Building systems for_interior designers phần 8 docx

itored through a visual display and audible alarms. They ensure that only one individual per valid card presented is granted access, preventing a second person from tail- gating through. An attempt to enter without presenting an authorized card sets off an alarm locally and alerts security personnel. Optical turnstiles can be finished to match the interior finishes of the lobby. Unattended barriers use magnetic, bar-coded, or proximity-reader cards. Electronic locks can be programmed for varying conditions and to prevent access to certain cards. Within buildings, they can limit access to copy and fax machines, phone lines, and other office facilities, preventing personal use. Newer technologies include biometric identification systems that compare physical characteristics such as eye patterns with a reference image. Biometric identification systems can also be used to scan crowds for facial pro- portions that match a database of criminal suspects. Securing the Building 313 High-speed telecommunications wiring, video cabling, and low-voltage wiring are becoming increasingly important technological upgrades in both new homes and remodeling projects. Prewiring a home in this way provides flexibility and offers the potential to turn any room into a home office, connect any TV to a cable or satellite hookup, or control both inside and outside lighting from one central location. Adding high-tech wiring for advanced communications, entertainment, and security systems can involve a number of major wiring systems. It is important to plan thoroughly before rewiring, mapping out where to put new televisions, home theaters, speakers, or computers. The interior designer should try to look ahead and plan for a possible office, a need for faster Internet connections, or more computers. It is valuable to try to predict what the client will want in five years so that the wiring will be available. You can reduce the number of walls that need to be re- moved or replastered in older homes by running wires through ceiling or floor moldings. The Internet requires fast speed and high bandwidth (information carrying capacity) to enable users to down- load photos, graphics, and music. In addition to the Internet, high-definition TV requires high bandwidth wiring to transmit crystal clear signals into a home, whether it has cable service or a satellite dish. Low-voltage wiring is used for whole-house lighting control, for control of heating and air-conditioning systems, and for integrating security systems into the other low-voltage systems in a home. Having all of these low-voltage systems create a unified network makes it possible to control the systems in a home whether a person is sitting in the living room or is miles away in a car sending commands over a cellular telephone. Prewired cables from the main entertainment center to other rooms in a home can direct both video and audio signals to outlets in every room. Home run wiring, where every wire or cable starts from one central distribution box inside a home and radiates out to each room, has several advantages. Each outlet or jack has its own wire or cable, independent of any other connection, so it’s easier to make changes in the future. It is simpler to diagnose problems with home run wiring, and when problems do occur, they’re isolated to that one wire or cable. Finally, home run wiring provides the best signal quality, and this is of critical importance for getting the best performance from the Internet and high- definition TV signals. Signal systems for private residences add to the value of the home. Sophisticated automated systems are available in the residential market that combine security, fire alarm, and time functions. A single panel can 38 Chapter Systems for Private Residences 314 control multiple residential systems, using an annunciator to display the location and type of the alarm. We discuss these residential systems in more detail shortly. RESIDENTIAL TELECOMMUNICATION AND DATA SYSTEMS The telephone company normally follows the route of the electrical service, either overhead or underground to the building’s service entrance. A separate service entrance must be provided for telecommunications wiring, either overhead through a sleeve in the wall, or underground with a separate entrance conduit. Unless the residence has many entering lines, no source of power is required for phone service. Wiring for telephone service inside the home can be done either by the telephone company or by the homeowner’s electrician. The huge increase in the number of private residences with multiple phone lines, dedicated fax lines, and special high-speed data transfer lines to home office outlets makes telephone system planning a neces- sity in a residential design. Unsightly surface-mounted cables will be visible if telecommunications wiring is left until after completion of construction of a residence. Prewiring cables on the wall framing and into empty device boxes to which instruments are connected later on can avoid objectionable visible cable. The designer must provide for multiple lines with adequate raceways. A local phone company technical representative can be very helpful. RESIDENTIAL INTERCOM SYSTEMS In large private residences, intercom systems allow occupants to monitor other parts of the house and communicate with one another. One or more master stations and several remote stations, including the front door, allow the intercom system to be answered from various points in the home. Visual identification at the entrance is achieved with the addition of