COMFORT STARTS WITH THE DETAILS
The right glass.
For the right place.
Daylight, solar heat, orientation and the complete window work together. Choose with the information that matters to your project.
READ THE LABEL
Understand the label.
Compare the complete window.
NFRC ratings make it easier to compare windows under standardized conditions. They describe the whole product, including the frame and glass. Glass-only data and glass-package names do not establish a window’s certified rating.
- U-factor
- How readily heat passes through the window. Lower means better insulation.
- Solar heat gain coefficient (SHGC)
- How much solar heat the window admits. Lower means less solar heat gain. Consider climate, sun exposure and shading when choosing.
- Visible transmittance (VT)
- How much visible daylight passes through the window. Higher means more daylight. VT is not a UV-blocking rating.
- Air leakage — when reported
- An optional rating of air passing through the product under test conditions. Lower means less air leakage.
- Condensation resistance — when reported
- An optional rating of resistance to interior condensation. Higher means greater resistance. Indoor humidity and conditions still matter.
Rating definitions: NFRC Consumer Guide to Windows (opens in a new tab).
Your label.
Your exact configuration.
Match the label and certified product record to the window being specified. Do not transfer a rating from another style or glass configuration. NFRC ratings do not account for installation; proper installation remains essential.
Search the NFRC Certified Products Directory (opens in a new tab)
NFRC guidance on certification and installation (opens in a new tab).
The label explanation from our resource library.
Keep the original illustrated guide handy while reviewing a label. Its sample label is an example, not a rating for an Advent window.
Open NFRC label explanation (PDF) — opens in a new tabENERGY STAR partner.
Configuration-specific choices.
Advent Windows & Doors is an ENERGY STAR partner. Product qualification depends on the exact certified configuration and the project's climate zone; partnership does not mean every window qualifies.
Understand ENERGY STAR criteria ↗NFRC ratings describe measured product performance. Match the product, glazing and configuration to the current record before using a rating in a quote.
Find Advent certified product records →