LBNL’s engine. The raw data. Every method stated.
Center-of-glass performance from LBNL’s Windows-CalcEngine, the full spectral record behind every glass, and every assumption printed on the result.
Numbers you can trace
1. Engine
Windows-CalcEngine, NFRC 100/200
U-factor, SHGC, visible light, reflectance, UV and color for any makeup, center-of-glass, stored with the run date and engine version.
2. Raw data
The full spectral record
“Raw data” on every glass, layer and calculation shows the exact values, including LBNL’s full spectral record, to copy or download. Nothing rounded or summarized.
3. Laminates
A validated, disclosed method
Custom laminates follow the NFRC laminate procedure; the validation against LBNL’s laminates is published, and anything outside the procedure is disclosed on the result.
4. Units
SI or inch-pound, method on every sheet
Thickness in mm or inches and the SI U-value or the NFRC U-factor as separate settings; the rating method is always printed.
Free for engineers and consultants
- Engineers and façade consultants qualify for GlassRef Specifier, free: unlimited saved makeups and sheets, every calculation, projects
- Spec finder: every coated glass in LBNL’s library calculated in typical 1" and 1-1/8" units
- Hard coat vs soft coat, with how each is known, never guessed
- Sound estimates with a published method and range (checked against 218 lab tests)
- Report an issue with any data point, straight to support
EN 673 / EN 410 ratings are on the roadmap, not available yet. Results are center-of-glass; whole-window values need the frame.
Start in a minute
- Sign up with your firm email address.
- Open Plan and tap Set up GlassRef Specifier.
- Open any glass and tap Raw data.
A real GlassRef screen.
Questions engineers ask
Which calculation engine does GlassRef use?
LBNL’s Windows-CalcEngine, center-of-glass to NFRC 100/200. Each result is stored with its run date and engine version and can be rerun. The engine is checked against textbook values such as single clear 1.03 and clear double 0.47 Btu/h·ft²·°F.
Can I download the spectral data?
Yes. Raw data on every glass shows LBNL’s full spectral record to copy or download, and every calculation shows the exact inputs.
Does GlassRef support EN 673 / EN 410?
Not yet; it is on the roadmap. Today results follow NFRC 100/200, and U-values can be shown in SI units (W/m²K). The rating method is printed on every result.
How are custom laminates validated?
Against LBNL’s measured clear PVB laminates the results are within 0.001 on visible light, solar transmittance and SHGC; tinted, named-interlayer and coated laminates within about 0.01. Methods outside NFRC’s procedure are disclosed on the result.
Is it free for engineering firms?
Yes. Engineers, façade consultants and specification writers can set up GlassRef Specifier free with the firm’s email address.
GlassRef publishes reference data and shows where every number came from. It does not test, certify or approve products; product certification belongs to bodies such as NFRC, and the design professional of record signs off on what goes into a building. GlassRef is independent and not affiliated with LBNL or any manufacturer.