closed-circuit TV. When left on, the intercom system can be used to monitor sounds in a baby’s room. Low-voltage, low- power wiring uses multiconductor color-coded intercom cable, which is run concealed in walls, attics, and basements. The system may also use the house power wiring to carry voice signals. This eliminates separate wiring and allows portable remote stations to plug into a power outlet. Voice/music intercoms allow you to answer the door from any intercom speaker as well as to communicate within the building. The system can include a bat- tery backup for up to 30 hours. Wireless radio remote control is also an option. Video door-answering systems give the security of screening callers by sight and sound. The system in- cludes a video monitor and door camera. OUTDOOR SECURITY LIGHTING Effective outdoor lighting is a major component of good security. The primary security function of exterior lighting is to deny would-be intruders the shroud of dark- ness and to scare them away. Additional functions are to ensure good visibility if occupants should have to exit in an emergency, and to illuminate the building number clearly to aid emergency response personnel. Good lighting is also a convenience and safety factor. For ex- ample, exterior lighting is helpful when you come home after dark with a trunk load of groceries, or late at night when no neighbors are likely to be awake if you should need help. All entrances to a home, garage, and outbuildings, as well as areas not clearly visible from the street or neighboring homes, should become well lighted as soon as anyone comes near. High-wattage floodlight lamps are best for illuminating areas directly below a fixture. Spotlight lamps are useful to reach an area from any height or distance. Specify exterior or weather-resistant lamps, to minimize the need to replace them. Ordinary entrance lights with 40- or 60-W lamps are usually mounted just above the door or alongside it. Locate security lighting fixtures high enough on walls or poles to be out of reach. Protect bulbs at any level against breakage with wire cages or tamper-resistant plastic housings. Because security lighting could be expensive to operate and bright enough to annoy neighbors, many homeowners prefer to have inexpensive low-voltage, low-intensity lighting for convenience and safety along sidewalks and steps. This is supplemented with bright security lighting in areas such as the back door and garage and the concealed sides of the house. The security lighting is controlled by sensors and comes on only when triggered by someone entering a protected zone. This will surprise and scare off most prowlers. Systems for Private Residences 315 The bright lights used for outdoor security lighting are usually powered by 120V household current. Codes require that exposed 120V wiring must run through metal conduit, which also protects wires from being cut. To ensure lighting even if household power is lost, you can specify lights powered by conventional batteries that must be replaced periodically, or by batteries that are recharged by the sun. Solar-charged batteries do not have to be replaced, but are not effective where sunlight is scarce in the win- ter or where they might become covered with snow. A hard-wired switch, a timer, a remote radio- frequency switch, or a sensor can activate outdoor lighting. The most widely used and effective sensors are a photoelectric cell, a passive infrared (PIR) sensor, and a microwave sensor. A photoelectric cell acts as a switch to turn on a light when the surroundings become dark. Timer controls respond to whatever schedule is set. For lighting that comes on only when someone enters a protected zone, choose an infrared (IR) or microwave sensor. As with photocells, you can specify fixtures with built-in sensors, or install separate sensors that connect to existing fixtures. Most include a photocell so that they will operate only after dark. A PIR for outdoor security lighting detects heat sources, such as people or car engines, within an un- obstructed field of coverage. A microwave sensor detects any movement within a field of high-frequency energy that it emits. Many units can be set to either flash on and off or to remain on continuously for a preselected length of time. You also can adjust the sensitivity so that a passing cat or swirling leaves will not turn on the light. The exterior units that are least prone to false triggering use a combination of PIR and microwave sensors. An exterior security fixture can power an alarm as well as lights, or exterior fixtures can be connected to a whole-house electronic security system to activate when triggered by sensors inside or outside the house. Some systems also let you operate the lights from a central control panel or by remote control. INTERIOR SECURITY LIGHTING The primary security function of interior lighting is to make a house look occupied when the occupants are away. That means having lights come on and go off in various parts of the house in what seems to be a normal pattern of use. Equipping a lighting fixture with a screw- in photocell socket into which the lightbulb is screwed will leave a light on all night, but for a more normal, varied pattern of light use, specify a timer control. A basic lighting timer uses a rotating dial with pegs that trip the switch on and off. A receptacle timer plugs directly into an outlet, and the device to be turned on and off plugs into the timer. A socket timer plugs or screws into an outlet or fixture and has a socket for a bulb. Some mechanical-switch timers can be set for only one on and one off