Export Portfolio
Factory-Direct High-Performance Windows & Architectural Systems
Explore our precision-engineered aluminum fenestration products manufactured to ISO 9001, CE, AS 2047, and North American NAFS/AAMA specifications.
Engineering Whitepaper
The Structural Metallurgy & Thermodynamics of Custom Double Hung Fenestration
An authoritative engineering analysis for facade consultants, structural engineers, and fenestration import directors.
In modern high-performance building envelopes, the vertical sliding fenestration system—conventionally recognized as the double hung window—has undergone a radical metallurgical and thermodynamic transformation. While historically manufactured from architectural timber or unreinforced uPVC profiles, contemporary commercial and luxury residential projects demand the unyielding structural integrity of extruded aluminum alloy frameworks, specifically Alloy 6063-T6 and 6061-T6. As an industry-leading OEM manufacturer and direct exporter with over 25 years of specialized fabrication experience, our engineering lines resolve the structural compromises historically associated with counterweighted fenestration systems.
A true architectural double hung system consists of two independently operating sashes—the upper (exterior) sash and lower (interior) sash—which travel vertically along precision-machined jamb channels. The fundamental physics of this configuration require stringent manufacturing tolerances: excessive lateral play introduces catastrophic air leakage and acoustic bypass, whereas thermal profile deflection or dimensional swelling can immediately induce sash binding and hardware fatigue. By incorporating state-of-the-art multi-cavity thermal break extrusions with polyamide (PA66 GF25) thermal struts, our fenestration profiles bridge the structural demands of extreme wind loading with unprecedented thermal envelope isolation.
Key Engineering Parameter: Deflection Resistance Under Dynamic Wind Loads
Our custom OEM aluminum double hung windows are engineered to achieve an structural deflection criterion of L/175 and L/240 under positive and negative pressures exceeding 3,000 Pa (equivalent to AS 2047 N6 and ASTM E330 standards). Interlocking sash meeting rails are reinforced with internal extruded aluminum stiffeners, guaranteeing structural continuity across expansive rough openings without requiring intrusive exterior mullion reinforcement.
Constant Force Coil Balances
Calibrated stainless steel coil balance systems provide effortless, finger-touch vertical operation across variable sash weights ranging from 15 kg up to 90 kg. Certified for over 25,000 continuous cycle strokes without tension degradation or binding.
Isobaric Thermal Isolation
Integrated 24mm to 34mm PA66 GF25 fiberglass-reinforced polyamide thermal break bars isolate interior climate zones from exterior ambient exposure, yielding whole-window thermal transmittance values (U-values) as low as 1.35 W/m²·K (0.24 BTU/hr·ft²·°F).
Tri-Barrier EPDM Weatherseals
Continuous peroxide-cured EPDM compression gaskets combined with high-density finned brush piles at meeting rails and sill perimeters. Ensures airtight integrity under negative suction (ASTM E283 air leakage < 0.1 CFM/ft²).
Technical Validation
Engineering Specifications: OEM Extrusion & Performance Matrix
Exhaustive testing benchmarks matching North American NAFS/AAMA, European CE, and Australasian AS 2047 structural requirements.
| Performance Criterion | Architectural Grade (Commercial) | Luxury Residential (Thermal Break) | Severe Weather / Coastal Cyclone |
|---|---|---|---|
| Alloy Metallurgy & Temper | Primary Billet 6063-T6 (EN AW-6063) | Primary Billet 6063-T5 / T6 | High-Strength 6061-T6 / 6082-T6 |
| Nominal Extrusion Wall Thickness | 2.0 mm – 2.5 mm | 1.6 mm – 2.0 mm | 2.2 mm – 3.0 mm (Impact Core) |
| Water Penetration Resistance (ASTM E331) | 720 Pa (15.0 psf) Zero Ingress | 500 Pa (10.4 psf) Zero Ingress | 1,000 Pa (20.9 psf) Hydrostatic Sill |
| Air Infiltration Rating (ASTM E283) | ≤ 0.08 L/s·m² (Exceeds NAFS Class AW) | ≤ 0.12 L/s·m² | ≤ 0.05 L/s·m² Multi-Point Locked |
| Structural Wind Load (AS 2047 / ASTM E330) | Serviceable: 3,500 Pa; Ultimate: 5,200 Pa | Serviceable: 2,400 Pa; Ultimate: 3,600 Pa | Serviceable: 4,500 Pa; Ultimate: 6,800 Pa (N6) |
| Acoustic Attenuation (Rw / STC) | Rw 42 dB (Laminated Acoustic IGU) | Rw 36 dB (Double Glazed Argon) | Rw 45 dB (Multi-Layer SentryGlas) |
| Surface Coating Standards | AAMA 2605 70% PVDF Fluoropolymer | Qualicoat Class 2 Powder Coat | Marine-Grade Anodized 25μm / AkzoNobel |
180,000+
m² Production Infrastructure
25+
Years Engineering Heritage
600+
Skilled Fenestration Specialists
100+
Patents & Global Certifications
Strategic Sourcing
Procurement Dynamics: Global Sourcing Shifts for Architectural Double Hung Units
Market intelligence for importers, commercial contractors, and developers optimizing margin efficiency and code compliance.
