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Home Security and Surveillance Systems

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This chapter is from the book

This chapter is from the book

Chapter 3: 3.0—Home Security and Surveillance Systems

Terms you'll need to understand:

  • Remote access

  • Bypass mode

  • Quad

  • ANSI/TIA/EIA-570

  • Video switchers

  • Passive infrared sensor

  • Charge coupled device (CCD)

  • Zone layout

  • Hard-wired

  • RJ-31x

  • Glass break sensor

  • Camera resolution

  • Lux rating

  • CCTV

Techniques you'll need to master:

  • Connecting a quad switcher to a VCR and cameras

  • Planning the installation of a smoke detector

  • Identifying the location of a glass break detector

  • Planning a security system zone layout

  • Selecting locations for keypads

  • Evaluating a wireless and hard-wired security system

  • Selecting a proper password for a monitoring station

  • Comparing the light sensitivity levels of various brands of surveillance cameras

  • Identifying the components contained in a security control panel

A home security and surveillance system is an essential part of any modern automated home. The basic design of a security system begins with analyzing the needs of the inhabitants, surveying existing technology and hardware, reviewing system costs, considering monitoring choices, and finally planning the installation.

In addition to perimeter and interior protection offered by a security system, surveillance monitoring includes features that enable the inhabitants to observe environmental conditions inside and outside the home when at home or away.

In a home surveillance system, video cameras and display systems are considered by most contractors to be optional items. Subject to the homeowner's choice, surveillance equipment can function independently from the basic features included in home security monitoring.

This chapter provides the information you will need to know as a home integrator for designing, integrating, and installing a home security and surveillance system.

Design Considerations

The design of a security and surveillance system should provide for the protection of the entire perimeter of a home as well as visual- and audio-based surveillance monitoring. Security system sensors are available that are designed to detect sound, window and door intrusion, air movement, body heat, motion, and other conditions that indicate an intruder is present. A good security system design should consider the best plan for existing homes as well as new construction. It should also consider the lifestyle of all the inhabitants, the location of valuables or any items to be protected, how the system is to be controlled, adequate smoke and fire alerting sensors, and the type of emergency response required. The design choices are numerous and varied due to advances in home security technology and the wide availability of compact, low-cost video surveillance systems.

Wireless Security Systems

Wireless home security systems use battery-powered radio transmitters and receivers to connect the various components such as cameras, sensors, area motion detectors, sirens, central controllers, smoke/fire detectors, keypads, and video displays. These types of security systems are usually available at a local hardware store or on the Internet and are often designed for do-it-yourself installation. The basic advantages of wireless security systems are

  • Wireless systems are easy to install—They avoid the expensive and time-consuming task of installing new wires in the walls of existing homes.

  • Wireless systems enable you to take the components with you when moving to a new location.

  • Wireless sensors are designed to transmit a unique identification code to a controller—The controller learns the identity of each sensor and links it to an appropriate zone. Each sensor also transmits status information such as battery voltage, condition of the sensor switch, and other diagnostic messages.

  • Some homeowner-installed wireless security systems can be set up to record a voice message and to call programmed numbers in the event of an alarm—This saves the cost of a professional monitoring service.

  • Wireless sensors, motion detectors, and video cameras can often be installed in locations that are not accessible for wired equipment.

The basic disadvantages of wireless security systems are

  • Wireless system design specifications can limit the distance between sensors, cameras, and the central controller.

  • Wireless systems can be vulnerable to electromagnetic interference (EMI) in some locations.

  • They require periodic replacement of batteries.

  • Most professional builders recommend wireless systems as a last choice.

Hard-wired Security and Surveillance Systems

Hard-wired security and surveillance systems use wires installed inside the walls, attics, crawl spaces, and underground to connect the sensors to a central controller. Surveillance cameras or microphones are also wired to speakers, video switchers, and video display monitors. A hard-wired system design normally uses power from the home AC power wiring as the primary source. A rechargeable battery pack is used by the controller for backup during power outages. The main components of a hard-wired system are similar to a wireless system but without the radio receiver and transmitter components. They include a central control panel, sensors, one or more keypads, motion detectors, smoke and fire sensors, cameras, camera switchers, video displays, and sirens. The advantages for a hard-wired security system are

  • Hard-wired security systems are considered by most contractors to be more reliable than wireless systems.

  • Hard-wired systems are usually installed by a professional security system contractor with warranties and maintenance support.

  • Hard-wired systems avoid the problem of EMI and radio range limitations inherent in some wireless security systems.

  • The hard-wired components are usually less visible and more aesthetically pleasing than wireless components.

  • Hard-wired systems do not depend on batteries except for power failure backup protection.

The disadvantages of a hard-wired security system are

  • Hard-wired systems are more expensive than wireless systems.

  • Hard-wired systems are usually leased from the company that installs the system. Unlike a wireless system, the hard-wired system remains an integral part of the home. The components are not capable of being moved to another home when the owner relocates.

  • Problems can arise in the installation of sensors in existing homes where some areas are not accessible for pulling wires inside the walls.