time, while others permit two or more pairs of settings. Many operate at exactly the same set times every day, but better models have optional ran- dom operation that varies the times by up to 20 minutes a day for a more normal pattern. Almost all have an override switch so you can turn the light on or off independently without disturbing the timing. Electronic timers can be programmed for multiple settings. They have a control ring, pushbutton, or keypad for entering timing settings, which are recorded on a magnetic chip that controls switch relays. Some provide a digital display of the settings as they are made. One such device is a timer switch that mounts in a wall box, in place of a standard switch, for automatic control. A solid-state master unit that controls individual appliance modules throughout the house provides the most versatile and sophisticated timing. From a central location, it can operate lights or appliances plugged into the modules without the need for special wiring. The control unit is plugged into any electrical outlet. Lights or other appliances are plugged into individual modules, which in turn plug directly into existing outlets. Various control units can handle from four to ten or more modules. Settings for each module are entered on the keypad of the control unit. At the programmed times, the control unit transmits on/off signals either over the existing electrical wiring or by a radio frequency. Override switches on the modules permit manual operation of the lights when desired, and the control unit permits independent manual operation as well. INTRUSION ALARM SYSTEMS FOR RESIDENCES Magnetic switches are commonly used for door and window intrusion alarm systems. Motion and/or PIR detectors are also common. The installation of a manual switch at the end of a long cord allows the occupant to set off an alarm when an intruder is heard. Commercial security services will wire a home with sensors and alarms and monitor the system for a monthly fee. The residential system is linked to a central monitoring station by telephone or radio. In most systems, one or more alarms go off in the building and 316 SECURITY AND COMMUNICATIONS SYSTEMS a signal is flashed to the center if a sensor is tripped. If there is no answer, or if whoever answers cannot provide the code number that identifies the building, the center notifies the local police, who then investigate. An alternative to commercially monitored systems consists of individual units located wherever the building owner wants to protect against intrusion. Systems for small buildings can be either wireless or wired. In one kind of wireless system, the sensors are connected to transmitters that are plugged into convenience outlets and communicate with the control unit over the building’s electrical circuits. The system is wireless in the sense of not requiring any new, special-purpose wiring, but an outlet must be near each sensor location. In another kind of wireless system, the sensors are connected to transmitters that exchange signals with the control unit by short-range radio. These transmitters may use building power or batteries. In a hard-wired security system, the sensors are connected to the control unit by low-voltage wires. This is far less expensive than a wireless system, but it involves running wires throughout the building and connecting them. There is no complex electrical work to be done and the thin, low-voltage wires are easy to handle, but holes for running wires must be drilled and concealed. The control unit is the component that determines whether a security system is reliable and easy to use. The best units have extension keypads. The control unit is located in a safe, concealed place, often in a closet. The keypads are located by the front and back or side exits. They give the occupants time to arm and disarm the door sensors as they come and go. Window sensors respond immediately, however, since it is unlikely that it is one of the building residents coming in through the window. In addition to sensor/alarm controls, a controller may have timing circuits for turning lights or appliances on and off. When power is lost, the best controllers will switch to built-in batteries, and revert to building current to recharge the batteries when power is restored. They also will silence an alarm after several minutes and reset the sensors automatically if no one is in the building to deal with the situation. Some controllers also respond to signals from smoke detectors wired into the system. How the control unit communicates with the user is important. Some units present messages in words on a display panel, indicating the room name. Some controllers that send signals through the household wiring can be set or activated by telephone. A controller that is linked to the telephone will also accept commands from an outside telephone, or let the user check the status of the system while away from the building. With an auto- dialing unit, the system can even signal the user at another location or call the police or any other programmed number. INTELLIGENT RESIDENCES The security system described above can be one part of an intelligent residence. Intelligent residences are also referred to as smart houses or automated homes. They coordinate control of lighting, sound systems, home theaters, heating and cooling equipment, and security systems. Touch-screen computer controls (Fig. 38-1) or portable plug-in programmable microprocessors are used to set the system. The best and most expensive systems can be controlled by the user’s phone. At least one system is available with