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| Overview: |
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With the aid of design of experiments, a researcher at the National Renewable Energy Laboratory (NREL) in Golden Colorado, "completed a successful three year study to find the most cost effective materials for solar air heaters." The experimenter states, "The use of factorial analysis was very important because I was able to examine a number of different conductivies and configurations." |
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| Fixed
Variables: |
Significance |
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Pitch (distance between
holes in the collector) |
Insignificant |
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Diameter (diameter of
each individual hole) |
Insignificant |
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Thickness (thickness
of the collector plate) |
Insignificant |
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Mass flux (mass flow
rate of the collector surface) |
Significant |
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Conductivity (material
thermal conductivity) |
Significant |
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| Response
Variables: |
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Efficency
of Heater |
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Amount of Heat |
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| Summary: |
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The case study revealed a suprising fact which was confirmed in confirmation experiments. The surprise conclusion indicated that the conductivity characteristics of the material fabricating the solar air collector yielded a minimal effect. This opens the way for use of other materials which had not been considered viable because of low conductivity characteristics. Now scientists' could justify looking at low-conductivity materials, including polymers, as well as less expensive metals. |
