Panic Bars Information
Figure 1: A set of doors in a U.S. school fitted with push bars. Source: Scott Brody/CC BY-SA 4.0 DEED
Panic bars and crash bars are seen in commercial buildings all over the world. Designed to allow occupants to easily exit a space during an emergency, panic bars have become quite commonplace. First designed after fatal fires involving hard to operate door locking mechanisms, panic bars have become the standard for ensuring people can evacuate during an emergency.
Theory of Operation
Panic bars, also known as crash bars or exit devices, operate on a straightforward yet effective principle designed for quick and easy use, especially in emergencies. These devices consist of a horizontal bar mounted on the inside of a door, spanning almost its entire width. When pressure is applied to this bar, it activates an internal mechanical system, typically housed within a box-like structure on the door.
This internal mechanical system usually comprises a series of springs and levers, which, when the bar is pressed, pivot or rotate to retract the latch mechanism from the door frame, thereby unlocking the door. This design ensures that doors can be opened rapidly from the inside to facilitate swift evacuation, while also complying with fire safety regulations that often require doors to remain closed to hinder the spread of fire and smoke.
Many panic bars are also equipped with features for external access, like key locks or keypads, and may include additional functionalities such as delayed egress, integrated alarms, or connectivity with broader building security systems. The key aspect of panic bars is their ability to allow occupants to exit quickly and effortlessly, without needing to operate complex mechanisms, which is crucial during high-stress emergency situations.
Figure 2: A rendering showing the difference between vertical rod Pullman latches versus center post latching in emergency exit doors. Source: Scott Brody/CC BY-SA 4.0 DEED
Specifications
The specifications for panic bars or crash bars are primarily governed by building codes and safety standards. These specifications ensure that the devices provide reliable and efficient egress during emergencies. Key specifications include:
Compliance with Codes and Standards
Panic bars must comply with local building codes and international standards, such as those set by the American National Standards Institute (ANSI) and the Builders Hardware Manufacturers Association (BHMA). Specific standards that can apply are addressed later.
Material and Durability
They are typically made from durable materials like steel or aluminum to withstand frequent use and potential abuse. The materials should also be fire-resistant to ensure functionality during a fire.
Width and Length of the Bar
The bar should span at least half the width of the door, allowing easy access to people pushing the bar from any angle. The panic bar must be easily operable, even during a chaotic period, to ensure it can serve its function.
Force Required for Activation
The amount of force needed to activate the bar is crucial. It must be low enough to allow children, the elderly, and people with disabilities to open the door with ease, typically not exceeding 15 pounds of force.
Mounting Height
The height at which the bar is mounted on the door should be accessible to all users, including wheelchair users. This is typically within 34 inches to 48 inches from the floor.
Door Type and Size Compatibility
Panic bars must be suitable for the type of door on which they are installed, whether it's a single door, a double door, or a door with particular dimensions.
Egress Capacity
The device should be capable of allowing a sufficient number of people to exit quickly in an emergency, which depends on the occupancy and use of the building.
External Locking
If the door is used for entry as well as exit, the panic bar may need to be compatible with external locking mechanisms while still allowing for immediate exit from the inside.
Delayed Egress Functionality
In some high-security areas, delayed egress panic bars are used, which delay the opening of the door for a few seconds after the bar is pressed.
Fire Exit Hardware
For fire exits, the panic bar must be certified as fire exit hardware, which means it can withstand fire conditions while still providing immediate egress.
These specifications can vary based on the jurisdiction and the specific application (commercial, industrial, educational, healthcare facilities, etc.), so it's important for builders and facility managers to be aware of the local regulations and standards applicable to their locations and types of buildings.
Figure 3: Typical "panic bar" hardware for emergency egress. Source: Jonathan Clemens/CC BY-SA 3.0 DEED
Types
Panic bars come in several types, each designed to suit different door configurations and security requirements. Here are the main types:
Rim Panic Bar
This is the most common type of panic bars. They feature a latching mechanism that is mounted on the surface of the door, typically on the inside. The latch engages with a strike plate mounted on the door frame. These panic bars are suitable for single doors and are relatively easy to install.