intuitive speech recognition that allows the homeowner to control the system by phone or a home computer. The system uses existing phone and power lines, and no rewiring is nec- essary. The user can talk to the computer from the home or anywhere else to manipulate lighting, thermostats, and other devices, or to retrieve information in real time. Groups of commands for specific lighting settings, security, home theater, and so forth can be preprogrammed in batches so that an entire home can be transformed with one verbal command. The system is designed to be easy to install, simple to use, and affordable. It is preferable that the components of an intelligent home system, such as the security system or lighting controls, are each wired to run independently of the central control system. If something goes wrong and the central controls fail, each system will continue to operate on its own. Systems for Private Residences 317 Figure 38-1 Touch-sensitive control panel. Communications and security systems for buildings are continually increasing in variety and complexity. Each type of occupancy has its own special challenges, and consequently its own types of security and communications equipment. It is important for the interior designer to discuss security and communications needs with the client. Individual suppliers often install these separate systems, and it is imperative to coordinate their installation with the general contractor. Otherwise, they are likely to be added on at the last minute, resulting in either exposed wiring or difficult snaking of wires through finished walls. Here is a rundown of some of the more common types. Many of these systems are ap- plicable to other building types as well. SYSTEMS FOR MULTIPLE RESIDENCES The problems of security in a residential setting are greatly magnified when many people share housing. Monitoring who is at the door becomes much more complex when the door serves hundreds of residents. Interior designers coordinate the appearance and location of lobby entry system panels and plan for the location of speakers or phones within each residential unit. Entry and Security Systems The simplest entry and security systems for multiple dwellings consist of a series of pushbuttons in the lobby with an intercom speaker or phone to connect with residents (Fig. 39-1). The tenant has a speaker microphone and a lobby door opener button. These systems can use the regular telephones of the residential units. Where there are a large number of units, an alphabetical roster with an apartment button panel is used to locate the tenant’s name. Even larger systems employ an alphabetical panel and a phone. With the addition of a closed-circuit TV, tenants can see and hear the caller. Some multiple residences use emergency call buttons within each apartment, in case an intruder gets past a lobby security check. In housing for elderly people, the emergency button unlocks the door so that help can reach the resident. Luxury apartments may have apartment doors monitored from a central security desk. The security personnel at the desk investigate any unscheduled door 39 Chapter Other Security and Communications Applications 318 movement. These systems are custom designed to the needs and requirements of the building owner. Television Systems for Multiple Residences All modern multiple residences supply each room with one or more TV/FM jack outlets. TV signals are trans- mitted from a rooftop satellite dish and the house VCR, or by cable TV with pay TV as an option. The systems are always subcontracted, so new buildings are con- structed with a system of empty conduits connected to cable pulling points in cabinets. The raceways are sized liberally to accommodate constant expansion in the electronic entertainment field. Surface mounted raceway with a removable cover is the most versatile solution, but is generally unsightly, so that many installations specify concealed raceway. Telephone Systems for Multiple Residences Service entrance space requirements for phone service in multiple dwelling buildings vary with the size of the building and the telephone capacity. A small apartment house three stories tall needs a clear wall space of between 122 and 180 cm (4–6 ft). A terminal (equipment) room is required only in large residential buildings. Where multiple telephone companies have the right to offer service to residents, there may be stiff competition for basement space. In rental apartment buildings and dormitories, the plans of all floors are similar, making it easy to run risers between floors. Cable is run in risers extending through vertically aligned closets in apartments. In a shaft other than a closet, conduit is used for easy installation, protection, and repair. HOTEL AND MOTEL SECURITY SYSTEMS Keys provide little more than a psychological barrier to unauthorized room access in a hotel. Electronic room locks allow the opening code to be changed with every guest in most modern hotels. They use coded pushbuttons, magnetically or punched-hole coded cards, or programmable electronic locks with coded keys. Guest rooms often have a television and possibly a VCR. Meeting rooms may be equipped with a TV, VCR, projectors, and computer terminals. Consultants spe- cializing in theft control have developed a number of methods to provide equipment security. One system type senses the disconnection of equipment from the power connection (wall outlet) and transmits an alarm over the power lines to an annunciator at a central location, notifying authorities immediately upon the re- moval of the equipment. Hotel and motel telecommunications