F-Series · Fiberglass
GR70 Fixed Window
A fixed 70 mm fiberglass window with hybrid vacuum glass: a whole-window U-value of 0.085 (R-11.8) in a slimmer frame, for picture windows and the fixed lites of an apartment or dorm elevation.
The GR70 fixed unit shares its 70 mm frame and finish with the GR70 Dual Action and Casement, so fixed and opening windows read as one elevation. With no sash, the frame face narrows to about 57 mm and almost the whole opening is glass.
Technical specifications
| Frame depth | 70 mm |
| Frame material | Pultruded fiberglass, powder-coated |
| Frame face width | About 57 mm (2¼ in) |
| Glazing pocket | Up to 40 mm |
| Opening | Fixed, non-operable |
| Whole-window U-value, ZERO 04 | 0.085 Btu/h·ft²·°F (0.48 W/m²K), R-11.8, at NFRC size 1200 × 1500 mm Calculated |
| Whole-window U-value, ZERO 05 | 0.090 Btu/h·ft²·°F (0.51 W/m²K), R-11.1 Calculated |
| Whole-window U-value, ZERO 24 double glazed | 0.243 Btu/h·ft²·°F (1.38 W/m²K), R-4.1, within the Massachusetts energy code Calculated |
| Reversed frame | ZERO 04: 0.084 (0.48 W/m²K), R-11.9 · ZERO 05: 0.089 (0.51 W/m²K), R-11.2 Calculated |
| Center-of-glass U-value | ZERO 04: 0.044 to 0.047 Btu/h·ft²·°F (R-21 to R-23) · ZERO 05: 0.054 (R-18.5) Calculated |
| SHGC, center of glass | KØLD 0.49 / 0.35 · MILD 0.35 / 0.27 · HEIT 0.26 / 0.20 (ZERO 05 / ZERO 04) Calculated |
| Visible light, center of glass | KØLD 76% / 64% · MILD 67% / 53% · HEIT 61% / 45% (ZERO 05 / ZERO 04) Calculated |
| Air infiltration | Tested to AAMA / NFRC Project-specific |
Certified values are published as NFRC and CSA testing completes. Calculated values come from LBNL THERM and WINDOW models of the specific assembly. Project-specific values depend on size and glass package.
What is a fixed window?
A fixed window is glazed into a frame that does not open. With no sash, hinges or locks, it has the slimmest frame for its size, the most glass, the lowest air leakage and nothing to wear out or adjust. Fixed windows are used for picture windows, transoms and sidelights, glass that is high or hard to reach, and the non-opening lites of a larger window wall.
Codes still call for opening windows for ventilation and emergency escape in many rooms, so fixed units are usually combined with dual-action or casement windows in the same elevation.
Thermal section (THERM heat map)
GR70 Fixed Window · Sill. Whole window 0.085 Btu/h·ft²·°F (R-11.8) with ZERO 04, 0.090 (R-11.1) with ZERO 05, at 1200 × 1500 mm. Calculated
Modeled in LBNL THERM 8.1 at NFRC winter conditions, 0°F outside and 70°F inside. The red band on the room side shows the frame and glass staying close to room temperature; the lines are isotherms every 3°C (5.4°F).
Full engineering image ›All sections, ZERO 04 (PDF, 5.9 MB) ›ZERO 05 (PDF, 5.9 MB) ›Every section we model ›
Glass & glazing options
Standard glazing is the hybrid vacuum unit in one of six ZERO packages: three climates, each at two levels. ZERO 05 Daylight admits the most light and solar heat; ZERO 04 Ultimate has the lowest U-factor. For code-level projects, the double-glazed ZERO 24 packages are also available.
| Package | Center-of-glass U / R · SHGC · visible light |
| KØLD 05 · cold | 0.054 / R-18.5 · 0.49 · 76% |
| KØLD 04 · cold | 0.047 / R-21.1 · 0.35 · 64% |
| MILD 05 · mixed | 0.054 / R-18.6 · 0.35 · 67% |
| MILD 04 · mixed | 0.044 / R-22.6 · 0.27 · 53% |
| HEIT 05 · hot | 0.054 / R-18.6 · 0.26 · 61% |
| HEIT 04 · hot | 0.044 / R-23.0 · 0.20 · 45% |
| ZERO 24 KØLD · double glazed | 0.244 / R-4.1 · 0.57 · 83% |
| ZERO 24 MILD · double glazed | 0.241 / R-4.1 · 0.40 · 73% |
| ZERO 24 HEIT · double glazed | 0.242 / R-4.1 · 0.30 · 68% |
Quanex Super Spacer® Premium silicone-foam warm-edge spacer, argon-filled outer cavity.
Triple glazing, laminated and acoustic build-ups are also available to suit the project. Compare the ZERO packages ›
