3250XT Thermal Strut Aluminum Windows
New energy-code requirements are driving demand for high-performance commercial aluminum windows. At Boyd Aluminum, we manufacture the Series 3250XT thermal strut commercial aluminum window line to deliver U-Factors as low as 0.34, a 3.25" frame depth, and a 39mm polyamide thermal strut for architects, contractors, glaziers, and project teams.
With a 39mm extra-wide polyamide crimped-in-place structural thermal barrier, the 3250XT system helps thermally separate the exterior and interior aluminum framing, reducing conductive heat transfer and supporting energy-efficient commercial building design.
The 3250XT line includes fixed, project-out, project-in, casement, and "-G" historic-replica configurations with interior glazing, snap-in glazing beads, and 1" and 1.75" glazing options.
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3250XT Thermal Strut Window Series
The 3250XT line offers multiple fixed, projected, casement, and historic-replica options. Final selection should match the project drawings, operation type, glazing, performance requirements, historic-replica requirements, opening conditions, and specifications.
3250XT thermal strut commercial aluminum window configurations.
| System | Common Use & Selection Notes |
|---|---|
| Series 3250XTP (PO) | Operation: Project-out projected window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Commercial openings requiring outward projection, interior glazing, snap-in glazing beads, and coordination with panning, receptors, mullions, and trim. |
| Series 3250XTP (PI) | Operation: Project-in projected window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Commercial openings requiring inward projection, interior access, and glazing coordination. |
| Series 3250XTC (PO) | Operation: Project-out casement window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Commercial casement openings requiring side-hinged project-out operation and hardware coordination. |
| Series 3250XTC (PI) | Operation: Project-in casement window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Commercial openings requiring inward casement operation and interior access. |
| Series 3250XTF | Operation: Fixed window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Non-operable openings needing superior thermal performance and visual coordination with operable 3250XT units. |
| Series 3250XTP-G (PO) | Operation: Historic-replica project-out projected window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Historic-replica openings requiring project-out operation and exterior snap-in muntin coordination. |
| Series 3250XTP-G (PI) | Operation: Historic-replica project-in projected window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Historic-replica openings requiring inward projection and muntin coordination. |
| Series 3250XTC-G (PO) | Operation: Historic-replica project-out casement window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Historic-replica casement openings requiring project-out operation and muntin coordination. |
| Series 3250XTC-G (PI) | Operation: Historic-replica project-in casement window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Historic-replica casement openings requiring inward operation and muntin coordination. |
| Series 3250XTF-G | Operation: Historic-replica fixed window. System depth: 3.25" frame depth. Maximum glazing: 1.75". Common use: Non-operable historic-replica openings needing thermal performance and visual coordination. |
Product Sheet & Downloads
Download the 3250XT product sheet for detailed specifications, U-Factors, AAMA ratings, and performance data.
Why Architects and Contractors Choose Thermal Strut Windows
U-Factors as low as 0.34: Published product-sheet values include 0.34 for the standard fixed configuration and 0.43 for standard projected and casement configurations based on 0.24 COG glass per NFRC 100.
39mm thermal strut: Extra-wide polyamide barrier helps reduce frame heat transfer.
3.25" commercial frame: Supports 1" and 1.75" glazing with strong detailing.
Multiple configurations: Fixed, projected, casement, and historic-replica options help maintain visual consistency across varied opening types.
Clean appearance: Flush vent appearance when closed for a sleek commercial look.
Project support: Drawings, schedules, glazing, operation type, accessory requirements, and bid needs can be reviewed with the Direct Assistance™ team.
Quick Specs
Thermal barrier: 39mm extra-wide polyamide crimped-in-place structural thermal barrier.
System depth: 3.25" frame depth.
Glazing: 1" and 1.75"; maximum listed glazing is 1.75".
Configurations: Fixed, project-out, project-in, casement, and "-G" historic-replica.
Published U-Factor data: 0.43 for standard projected and casement configurations; 0.34 for the standard fixed configuration.
AAMA ratings: AW-PG80 for standard projected configurations; AW-PG100 for standard casement and fixed configurations.
Project-specific note: Ratings vary based on glass selection, spacer selection, opening conditions, and project requirements.
Thermal Strut vs Non-Thermally Broken Aluminum Windows
Thermal strut windows use a polyamide structural barrier to separate the exterior and interior aluminum framing. This can help support lower U-Factors, reduced condensation potential, occupant comfort, and improved energy performance compared to non-thermally broken aluminum framing.
