EPS Industry Alliance Publishes Paper on Effective R-Values for Polystyrene Foam Insulation
CROFTON, Md., June 13, 2019 /CNW/ -- Thermal insulation materials are critical to a building's design and its ability to reduce energy consumption. In 2017, the ULC Standards Committee on Thermal Insulation Materials and Systems approved an updated fifth edition of the CAN/ULC-S701.1, Standard for Thermal Insulation, Polystyrene Boards. This standard specifies the requirements for rigid expanded polystyrene (EPS) and extruded polystyrene (XPS) insulation.
Following the S701.1 standard update, the Canadian Commission on Building and Fire Codes has recognized the Fifth Edition as the new reference document for EPS and XPS insulation in the interim revision to the 2015 National Building Code of Canada. Now that NBC 2015 recognizes S701.1, Canadian provinces can adopt the requirements in Provincial jurisdictions. Three provinces, Alberta, British Columbia, and Saskatchewan have already adopted the NBC 2015.
Two changes to the Fifth Edition were significant for providing greater clarity on thermal performance. First, this edition removed the conditioned thermal resistance requirements for XPS in favor of requiring the Long-Term Thermal Resistance (LTTR) determined using CAN/ULC-S770-15, Standard Test Method for Determination of Long-Term Thermal Resistance of Closed-Cell Thermal Insulating Foams.
This test method is used to determine the LTTR for products that contain a cell gas (other than air) which diffuses over time, i.e., foam plastic insulation like XPS that are subject to aging. CAN/ULC-S770 predicts the 5-year aged R-value (equal to the 15-year time-weighted average R-value). In contrast, EPS insulation, which contains only air in its closed cell structure and therefore does not age, continues to have its R-value determined by ASTM C518.
The second change mandated that the LTTR, rather than the initial R-value or conditioned R-value, be marked on the XPS insulation products for greater clarity for consumers and designers. These two changes are consistent with the requirements of the building code to use LTTR values in energy calculations for foam plastic insulations that retain a blowing agent other than air for a period longer than 180 days.
To characterize the effective R-value of polystyrene insulation considering the effects of aging and conditions of application, the EPS Industry Alliance has recently published a paper, Polystyrene Foam Insulation in Long-Term Building Applications, Effective R-Values, that provides a method to estimate R-value by accounting for these factors.
R-value test standards, specifications, and labeling requirements are critical to providing consumers and designers with information necessary to predict the thermal performance of the insulation product. Without an understanding of aged R-value, consumers, building designers, and specifiers will overestimate the insulation's performance and underestimate the energy consumption of the building over its lifespan.
The EPS Industry Alliance is the North American trade organization representing the expanded polystyrene industry and focuses on the advancement and innovation of EPS products in construction and packaging.
For more information, please contact Betsy Bowers at 800-607-3772 or [email protected].
Contact: Mike Robertson, EPS Industry Alliance
E-mail: [email protected]
SOURCE EPS Industry Alliance