Revolving Doors: Design, History, and Energy‑Saving Benefits

Background

A revolving door is a traffic‑control system that also regulates building HVAC performance. The unit consists of multiple door panels, a central shaft, a rotunda (or drum) with glass, and a ceiling that houses either a mechanical brake or an electronically‑driven motor. The design guarantees that at least one panel is always sealed, dramatically reducing heat loss and cooling draw.

Each panel is fitted with a rubber‑felt weather seal that must be replaced periodically as it wears. This maintenance is an integral part of the door’s long‑term performance.

History

Revolving doors first appeared in Chicago around 1790. Early models were wooden because metal fabrication was too costly. Today they are ubiquitous in commercial, institutional, and high‑traffic buildings worldwide.

Raw Materials

Construction typically uses aluminum extrusions, steel tubes, marine‑grade plywood, curved and flat glass, felt, rubber, and precision machined steel hardware. Some premium models employ stainless steel or brass for enhanced aesthetics, but this can triple the cost.

Design & Customization

Architects select a revolving door based on energy conservation goals, traffic volume, and security requirements. While the core mechanism remains the same, variations in panel count, width (common width: 8 ft / 2.4 m), finish, and automation level allow tailoring to each project’s needs.

The Manufacturing Process

1. Aluminum Extrusion
   Extruded panels are cut to size using high‑precision presses that shape the aluminum through steel dies. These panels lock together to form a rigid frame.
2. Rotunda Formation
   The rotunda walls are bent from aluminum strips until the desired radius is achieved. Bending is performed on a three‑roller system, ensuring a smooth 360° rotation without contact.
3. Welding & Assembly
   Panels, frames, and hardware are welded together. The central shaft is fitted with breakout hardware required by the Uniform Building Code.
4. Ceiling Construction
   A 1‑in (2.54 cm) marine plywood core is laminated with a 0.125‑in (0.318 cm) aluminum sheet to form the interior ceiling.
5. Speed Control Installation
   A spring‑loaded brake shoe assembly is mounted either in the ceiling or on the floor to prevent “free‑wheeling” and maintain safe operating speed.
6. Breakout System
   The central shaft includes breakout plates that allow the panels to fold for emergency egress. These plates accommodate the required safety clearances and comply with building codes.
7. Final Assembly & Testing
   The door is fully assembled in the factory, tested for height, width, speed, and emergency function, then disassembled and packaged for transport.

Quality Control

On‑site inspections verify dimensions, speed control, breakout operation, and weather sealing. All electronic and security functions are double‑checked. Inspectors sign off on a detailed report before the system is installed.

Byproducts & Waste Management

All waste—wood, aluminum, and steel—is recyclable. No hazardous chemicals are used in the manufacturing process.

The Future of Revolving Doors

Innovations include advanced security features for airports and correctional facilities, such as metal and chemical detectors and video recognition. While the core design remains unchanged, some high‑capacity models now reach 20 ft (6.1 m) in diameter, supporting multiple occupants simultaneously. Despite higher costs and maintenance demands, revolving doors will continue to be the most efficient HVAC barrier in extreme climates and will remain essential for access and traffic control.

Where to Learn More

Other Resources

Manfredi, Bob. Revolving Doors: An Open And Shut Case. December 2001. Link

Sierra Automatic Doors, Inc. Web Page. December 2001.

O. Harold Boutilier