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8+12A+8 (28mm) and 8+16A+8 (32mm) insulated glass units for high-rise curtain walls, structural glazing, and hurricane-zone facades. Two 8mm glass panes with 12mm or 16mm gap. Available with Low-E, tempered, laminated, argon/krypton fill. Max size 3300x12000mm. U-value from 1.1 W/m²K. CE / EN 1279 / ISO 9001 certified. Request FOB quote.
8+12A+8 / 8+16A+8 Insulated Glass | 28mm & 32mm Heavy‑Duty Double Glazed IGU for High‑Rise Curtain Walls & Structural Glazing
28mm & 32mm Heavy‑Duty Double Glazed IGU – The High‑Rise Curtain Wall & Structural Glazing Standard
8+12A+8 insulated glass (also written as 8+12A+8 double glazing, 8+12A+8 IGU, or 28mm insulated glass) and 8+16A+8 insulated glass (32mm total thickness) are the two heavy‑duty double glazed configurations specified for high‑rise curtain walls, structural glazing systems, and hurricane‑zone façades worldwide.
Both configurations consist of two 8mm glass panes — the heaviest standard substrate used in high‑volume IGU production — separated by an aluminum or warm‑edge spacer (12mm or 16mm), hermetically sealed to form a single insulating glass unit. The 8mm glass thickness provides the structural rigidity required for tall buildings, large‑format curtain wall panels, and extreme wind‑load conditions, while the sealed cavity delivers proven thermal and acoustic insulation.
💡 Industry context: 8+12A+8 is the de facto standard for structural glazing (four‑sided SSG) curtain walls on buildings above 15 stories. The 8mm glass thickness is the minimum practical substrate for structural silicone adhesion — anything thinner risks edge pull‑out under wind load. The 16mm gap variant (8+16A+8) is the upgrade path when projects target LEED Gold/Platinum, Passive House, or hurricane‑zone compliance (Miami‑Dade TAS 201/202).
The jump from 6mm to 8mm glass is the single most important decision in high‑rise IGU specification:
| Property | 6+12A+6 (24mm) | 8+12A+8 (28mm) | Improvement |
|---|---|---|---|
| Glass thickness | 6mm | 8mm | +33% thickness |
| Bending strength | Baseline | +78% | Significantly stiffer |
| Wind load resistance (same span) | ~3.0 kPa | ~5.0 kPa | Handles hurricane/typhoon zones |
| Typical max floor height | 6–15 stories | 15–60+ stories | High‑rise capable |
| Structural silicone SSG | Marginal | Optimal | 4‑sided SSG rated |
| Weight per m² | ~30 kg | ~40 kg | +33% (requires crane) |
| Cost premium | Base | +25–35% | Moderate Bottom line: 8mm panes let you glaze taller buildings, larger panels, and wider spans with confidence. They are the minimum thickness for four‑sided structural silicone glazing (SSG) systems — the dominant curtain wall method for buildings above 20 stories. |
| Parameter | 12mm Gap (8+12A+8) | 16mm Gap (8+16A+8) | Why It Matters |
|---|---|---|---|
| U‑Value (Clear/Air) | ~2.5 W/m²K | ~2.4 W/m²K | 16A is ~4% better thermally |
| U‑Value (Low‑E/Argon) | ~1.5 W/m²K | ~1.3 W/m²K | 16A squeezes out extra performance |
| U‑Value (Triple Silver/Krypton) | ~1.2 W/m²K | ~1.1 W/m²K | 16A + Krypton = near‑Passive House |
| Sound Reduction (Rw) | ~32 dB | ~33 dB | 16A adds ~1 dB |
| Argon gas retention | Good | Better | Wider gap = more gas volume |
| Desiccant capacity | Standard | Larger | Longer seal life |
| Hurricane/typhoon ready | Yes | Yes (enhanced) | 16A adds margin |
| Cost premium | Base | +10–15% | Modest upgrade Rule of thumb: |
| Configuration | U‑Value (W/m²K) | SHGC | Relative Cost |
|---|---|---|---|