Mortise Panic Bar
This type integrates into a mortise lockset in the door. The panic bar mechanism and the lock are housed within a pocket (mortise) in the door. This type offers a higher level of security and a more aesthetic appearance since most of the hardware is concealed. They are commonly used in commercial buildings where both security and aesthetics are important.
Vertical Rod Panic Bar
These exit bars are available in two sub-types: surface vertical rod and concealed vertical rod. These devices have rods that extend from the panic bar mechanism to the top and bottom of the door. They latch at both the top of the door frame and the floor, providing additional security and stability. They are quite useful for double doors and tall doors.
Concealed Panic Bar
The mechanism of this panic bar is mostly concealed inside the door, with only the push pad visible. It offers a clean, less industrial look and is often used in more design-conscious settings. They are typically more expensive due to the complexity of the design and installation.
Multipoint Panic Bar
This type locks the door at multiple points, providing extra security. It is often used in high-security areas or in environments like schools, where additional locking points can enhance safety.
Electronic Panic Bars
These panic bars incorporate electronic components for integration with alarm systems, access control systems, or automatic door openers. They are often used in buildings with advanced security systems.
Each type of panic bar has its own set of advantages and is chosen based on the specific needs of the building, such as the type of door, the level of security required, aesthetics, and compliance with local safety codes.
Figure 4: Panic bar. Source: Atomic Taco/CC BY-SA 2.0 DEED
Features
Panic bars come with a variety of features designed to enhance safety, security, and convenience. Here are some common features:
Alarms
Some panic bars are equipped with integrated alarms that sound when the bar is pressed. This feature is particularly useful in preventing unauthorized exits or alerting security personnel when an exit is used.
Delayed Egress
This feature temporarily prevents the door from opening immediately after the panic bar is pressed. It's often used in high-security areas or in settings like retail stores to deter theft. The delay is usually for a few seconds, with an alarm sounding during this period.
Electronic Integration
Higher-end panic bars can be integrated with electronic access control systems. This allows for features like remote locking/unlocking, exit tracking, and linkage to building security systems.
Touchpad Operation
Instead of a traditional push bar, some models feature a touchpad, which can be easier for some users to operate.
Visual Indicators
Some panic bars include visual indicators to show if the door is locked or unlocked, which can be useful in quickly assessing security status.
These features can be mixed and matched depending on the specific requirements of the building and the doors where the panic bars are installed. It's important to choose the right combination of features to balance safety, security, and usability.
Figure 5: Panic bars are also known as crash bars or push bars. Source: TESA/CC BY-SA 2.5 DEED
Manufacture
The manufacturing process of panic bars, also known as crash bars or push bars, involves several key steps, incorporating both mechanical engineering and material science principles. The process begins with detailed design and engineering. This involves creating technical drawings and specifications that outline dimensions, materials, mechanical properties, and safety features. CAD software is often used to create precise models and simulations of the panic bar.
Materials are then chosen based on strength, durability, resistance to corrosion, and fire safety standards. Common materials include steel, stainless steel, aluminum, and sometimes brass or plastic for certain components. The selected materials are cut and shaped into the various components of the panic bar. Techniques like laser cutting, punching, or die casting may be used, depending on the material and the part.
Precision machining processes like milling, drilling, and turning are used to create specific features on the components, such as holes for screws, slots for levers, and grooves for springs. The panic bar comprises several components, including the push bar, internal mechanism (springs, levers, latches), mounting plates, and fasteners. These parts are assembled, often using both automated and manual assembly processes.
Components may undergo surface treatment processes like powder coating, galvanization, or anodizing to improve corrosion resistance and aesthetic appeal. Throughout the manufacturing process, rigorous quality control is essential. This includes checking dimensions, material properties, mechanical operation, and safety features.
