Panic devices for glass entrances: overcoming design and specification challenges

Glass entrance design and operational safety considerations
The types of door systems being manufactured today reflect the desire to create unique and appealing entrances while meeting code requirements for safety and performance.

First and foremost, panic devices are engineered to save lives; therefore, close attention must be placed on the design of the entrance system itself to ensure compatibility and safety. Nearly every glass entrance is custom designed, comprising an iteration of the thousands of possible glass and panic hardware configurations available. For this reason, critical considerations must be addressed early in the design phase before the hardware specifications are written.

While seemingly obvious, many fundamental questions are often overlooked. For example, what are the sidelite conditions? What is above the door? Answering these types of questions will clarify what hardware is required to maintain safety and performance. Another consideration is door and opening sizes; these will dictate the glass thickness, support system, and hardware required to mitigate deflection and ensure proper performance. The doorframe depth will dictate the panic handle location.

For best practices in glass entrance system and tubular panic design, follow the guidelines set forth in the Glass Association of North America (GANA) Fully Tempered Heavy Glass Door and Entrance System Design Guide. It specifies important parameters regarding door sizes, glass thicknesses, hardware required, etc.

In the author’s experience, the main issues encountered with tubular panic and glass door quotes are: glass template errors, doors that are out of spec, and hardware incompatibility. Working with an experienced manufacturer will often prevent these issues. Some designers use proprietary design software capable of providing automatic alerts if any component of the emergency egress system is out of spec.

Certified glass fabricators and temperers are also a valuable resource to help ensure glass door and tubular panic designs are functionally sound and meet safety standards. They typically have a direct working relationship with the panic device manufacturer, which allows them to deliver single-source glass entrance system solutions.

Although glass is a specialized material, glass fabricators are experts in the field and will prevent detrimental outcomes, such as hardware compatibility issues, glass breakage, compromised safety, violations of GANA guidelines, and voided manufacturer warranties. Working with a local glass fabricator provides additional benefits in terms of logistics and experience with regional codes.

Achieving the desired aesthetic
The original tubular panic was patented more than 50 years ago. Since then, architects, specifiers, and end-users have come to value the style’s slim and elegant design.

When paired with glass doors, tubular panics maintain clean, unobstructed views and do not impede daylight from flowing through building interiors.

A principal objective for architects is designing for quick and easy egress during emergency scenarios. The challenge is specifying exit systems that do not interfere with an all-glass aesthetic intent. Access control devices that maximize safety and security without compromising visual appeal are therefore preferred.

Fortunately, manufacturers have been paying attention and the industry is beginning to see much-needed innovations in panic device design. For example, a panic device featuring an independent, ultra-narrow crash bar is now available. The crash bar is engineered to easily and securely attach to the vertical tubular panic component. This two-piece system allows architects to specify a panic device with back-to-back ladder pulls. The panic device can be mounted onto both monolithic heavy glass and double-glazed insulating glass. This is particularly important in light of increasingly stringent energy codes—the future of glass entrances might very well be thermally broken systems incorporating insulating glass units (IGU).

In many regions, evolving energy codes have already essentially mandated exterior entrances with thermally broken doors and insulating glass. To meet thermal performance requirements without compromising aesthetics, specify an all-glass entrance system that can accommodate tubular panics on standard 25.4-mm (1-in.) insulating glass. Be aware the tubular panics must be able to handle the loads imposed by the emergency exit test required by UL.