| 8+12A+8 Clear / Air | ~2.5 | ~0.76 | Base |
| 8+12A+8 Low‑E / Air | ~1.7 | ~0.65 | +15–20% |
| 8+12A+8 Low‑E / Argon | ~1.5 | ~0.63 | +25–35% |
| 8+12A+8 Triple Silver / Krypton | ~1.2 | ~0.58 | +50–65% |
| 8+16A+8 Clear / Air | ~2.4 | ~0.76 | +8% |
| 8+16A+8 Low‑E / Argon | ~1.3 | ~0.62 | +35–45% |
| 8+16A+8 Triple Silver / Krypton | ~1.1 | ~0.57 | +60–80% With triple silver Low‑E and krypton fill, 8+16A+8 achieves U‑value 1.1 W/m²K — sufficient for Passive House certification in most climate zones. |
| Glass Combination | Rw (dB) | Traffic Noise Reduction |
|---|---|---|
| 8mm Clear + 12A + 8mm Clear | ~32 dB | Good |
| 8mm Clear + 16A + 8mm Clear | ~33 dB | Good+ |
| 8mm Laminated + 12A + 8mm Clear | ~39 dB | Very Good |
| 8mm Laminated + 16A + 8mm Laminated | ~42 dB | Excellent |
| 8mm SGP Laminated + 16A + 8mm SGP Laminated | ~44 dB | Near‑Silent |
8+12A+8 and 8+16A+8 with tempered/tempered configuration are the standard for Miami‑Dade County NOA‑approved curtain walls, capable of withstanding:
| Glass Combination | UV Blockage |
|---|---|
| 8+12A+8 Clear / Clear | ~72% |
| With Low‑E coating | ~85% |
| With laminated pane (PVB) | >99% |
| With SGP laminated pane | >99.5% |
| Specification | 8+12A+8 (28mm) | 8+16A+8 (32mm) |
|---|---|---|
| Configuration | 8mm + 12mm gap + 8mm | 8mm + 16mm gap + 8mm |
| Total Thickness | 28mm | 32mm |
| Glass Types Available | Clear, Low‑Iron, Low‑E, Tempered, Laminated, Tinted, Reflective, Ceramic Frit | Same |
| Spacer Options | Aluminum, Warm Edge, Stainless Steel, Structural Silicone (SSG) | Same |
| Gas Fill Options | Air, Argon, Krypton | Same |
| Maximum Size | 3300 × 12000 mm | 3300 × 12000 mm |
| Weight (clear/Air) | ~40 kg/m² | ~40 kg/m² |
| U‑Value (Clear/Air) | ~2.5 W/m²K | ~2.4 W/m²K |
| U‑Value (Low‑E/Argon) | ~1.5 W/m²K | ~1.3 W/m²K |
| U‑Value (Triple Silver/Krypton) | ~1.2 W/m²K | ~1.1 W/m²K |
| Sound Reduction (Rw, Clear) | ~32 dB | ~33 dB |
| Sound Reduction (Laminated) | ~39–42 dB | ~42–44 dB |
| Wind Load Resistance | Up to 5.0 kPa | Up to 5.0 kPa |
| Certifications | EN 1279, CE, ISO 9001, CCC, SGS, IGCC | Same |
| MOQ | 1 × 20′ FCL (~150–220 m²) | 1 × 20′ FCL (~140–200 m²) |
| Lead Time | 3–5 weeks | 3–5 weeks |
| Outer Pane (Exterior) | Inner Pane (Interior) | Best For |
|---|---|---|
| 8mm Clear Float | 8mm Clear Float | Budget commercial, standard curtain walls |
| 8mm Low‑E (Single Silver) | 8mm Clear Float | Good thermal performance |
| 8mm Low‑E (Double Silver) | 8mm Clear Float | Most popular for office towers |
| 8mm Low‑E (Triple Silver) | 8mm Clear Float | Premium energy performance |
| 8mm Tempered | 8mm Clear Float | Safety glazing (doors, low windows) |
| 8mm Tempered | 8mm Tempered | Full safety (SSG, hurricane zones) |
| 8mm Laminated (PVB) | 8mm Clear Float | Acoustic insulation, security |
| 8mm Laminated (PVB) | 8mm Laminated (PVB) | Maximum security + soundproofing |
| 8mm Reflective (Online CVD) | 8mm Clear Float | Solar control + privacy |
| 8mm Ceramic Frit | 8mm Low‑E | Spandrel panels with thermal performance |
| 8mm Low‑E Tempered | 8mm Tempered Laminated | Premium combo – thermal + safety + acoustic |
| 8mm SGP Laminated | 8mm SGP Laminated | Blast mitigation, maximum security |
💡 Industry‑standard specification for high‑rise curtain walls: 8mm Double Silver Low‑E (outer, #2 surface) + 12A/16A Argon + 8mm Clear Tempered (inner). This achieves U‑value ~1.5/1.3 W/m²K, meets Miami‑Dade impact requirements (with tempered/tempered), and satisfies most international energy codes.
