Designing a HomeSecurity System

In this chapter, you will learn about

• Design issues for a home security system
• Planning the structured wiring for a home security system
• Lighting interfaced to the security system

The basic idea behind the inclusion of a home security system is to protect the home’s occupants and their belongings. The design of a home security system must secure any possible point of entry into a home, detect any breach in that security, and notify and alarm the home’s occupants and any desired outsiders such as monitoring services or family and friends should there be a breach of security. When the security system interfaces with a home control system it adds safety and gives the homeowners and occupants peace of mind.

The residential security system technology must fit the requirements of the homeowners, as well as their budget. This chapter focuses on the issues you need to considered when designing a home security system and using security lighting systems, and a look at some options that can make the system more effective.

Design Considerations for a Home Security System

The first consideration when designing a home security system is whether the home is a new construction or an existing house. The options in a new construction situation are numerous since you have more flexibility in planning and installing a structured wiring environment. In an existing home, the choices are more challenging and may be more limited.

Deciding What Should Be Secured

In many cases, homeowners aren’t sure exactly what they wish to have included in a home security system; they just want their home secured and to feel safe. Considering that most customers also have a limited budget for this type of project, it is important to identify the minimum protections they should consider installing as well as options to further enhance the system.

Based on the recommendations of the security services industry and several police and fire department checklists, the questions listed in Table 32-1 should provide the information you need to determine the must-haves and the could-haves of a home security system.

Interview the homeowners to identify how much interior and exterior detection and protection they desire. Review the floor plans and be sure to discuss the following items:

• Doors—all entry doors as well as and doors to separate areas of the house.
• Windows and/or screens to be protected.
• Interior motion sensor locations.
• Fire protection. Has an electrician installed it? Is it interfaced to security system? Be sure to follow local codes.
• Environment considerations—wine cellar, pool, spa, basement, low temperature areas.
• Keypads at main entry points, plus the master bedroom.
• Exterior motion detection and actions.
• Desire to interface with home control of lighting and Heating, Ventilating, Air Conditioning (HVAC).

In addition, be sure to discuss how many security access codes the homeowners would like and if they want to be able to secure a portion of the house while using the rest of it (this is called partitioning in security jargon). The results of this interview will help determine the security panel and components you will use.

Security System Technologies

In new construction situations, wired security systems are the first choice. They are easy to install during the pre-wire stage and are cost-effective over wireless technology components. However, wireless systems can be easily retrofitted into an existing home, though wiring is an option if the attic, crawlspace and basement allow for retrofit wiring.

Other technologies, such as infrared (IR), ultrasonic, electromagnetic induction, and digital signal processors (DSP) are used in the sensors and detectors that can be incorporated into the system. However, the most important consideration when designing a security system is the technology that is to be used to interconnect the components of the system, wired or wireless.

Security Zones

An important element in the design of a security system is the planning of the security zones and how the security system’s components are to be placed in each zone. A security system zone includes the adjacent areas of a home that will be reported together when an alarm occurs. Each zone in a home can have a different number of doors and windows, and can include different contents of the room or rooms. A security zone may be a single room, multiple rooms, open areas, or the exterior of the home.

The zoning of a home should be based on the floor plan or layout of the home, the requirements of the homeowners, and the capabilities of the selected security system. For example, the zoning plan illustrated in Figure 32-1 creates five zones, each of which has different needs and requirements. Table 32-2 lists these five zones and their security needs.

Figure 32-1: An example of a zone layout plan

Beyond the planning shown in Figure 32-1 and Table 32-2, additional information must be included, such as:

• Most fire safety laws and building codes require smoke detectors in all sleeping areas, hallways, kitchens, and on each level of a home.
• Four of the bedroom windows are located on the street side of the home.
• The two doors leading to the patio and the family room door leading to the porch are glass sliding doors.

Security Component Planning

The owners of the home illustrated in Figure 32-1 have expressed a desire for the security system, when it’s enabled, to detect doors and windows being opened, glass breaking on street-side windows and sliding doors, a person entering through the main doorway or the home office, and a vehicle on the driveway. In addition, they are considering installing security cameras on the exterior of the home and security lighting on the front and street sides of the home. Table 32-3 summarizes the components required to provide this level of security by zone.