and data systems are important and complex. Hotels for business guests provide computer terminals and modems in an increasing number of function and guest rooms. These constantly increasing needs require adequate raceways and cabling facilities. Business meetings and technical conferences in hotels entail very heavy electronic equipment use in conference and meeting rooms. This equipment must be installed and rearranged quickly. Access flooring and modular cabling help facilitate quick changes. SYSTEMS FOR SCHOOLS Intrusion alarms and security systems are now routinely part of normal school requirements. Sensors on doors and windows are arranged to trip local alarm devices and to notify police headquarters. Vandals may be frightened off by an alarm system that lights up exterior and interior building areas. Perimeter alarm detection systems are used for particularly vandal-prone areas to prevent after- hours entry. They are expensive to install, but very frequently cost-effective in preventing building damage. Other Security and Communications Applications 319 Figure 39-1 Apartment building intercom. Exit control alarms in schools lock doors from the outside but must be able to be opened from the inside in an emergency. When the door is opened, an audible, visible or remote alarm is triggered. Exit control alarms may have a timed bypass for keyed operation by authorized personnel that prevents the door from being held open without alarming. One type gives an immediate alarm, but takes 10 to 20 seconds of pressure before opening. This gives time for the staff to investigate who is using the door, but increases the time it takes for people to leave the area in an emergency. Clock and Program Systems Class-change signals are part of a master clock system. A programmable clock can control clock signals, audible bells, and other switching functions. Large-faced analog clocks are easiest to read in all ambient light situations. Digital clocks using light-emitting diodes (LEDs) must be viewed directly, not at an acute angle. Audible devices include bells, gongs, buzzers, horns or tones reproduced on classroom loudspeakers. Tones from classroom loudspeakers are preferred, as they are clearly audible in each classroom and adjustable to the noise level in the room. The loudspeaker’s sound will not be confused with fire alarm gongs or other emergency signals. The classroom loudspeaker has multiple uses and complete flexibility of programming so that special programs can be directed to selected groups of students. Intercom Systems In a small school, a simple wired intercom system con- nects various offices and outside phones in the admin- istration offices with the paging system integrated into the school sound system. In larger buildings, a private phone system can be connected with the school sound system. This provides an intercom between staff mem- bers and offices and direct communication with classrooms either selectively or all at once. Larger systems offer paging zones, group calls, and conference calls, and can be connected with outside phone systems. Combi- nation program/intercom controllers use direct pushbutton dialing and programming, eliminating switch- boards and operators. Sound Systems A sound-paging-radio system provides the means to distribute recordings via CDs or tapes, broadcast AM/FM, or live sound to preselected areas of the school. In a simple system, a CD player with a single microphone input and single channel is distributed to all the speakers in the school. More complex systems might use three simultaneous input signals distributed to six different areas of the school. Conventional systems use a control console with most of the input units, amplifiers, switching devices, and connections to remote loudspeakers. The inputs may be one or more AM/FM tuners, a VCR, a CD player, a tape deck, or microphones. Usually, one microphone will be located at the console, one in the principal’s office, and others in the auditorium, the school office, and so forth. Microphone outlets may be placed throughout the school so that a microphone and stand can be plugged into any outlet. Loudspeakers are located in classrooms, the gym- nasium, the auditorium, the cafeteria, and outdoors. Loudspeakers can be mounted flush or in surface baffles. Loudspeakers for large areas have volume controls, and can be specified with a locking cover. Small systems can be installed in a compact desk- top console. Larger systems require a console that is usually built into a desk arrangement. The interior designer should provide adequate space for the console and the person who operates it. Electronic Teaching Equipment The use of electronic media for teaching is growing and changing rapidly. A differentiation is generally made between passive mode and interactive mode educational computer use. Passive-mode usage makes all recorded material available to students via some form of information retrieval technology, including printing, audio, and video means. Passive-modes include both conventional and electronic library forms. In interactive modes, each student uses a computer- teaching terminal to study at his or her own pace. The computer acts as a one-on-one tutor. Modern teaching programs sense a student’s weak points and emphasize these areas in the program. By providing adequate electrical power, cable raceway, lighting, and heating, venti- lating, and air-conditioning (HVAC) provisions, the building designer can try to accommodate the rapid change in computer technology. 