Electrochromic Insulating Glass Unit (IGU)- TGU

Declaration details

Manufacturer

SAGE Electrochromics, Inc. Saint-Gobain

Program operator

Smart EPD

Declaration number

SmartEPD-2024-032-0160-01

Date of issue

August 19, 2024

Valid until

August 19, 2029

Product category rules (PCR)

Part B: Processed Glass (version 1)

Standard

ISO 14025:2006 and ISO 21930:2017

Declared unit

1 m2 of product

System boundary

Cradle to gate (A1 - A3)

Product specificity

Product Specific

Manufacturing specificity

Facility Specific

Manufacturing plant

SageGlass (2 Sage Way, Faribault, MN 55021, USA)

Product category

Openings › Glazing › InsulatingGlazingUnits

Verifier

Jack Geibig, Ecoform, LLC

LCA software

LCA for Experts 10.7

Program instructions

Smart EPD General Program Instructions v.1.0, November 2022

Life cycle assessment results

Results per 1 m2 of product.

Environmental Impact Assessment Results

Resource Use Indicators

Waste and Output Flow Indicators

ND = not declared. Life cycle modules: A1-A3 product stage, A4-A5 construction process, B use stage, C end of life, D benefits and loads beyond the system boundary.

Material composition

Hazardous substances

No regulated hazardous or dangerous substances are included in this product.

Product description

The SageGlass electrochromic insulating glass unit (IGU) is a type of dynamic glazing for use in buildings which tints automatically or on demand to control sunlight admission, controlling heat and glare, while maintaining a view to the outdoors and reducing energy consumption. The dynamic functionality is provided by the SageGlass electrochromic coating which is located on the cavity facing surface of the exterior laminate of the insulating glass unit. The SageGlass coating comprises multiple layers of ceramic materials of less than a micron thick that together, and upon application of a low voltage direct current, provides the ability to reversibly tint the glass to dynamically control the admission of the sun’s heat and light. SageGlass electrochromic insulating glass units are available in a range of product configurations according to customer specifications. A typical IGU configuration comprises (i) a support lite of heat treated, float glass, the thickness of which depends on the application that is laminated to the 2.2mm device lite, (ii) a 2.2mm thick, annealed float glass lite on which the electrochromic coating is deposited (called the device lite), (iii) a third lite of heat treated float glass which is called the middle lite in the case of a triple glazed unit (TGU), or called the cover lite in case of a double glazed unit, (iv) a fourth lite of heat treated float glass which is the inboard lite of Triple glazed units (called a cover lite), the thickness and type of which depends on the application, and (v) associated insulating glass materials which comprise metallic spacer, desiccant, sealants, laminating interlayer materials, and wiring.

This EPD is for the triple glazed unit (TGU). A separate EPD is available for the double glazed unit (DGU).

Interpretation

Interpretation

This study was conducted following appropriate ISO standards and best practices and is intended for internal use to assist SageGlass with understanding the life cycle impacts of their products, as well as having the results published in an EPD. All data for the operation of the manufacturing facility, as well as transportation distances and modes, was collected directly from SageGlass. Efforts were made to check the data for internal consistency and to verify data with plant personnel. Sub-metering of energy use for each critical stage in the manufacturing process would allow for more detailed analysis and is recommended.

Based on the results from the life cycle assessment, the life cycle impacts are strongly driven by the manufacturing process and the raw materials, contributing as much as 72% and 20%, respectively, of the cradle-to-gate impacts of SageGlass IGU's GWP-total. The electricity and natural gas consumption are largely driving the impacts. The float glass, heat strengthened coated, and heat strengthened uncoated glass were the highest impact raw materials. Identifying alternate uses or recycling options for the product at the end of its useful life will reduce the end-of-life and potential raw materials burdens of recycled product. If possible, incorporating more recycled content into the product will help reduce the environmental impacts of the raw materials stage in the life cycle of the product.

Limitations

The findings in this research are limited by the inherent uncertainty of creating a representative model through LCA. Many assumptions were made in the modeling of the product system with representative processes and datasets. While quality control was undertaken at each step in building the LCI and conducting the LCIA, uncertainty is present in the results since the data represents only one year of manufacturing information from manufacturing location. Some level of uncertainty is inherent in conducting LCA and decision making must reflect this fact.