Frame
Supports the opening, resists movement, manages drainage, and influences sightlines, finish, strength, and thermal behavior.
Window Academy
Understand the window before you buy the window.
A plain-English guide to the parts, ratings, and tradeoffs that shape comfort, light, durability, and cost in an Arizona home.
Request a free estimateWindow anatomy
A window is a system, not a pane of glass.
Frame material, sash design, insulated glass, coatings, spacers, seals, hardware, and installation all work together. A strong number in one category cannot compensate for a poor fit somewhere else.
Sash
Holds the insulated glass and moving hardware. Reinforcement, locks, rollers, balances, and weatherstripping affect operation and longevity.
Insulated glass unit
Two or more panes separated by a sealed spacer create the core thermal and solar-control system.
Low-E coating
Microscopic coatings reflect selected infrared and ultraviolet energy while allowing useful visible light through.
SHGC
Solar Heat Gain Coefficient measures how much solar heat enters through the full window. Lower numbers reject more solar heat.
U-factor
Measures heat transfer through the whole window. Lower values indicate better insulating performance.
Visible transmittance
Describes how much visible light passes through. It helps balance daylight with solar control and tint.
Air leakage
Measures unintended air movement through the assembled window. Installation and perimeter sealing matter alongside the product rating.
Arizona glass choices
Lower is not automatically better everywhere.
Strong solar control can make sense on exposed west-facing glass, while another room may benefit from more visible light. Northern Arizona also places more weight on winter insulation and condensation resistance. The best package can vary by elevation, orientation, room, shade, and glass area.
Compare NFRC whole-product ratings for the exact size and configuration proposed. Center-of-glass marketing numbers are not the same thing.
Start with a clearer plan
Bring the ratings back to the actual room.
Tell us about your home and what you want to improve. We’ll help narrow the right materials, styles, glass packages, and installation approach.