Panic bars are tested to ensure they meet regulatory standards and performance criteria.
Tests may include durability testing (to simulate repeated use), fire resistance testing, and force testing (to ensure the bar operates with the correct amount of pressure). Once manufactured and tested, the panic bars are packaged with installation instructions and shipped to distributors or end-users.
The manufacturing process is designed to ensure that panic bars are reliable, durable, and meet the strict safety standards required for emergency exit devices. Advanced manufacturing techniques and stringent quality control measures are critical in this process, reflecting the importance of these devices in ensuring public safety.
Figure 6: Emergency exit doors. Source: Mike Mozart/CC BY 2.0 DEED
Applications
Panic bars, widely known for their role in emergency egress and safety, are used in a variety of settings and applications. Here are some of the key areas where they are commonly applied:
Commercial Buildings
In office buildings, shopping centers, and other commercial establishments, panic bars are standard on emergency exits and fire doors. They ensure a quick and barrier-free escape route for a large number of people.
Educational Institutions
Schools, colleges, and universities use panic bars to provide safe exit routes for students and staff. They are particularly important in scenarios like fire drills or actual emergencies where rapid evacuation is necessary.
Healthcare Facilities
Hospitals, clinics, and nursing homes often use panic bars on exit doors to ensure patient and staff safety. They are crucial in areas where patients may not be able to operate traditional door handles easily, especially during emergencies.
Industrial and Manufacturing Plants
Panic bars are used in factories and warehouses where there's a need for quick evacuation due to the potential risks associated with machinery, hazardous materials, or other industrial hazards.
Public and Government Buildings
Facilities like libraries, museums, town halls, and other government buildings use panic bars to comply with public safety regulations and to ensure the safety of visitors and employees.
Entertainment Venues and Sports Facilities
Theaters, concert halls, stadiums, and arenas, where large crowds gather, require panic bars for mass egress in emergencies like fires, earthquakes, or other incidents.
Transportation Hubs
Airports, train stations, and bus terminals use panic bars to secure exit doors, allowing for rapid evacuation of passengers in case of emergency.
Residential Applications
In some cases, panic bars are used in residential buildings, particularly in multi-unit dwellings like apartment complexes, for common area exits.
Each application of panic bars takes into account the specific needs of the environment, such as the flow of people, the nature of potential hazards, and regulatory requirements. This ensures that in the event of an emergency, occupants can exit the premises quickly and safely.
Figure 7: Panic bars must adhere to specific standards to ensure reliability and effectiveness. Source: CC BY-SA 3.0 DEED
Standards
Panic bars, crucial for safety and emergency egress, must adhere to specific standards to ensure reliability and effectiveness. These standards vary by region but some of the most widely used standards include:
- NFPA 101
- ANSI/BHMA A156.3
- ADA
- EN 1125
- EN 179
The American National Standards Institute (ANSI) and Builders Hardware Manufacturers Association (BHMA) have established standards for panic bars. ANSI/BHMA A156.3 is the specific standard covering exit devices, including requirements for performance, endurance, strength, and dimensional criteria.
The National Fire Protection Association's Life Safety Code (NFPA 101) outlines requirements for means of egress, including specifications for panic hardware in certain types of buildings. ADA guidelines specify the usability of panic bars, ensuring they can be operated with minimal force and without requiring tight grasping, pinching, or twisting of the wrist.
European standards like EN 1125 specify requirements for panic exit devices operated by a horizontal bar. The standard covers aspects like safety, durability, and performance under fire conditions. EN 179 is similar to EN 1125 but for emergency exit devices operated by a lever or push pad. It's intended for use in buildings where users are familiar with the exit and its hardware.
These standards ensure that panic bars are manufactured and installed to meet essential safety, usability, and durability criteria. Compliance with these standards is not only a matter of meeting legal requirements but also a crucial aspect of ensuring public safety in buildings.