Case Study
Read the related 3250XT case study on how the line supports energy-conscious commercial projects and the 2030 Challenge.
System Advantages
39mm polyamide thermal barrier supporting listed thermal performance values.
3.25" frame depth.
Interior glazed with snap-in glazing beads.
0.125" structural wall areas.
1" and 1.75" glazing options.
Flush vent appearance when closed.
Exterior snap-in muntins available on "-G" configurations.
Panning, receptor systems, caulk backers, mullions, snap trims, and screens available.
Two rows of weather stripping and pressure equalization.
Meets Performance Level 10 forced-entry requirements.
Performance Data
Performance values below are from the 3250XT product sheet and are based on 0.24 COG glass per NFRC 100. Job-specific results vary based on glass selection, glass spacer selection, opening conditions, and project requirements.
Historic-replica note: Exterior snap-in muntins are available with the "-G" option. The performance table below reflects the standard 3250XT product-sheet rows; project-specific performance for historic-replica configurations should be confirmed when required.
| Configuration | Listed Product Data |
|---|---|
| 3250XTP (PO) | Product type: Awning / project-out. System depth: 3.25". U-Factor: 0.43. AAMA rating: AW-PG80. Air infiltration: 0.06 @ 6.2 psf. Water resistance: 15 psf. Structural performance: 120 psf. Maximum glazing: 1.75". |
| 3250XTP (PI) | Product type: Awning / project-in. System depth: 3.25". U-Factor: 0.43. AAMA rating: AW-PG80. Air infiltration: 0.06 @ 6.2 psf. Water resistance: 15 psf. Structural performance: 120 psf. Maximum glazing: 1.75". |
| 3250XTC (PO) | Product type: Casement / project-out. System depth: 3.25". U-Factor: 0.43. AAMA rating: AW-PG100. Air infiltration: 0.06 @ 6.2 psf. Water resistance: 15 psf. Structural performance: 150 psf. Maximum glazing: 1.75". |
| 3250XTC (PI) | Product type: Casement / project-in. System depth: 3.25". U-Factor: 0.43. AAMA rating: AW-PG100. Air infiltration: 0.06 @ 6.2 psf. Water resistance: 15 psf. Structural performance: 150 psf. Maximum glazing: 1.75". |
| 3250XTF | Product type: Fixed. System depth: 3.25". U-Factor: 0.34. AAMA rating: AW-PG100. Air infiltration: 0.05 @ 6.2 psf. Water resistance: 15 psf. Structural performance: 150 psf. Maximum glazing: 1.75". |
Historic-Replica 3250XT-G Options
The "-G" configurations provide historic-replica appearance with exterior snap-in muntins while supporting modern thermal-strut window design. Project-specific performance for historic-replica configurations should be confirmed when required.
Project Support
Send the project details, drawings, schedules, operation type, glazing requirements, and accessory needs. The Direct Assistance team can help with configurations, specifications, details, and bidding.
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Thermal Window Questions
What do AW-PG80 and AW-PG100 ratings on commercial windows mean?
AW is the Architectural Window performance class in the AAMA/NAFS window standard, commonly used for heavy commercial and institutional window applications. PG stands for performance grade, and the number identifies the tested pressure level for the window's combined air, water, and structural performance. In the 3250XT product-sheet data above, the projected configurations are listed at AW-PG80, while the casement and fixed configurations are listed at AW-PG100; that difference aligns with the higher listed structural performance for the casement and fixed rows. Confirm the rating for the selected configuration and glazing package against the current product sheet and project requirements.
Do thermally broken aluminum windows reduce condensation?
Thermally broken aluminum windows can reduce condensation potential by keeping the interior frame surface warmer than a non-thermal aluminum frame. Condensation forms when an interior surface becomes cold enough to reach the dew point, and bare aluminum conducts cold quickly. A thermal break helps interrupt that transfer, although interior humidity, glazing, spacer selection, and installation conditions also affect condensation risk.
What is a good U-factor for a commercial aluminum window?
Lower U-factors indicate better insulation, but the required U-factor depends on the project's climate zone, building type, energy code, glass selection, spacer selection, and configuration. For reference, the 3250XT product sheet lists U-factors of 0.34 for the standard fixed configuration and 0.43 for standard projected and casement configurations based on 0.24 COG glass per NFRC 100. Confirm the required U-factor and job-specific results for the selected window configuration and glazing package.
Need help reviewing 3250XT thermal strut windows for a commercial project? Send Boyd the drawings, window schedule, glazing requirements, operation type, performance targets, and bid deadline so the correct configuration and documentation can be reviewed.