PRANCE metalwork is a leading manufacturer of metal ceiling and facade systems.
What are the thermal performance requirements for a glass curtain wall system in high-rise commercial buildings?
Designing thermal performance for a glass curtain wall system in high-rise commercial buildings requires an integrated metal-framing strategy that balances energy code compliance, occupant comfort, and façade longevity. For clients in the Gulf (Dubai, Riyadh, Abu Dhabi, Doha) and Central Asia (Almaty, Astana, Tashkent), priorities include low center-of-glass U-values, solar heat gain control (SHGC), and thermally broken aluminum mullions to limit conductive heat transfer. A practical specification couples double- or triple-insulated low-e glazing with a thermal break in the aluminum framing system; this approach minimizes thermal bridging while delivering high visible light transmittance where required.
Performance targets typically align with local energy codes and international standards: U-values for assemblies often range from 0.35 to 1.2 W/m²K depending on climate and glazing strategy, while SHGC targets are set lower in hot desert climates to reduce cooling loads. Use high-performance low-e coatings and warm-edge spacer systems to control radiative losses; consider selective coating placement to optimize daylight without excessive solar gain.
Condensation risk must be assessed via dew-point modeling across the assembly, especially where interior humidity is high (malls, hospitality). Metal curtain wall systems should include continuous thermal breaks, insulated spandrel panels, and appropriate cavity ventilation or desiccant spacers. For retrofit or mixed-climate projects (e.g., projects spanning Gulf markets and Central Asia), provide alternative glazing packages: higher SHGC and thicker insulation for cold regions and lower SHGC packages for hot-arid zones.
Specify testing: whole-unit U-value verification, thermal transmittance via ISO 10077 or ASTM C1363, and condensation resistance indices. Finally, coordinate with mechanical engineers to optimize HVAC setpoints and ensure the metal curtain wall contributes to net-zero and LEED/BREEAM targets where applicable.