Defining the zones and sensors to be included helps you outline the specifications for selecting the security control panel. Most panels come with a standard number of zones, such as eight, and the panel can be expanded to add more zones. When designing which devices will be on what zones it is important to look at each of the device’s power requirements and the maximum power that can be supplied by the security panel. It may be necessary to add additional power sources to feed all of the powered devices. Consult the manufacturer’s documentation for details.

If the security system design includes either interior or exterior surveillance cameras or motion detectors, consider their placement carefully to ensure they can “see” the areas they are intended to view.

Security Systems and Structured Wiring

The next step in the design of the security system is to plan the cable requirements for the system. If the plan is to install home run wiring to each of the security system components, the structured wiring plan must be adapted to include these cable runs.

Security System Wiring

In a structured wiring environment, wiring is terminated at the security system’s master unit, or panel, from each sensor, keypad, contact, smoke or heat detector, or alarm sounding device. The wiring, like all structured wiring, is installed in a star topology with a home run between the security system control panel and each device.

Be sure to include the security wiring on the structured wiring chart or make a separate chart for it.

Hard-Wired Systems

The wiring installed to connect each component to the security system control unit should be home runs between the security panel and each of the security devices. Looping, that is installing several devices, such as window or screen contacts, on a single loop of wire in series, should be minimized, if possible. Any security device that will be used to trigger the action of another home system device, such as a door contact or motion detector signaling a room’s lights be powered on, must be wired separately and individually.

Table 32-4 lists the more commonly used security system components and the wire type recommended for each device.

Wireless Systems

Wireless security systems communicate with RF signaling that is typically in the range of 300 to 900 megahertz (MHz). In many situations, a combination of wireless and wired devices may prove to be a more reliable design, depending on the distance from the wireless device to the base unit (range) or the necessity to install wireless devices to eliminate the need to pull wiring into the walls of a home. Be sure to read and follow the specifications of the manufacturer’s products when installing wireless devices to ensure good performance. Also be sure to note battery replacement is recommended annually.

RJ-31X Connections

If the security system is to include a telephone link for calling out, such as to the homeowners cell phone or a security monitoring service ,when an alarm condition occurs, the design should consider whether a single phone line connection or multiple line connections are best for the home.

In the event of a security event (break-in, fire, and so on), the system can call out on a standard phone line; or by using an RJ-31x phone jack, it has the capability to seize the telephone line and hang up any phone call in progress, preventing any disruption from interfering with the automated telephone alert process.

Lighting Interfaced to the Security System

Security lighting has been proven to prevent intrusions, to deter malicious activity, and to enhance the aesthetics of a home. By interfacing with a home control system the lights can be programmed to go on when an alarm sounds, blink when a fire alarm sounds, and even turn on and off while the homeowners are away to make the house look occupied. All of this can be linked to the time of day so it only occurs when it is dark. Many security systems today have some form of lighting control built into them for just these reasons, and act as the home control system.

The design goal for a security lighting system should be to light the areas of a home’s exterior, especially those close to the home, that would, without lighting, be shadowed or dark. Motion detectors can be used to turn on lighting around the home should movement be detected. These same outdoor motion sensors can also be set up to sound a simple chime inside the home to alert the occupants that someone is outside.

When designing lighting control for security purposes, consider the following:

• Accent lightingdownlights, coach lights, landscape lighting
• Security lightingflood lights
• Interior lightingkitchen lights, living room lights, bedroom lights for a “lived-in” look

Make a list of the lighting loads to be controlled, and be sure to communicate with the electrician that these loads will be controlled by the security/home control system, so no timers or daylight sensors are needed.

The best way to provide good lighting and vision in exterior areas is to install medium intensity, nonglare lighting fixtures that are aimed downward or shielded. For exterior lighting, three types of lamps can be used:

• HalogenHalogen lamps are commonly used as floodlights or landscaping lights because they provide a bright white or near-white light. Halogen lamps can be used to brightly light an area in connection with a motion detector sensing movement in its monitoring area.
• High-Intensity Discharge (HID)HID lamps include mercury vapor, metal halide, high-pressure sodium, and fluorescent lamps. With the exception of fluorescent lamps, HID lamps require a warm-up period before reaching their full brightness. For this reason, HID lamps should not be used in situations where the security system requires instant-on lighting. HID lamps are better used as general lighting to constantly light an area, such as landscape or accent lighting.
• IncandescentHigh wattage incandescent lamps can be used in just about any security lighting situation. However, because of their relatively limited life, they can be prone to burn out and defeat the purpose of the security lighting system if they are not properly maintained with a regular group replacement scheme.