| Spacer Type | Material | Thermal Performance | Edge Condensation | Relative Cost |
|---|---|---|---|---|
| Aluminum | Extruded aluminum box | Standard (thermal bridge) | Moderate risk | Base |
| Warm Edge (TPE) | Thermoplastic elastomer | Improved (−0.15 U) | Low risk | +10–15% |
| Swisspacer | Reinforced polymer | Best (−0.2 U) | Very low risk | +20–30% |
| Stainless Steel | Box‑section stainless | Good (compromise) | Low risk | +15–20% |
| Structural Silicone (SSG) | 4‑sided silicone bite | Good | Low risk | +25–40% |
| Gas Fill | Thermal Improvement vs. Air | Cost Impact | Best For |
|---|---|---|---|
| Air | Baseline | None | Budget projects, mild climates |
| Argon | ~15% better U‑value | Low (+$1–2/m²) | Most common upgrade – best ROI |
| Krypton | ~25% better U‑value | Moderate (+$5–8/m²) | Passive House, extreme climates |
| Xenon | ~30% better U‑value | High (+$15–25/m²) | Specialty applications |
| Coating Position | Surface | Effect | Best For |
|---|---|---|---|
| #2 surface (outer pane, interior face) | Recommended default | Maximizes solar heat gain in winter | Cold climates – retains interior heat |
| #3 surface (inner pane, exterior face) | Alternative | Blocks solar heat gain | Hot climates – Dubai, Miami, Singapore |
| Dual Low‑E (both #2 and #3) | Premium | Maximum thermal performance | Extreme climates – Arctic or desert |
| Aspect | 8+12A+8 Limit | 8+16A+8 Limit | Notes |
|---|---|---|---|
| Maximum Width | 3300 mm | 3300 mm | Jumbo width |
| Maximum Height | 12000 mm | 12000 mm | Jumbo length |
| Maximum Area | 15.0 m² | 15.0 m² | Practical limit for handling |
| Minimum Size | 250 × 400 mm | 250 × 400 mm | Smaller sizes possible |
| Weight (Clear/Air) | ~40 kg/m² | ~40 kg/m² | Mechanical assist above 80 kg |
| Recommended Max Panel | 10.0 m² | 10.0 m² | Optimal for curtain wall framing |
| Max Wind Load (Tempered/Tempered) | Up to 5.0 kPa | Up to 5.0 kPa | Dependent on panel size |
⚠️ At ~40 kg/m², an 8+12A+8 panel of 3.0 × 2.0m weighs approximately 240 kg. All handling must use mechanical lifting equipment. For units larger than 10.0 m² or weighing over 200 kg, both panes must be tempered and wind load calculations must be submitted to our engineering team for review.
