You would be hard-pressed to find an architect or designer who wouldn’t prefer an all-glass entrance system to a bulky, full-framed counterpart. Can you blame them? Less metal and more glass translates to improved daylighting, unobstructed views, and a high-end, contemporary aesthetic.
Unfortunately, there is a problem. Increasingly stringent energy and air infiltration codes—such as California Title 24—pose a challenge when specifying exterior entrance systems with all-glass visuals. Think Herculite-style, monolithic heavy-glass doors. It becomes a balancing act that can ultimately result in selecting standard, aluminum-framed thermal doors at the expense of attractive aesthetics.
So how do you achieve an ideal balance between high performance and aesthetics? With codes on the trajectory that they’re on, it’s easy to see that the future of all-glass entrances can very well be thermally broken systems with insulating glass (IG). IG units can significantly reduce heat transfer year-round to lower energy usage and costs.
In the past, IG units went hand-in-hand with thermal doors that incorporate wide vertical stiles. Handle hardware was traditionally mounted onto these wide door stiles. Although this approach provides great utility and performance, it lacks the premium appearance of an all-glass entrance system.
It’s a good thing some manufacturers have been listening. The industry is starting to see much needed innovations in all-glass entrance design. CRL-U.S. Aluminum, for example, has released its Entice Entrance System, which allows handle hardware—including panic devices—to be mounted directly onto IG units using proprietary through-glass fittings. This produces a distinctive floating-on-air look while being able to handle the loads imposed by emergency exit hardware during the emergency exit test required by UL. Because it’s a dry-glazed system, the IG perimeter seal is not compromised over time.
Entice features ultra-narrow 1-1/8-inch vertical stiles, as well as thermally broken framing and cladding that deliver U-factors as low as 0.33. In essence, the system provides all-glass aesthetics and the full-frame thermal performance required to meet codes, including those set forth in ASHRAE 90.1-2016.
Since it’s now possible to mount handle hardware onto IG units, tubular panic devices can serve as a complement to all-glass thermal doors. Their slim and elegant design enhances the minimalist visual while simultaneously improving safety, security, and performance.
With any project that involves fenestration, architects must be aware of the local codes that specify energy performance requirements. Partnering with the manufacturer and Authority Having Jurisdiction in the early stages of the design process is highly advised.
"We’re going to see many states rollout rigorous energy codes. Ensure that the entrance systems specified to meet these codes by working with the manufacturer at the start of the project," said Ron Wooten, FenestrationMaster and Director of Product Testing & Certification at CRL-U.S. Aluminum.
Energy codes are getting stricter and calling for higher thermal performance. Plan ahead by understanding the role insulating glass will play in all-glass entrance system design. With careful consideration, you’ll never have to specify performance at the expense of aesthetics again.
