Coeur d'Alene 1121 Single-Slide Window

The Coeur d’Alene 1121 delivers commercial-grade sliding window performance at residential pricing. With steel-reinforced interlocks and a PG-35 rating at 71x55mm, this window handles Montana’s temperature swings better than standard vinyl sliders. The 2 3/4” frame achieves U-values as low as .24 with foam-filled frame and indium coating, with SHGC ratings ranging from .22-.30 across glass configurations.

Energy Performance That Matters in Montana

The numbers tell the story. With indium coating, argon gas, and foam-filled frame using 2.2mm/3mm glass, the 1121 hits a .24 U-value and .30 SHGC. That’s triple-pane performance from a double-pane window. The LoE³-366 triple-silver coating option delivers .29 U-value with .22 SHGC using 2.2mm/2.2mm glass — perfect for south-facing installations where solar heat gain becomes a summer cooling load.

Standard argon gas fill comes with every configuration. No upcharge. The LoE³-270 standard Low-E with foam frame and 4mm/3mm glass configuration achieves .28 U-value and .23 SHGC. Those numbers meet Climate Zone 6 requirements without breaking the budget.

Glass Configuration	U-Value	SHGC
Indium + Argon + Foam Frame (2.2/3mm)	.24	.30
LoE³-270 + Argon + Foam Frame (4/3mm)	.28	.23
LoE³-366 + Argon (2.2/2.2mm)	.29	.22
LoE³-270 + Argon (2.2/2.2mm)	.30	.30

Optional foam-filled frame prevents heat distortion — critical when Montana summer sun hits black or bronze frames. That foam fill also drops U-values by .02-.06 depending on glass configuration.

Built Stronger Than It Needs to Be

Steel-reinforced interlocks solve the common vinyl slider failure point. When temperature swings stress the frame, that steel keeps panels aligned. Welded corners for reduced moisture intrusion mean water stays out even after years of freeze-thaw cycles.

The AAMA LC PG-35 rating at 71x55 test size puts this window in light commercial territory. That’s 35 PSF design pressure — enough for 105 mph winds. The 2 3/4 inch extruded PVC frame provides the backbone, while clean, unobstructed sight lines with no accessory framing lines maximize glass area.

Glass Technology Choices

The Endur IG insulating glass system anchors every configuration. Glass coating options match specific needs:

• LoE³-366 triple-silver coating blocks 95% of UV rays while maintaining visible light transmission
• LoE³-270 standard Low-E balances cost and performance
• LoE³-340 falls between the other two options
• Indium-coated i89 on the #4 surface reflects heat back into the room

NEAT hydrophilic coating uses UV rays and rainwater to clean glass surfaces. Worth it on second-story installations where ladder access costs money. Preserve protective film protects glass during construction — peel it off after the drywall dust settles.

Installation and Applications

Professional installation by certified installers (FGIA/AAMA Installation Masters, OSI, or AWDI) is highly recommended, following AAMA-2400-02 for New Construction and AAMA-2410-13 for Flush Fin applications. Detailed PDF guides available for basic installation, painted products, and sealant (OSI) application.

Applications include new residential construction, aluminum window replacement projects, renovations requiring a single-slide format, and severe weather exposure and demanding climates. Optimized for the ‘Rugged West’ environments, including high altitude and coastal areas.

Compatible with standard cam-locks and optional auto-locks, and works with SDL (Simulated Divided Lite) and internal grids to match various architectural styles.

Market Position

Users find them to be a good value for the price. Generally priced lower than Milgard (e.g., Tuscany/Trinsic) and Simonton equivalents, positioned as a more affordable alternative to premium brands while maintaining performance. Comparable to Alpine Series 80, Pella 250, and Andersen 100 series.

The 1000 Series (1121) uses a 2 3/4” frame, while the 3000 Series uses a wider 3 3/8” profile for higher load capacity. Both share similar energy performance tables.

Lifetime warranty against manufacturing defects on frame, hardware, and glass for original owners. Transferable to subsequent owners with reduced coverage: 10 years on frame/hardware and 20 years on insulated glass unit. Improper installation is a primary reason for warranty rejection.

Bottom Line

The 1121 single-slider earns its keep through verified performance numbers, not marketing promises. That .24 U-value with foam frame and indium coating competes with windows costing twice as much. Steel reinforcement and welded corners address the weak points that kill vinyl windows in freeze-thaw climates.

For contractors tired of callbacks on failed sliders, the 1121’s structural upgrades justify the modest premium over builder-grade options. Priced below Milgard and Simonton while maintaining performance, it fills the gap between cheap and premium. Not perfect for every application, but for projects where energy performance and structural integrity matter more than brand prestige, Coeur d’Alene delivers what Montana buildings need.

FAQ

What makes the 1121 different from standard vinyl sliding windows?

Steel-reinforced interlocks and welded corners for moisture resistance set it apart from basic vinyl sliders. The optional foam-filled frame achieves U-values as low as .24, matching triple-pane performance from a double-pane design.

Do all glass options come with argon gas fill?

Yes. Argon gas fill is standard across all configurations, not an upcharge option.

What’s the actual tested performance rating?

AAMA LC PG-35 at 71x55 test size. That’s 35 PSF design pressure, suitable for 105 mph wind zones.

How does it compare to premium brands?

Generally priced lower than Milgard (Tuscany/Trinsic) and Simonton equivalents, positioned as a more affordable alternative to premium brands while maintaining performance. Comparable to Alpine Series 80, Pella 250, and Andersen 100 series.

What warranty coverage should contractors expect?

Lifetime warranty on frame, hardware, and glass for original owners. Transferable with reduced coverage: 10 years on frame/hardware, 20 years on IGU. Improper installation is a primary reason for warranty rejection — follow the installation guides.