| Parameter | 8+12A+8 | 8+16A+8 |
|---|---|---|
| Glass Configuration | 8mm + 12mm gap + 8mm | 8mm + 16mm gap + 8mm |
| Total Thickness | 28mm (±1mm) | 32mm (±1mm) |
| Glass Types | Clear, Low‑Iron, Low‑E, Tempered, Laminated, Tinted, Reflective, Ceramic Frit | Same |
| Spacer Types | Aluminum, Warm Edge, Swisspacer, Stainless Steel, Structural Silicone | Same |
| Desiccant | Molecular sieve (3Å) in spacer | Same |
| Primary Seal | Polyisobutylene (PIB) | Same |
| Secondary Seal | Polysulfide, Silicone, or Hot Melt | Same |
| Gas Fill | Air, Argon, Krypton (≥90% initial fill) | Same |
| U‑Value (Clear/Air) | ~2.5 W/m²K (EN 673) | ~2.4 W/m²K (EN 673) |
| U‑Value (Low‑E/Argon) | ~1.5 W/m²K (EN 674) | ~1.3 W/m²K (EN 674) |
| U‑Value (Triple Silver/Krypton) | ~1.2 W/m²K | ~1.1 W/m²K |
| SHGC (Clear/Air) | ~0.79 | ~0.79 |
| SHGC (Low‑E/Argon) | ~0.63 | ~0.62 |
| Sound Reduction (Clear) | Rw 32 dB | Rw 33 dB |
| Sound Reduction (Laminated) | Rw 39–42 dB | Rw 42–44 dB |
| Visible Light Transmittance (Clear) | ~79% | ~79% |
| Visible Light Transmittance (Low‑E) | ~68% | ~68% |
| UV Blockage (Clear) | ~72% | ~72% |
| UV Blockage (Laminated PVB) | >99% | >99% |
| Wind Load Resistance (Tempered/Tempered) | Up to 5.0 kPa (ASTM E1886 / TAS 202) | Same |
| Impact Resistance (Hurricane) | Large & small missile (ASTM E1996 / TAS 201) | Same |
| Seal Life Expectancy | >20 years (EN 1279‑2/‑3) | >20 years (EN 1279‑2/‑3) |
| Standards | EN 1279, CE, ISO 9001, CCC, SGS, IGCC, ASTM E2190 | Same |
| Packaging | Vertical A‑frames or horizontal crates | Same |
| MOQ | 1 × 20′ FCL (~150–220 m²) | 1 × 20′ FCL (~140–200 m²) |
| Lead Time | 3–5 weeks | 3–5 weeks |
8+12A+8 is the defining IGU configuration for high‑rise curtain wall systems on buildings from 15 to 60+ stories. Office towers, government buildings, hotels, and mixed‑use developments rely on this configuration for its proven structural performance, thermal efficiency, and compatibility with four‑sided structural silicone glazing (SSG).
Four‑sided SSG curtain walls depend on the adhesion of structural silicone to the glass edge. 8mm is the minimum practical glass thickness for reliable silicone bite — the larger edge area provides sufficient bond surface for wind load transfer. Both panes are typically tempered for safety.
Coastal high‑rises in Miami, Houston, the Philippines, Taiwan, and the Gulf Coast specify 8+12A+8 or 8+16A+8 with tempered/tempered configuration to meet Miami‑Dade NOA, Florida Building Code HVHZ, and CWCT TN‑71 impact and cyclonic debris requirements.
Speculative office developments and corporate headquarters worldwide specify 8+12A+8 as the default. With double silver Low‑E and argon, it meets ASHRAE 90.1, EU EPBD, and Singapore Green Mark requirements.
High‑end hotels specify 8+12A+8 with laminated inner pane for acoustic insulation (guestroom quiet) and tempered outer pane for safety. Properties in hurricane zones add impact‑rated laminates.
Airport terminals, train stations, and metro stations use 8+12A+8 for large‑span glazing systems. The 8mm glass handles the thermal stress of expansive atriums and the acoustic demands of busy terminals.
Embassies, courthouses, and continuity‑of‑government facilities specify 8+12A+8 with enhanced security options (SGP laminated, blast‑rated) for forced‑entry and blast mitigation.
Iconic buildings — museums, concert halls, cultural centers — specify 8+16A+8 with triple silver Low‑E and krypton fill to achieve the lowest possible U‑value while maintaining the design intent.
