R-value measures resistance to heat flow. R-values given in labels, fact sheets, ads, or other promotional materials must be based on tests done under the methods listed in paragraphs (a) through (d) of this section.

(a) All types of insulation except reflective insulation must be tested with ASTM C177-13, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus;” ASTM C518-17, “Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus;” ASTM C1363-11, “Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus” or ASTM C1114-06, “Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus.” The tests must be done at a mean temperature of 75 degrees Fahrenheit and with a temperature difference of 50 degrees Fahrenheit plus or minus 10 degrees Fahrenheit. The tests must be done on the insulation material alone (excluding any airspace). R-values (“thermal resistance”) based upon heat flux measurements according to ASTM C177-13 or ASTM C518-17 must be reported only in accordance with the requirements and restrictions of ASTM C1045-07, “Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions.”

(1) For polyurethane, polyisocyanurate, and extruded polystyrene, the tests must be done on samples that fully reflect the effect of aging on the product's R-value.

(2) For loose-fill cellulose, the tests must be done at the settled density determined under paragraph 8 of ASTM C739-17, “Standard Specification for Cellulosic Fiber Loose-Fill Thermal Insulation.”

(3) For loose-fill mineral wool, self-supported, spray-applied cellulose, and stabilized cellulose, the tests must be done on samples that fully reflect the effect of settling on the product's R-value.

(4) For self-supported spray-applied cellulose, the tests must be done at the density determined pursuant to ASTM C1149-17, “Standard Specification for Self-Supported Spray Applied Cellulosic Thermal Insulation.”

(5) For loose-fill insulations, the initial installed thickness for the product must be determined pursuant to ASTM C1374-14, “Standard Test Method for Determination of Installed Thickness of Pneumatically Applied Loose-Fill Building Insulation,” for R-values of 13, 19, 22, 30, 38, 49 and any other R-values provided on the product's label pursuant to § 460.12.

(b) Single sheet reflective insulation materials must be tested with ASTM E408-13, “Standard Test Methods for Total Normal Emittance of Surfaces Using Inspection-Meter Techniques,” or ASTM C1371-15, “Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers.” This test determines the emittance of the reflective surfaces—its power to radiate heat. To get the R-value for a specific emittance, air space, and direction of heat flow, use Table 3 in the ASHRAE Handbook, Chapter 26, if the product is intended for applications that meet the conditions specified in the tables. You must use the R-value shown for 50 degrees Fahrenheit, with a temperature difference of 30 degrees Fahrenheit.

(c) Reflective insulation systems with more than one sheet, and single sheet systems that are intended for applications that do not meet the conditions specified in Table 3 in the ASHRAE Handbook, Chapter 26 must be tested with ASTM C1363-11, “Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus,” in a test panel constructed according to ASTM C1224-15, “Standard Specification for Reflective Insulation for Building Applications,” and under the test conditions specified in ASTM C1224-15. To get the R-value from the results of those tests, use the formula specified in ASTM C1224-15.

(d) For insulation materials with reflective facings, you must test the R-value of the material alone (excluding any air spaces) under the methods listed in paragraph (a) of this section. You can also determine the R-value of the material in conjunction with an air space. You can use one of two methods to do this:

(1) You can test the system, with its air space, under ASTM C1363-11, “Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus” If you do this, you must follow the requirements in paragraph (a) of this section on temperature, aging and settled density.

(2) You can add up the tested R-value of the material and the R-value of the air space. To get the R-value for the air space, you must follow the requirements in paragraph (b) of this section.

(e) The standards required in this section are incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection at the FTC Library (202-326-2395), Federal Trade Commission, Room H-630, 600 Pennsylvania Avenue NW, Washington, DC 20580 and is available from the sources listed in paragraphs (e)(1) and (2) of this section. It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030 or go to www.archives.gov/federal-register/cfr/ibr-locations.html.

(1) ASHRAE Headquarters, 1791 Tullie Circle, NE, Atlanta, GA 30329; telephone (404) 636-8400; https://www.ashrae.org.

(i) 2017 ASHRAE Handbook—Fundamentals, Chapter 26: Heat, Air, and Moisture Control in Building Assemblies—Material Properties, Inch Pound (I-P) Edition (Copyright 2017).

(ii) [Reserved]

(2) ASTM Int'l, 100 Barr Harbor Drive, P.O. Box C700, West Conshocken, PA 19428-2959, 877-909-2786, www.astm.org/.

(i) ASTM C 177-13, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus” (published October 2013).

(ii) ASTM C 518-17, “Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus” (published July 2017).

(iii) ASTM C 739-17, “Standard Specification for Cellulosic Fiber Loose-Fill Thermal Insulation” (published August 2017).

(iv) ASTM C 1045-07 (Reapproved 2013), “Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions” (published January 2014).

(v) ASTM C 1114-06 (Reapproved 2013), “Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus” (published January 2014).

(vi) ASTM C 1149-17, “Standard Specification for Self-Supported Spray Applied Cellulosic Thermal Insulation” (published October 2017).

(vii) ASTM C 1224-15, “Standard Specification for Reflective Insulation for Building Applications” (published November 2015).

(viii) ASTM C 1363-11, “Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus” (published June 2011).

(ix) ASTM C 1371-15, “Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers” (published June 2015).

(x) ASTM C 1374-14, “Standard Test Method for Determination of Installed Thickness of Pneumatically Applied Loose-Fill Building Insulation” (published May 2014).

(xi) ASTM E 408-13, “Standard Test Methods for Total Normal Emittance of Surfaces Using Inspection-Meter Techniques” (published June 2013).