The international fenestration supply chain is undergoing a structural realignment driven by stringent energy efficiency directives (such as the updated ASHRAE 90.1, Energy Star Version 7.0, and the Australian National Construction Code 2022) alongside escalating landed material costs in Western markets. Historically, developers in North America, Australasia, and the Middle East sourced standardized double hung units from domestic assembly plants that rely on outsourced extrusions. Today, Tier-1 developers and architectural distributors bypass local tier-2 distributors to establish direct-from-source OEM partnerships with large-scale Chinese extrusion and window manufacturing centers.
Direct manufacturer engagement eliminates between 28% and 42% of redundant distributor margins while providing direct oversight of CAD/BIM shop drawings, custom thermal-break dies, and bespoke hardware finish matching. Furthermore, the volatility of regional lumber and high lifecycle degradation of vinyl sashes under extreme UV index regions have positioned thermally improved aluminum double hung windows as the dominant fenestration category for luxury residential estates, municipal renovations, and high-density commercial hospitality developments.
Pre-Engineered Shop Drawings
Direct OEM engagement includes factory-drafted CAD and BIM files tailored directly to architectural opening elevations, preventing on-site framing discrepancies.
Consolidated Freight Logistics
Full Container Load (FCL) packing combining double hung units, heavy pivot entrance systems, and curtain walls into unified shipments to optimize container cubing.
Rigorous Third-Party Auditing
International laboratory verification covering CE, AS 2047, and UL fire ratings ensures zero risk during port customs clearance and municipal building inspection.
Lifecycle Carbon Accounting
Utilization of certified low-carbon recycled aluminum billets backed by Environmental Product Declarations (EPDs) to satisfy LEED and BREEAM green building thresholds.
Fenestration Evolution
Technological Trajectories: The Future of Aluminum Double Hung Systems
How next-generation automation, micro-cavity thermal engineering, and thin-glass vacuum glazing are redefining performance.
Looking ahead toward 2030, the traditional sash window is transitioning from a passive structural fixture into an active, intelligent building envelope module. Leading this evolution is the integration of Concealed Motorized Sash Actuation. Through proprietary ultra-compact linear actuators integrated directly within the aluminum jamb cavity, sashes can be vertically manipulated via Building Management Systems (BMS), smart home automation (KNX, Zigbee, Matter), or automated indoor air quality (IAQ) sensors. These automated systems facilitate night-purge natural ventilation strategies, drastically reducing HVAC electrical loads in institutional and high-end residential settings without compromising safety or weather barrier seals.
Simultaneously, the fenestration sector is witnessing the rise of Hybrid Vacuum Insulated Glass (VIG) integration. Standard double hung frames are historically constrained by sash thickness: accommodating bulky 32mm triple-pane insulated glass units (IGUs) causes sashes to widen awkwardly, compromising the slim, historic sightlines desired in urban conservation zones. VIG technology introduces an ultra-thin 8.3mm profile that matches the thermal performance of a 44mm triple-glazed cavity (U-values ≤ 0.60 W/m²·K). Our research and development engineering teams have engineered dedicated sash extrusions optimized for VIG glazing beads, allowing historic architectural replication paired with Passivhaus-level thermal efficiency.
Smart Actuation & Micro-Sensors
Internal magnetic contact sensors and brushless DC actuators concealed in the head and sill provide automated environmental venting, automatic rain closure, and integrated burglar intrusion telemetry.
Monolithic Cyclone Barricade
Advanced resin-laminated glass configurations (SentryGlas® interlayers) paired with heavy-duty aluminum interlocks engineered to withstand 90 lb/ft² missile impacts during Category 5 hurricane conditions.
Concealed Tilt Wash-In Latches
Ergonomic, low-profile flush-mount latches permit interior-facing 90-degree tilting for both upper and lower sashes, allowing rapid, secure glass cleaning from within multi-story architectural facades.
Enterprise Strength
DERCHI (Guangdong Dejiyoupin): World-Class Industrial Manufacturing
Recognized among China's Top 10 premium door and window brands, operating from Foshan's premier architectural industrial hub.
Headquartered in Foshan, Guangdong—the globally celebrated center of precision aluminum manufacturing—Guangdong Dejiyoupin Doors and Windows Co., Ltd. (DERCHI) operates an expansive, vertically integrated industrial base spanning over 180,000 square meters. Staffed by an elite team of 600+ fenestration technicians, CNC operators, and structural facade engineers, our manufacturing campus houses computerized extrusion handling, multi-axis automated German machining centers, robotic glass processing, and in-house climatic simulation test chambers.