Our 8+12A+8 and 8+16A+8 insulated glass units are manufactured to EN 1279 standards in our 12,000 m² production facility:
| Standard | Region | Requirement |
|---|---|---|
| EN 1279‑1 | Europe | Terminology and definitions |
| EN 1279‑2 | Europe | Long‑term test method for gas leakage |
| EN 1279‑3 | Europe | Long‑term test method for moisture penetration |
| EN 673 | Europe | U‑value calculation method |
| EN 674 | Europe | U‑value measurement method |
| CE Marking | Europe | Mandatory for EU market |
| ISO 9001 | International | Quality management |
| CCC | China | Mandatory for Chinese market |
| SGS | Global | Third‑party inspection |
| IGCC | USA/Canada | Insulating Glass Certification Council |
| ASTM E2190 | USA | IGU performance standard |
| ASTM E1886 / E1996 | USA | Cyclic pressure / missile impact (hurricane) |
| Miami‑Dade NOA | USA (FL) | Notice of Acceptance (HVHZ) |
| CWCT TN‑71 | UK | Curtain wall testing standard |
| Package Type | Orientation | Capacity | Suitable For |
|---|---|---|---|
| Vertical A‑Frame | Edge‑vertical | Up to 25 units/frame | Standard sizes, ≤6.0 m² |
| Horizontal Crate | Face‑horizontal | Up to 10 units/crate | Jumbo panels, >6.0 m² |
| Stillage Rack | Edge‑vertical | Up to 35 units/rack | Bulk orders, repeated sizes All packaging includes paper interleaving, corner protectors, edge protectors, stretch wrap, plywood crates for sea freight, shock‑absorbing spacers, and desiccant packs inside crates. |
| Glass Combination | Gas Fill | FOB Indicative Range (USD/m²) |
|---|---|---|
| 8mm Clear + 12A + 8mm Clear | Air | $26–38 |
| 8mm Clear + 12A + 8mm Clear | Argon | $28–40 |
| 8mm Low‑E (Single Silver) + 12A + 8mm Clear | Air | $30–44 |
| 8mm Low‑E (Double Silver) + 12A + 8mm Clear | Argon | $34–48 |
| 8mm Low‑E (Triple Silver) + 12A + 8mm Clear | Krypton | $42–58 |
| 8mm Tempered + 12A + 8mm Tempered | Air | $34–48 |
| 8mm Laminated (PVB) + 12A + 8mm Clear | Air | $40–56 |
| 8mm Laminated (PVB) + 12A + 8mm Laminated (PVB) | Air | $52–70 |
| 8mm Low‑E Tempered + 12A + 8mm Tempered Laminated | Argon | $44–60 |
| Glass Combination | Gas Fill | FOB Indicative Range (USD/m²) |
|---|---|---|
| 8mm Clear + 16A + 8mm Clear | Air | $28–40 |
| 8mm Clear + 16A + 8mm Clear | Argon | $30–42 |
| 8mm Low‑E (Double Silver) + 16A + 8mm Clear | Argon | $36–50 |
| 8mm Low‑E (Triple Silver) + 16A + 8mm Clear | Krypton | $44–62 |
| 8mm Tempered + 16A + 8mm Tempered | Air | $36–50 |
| 8mm Laminated (PVB) + 16A + 8mm Laminated (PVB) | Air | $54–74 |
| 8mm SGP Laminated + 16A + 8mm SGP Laminated | Argon | $62–82 |
| 8mm Low‑E Tempered + 16A + 8mm Tempered Laminated (SGP) | Krypton | $58–78 |
💡 Final FOB pricing varies with glass type combinations, spacer type, gas fill, panel dimensions (jumbo sizes incur surcharge), and order volume (FCL vs. LCL). For hurricane‑rated configurations (tempered/tempered + impact laminates), add 15–25% to base pricing. For a precise project quotation including U‑value calculations and wind load analysis, send us your curtain wall elevation drawings or glass schedule.
Q1: What does 8+12A+8 mean?
8mm glass + 12mm air gap + 8mm glass. "A" stands for air gap. Total thickness = 28mm.
Q2: What is the difference between 8+12A+8 and 8+16A+8?
The gap width: 12mm vs. 16mm. The 16mm gap provides ~4% better U‑value, slightly better acoustics (~1 dB), better argon retention, larger desiccant capacity, and room for krypton fill — at a ~10–15% cost premium.
