The Role of Continuous Geared Hinges in the Evolution of Glass Doors

From an aesthetic standpoint, glass entrance systems have evolved in recent years. The longstanding objective among many commercial building designers is the pursuit of glass-focused exteriors. Architects want more glass, even an all-glass look.

This idea of building envelopes featuring more and more glass has trickled all the way down to entrance systems. In recent years, taller, heavier glass doors have become popular design statements, especially in retail and hospitality projects. Over two decades ago, the typical height of exterior doors was seven feet. That typical height has grown, with many glass doors being specified at eight feet or taller.

As architects continue to favor all-glass designs, new hardware is needed to accommodate taller, heavier doors.

Understanding offset pivot hinges in relation to heavy glass doors

For decades, offset pivot hinges have been the most common door swing hardware application for exterior commercial doors. Their design is simple: for the typical seven-foot-tall door, there are just two pivots, one at the head and one at the sill, so installation is quick and straightforward. Offset pivots also deliver good aesthetics as they are largely hidden from view.

Unfortunately, offset pivot hinges fail over time. Typically, it’s the top hinge that is subjected to most of the torque when heavy glass doors are opened and closed. Time and repeated use will eventually cause failure. It may take years, but it will happen, leading to costly repairs or, in some cases, the need for door replacement.

Pivot hinge failure is also an important safety consideration. It’s impossible to know when the upper pivot is going to fail. There are no warning signs and it can happen suddenly. Today’s glass doors can weigh hundreds of pounds, meaning pivot hinge failure can cause serious injury.

As door heights have grown, so has the need for intermediate pivots. Because aluminum glass doors exceeding eight feet in height are subject to bowing, manufacturers require the use of intermediate pivots to support the door’s added dimensions. Ultimately, oversized doors require additional, more robust hardware, which has led to the rise of continuous geared hinges.

Benefits of a continuous geared hinge

The advantages of the continuous geared hinge are significant in regard to glass doors. Aesthetics, performance and reliability are key benefits of the continuous hinge.

For example, the CRL Entice HP+ Glass Entrance System incorporates a 760-pound-rated continuous geared hinge that is engineered to perform in year-round weather conditions. The Entice HP+ system itself features a full perimeter seal around doors, thermally broken components, and 1-inch insulating glass. The engineering of this door delivers strong thermal and wind load performance, strong OITC ratings, as well as improved air infiltration resistance. The continuous geared hinge complements and supports these features and characteristics, including its very narrow door stiles.

The impact of hinges on the look of the door and on the envelope as a whole is important. Even vastly superior products will never be specified by architects if they detract from the aesthetic vision. New iterations of the continuous geared hinge can be cosmetically engineered to be almost unnoticeable, complementing a building envelope’s streamlined design.

The continuous geared hinge is great for the reputation of the glazier because it reduces callbacks. And if the glazier is called back for a repair, there’s a near-zero chance the continuous geared hinge is at fault. Also, general contractors notice when they don’t have to call on subcontractors for installations done years ago. The continuous geared hinge may take a few more minutes to install, but the time and cost are negligible when door failures have to be addressed in the future.

As we move into the future, there will be a growing, widespread acceptance of the continuous geared hinge. With attention to detail, this hinge design can be specified to deliver aesthetics that complement today’s pursuit of large-scale glass doors. In all, the continuous geared hinge offers outstanding visuals and extremely reliable, long-term performance.