Calculating the R-Value of InsulationĬalculating the R-value of insulation requires knowledge of its K-factor, R-factor (a mathematical term), and the amount of installed insulation. The R-value is determined by ASTM methods for thermal testing and quantifying of an insulation product’s ability to restrict heat flow-values. The R-value Rule requires installers, home insulation manufacturers, new home sellers, and retailers to provide the R-value of the insulation. The objective of the Rule was to make it easier to compare different brands of similar insulation products. In response to rising fuel costs in the 1970s and the Organization of Petroleum Exporting Countries (OPEC) oil embargo of 1973, the R-value of insulation, or t he R-value Rule, was developed by the Federal Trade Commission and the insulation industry as an objective method for evaluating the performance of residential insulation materials. All zones in Texas have different insulating requirements to achieve energy-efficient, durable, healthy, and comfortable buildings and homes. The state of Texas includes three of these zones, ranging from hot and mild to humid and dry climates. It is based on eight geological climate zones in the United States.
#Ashrae 90.1 insulation thickness code#
The International Energy Conservation Code (IECC) and the ASHRAE 90.1 mandate the R-values of insulation required to achieve best practices in insulating commercial and residential structures. However, the metric equivalent of R-values is the relative strength index (RSI) value expressed as ☌ m 2 sec/ J. Expression of the R-value is often in imperial units as☏ ft 2 sec/ BTU. The R-value (resistance value) of insulation represents its resistance to heat flow through a given thickness of a material. Therefore, by merely choosing the an ICF Wall System, Texas homeowners and builders are assured of an insulated wall system with R-values that are code compliant with all climate zones throughout Texas. Most insulated concrete forms exceeds the ASHRAE 90.1 minimum R-value requirements for continuous insulation for all climate zones in Texas.