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Weekly UpdatesDesigning a building without considering the placement of plumbing, heating ducts or electrical wiring would be impractical, yet it happens all the time with another critical building component. Access control has traditionally been treated as an afterthought in building construction--a design approach that can lead to additional installation expenses and compromises in aesthetics, not to mention poor integration of security components that were hastily lumped together.
This oversight causes problems for building owners. Doors and hardware--essential elements of an access control system--constitute less than two percent of overall construction expenses, but statistics show they figure in about 25 percent of all punch list items at project closeout. Most of these punch list items can be eliminated by simply devising an effective access control system that is incorporated into the overall building design.
Making Buildings Safer by Integrating Equipment and Procedures
Think of security as a circle, a closed loop without gaps. A building may have numerous security components in place, but a single interruption breaks the loop and compromises the whole system. For that reason, it is vital to take a comprehensive approach to security so every possible risk is minimized.
Regardless of the building type (school, hospital, office), components of the access control system will fall under the categories of design, hardware and procedures. These components should be meshed together to create an access control system that delivers security, convenience and life-safety.
Much to the delight of architects and design professionals, today's door control hardware is capable of performing a given task with a certain degree of stealth. In other words, properly functioning hardware is able to go unnoticed as it performs the basic tasks of providing security, life-safety and convenience. There is no need for safety and security to be difficult or obtrusive, at least not with the locking hardware options now available.
This stealth-like effect is created by seamless integration of the door control hardware with the rest of the building's security controls. When working in tandem the security controls should deliver uninterrupted service and facilitate easy access and egress. Much like a traffic light, properly functioning doors should allow orderly flow of traffic. A broken or malfunctioning traffic light at a busy intersection creates backups, delays and safety hazards. Likewise, a mish-mash of hardware controls leads to doorways that impede safety and security.
Access Control Components
Locking hardware controls who enters the facility by limiting the number of access points. This funnels all building occupants and visitors through central doorways that can easily be monitored to keep out unauthorized individuals. Internal doorways can also be configured to only allow access to authorized personnel. The options available for accomplishing this task are numerous.
A mechanical lock and key system is the simplest from a technology standpoint, but requires extensive upkeep. Meticulous record keeping is needed to track all keys. If one key is lost or stolen, it will be necessary to look back in the records and determine which locks are accessible with the missing key. The cylinders on those locks would then be replaced and new keys would have to be issued to anyone with access to those doors.
Key duplication is another concern, but can be easily rectified by selecting a patented high-security key system that offers factory protection of key blanks. This means the manufacturer of the key system will not distribute key blanks without written permission from authorized facility personnel. Even if electronic hardware is used, a master key override is employed on most locking systems.
Electromechanical door controls--either stand-alone or hardwired locksets--sidestep the key control issue and allow even greater levels of access control. Stand-alone locks are battery powered, require no hardwiring and, therefore, are generally less expensive to install. A stand-alone lock can be operated by magstripe card, key fob, keypad or a combination of card and keypad or fob and key pad. The locks can be interrogated for security purposes and programmed to allow varying levels of access privileges. Unless the locks offer wireless networking capabilities, however, most stand-alone locksets on the market are unable to communicate directly with other building security controls.
Hardwired door hardware offers the ultimate in door control. A hardwired opening can be linked to a network, allowing user access privileges to be changed instantly. Important security tasks--interrogation of door locking hardware, changing user profiles, identifying possible security breaches and issuing lockdowns--can all be completed from a centralized computer. In addition, hardwired openings can be linked with the facility alarm controls. If a fire alarm is activated, the control panel will send a signal to automatically close all fire doors and bypass delayed egress exit devices. This versatility makes hardwired openings ideal for facilities that require tight control over security and life-safety.
The type of hardware used will vary. Mechanical hardware will usually consist of mortise locks, cylindrical locks and exit devices, while stand-alone locks are typically available as mortise locks, cylindrical locks or exit devices. Electromechanical hardware will also include mortise locks, cylindrical locks and exit devices along with electric strikes, magnetic locks, keypads, card/prox readers, automatic openers and door position switches.
When and where should each type of hardware be employed? Following are some basic guidelines.
Door Locking Hardware
Mortise locks fit into a mortise in the door edge, and typically feature levers to operate a latchbolt. They provide greater torque resistance, security and variety of functions than typical cylindrical locksets and are recognizable by the separate key cylinder above the lever.
Mortise locks can be applied to any door in a facility that requires latching or locking that doesn't require panic hardware. The brute strength of a mortise lock makes it a popular choice for securing sensitive areas such as, executive offices, storage closets, computer/medical labs and stairwell doors.
Cylindrical locks are a step down from the strength and durability of a mortise lock and are more appropriate for securing interior openings. A cylindrical lock requires less door preparation than a mortise lock and is also less expensive and easier to install.
Exit devices, also known as panic hardware, allow safe egress while restricting access from outside a building. Exit devices consist of a push pad or bar which extends across the push side of the door. When depressed, the device retracts a latchbolt to allow the door to be pushed open. Think of these as a one-way valve through which people can exit but not enter unless authorized. Life-safety codes establish occupancy or space requirements that dictate which doorways must be equipped with an exit device. Generally speaking, rooms within education, healthcare, and assembly occupancies with an occupant load greater than 50 persons will require panic hardware.
Electromechanical versions of mortise locks, cylindrical locks and exit devices enhance access control by requiring ID credentials such as a keypad, card/prox reader, key fob or biometric identification device. They also feature fail safe or fail secure options in the event of power loss. A fail safe device becomes unlocked in the event of a power failure, while a fail secure lockset is automatically locked. Linking the locks into a centralized computer system permits constant monitoring of the doorways. If a door is propped open, for example, the computer will immediately detect the anomaly and warn of the possible security breach. This requires the use of a door position switch.
Exit devices offer the greatest number of electromechanical functions. Delayed egress exit devices, for example, sound an alarm and remain locked for 15 seconds when the push bar is pressed. After the 15 second delay, the push bar is unlocked and egress is allowed. This is an ideal application for openings where material can be snuck out the back door. In the past, the best available option was an exit alarm, which would merely alert facility personnel when someone had walked off with something. Delayed egress devices give time to apprehend a would-be thief, and become a significant deterrent against theft.
Another electronic exit device function is the electric latch retraction exit device. This device operates as a normal exit device, until power is applied. When power is applied to the device, its latchbolt is retracted, and the door can be pulled (or pushed) open without depressing the push rail or operating any trim, such as a lever. This can be applied to an entrance which may either have a card reader for access, or be remotely controlled by a time clock or other switching device. Some manufacturers' devices actually retract both the latchbolt and the push rail on the exit device, making the device completely silent when operated. This is ideal for auditoriums, theaters, music rooms, or any other space where acoustics and quiet door operation are important.
Strikes and Maglocks
Electric strikes or magnetic locks can be used to further regulate who passes through access points, providing an even greater level of protection. Electric strikes are door locking devices, usually solenoid-operated, that will unlock the door when electrical power is applied to it. An opening that requires a person to be "buzzed in" is equipped with an electric strike. The buzzing sound is created when a button is pushed, sending an AC current through the device. This action disengages the device and allows the door to open. The operation just mentioned is a fail secure mode of operation, the most common function of an electric strike. A fail safe configuration will operate in the reverse condition; normally locked when power is applied and unlocked when power is interrupted. If desired, the buzzing sound can be eliminated by using a DC power source.
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