Remote Access Systems

A remote access system provides the capability to monitor and control a home security system from a location away from the home. A telephone call to the home followed by a key number code allows the caller to obtain status information concerning environmental and alarm system condition. Remote systems can also be programmed to call a specific phone number when certain environmental conditions exceed an established threshold. A special synthesized voice response system provides the caller with an audible report. The caller, with proper coded inputs, can also perform all the same control functions from a distant location that are available on the keypad in the home.

Features of remote access systems vary among vendors, but most systems have features similar to those listed here:

  • Monitoring and reporting temperature inside and outside the home

  • Reporting on any sensors that have exceeded preset thresholds

  • Reporting on the date and time of any alarm conditions that existed

  • Monitoring loud noises that exceed a set time interval using a built-in microphone in the home security system

  • Reporting the status of smoke alarms or heat sensors

Fire Detection Systems

Fire detection sensors are available in two categories called heat detectors and smoke detectors. They operate on a principle of detecting heat rise or smoke in the home and can be either hard-wired with voltage supplied by the AC power wiring or battery operated. Most fire detectors currently available are powered by 9-volt DC transistor radio batteries, 120-volt AC power wiring, or 120-volt AC power with battery backup. Wired-in smoke detectors connected to a fire or security system are usually powered by DC from the security panel. This gives the detectors a natural battery backup in the event of a power failure. Common voltages are 6v, 12v, and 24v DC with 12v DC being the most common.

Some 120v AC units have the capability to interconnect so that when one unit activates, it causes the audible alarm in the other units to sound. Units can also be purchased that have a relay output for connection to any security system control panel or wireless transmitter. The most common types available in hardware stores operate as independent sensors that are battery powered, are not connected to the security system, and have their own audible alarm sounder. Heat sensors operate using a different technology from smoke detectors. The basic design features of each type are summarized in the following paragraph.

Heat Sensors and Smoke Detectors

Heat sensors are designed to detect a rapid rise in temperature. They also have a feature that sets off an alarm when a fixed temperature is reached. Smoke detectors do not react to heat but use one of two common sensor designs to detect smoke. An ionization type of detector forms an electrical path inside a small chamber with a very small amount of radioactive material. When smoke enters the chamber, the particles attach themselves to the ions and change the electrical current flow. A photoelectric type of detector works by using a photoelectric cell and a light source. The light does not usually reach the photoelectric cell, but when smoke is present the light is dispersed and reaches the photoelectric cell, triggering the alarm. The main difference between the two types is photoelectric types are more sensitive to large particles and ionization types are more sensitive to small particles. Modern home design should include at least one of each type. Smoke and heat detectors should be located in each sleeping area and on each story of the home and placed on the ceiling or on the wall 6''–12'' from the ceiling.

CAUTION

Remember that heat and smoke detectors operate on different types of technology. Heat detectors react to abrupt changes and go into an alarm condition when a temperature changes rapidly or reaches a fixed value. Smoke alarms do not react to heat but go into an alarm condition when smoke enters the sensor area. The two main types of smoke detectors are ionization and photoelectric.

Environmental Monitoring

Environmental monitoring can be incorporated into the design of a home security and surveillance system to monitor the status of specific conditions. This might be applicable to rural homes, vineyard owners, farmers, fruit growers, and ranchers. Environment monitoring includes the tracking and measurement of external as well as internal parameters. The following are examples of the types of environmental data that can be monitored with existing sensor systems:

  • Inside and outside temperatures

  • Barometric pressure

  • Frost alarm

  • Minimum and maximum temperature memory

  • Temperature trend indicator

  • Humidity

Emergency Response Systems

An emergency response system is a valuable optional enhancement to a home security system. A large number of designs are available from which to choose, depending on the personal needs of members of the household.

A personal emergency response system is usually designed for elderly or disabled individuals living alone who need to contact a doctor or relatives in an emergency with a minimal number of actions. Systems are available incorporating some or all of the following physical and functional features:

  • Emergency response requests—These are initiated by the user using a miniature wireless radio transmitter with a built-in help button carried or worn as a pendant by the user. Transmitters are lightweight, battery-powered devices activated by pressing one or two buttons.

  • A receiver console connected to the telephone—This receives radio signals from the user's transmitter and dials an emergency response center number.

  • An emergency response center—This is similar to an alarm monitoring service except the personnel in an emergency response center are experienced medical response personnel.

Temperature Sensors

Temperature sensors are used as one component of an environmental monitoring and security system mentioned earlier. They are normally used to monitor high and low temperature values in vacation homes, water pipes, furnace and heating vents, outside farm buildings, computer equipment, utility rooms, or areas that might sustain damage with extreme temperature swings.

Temperature sensors are often integrated with a central controller that includes a display, a keypad, and an automatic telephone dialer that can alert the homeowner or monitoring center when temperature limits are exceeded. Temperature sensors use a variety of electronic designs and components to measure temperature, including both analog and digital signal outputs that change value with a change in temperature and operate remote switches or active alarms.

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