320 SECURITY AND COMMUNICATIONS SYSTEMS Interior designers are often called upon to help update the finishes or reorganize the layout of an existing office. Within short order, it becomes obvious that the critical factor in deciding whether to rearrange the cubicles is not the aesthetic or functional issues, but the diffi- culty of wiring the multitude of workstations and peripheral equipment. Even the decision as to whether to replace the carpet may depend on how hard it is to move the cubicles and all their wiring out of the way. Discus- sions of planning options turn into arcane conversa- tions about “UTP cables.” (If you don’t yet know, that’s “untwisted shielded pair cables,” and they’re explained below.) The location of the service closets can end up driving the space plan’s design. Here is an introduction to the world of office communications systems. Al- though new technology is always being developed, many existing facilities are making do with wiring technology from the past. Office building communications require large amounts of space in critical locations. Planning for communications must be done simultaneously with other space planning, although exact amounts of space needed are usually not known at the planning stage. Planning must take into account changes in space use and increases in communications and data transmission services that are likely in the future. Estimates for planning are based on usable office area. Fiber optic and other technical advances reduce the equipment size and space requirements. Systems are designed for current requirements with reasonable estimates for the future based on expert advice. Some types of offices, like bro- kerage houses, are especially heavy users of communications systems. The user can purchase or lease as much of the office communications system as desired, so the system may be all privately owned, owned completely by the telephone company, or some combination. Some instruments and switching equipment are used for both intercoms and outside connections. Typically, an office building has a service entrance room or equipment room where the incoming cable or network cable enters. The service entrance room contains terminated empty conduits for expansion and data cables and a network cable splice box. Connection (network interface) cabinets connect building equipment, including phones, modems, and faxes. The service entrance room should be dry, well ventilated, and well lighted for close work in wiring and color recognition. A minimum of two 20-A duplex convenience circuits on a separate circuit should be supplied. Larger equipment rooms need space for circulation and egress as well as emergency lighting and power. 40 Chapter Office Communications Systems 321 Riser spaces (shafts) and riser closets are stacked vertically to carry the main cables through the building’s floors. Sleeves that can be sealed and fireproofed are set in floors to connect vertically aligned closets. Commu- nications closets are preferably separated from electrical power closets. Cables from the riser system are connected to switching and power equipment in zone closets, also called apparatus closets. These closets need a switched ceiling light and a separate 20-A, 120V circuit with two duplex receptacles. A source of emergency power is a good idea, as it prevents phone service outages during power outages. Satellite closets are distributed on floors as required. Satellite closets don’t contain any switching or power equipment. They supply a cable-connecting and termi- nating facility in large, complex buildings where the riser closet space is not sufficient. Auxiliary equipment rooms are used for extensive cross-connection or when tenants have their own private switchboard (PBX) equipment. Auxiliary equipment rooms are relatively small alcoves or closets. They need a 20- to 30-A, 120/208V circuit, plus a 20-A, 120V outlet, and a grounding point. Adequate equipment space, good lighting, and ventilation are required. The room should have absorptive acoustic material on the ceiling and on at least one wall. Wiring is distributed horizontally between the closets and the end devices through conduit, boxes and cabinets, underfloor raceways, and over-ceiling systems. Distribution is often located in ceiling and plenum spaces and under carpets. Large volumes of wiring are required, and conduit is not often used. OPEN OFFICE CABLING The growth of computers and their peripheral equipment has resulted in increasing needs for connections within offices and with the rest of the world. Local area networks (LANs) are commonly found in offices to connect computers, fax modems, printers, and scanners. The proliferation of LANs has increased the need for more flexible, cost-effective cable systems with greater data capacity. Wireless technology is becoming more common, but cabling is still the primary way office computer equipment is connected. New cable types and better ways of transferring information provide more information more quickly than before. Standardized prein- stalled cable systems are widely used. The importance of handling and managing cables correctly is often over- looked, leading to serious and costly information system problems. These problems may become chronic and difficult to diagnose. In the past, office furniture systems have been an impediment to effective cable management. Recently, the office furniture industry has begun to address the critical need for handling greater volumes of complex, vulnerable cables. Standards for the design and installation of cable infrastructure in the United States recognize three types of communications cables. The most common is Cate- gory 5 unshielded twisted pair (UTP) cable. A second type is shielded twisted pair (STP) cable. The third type, optical fiber, is becoming more common as demand for ultra-high-speed information transfer rates increases and costs for fiber optics decrease. 