Product Overview

Heavy-duty French-style double inward windows feature a dual-sash design without a fixed center mullion, opening completely for an unobstructed panoramic view. Engineered with reinforced profiles and high-load capacities, these systems support oversized architectural glazing while delivering elite thermal and acoustic insulation for premium commercial and residential projects.

Performance

Product Details

Sound insulation

36dB

Thermal insulation

Class 7 (GB/T 8484)

Air tightness

Class 6 (GB/T 7106)

Water tightness

Class 4 (GB/T 7106)

Wind pressure resistance

Class 9 (GB/T 7106)

Component / Feature	Core Specifications	Key Benefits & Advantages
Aluminum Profile	High-precision 6063-T5 Alloy (Primary Ingot) • Wall thickness: 1.8mm	High-strength structural integrity and heavy-duty durability.
Surface Treatment	Advanced metallic powder coating	Weather-resistant finish with excellent color retention.
Thermal Insulation	PA66 Multi-cavity Nylon Strips	High-efficiency thermal break to reduce energy costs.
Glass Solution	Xinyi Automotive-Grade Tempered Glass • Specs: 5mm + 16A + 5mm	High-strength safety glass providing crystal-clear vision.
Hardware System	Standard Simtak hardware	Heavy-duty components ensuring smooth and reliable operation.
Weather Sealing	Standard Haida EPDM foam sealing strip	Premium airtightness, watertightness, and soundproofing.
Screen Option	304 High-Transparency Mesh / High-Security Mesh	Durable insect protection with optional anti-theft security.
Product Color	Metallic Gray, Espresso Brown, Graphite Black (Custom Colors Available)	Versatile palette to perfectly match modern architectural styles.

Product Features

Reinforced Dual-Sash Interlocking: A multi-tiered interlock geometry combined with continuous compression gaskets seals the central meeting stile tightly against air and water penetration.
Four-Layer EPDM Gasket System: Utilizes continuous co-extruded central and perimeter EPDM gaskets to maintain tight structural pressure under extreme weather.
Heavy-Duty Concealed Drainage: Multi-stage, low-pressure drainage pathways channel internal condensation and exterior driving rain away without visible face caps or weep holes.

Certified Quality Assurance

North American Compliance: Tested and fully certified under AAMA/WDMA/CSA 101/I.S.2/A440 (NAFS) for commercial-grade structural ratings.
European Union Certification: CE marked in accordance with EN 14351-1, verified by independent European notified testing bodies.
Thermal Verification: NFRC-certified thermal performance ratings, ensuring compliance with ASHRAE 90.1 energy standards and LEED project credits.

Window System Applications

Double Tilt-Turn System: The master sash operates in both tilt-for-ventilation and turn-for-opening modes, while the slave sash unlocks to swing fully open.
Double Inward Casement System: Both sashes operate strictly on heavy-duty side-hung hinges, maximizing wide-span open areas without tilting mechanics.
Integrated Juliette Balcony System: Designed with built-in outer guardrail channels, allowing the double windows to act as secure floor-to-ceiling French doors.
Acoustic Double-Window System: Specifically optimized with asymmetric heavy laminate glass configurations for high-rise commercial structures requiring extreme acoustic containment.

Packaging & Logistics

Export Packaging: PE surface film, shock-absorbing foam corner guards, and reinforced, ISPM-15 compliant wooden crates secured with heavy-duty tension strapping.
Lead Times: 25–30 business days for standard projects; 40–50 business days for bespoke or high-volume commercial orders (from technical sign-off).
Logistics & Terms: Full compatibility with FOB, CIF, DDU, and DDP terms via ocean freight (FCL/LCL), intermodal rail, and expedited air transport.

Why Choose Us

Advanced Industrial Capacity: 60,000 sqm facility with automated German Elumatec CNC centers, ensuring precision tolerances within 0.1mm.
High Production Volume: Robust annual manufacturing capacity of over 300,000 square meters of premium windows and doors to handle large-scale projects.
Verified Credibility: ISO 9001/14001 certified manufacturer with a 20-year history supplying major commercial developers in North America and Europe.
Strict Material Traceability: Every batch of primary aluminum and polyamide thermal strip includes certified mill test reports for full supply chain compliance.
Flexible MOQ: Client-centric minimum order quantities starting from 50 square meters, perfectly adapting to both bespoke residential and massive commercial rollouts.
Robust Warranty & After-Sales: Backed by a 10-year structural, 5-year glass, and 3-year hardware warranty. Includes lifelong remote technical support and 48-hour expedited international shipping for spare parts.

FAQ

Q1: How does the center flying mullion resist high wind loads without a fixed central structural beam?
A: The master and slave sashes lock together via an interlocking profile reinforcer and multi-point hardened steel hook bolts. This creates a unified structural spine when closed, distributing wind loads evenly across the heavy-duty outer frame to meet commercial building codes.
Q2: Can these heavy-duty double windows be fitted with integrated insect screens?
A: Yes. We supply custom, heavy-duty pleated sliding screens or outward-opening insect screens that mount independently to the exterior frame, ensuring insect protection without blocking the inward swing of the window sashes.
Q3: What measures are taken to prevent the heavy dual sashes from sagging over time?
A: We utilize structural corner joints with cast-aluminum corner cleats injected with two-part polyurethane structural adhesive. Combined with our 180 kg rated heavy-duty hinges and internal glass packing shims, the weight of the glass is distributed directly to the hinges, preventing frame distortion.