r-value, definition of

The R value or R-value is a measure of thermal resistance used in the building and construction industry. The bigger the number, the better the building insulation's effectiveness. R value is the reciprocal of U-value. Often used as a measure of bulk insulation products, such as a roof insulation Batts.

Original Wikipedia entry

• What is R-Value, U-Value and how do they relate to insulation?
  How the R-value of a buildings insulation or home is calculated and the factors that effect the final R value, and how to use it.

• R-value to U-value Calculator
  R-value to U-value conversion calculator
• Insulation Batts Coverage Calculator
  Calculator for the number of insulation batt packs required for a ceiling or wall. Also works out how downlights effect the final insulation R-Value.
• R-Value Area Calculator
  Calculator to help work out the total R-Value of a wall with a window or other fitting within it.
• R-Value Calculator
  R-Value calculator to work out the total R-Value of a set of materials, say in a wall, ceiling or floor. Great for working out rate of heat loss or gain.

• New rSTUD Significantly Increases Wall Insulation Performance
  A dirty little secret in the building industry is that the promised r-value of a wall is usually just a measure of the cavity insulation in a perfect installation...
• Space-age Aerogel Insulation Now Cheaper and Available in Sheets
  Insulation may not be sexy, but it is important. Over the past years we’ve seen leaps and bounds towards creating cheaper, thinner, more breathable materials with higher R-values. There still isn’t “one” insulation out there that...

Related Tags: insulation, building, energy efficiency