146 - A Deep Dive on Windows: Glass, Performance & Condensation

Windows are one of the most confusing—and consequential—components of a high-performance home. In this episode, the crew takes a deep dive into window and glass selection, aiming to make things clear without letting your eyes glaze over.

The discussion covers dual-pane versus triple-pane insulated glazing units, IGU numbering conventions, and the relatively new i89 coating—including what it means for thermal performance and condensation risk. They also unpack the difference between center-of-glass values and full-window NFRC performance numbers, and why those distinctions matter when making real design decisions.

One gem of a takeaway sums it all up, with Jake quoting Steve: “The windows, the envelope, and the HVAC are one line item.”

Pete’s Resources:

• Cardinal Glass Technical Guide (2025 Version 3.1)
• BA 0402 “Singing the Blues in the Key of Low-E”
• A Review of Advanced Architectural Glazing Technologies
• Efficient Window Coverings