Products, Design

Thermal Performance – Fenestration for the seasons

As the seasons change and our heating systems start to come on in many parts of the country, we’re reminded of the importance of our façade for occupant well-being, the environment, and our pocketbooks. Façade systems like window wall used in multi-family projects, curtain wall systems often found in office buildings and storefronts that frame our retail stores, coffee shops, libraries, and restaurants, all have a direct and profound impact on the comfort of those that use them and operations of the building.

Designers are consistently looking to balance expansive glass for access to natural light that enhances well-being and health, with performance for the region they’re in and the budget of the project. Across systems, the performance is driven by both the framing system and the glass to achieve U-factors that meet code and project and client requirements, along with other performance metrics like Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT).

Storefront systems can range in performance U-factors from 0.60 and above to as low as 0.24 and below, depending on the thermal break used, the air space, and importantly, on the glass used. Insulating glass units are a critical part of a system’s performance and moving from clear to low-E glass can lower U-factors from 0.54 to as low as 0.34 in a system like the Series 6000 Thermal MultiPlane. Depending on the region, a storefront like ThermaStackTM can be the perfect solution to reach a system U-factor of 0.36 with a low-E glass with COG of 0.28. This type of system offers enhanced aesthetics using a Front Set Stack that provides a flush-glaze installation for a cleaner exterior appearance while simultaneously ensuring a simpler field installation with no required notching, for a faster installation.

Compare thermal storefronts here.

An innovative window wall solution like the TCR-225 can achieve a U-factor of as low as 0.30 without the need for triple glazing, by leveraging high-performing thermal strut technology and a glass makeup with 0.24 Center of Glass (COG) performance. This means enhanced building performance for occupants in multi-family buildings, office buildings and even educational institutions, saving long-term costs.

Explore window wall solutions here.

Our newest curtain wall, Reliance -TC LT, achieves a U-factor of 0.29 without the need for triple glazing, in a lightweight, easy to install system. Similarly, Reliance™-HTC can be used for more stringent thermal performance criteria. The system achieves a U-factor of 0.19 using Low-E 1-3/4″ insulating glass by leveraging polyamide strut technology.


See curtain wall systems here.
With a number of criteria to consider, and glass and framing both being critical components to the performance of the building, you can leverage Oldcastle BuildingEnvelope’s free, online tool SystemSelectTM to see system performance across a variety of products and quickly adjust and substitute to find the perfect solution for your project. It provides U-factor along with SHGC, solar transmission, shading coefficient and more. The tool also provides LEED v.4 details and documents like Environmental Product Declarations.