Thermal Performance of Spandrel Assemblies in Glazed Wall Systems: Phase 1

Charles Pankow Foundation Research Grant RGA #04-22

Glazed wall systems, such as curtain walls or window walls, form part of the building envelope and are commonly used in modern buildings. They comprise transparent, translucent, and opaque areas. However, because of the complex arrangement of materials and structural components which bridge the insulation, spandrel assembly thermal performance is often lower than assumed. This can contribute to building energy loss, condensation, and other performance issues.

The overall goal of this program is to provide the industry with a repeatable and accurate procedure for estimating the thermal performance of spandrel panel systems. Based on this physically validated simulation procedure, jurisdictions may choose to recognize the performance of spandrels in different ways, including requiring use of the procedure when reporting performance or by setting targets independent from those of other opaque wall assemblies.

The program objectives in the short-to-mid term are to provide research findings that lead to publication of a design guide: “Design Guidance for Thermal Performance of Spandrel Assemblies in Glazed Wall Systems.” The goals of the Design Guidance Document are to provide shorter-term guidance to improve existing practice and to inform codes and standards changes over a ten-year time horizon.

Project Phases
The overall project is divided into the following four phases:
• Phase 1: Design Test Program
• Phase 2: Perform Physical Testing and Analysis
• Phase 3: Define Spandrel Thermal Performance Requirements
• Phase 4: Prepare Design Guidance Document

Morrison Hershfield Authors: Stéphane Hoffman, Ivan Lee
Contributors: Kelvin Liu, Sadie Mansour, Barilelo Nghana

Date Published: May 2023