If security lighting is being included in the security system design solely to provide lighting for exterior surveillance cameras, consider using cameras that include IR lighting capabilities that allow the camera to virtually see in the dark.

Review

An important element in the design of a security system is planning the security zones and how the security system’s components are to be placed in each zone. A security zone may be a single room, multiple rooms, open areas, or the exterior of the home. The zoning of a home should be based on the floorplan or layout of the home and the requirements of the homeowners.

The design of the security system should include a plan for the system’s cable requirements. Structured wiring is installed in a star topology with a home run from the security system master unit to each device. Wireless security systems communicate with RF signaling. A combination of wireless and wired devices may prove to be more reliable.

If the security system is to include an RJ-31x jack to provide the system with a telephone link, the system will have the capability to seize a telephone line to place an automated telephone alert.

Security lighting has been proven to prevent intrusions, to deter malicious activity, and to enhance the aesthetics of a home. The design goal should be to light areas along a home’s exterior that are in the shadows or dark. Motion detectors can be used to turn on lighting around the home should movement be detected. In addition, lighting should be identified and controlled to give the home the “lived-in” look.

Questions

1. Which of the following questions may not be asked during a design interview with a homeowner?
   1. Do all exterior doors have deadbolt locks?
   2. What are the homeowners’ occupations?
   3. Do all the windows have locks?
   4. Are the smoke or carbon monoxide detectors hard-wired or battery powered?

2. Which type of wiring provides the best solution for a security system being installed as a part of a new home construction project?
   1. PLC
   2. Wireless
   3. Structured wiring
   4. Daisy-chain

3. What is the primary characteristic of a security zone?
   1. It contains only one type of security system device.
   2. It includes adjacent areas that have the same security requirements.
   3. It is easily reached with home run wiring.
   4. It is frequently occupied or used.

4. Fire safety and building codes require smoke detectors be placed in which areas of a home?
   1. Near or in bedrooms
   2. Hallways
   3. Stairways
   4. Kitchens
   5. All of the above

5. The design of a security system can impact which other home automation designs or plans?
   1. Lighting
   2. Structured wiring
   3. Telephone
   4. Data network
   5. All of the above

6. Which type of security system sensors or contacts can be wired in series on a loop?
   1. Door contacts
   2. Window or screen contacts
   3. Cameras
   4. Motion sensors

7. In general, what is the recommended cabling for window and door contacts and sensors in a home security system?
   1. 14 AWG 1-conductor copper wire
   2. 22 AWG 2-conductor copper wire
   3. Cat 5e
   4. RG6

8. What type of connection is used to link a security system to the telephone interface to allow for line seizure?
   1. BNC
   2. RJ-11
   3. RJ-31X
   4. RJ-45

9. Which of the following lamp types is/are commonly used for brightly illuminating the exterior area in a security lighting system?
   1. Halogen
   2. HID
   3. Incandescent
   4. IR
   5. All of the above

10. Which of the following lighting system characteristics should be included in the design of a security lighting system?
    1. Medium intensity
    2. Non-glare
    3. Downward
    4. Shielded
    5. All of the above
    6. None of the above

Answers

1. B. Although this information could be important in a small way to the design, it really has no bearing on the need to secure the home. If this were important to the design, the homeowner would certainly volunteer it. The other choices are questions you should likely ask.
2. C. Daisy chaining is a no-no, PLC and wireless can be incorporated into a security system, and structured wiring is typically the best way to go.
3. B. This answer just about says it all.
4. E. Be sure you verify these requirements with the local fire department or building code authority.
5. E. In a home technology integration environment, any system design can impact any or all other system designs.
6. B. Window or screen sensors can be wired in a series-connected loop. All other security system devices should be wired in parallel with individual home runs.
7. B. These devices require only two-conductor wire.
8. C. This is a special-purpose connector that provides an interface between the security system and the telephone system.
9. A, B, and C. IR lighting is used to allow security cameras to see in the dark, but it won’t work to light up the exterior area of a home.
10. E. These are the lamp and fixture characteristics that provide the best exterior lighting.