F-Series · Fiberglass
GR85 Dual Action Window
The workhorse Passivhaus window, and the one F-Series system tested and rated to PHIUS. A dual-action fiberglass frame at 85 mm depth, carrying triple or vacuum glazing for the lowest whole-window U-values in the range.
Every F-Series fiberglass frame suits a Passivhaus project. The GR85 Dual Action is the system that has been tested and rated to PHIUS, so specify it when the target is certification or the lowest possible heat loss. The deep fiberglass frame isolates the glazing edge, and the tilt-turn action gives both trickle ventilation and a wide egress opening from a single handle.
Technical specifications
| Frame depth | 85 mm |
| Frame material | Pultruded fiberglass, powder-coated |
| Glazing pocket | Up to 42 mm |
| Opening | Dual action / tilt-turn, inward |
| Whole-window U-value | 0.045 W/m²K equiv. R-22 Calculated |
| SHGC | 0.20–0.50 by glass Project-specific |
| Passivhaus | PHIUS tested and rated PHIUS |
| 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 tilt-and-turn (dual action) window?
A tilt-and-turn window, also called a dual-action window, does two jobs from a single handle. Turn the handle one way and the whole sash swings inward like a door for full ventilation, easy cleaning from inside, and a clear egress opening. Turn it the other way and the sash tilts inward at the top only, for secure background ventilation with the opening out of easy reach. All of the operating hardware is concealed inside the frame. It is the standard operable window across Europe, and it is the right choice wherever a window has to both ventilate securely and open wide.