Q3: What is the U‑value of 8+12A+8 insulated glass?
With clear glass and air fill: ~2.5 W/m²K. With double silver Low‑E and argon: ~1.5 W/m²K. With triple silver Low‑E and krypton: ~1.2 W/m²K.
Q4: Can 8+12A+8 be tempered?
Yes. One or both panes can be tempered. For curtain walls above 15 stories and all hurricane‑zone applications, both panes must be tempered.
Q5: What is the maximum size?
Up to 3300 × 12000 mm for both configurations. This is the largest standard IGU format in the industry.
Q6: How much does 8+12A+8 weigh?
Approximately 40 kg/m² with clear glass. A 3.0 × 2.0m panel weighs approximately 240 kg. Mechanical lifting equipment is mandatory.
Q7: What is the difference between 8+12A+8 and 6+12A+6?
8+12A+8 uses 8mm panes vs. 6mm. This provides ~78% higher bending strength, wind load resistance up to 5.0 kPa (vs. ~3.0 kPa), and suitability for buildings above 15 stories — at ~33% weight increase and ~25–35% cost premium.
Q8: Which spacer should I choose?
Aluminum for budget projects; Warm Edge TPE for improved thermal performance; Swisspacer for Passive House or LEED Platinum; Structural Silicone for four‑sided SSG systems.
Q9: Is 8+12A+8 suitable for hurricane zones?
Yes — when both panes are tempered and the unit is configured with impact‑rated laminated glass. Our hurricane‑rated 8+12A+8 units meet Miami‑Dade NOA, ASTM E1886/E1996, and TAS 201/202 requirements.
Q10: How long does the seal last?
Properly manufactured IGU seals last 20+ years. Our units pass EN 1279‑2 (gas leakage) and EN 1279‑3 (moisture penetration) accelerated aging tests.
Q11: What certifications do you provide?
EN 1279 (full series), CE, ISO 9001, CCC, SGS, IGCC, ASTM E2190. Miami‑Dade NOA and NFRC certification available on request.
Q12: Can I get a sample?
Yes. We provide free samples (typically 300×300mm); customer covers courier freight.
Q13: What is the lead time?
3–5 weeks after deposit for standard FCL orders. Hurricane‑rated or extensive processing may extend to 5–7 weeks.
Q14: Should I choose 12A or 16A for my curtain wall project?
Choose 12A for standard high‑rise curtain walls (15–40 stories) and typical energy codes. Choose 16A for hurricane zones, LEED Platinum targets, Passive House certification, or panel sizes exceeding 4.0 × 2.5m.
Q15: Can 8+16A+8 be filled with krypton?
Yes. Krypton fill in the 16mm gap achieves U‑value as low as 1.1 W/m²K — suitable for Passive House certification in most climate zones.
Q16: Do you provide wind load calculations?
Yes. For all curtain wall projects, we provide engineering calculations per ASTM E1300, CWCT TN‑71, or local building code requirements.
Tell us your project requirements and we'll respond within 48 hours with a competitive FOB quotation, preliminary U‑value calculations, and wind load analysis.
Please provide:
•5+9A+5 / 5+12A+5 Insulated Glass – 20mm & 22mm IGU for residential & light commercial
•6+12A+6/6+16A+6 Insulated Glass–24mm/28mm IGU for heavier duty applications
•8+12A+8/8+16A+8 Insulated Glass – 28mm/32mm heavy‑duty IGU
•10+12A+10/10+16A+10 Insulated Glass – 32mm/36mm high‑performance IGU
•Double Glazed Glass – Standard IGU overview
•Triple Glazed Glass – Three‑pane IGU for Passive House
•Low‑E Insulated Glass – Energy‑efficient IGU with Low‑E coating
•Laminated IGU/safety insulated glass – Acoustic & security insulated glass
•Jumbo Insulated Glass – Up to 3300×12000mm oversized IGU
With over 20 years of experience and expertise in glass manufacturing and processing, we are seasoned glass specialists, ready to answer your questions and provide guidance on product selection, installation, and maintenance.