With more than 25 years of continuous operational excellence, DERCHI has earned over 100 international patents and testing certifications. Our fenestration lines are rigorously certified to CE, ISO 9001, AS 2047 (including extreme N6 cyclone benchmarks), and UL fire-rated standards. Having successfully delivered multi-container architectural projects across the United States, Canada, Australia, the Philippines, the Middle East, and South Asia, DERCHI provides an airtight end-to-end ecosystem: from initial architectural CAD detailing, custom extrusion die manufacturing, and automated assembly to heavy-duty export plywood crating and dedicated English-speaking technical site guidance.
Custom Tooling & Dies
In-house tooling facility capable of producing custom architectural profiles, bespoke sightline extrusions, and historic replication molds in under 21 business days.
Automated CNC Precision
State-of-the-art CNC machining centers perform miter cutting, drain slot routing, and hardware mortising with microscopic tolerances (±0.2mm).
Internal Testing Laboratory
Every production batch undergoes dynamic air infiltration, hydrostatic water testing, sash balance fatigue cycling, and corner-weld tensile tests prior to packaging.
Heavy Export Packaging
Multi-layer protective film, foam edge guards, and ISPM-15 compliant fumigated wooden crates engineered specifically for overseas sea container transit.
Procurement Guide
Frequently Asked Questions: B2B Procurement & Technical Specifications
Critical technical considerations answered by our senior fenestration engineering and export operations directors.
What specific structural criteria distinguish commercial-grade aluminum double hung windows from residential systems?
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Commercial-grade double hung windows (classified as Class CW or AW under North American AAMA/WDMA standards) feature profile wall thicknesses exceeding 2.0mm, internal structural meeting rail reinforcements, and heavy-duty balance hardware rated for sashes exceeding 50 kg. Residential systems generally employ 1.4mm to 1.6mm wall thicknesses and lighter coil springs. Commercial units also require significantly higher air, water, and structural performance thresholds (e.g., minimum 500 Pa to 720 Pa water resistance vs. 300 Pa for standard residential builds) to withstand high-altitude wind pressure across multi-story facades.
How do you prevent sash binding and balance failure across oversized architectural double hung openings?
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Sash binding typically occurs due to frame rack (out-of-square deflection) or inadequate balance calibration. DERCHI mitigates this by utilizing heavy extruded corner keys crimped with two-component polyurethane bonding adhesives, ensuring perfect 90-degree frame rigidity under diagonal shear stresses. For oversized sashes, our engineers compute precise glass weight distribution curves and specify multi-spring constant force balances paired with low-friction nylon or acetal shoe guides running in lubricated extruded jamb tracks, ensuring smooth vertical glide without racking.
Can your factory provide custom simulated divided lites (SDL) and historic sightline profiles?
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Yes. We regularly produce custom OEM double hung windows for heritage preservation and historic replication projects. We offer internally spacer-aligned simulated divided lites (SDL), true divided lites (TDL), and historic exterior putty-line bevel profiles. Our engineering team can create custom aluminum extrusion dies to replicate existing timber mullion sightlines while incorporating modern high-efficiency double or triple insulated glass units (IGUs).
What surface finish options are available to guarantee coastal corrosion resistance?
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For extreme coastal marine environments (such as high-salinity beachfront villas or tropical monsoon zones), we recommend either our certified 70% Kynar 500 / Hylar 5000 PVDF fluorocarbon coatings conforming to AAMA 2605 specifications, or 25-micron architectural-grade hard anodizing (Class I). These coatings are lab-tested to endure over 4,000 to 5,000 hours of continuous neutral salt spray (ASTM B117) without blistering, chalking, peeling, or color degradation.
How does DERCHI manage international shipping, crating, and site installation risk?
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Windows are pre-glazed and fully factory-tested for operating balance, latch alignment, and water tightness before disassembly or packing. Finished units receive surface-protective static films, closed-cell corner foam buffers, and are secured inside heavy-duty, reinforced plywood crates designed for overhead crane and forklift handling. Every shipment includes comprehensive CAD shop drawings, numbered installation sequences, and remote live video consultation with our bilingual engineering team during site installation.
What are the minimum order quantities (MOQ) and production lead times for custom OEM orders?
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Standard OEM production batches have an MOQ of 50 square meters for standard inventory extrusion colors (architectural black, deep bronze, pearl white, clear anodized). Custom die extrusions require an MOQ of 300 square meters. Standard fabrication lead times range from 25 to 35 business days following final approved shop drawings and hardware schedule sign-off. Accelerated expedited production schedules are available for time-sensitive commercial projects.
Can double hung systems achieve emergency fire escape (egress) compliance?
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Yes. Building codes (such as the International Residential Code - IRC Section R310) dictate clear opening dimensions: minimum 5.7 sq ft net clear opening, minimum clear height of 24 inches, and minimum clear width of 20 inches. Because double hung windows only open to half their vertical frame height, our engineering team optimizes sash rail dimensions and balance travels specifically to ensure clear egress compliance on designated bedroom elevations.