ASTM C1668-09 - 15.5.2009
 
1. Scope

1.1 This specification covers the requirements and physical properties of reflective insulation systems applied externally to Rigid Heating, Ventilation, and Air Conditioning (HVAC) duct systems operating at or below 250ºF (121.1 °C). These insulation systems consist of one or more low-emittance surfaces, such as metallic foil or metallic deposits, mounted on substrates to produce reflective air spaces. Reflective insulation systems derive their thermal performance from surfaces with an emittance of no greater than 0.1 facing enclosed air spaces.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 
2. Referenced Documents

C1258-21a(2026)

Standard Test Method for Elevated Temperature and Humidity Resistance of Vapor Retarders for Insulation (Includes all amendments and changes 3/24/2026).

C1338-25

Standard Test Method for Determining Fungi Resistance of Insulation Materials and Facings

E96/E96M-24a

Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials (Includes all amendments and changes 11/20/2024).

E2231-26a

Standard Practice for Specimen Preparation and Mounting of Pipe and Duct Insulation Materials to Assess Surface Burning Characteristics (Includes all amendments and changes 8/26/2026).

TAPPI Standard T-512 sp-02

Creasing of Flexible Packaging Material Paper Specimens for Testing Available from Technical Association of the Pulp and Paper Industry (TAPPI), 15 Technology Parkway South, Norcross, GA 30092, http://www.tappi.org.

C168-25

Standard Terminology Relating to Thermal Insulation

E84-26a

Standard Test Method for Surface Burning Characteristics of Building Materials (Includes all amendments and changes 4/15/2026).

C1045-19(2026)

Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions

C411-26

Standard Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation

C390-08(2024)

Standard Practice for Sampling and Acceptance of Thermal Insulation Lots

C335-05a

Standard Test Method for Steady-State Heat Transfer Properties of Pipe Insulation

C1371-15(2022)

Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers