standards. Hartlein says he has met with a major engineering company in the United States, and the representatives are very interested in the capabilities of new fans. “We are bidding many projects now and should be shipping our first projects by the end of the year,” he says.
According to Hartlein, the tunnel industry is busy and is projected to continue growing. “If you look around major metropolitan areas, there’s no place to put traffic, so it goes underground. This is driving a busy tunnel ventilation market,” he says. There are also opportunities for installing fans in existing tunnels due to stricter air quality standards.
As this innovative application of NASA technology is projected to keep people safer, it is also helping the inventor of the technology answer an important question. “One of the most frequently asked question that I have encountered over the years is, ‘What does the Space Program do for me?’ Unfortunately, few people are aware of the benefits that NASA technology provides to our society,” says Lee. “I am honored to know that my innovation has moved beyond NASA to benefit private companies and their customers in a way that can significantly improve the quality of our daily lives.”