Examining Methods for Preserving and Improving the Energy Performance of a Historic, Aluminum Framed Curtainwall System
With respect to thermal performance, historic aluminum-framed curtainwall systems perform poorly compared to modern counterparts. These systems are ideal candidates for replacement with newer thermally efficient systems during building retrofits. However, there are situations where replacement of the curtainwall system is not feasible due to other factors such as historic significance, constructability, or excessive costs. When a facade is designated as historically significant by local preservation authorities, the appearance of the curtainwall system must be maintained. This may be difficult with modern replacement systems, and customization may be cost prohibitive. This session explores a method that was developed to thermally retrofit in-situ a historic curtainwall framing system while maintaining the original appearance of the system. The change in thermal performance is modeled to estimate improvements that can be achieved through retrofitting existing framing and compared to the improvement in replacing the existing framing. Finally, an energy cost-benefit analysis is conducted to account for embodied energy associated with the new framing system. The primary intended audience is designers and constructors focused on building restoration. Some background knowledge of building science fundamentals will assist the attendee's understanding.
Learning Objectives
At the end of this session, the attendee will be able to:
- Explain why historic curtainwall systems perform poorly compared to modern systems with respect to heat transfer.
- Discuss the life-cycle analysis of glazing components and associated embodied energy.
- Identify factors that impact a cost benefit analysis between retrofitting and replacing existing glazing systems.
- Recognize how specific boundary conditions around existing glazing impact the practicality of replacement.
Length: 00:47:18
Last Updated: April 28, 2025
