The Design 70 wheel was developed for open wheel installations and utilizes a solid, single surface airfoil blade to provide Chicago’s Plug Fan with one of the industry’s highest efficiencies. With reduced horsepower requirements, energy savings are significant, up to 84% efficient. Although the Design 70 High Efficiency Plug Fan has ambient air applications, it is typically utilized for temperatures up to 1000°F. For higher temperatures consult the factory. Sound levels are generally low over the entire performance range.