Look up: R-value

1. 
   R factor or value
   - A measure of a materials resistance to the passage of heat. New homewalls are usually insulated with 4' of batt insulation with an R value of R-13, and a ceiling insulation of R-30.
   Found on http://www.homebuildingmanual.com/Glossa
   
   
2. 
   R Value
   A measure of insulation. For example, typical new home's walls are usually insulated with 6' of batt insulation with an R value of R-19, and a ceiling insulation of R-28.
   Found on http://www.soundhome.com/glossary
   
   
3. 
   R-Value
   A unit of thermal resistance used for comparing insulating values of different material. It is basically a measure of the effectiveness of insulation in stopping heat flow. The higher the R-value number, a material, the greater its insulating properties and the slower the heat flow through it. The specific value needed to insulate a home depends on ...
   Found on http://www.neo.ne.gov/statshtml/glossary
   
   
4. 
   R-value
   `R-value` can refer to: * Properties of materials: **R-value (insulation), the efficiency of insulation **R-value (soils), stability of soils and aggregates for pavement construction *`r-value`, usually uncapitalized, is also term used in computer science. See value (computer science). *In crystallography, the R-factor (also known as `R-value`), is a measure of the agreement between the crystallographic model and the diffraction data. *In stat...
   Found on http://en.wikipedia.org/wiki/R-value
   
   
5. 
   R-Value
   Resistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value.
   Found on http://www.hhwindow.com/glossary.html
   
   
6. 
   R-VALUE
   The thermal resistance of a glazing system. The R-value is the reciprocal of the U-value. The higher the R value, the less heat is transmitted throughout the glazing material.
   Found on http://www.proofrock.com/construction_te
   
   
7. 
   R-Value
   A measure of the capacity of a material to resist heat transfer. The R-Value is the reciprocal of the conductivity of a material (U-Value). The larger the R-Value of a material, the greater its insulating properties.
   Found on http://www.electromn.com/glossary/r.htm
   
   
8. 
   R-value
   A measure of the capacity of a material to resist heat transfer. The R-value is the reciprocal of the conductivity of a material (U-value). The higher the R-value of a material, the greater its insulating properties. It is important to be aware that R-values depend not only on thickness but also on ...
   Found on http://www.daviddarling.info/encyclopedi