Introduction To Alarm Systems
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INTRODUCTION
Electronic security alarm systems can be an important contributor to the securing of life, property and possessions. When used properly, a security system can be an effective tool when used in conjunction with other sensible, overall crime prevention measures.
SECURITY SYSTEM COMPONENTS
Keypads display the status of the system using indicator lights or English-language displays. Entering your personal code turns the system on or off.
Sirens installed inside and outside can discourage intruders and alert you and your neighbors.
Contacts detect the opening of a door or window. Some contacts are flush-mounted, and are not visible when the door or window is closed. Sometimes, custom-made alarm screens can be used to protect windows, even when they are open.
Smoke Detectors are powered by the control panel's battery. If your system is monitored, these smoke detectors can send a signal, while you are home or away, to dispatch your local fire department for help.
Glass Break Detectors can provide early detection of a burglary attempt. Some glass break detectors listen for the sounds of breaking glass, while others detect the impact of an attack on the glass.
Motion Detectors sense an intruder's movement, regardless of how he got inside. Security systems often include a way to bypass the motion detectors while you're inside so you can arm the perimeter of your home, yet move freely about inside without setting off your alarm. Some motion detectors are designed to ignore small pets.
Control Panels are the heart of security alarm systems. Control panels monitor all of the various sensors, checks the keypads, and sounds the sirens. It can also transmit alarms to a monitoring center called a "central station." A rechargeable battery powers the system for several hours during power failures.
RESIDENTIAL FIRE ALARM SYSTEMS
The primary purpose of any residential fire alarm system is to alert residents so they can escape. The National Fire Protection Association's (NFPA) minimum standards include one smoke detector on each level of the house and at the top of the basement stairs. While battery-operated smoke detectors are acceptable for existing homes, they do not provide as much protection as interconnected "system" type smoke detectors.
A drawback of independent battery-operated smoke detectors is that only the detector which detected smoke will sound an alarm. For example, if a basement smoke detector sounds an alarm, there is the potential, depending upon the layout of your house, that you might not hear the alarm and be awakened by the sound while in an upstairs bedroom. Another drawback is that people often forget to change the batteries.
Newly built homes are generally required to meet more stringent safety standards than existing homes. This includes smoke detectors inside each sleeping area, as well as the minimum requirement of one smoke detector on each level of the house. Advantages of interconnected "system" type smoke detectors are that whenever one detector senses smoke, the horns in all detectors will sound. This means a fire in a remote part of the house would cause an alarm that would then trigger all other alarms throughout the house to sound. This would allow residents to hear the alarm throughout the house, even if interior doors are closed. This type of smoke detection system is generally powered by your house's electrical supply and generally does not work when the power is off. Some detectors do include standby batteries, but these are the exception rather than the rule.
The best type of household fire warning system will include the following:
- Smoke detectors inside each sleeping area and on each level of the home.
- Standby battery power to operate the entire system for at least 24 hours during power failures.
- The ability to connect heat detectors to the system to provide protection in garages, attics, and kitchens--areas not suitable for smoke detectors.
- Supervision of the interconnecting wiring and batteries, so that problems can be detected promptly.
- The ability to connect the system to a central station, which can dispatch the fire department when needed.
COMMERCIAL FIRE ALARM SYSTEMS
There are many different types of commercial buildings, ranging from small retail stores to warehouses, schools, factories, theaters, etc. Each of these "occupancies" is treated differently by the fire departments and insurance companies. Types of fire alarm systems can vary greatly from one occupancy to the next. Exact requirements can also vary from one jurisdiction to another.
"Life Safety" Fire Alarm Systems
This type of fire alarm system is principally intended to warn occupants of a building and give them time to escape. The system may also summon the fire department or protect the building while it is empty, but the system is designed primarily to protect life.
This type of system is generally subject to the approval of the local fire department and/or other government agencies, and usually requires submission of formal plans, obtaining permits and inspections. This type of system is generally required in schools, hospitals, nursing homes, apartment buildings, high rise buildings, theaters, and similar locations where a large number of lives are at risk.
These systems rely heavily on smoke detectors for early fire warning, but often include heat detectors in areas not suitable for smoke detectors. There are also manual pull stations, which permit people to activate an alarm when needed. If the building has automatic fire sprinklers, the sprinkler system will also be connected to sound the alarm whenever a sprinkler is activated.
Since the emphasis is on life safety, there will be an extensive network of alarm bells and/or horns throughout the building. Because of the requirements of the Americans With Disabilities Act (ADA), fire alarm horns with bright strobe lights are required in most larger buildings to protect the hearing impaired.
Life safety fire alarm systems often perform other functions which protect life, such as shutting down air conditioning systems to reduce the spread of smoke, unlocking doors, and activating smoke extraction systems in stairwells.
