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How to Convert a Thermal Resistance Unit

In 2006, buildings consumed almost 40 percent of overall energy in the United States, according to a report from Massachussetts Institute of Technology. In today’s environmentally-sensitive times, thermal insulation contributes to optimization of energy usage, ensuring that unwanted heat transfer between warm and cool areas is minimized. The thermal resistance, or R-value, of insulation material is a measure of its ability to prevent the flow of heat energy in either direction, and in the United States is usually measured in square feet-degrees F-hour per British thermal unit. Converting R-values to the equivalent thermal conductivity, U-values or to metric units is easily accomplished.

Things You'll Need

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Instructions

  1. Convert R-Value to U-Value

    • 1

      Note the R-value that you wish to convert. This may be expressed in the form R-19 or simply as a number. Check that it is given in square feet-degrees F-hour per Btu.

    • 2

      Divide the R-value into 1 and note the result. For example, if the R-value is 19, the result is 0.0526.

    • 3

      Check your calculation. Record the result, which is the R-value converted to the U-value in Btu per square foot-degrees F-hour.

    Convert Imperial to Metric

    • 4

      Note the R-value that you wish to convert. This may be expressed in the form R-19 or simply as a number. Check that it is given in square feet-degrees F-hour per Btu.

    • 5

      Multiply the R-value by 0.1762 and note the result. For example, if the R-value is 19, the result is 3.348.

    • 6

      Check your work. Record the result, which is the R-value converted to square meters-degrees Celsius per watt.