"Property Protection" Fire Alarm Systems
Many businesses are not actually required to have a fire alarm system by the local fire department. However, a property owner may wish to protect his building while it's unoccupied. In some cases, an insurance company will also require a fire alarm system as a condition of coverage. The fire department may or may not have specific requirements, depending on the perceived fire hazard and the number of people at risk.
Since these systems are primarily intended to protect property, rather than lives, the emphasis is on detecting a fire and summoning the fire department, rather than on sounding an audible alarm and evacuating the building.
Sprinkler Monitoring
Sprinkler monitoring is an effective and low cost fire alarm system. Each sprinkler head contains a piece of metal which melts at a specific temperature, usually 165 degrees, thereby allowing water to flow out of the sprinkler head. Contrary to popular belief, water does not flow out of all the sprinkler heads, only those exposed to high heat. Waterflow switches detect the flow of water through the system, sounding an alarm and transmitting an alarm signal to the central station. Tamper switches often protect sprinkler shutoff valves, and in colder climates, other types of supervisory devices help assure the sprinkler system is ready to operate when needed.
A red "waterflow switch" detects the flow of water through the main sprinkler "riser."
Sprinkler monitoring is important because, on rare occasions, a sprinkler head can malfunction and release water when there is no fire. When a sprinkler head is activated for any reason, water continues to flow until someone shuts off the water. Therefore, if this happens in an unmanned or unmonitored building at night or on a weekend, the water damage could be substantial.
WHAT'S THE DIFFERENCE BETWEEN A WIRELESS SYSTEM AND A HARD WIRED SYSTEM?
While there are many types of products available on the market, the actual system you purchase can be either hard wired or wireless. The difference is that for hard wired systems there is a wire connecting each device to the central control panel. A skilled installer uses special tools to conceal the wire inside walls, attics and crawl spaces. In a wireless system, small radio transmitters "connect" the sensors and keypads to the control panel. Higher quality wireless systems use frequent test signals to verify the operability of each transmitter.
Hard wired and wireless systems often cost about the same. Hard wired systems look nicer, but take much longer to install. Wireless systems are a good solution when there's no way to get a wire from "here to there," however, each wireless transmitter will periodically need a new battery. Each type of system has it's advantages and disadvantages. The choice between a wireless or hard wired system is one you should make in consultation with your alarm company. They can help you choose the system that's best for you and your circumstances.
WHAT IS A CENTRAL MONITORING STATION?
An alarm system can be installed to emit a local alarm using a bell or siren, and/or it may be connected via a common carrier network (i.e. telephone lines) to a monitoring or "central" station where trained operators verify the alarm and dispatch the appropriate response authority (police, fire or medical) when the system transmits a signal. They may also notify you or your designee of the alarm signal. Alarm signals are usually transmitted over telephone lines, but some systems transmit signals by radio or cellular phone for added security. In addition to the police, fire or emergency medical dispatch, a monitored system may also emit a local siren when activated. A "local only" system does not, in itself, dispatch emergency response.
In order to receive emergency police, fire or medical response, you must either rely on a neighbor calling in the alarm (in the case of a local system) or you must have the system monitored (24 hrs) by a monitoring station. For this service, a monthly fee is paid and is arranged through your alarm installation company. In most municipalities alarm systems may not be connected directly to the police.
While there are a number of companies which install and monitor their own accounts, there are many more that install systems and contract with a third party monitoring facility. When you are deciding on which company to use, be sure to understand the service provided. The fact that the installing company subcontracts monitoring services is not a negative feature but, rather, is simply a standard practice in the industry. Because of advances in telecommunications, it is common practice to have your account monitored by an out-of-town or an out-of-state station.
WHAT SHOULD AN ALARM SYSTEM DO FOR ME?
An alarm system is installed to deter and detect intruders, to detect smoke, or to summon emergency medical assistance. A basic security system will consist of both perimeter and space protection to secure your premise. The first stage secures vulnerable perimeter access points such as doors and windows; the second stage consists of space detection such as interior motion detectors, which monitor movement inside the premise, and smoke detectors to detect a fire. The level of security you purchase is determined by the number of protective devices and the sophistication of the system you will have installed.
WHAT SHOULD A QUALIFIED COMPANY DO FOR ME?
A qualified company should perform a site inspection and discuss your individual security needs. Each person and premise is unique and the system should be tailored to fit your needs, lifestyle and price range. The company should provide you with an evaluation of your premise, highlighting the measures you can take to improve the security of your home over and above the addition of an electronic alarm system. They might suggest such simple measures as clearing brush around entranceways and installing proper locks. When comparing companies, be sure to make a true comparison by thoroughly reviewing the number and types of products to be installed. If there is a discrepancy, be sure you understand the impact it will have on the overall level of security you are purchasing.
Many thanks to The Canadian Alarm & Security Association (CANASA) and the Southern California Security Alarm Association, Inc. (SCSA) for the above information.