322 SECURITY AND COMMUNICATIONS SYSTEMS When Yelena met with the prospective client to discuss the scope of work for the office renovation, the client emphasized that the project’s chief goal was to replace the patchwork of carpeting throughout the space and to repaint the walls. Other aspects included new artwork, and possibly some reorganization of the waiting area and conference rooms. Once Yelena got the job, she realized that replacing the carpet was much more com- plicated that she had anticipated. The space was organized with a perimeter of enclosed and semi-enclosed offices surrounding a large central open area full of cubicles. The high-tech client had linked just about every workstation with data and power cabling, which was run through the cubicle par- titions. To complicate matters, various types of cabling had been installed at various times, and connections had been spliced repeatedly. To remove and replace the carpeting, the cubicles would have to be disassembled and moved, along with their wiring. The office technical wizard wanted to rip the whole system out and install new, state-of-the-art wiring. He was concerned that the terminations wouldn’t accept another round of cutting and splicing. When the client started running some numbers, however, he realized that the budget for such a major rewiring job didn’t exist. Suddenly the prospect of new carpet was gone, and Yelena found her- self trying to spruce up the space with paint and artwork that accommodated the existing mismatched carpets. [...]... existing building materials, they could reduce the entire building classification This would reduce building safety and could affect building insurance and liability The goal of the code requirements is to protect the building from fire and to contain the fire long enough for people to evacuate the building safely Building codes set forth height and area limits in relation to the occupancy or use of the building. .. within systems furniture, the furniture must be permanently attached to the building surface by anchoring to a permanent wall or building column The preferred location is in the same panel as 325 the wall or ceiling feed, avoiding disruption if other adjacent panels are later moved Connecting the Building to the Systems Furniture The cabling from the telecommunications closet is connected to the systems. .. Selecting furniture systems with good ability to distribute cable horizontally and vertically can minimize the number of ceiling connections, allowing large clusters to be fed from a single pole Floor Entry Cabling can enter systems furniture from a floor monument fixed by the building architecture Buildings with cellular or similar floor feed systems tend to limit the entry points to a specific building grid... costs are going down as it becomes more common Wireless Systems Wireless systems allow mobile communications inside buildings As we discussed earlier, wireless systems currently have limitations that make them less adaptable than wired systems Products are coming on the market with built-in antennas that make wireless technology a part of the building finishes and reduce the need for communications... and firefighters have had a reasonable chance to save the building The building may survive to be salvaged rather than being demolished after the fire Protecting the structure maintains the value of the building It protects the occupants, firefighters, and neighboring buildings Tall buildings present a significant danger if all or part of the building falls The most important elements of the structure... surrounding Boston, Massachusetts A building is like a stove in that it contains the fire and encourages its growth The building concentrates heat and flammable combustion gases Vertical passages through the building that are open to the fire create strong convective drafts that fan the flames As the fire spreads up through the building, it finds new sources of fuel Buildings often hold dense concentrations... (UL) performs testing, approves building materials and assemblies, and publishes the results in the UL Building Materials Directory As you already know, the UL label is frequently found on electrical appliances Codes often relax prescriptions when an active fire suppression system is designed into the building Size limits may be exceeded in a sprinklered building, or when a building is divided by firewalls... Safety When we design a building to resist the start and spread of a fire, we not only protect the building itself and its contents but, more importantly, we protect the lives of the people who occupy the building To react safely to a fire emergency, you need early warning, the means to extinguish a small fire, and at least two ways out of the building Once a fire has started in a building, you may have... Other people in the building might be panicking, and you know you need to get to a door immediately Will the design of the building help you, or lead you into an inferno or dead end? OBJECTIVES FOR FIRE SAFETY In older buildings, the goal of fire safety design decisions was to keep the fire from spreading to other buildings With increased fire-resistant construction and control by building codes, fires... single building The addition of fire suppression systems has contained most fires to one or two floors of a building With technically advanced automatic detection and suppression systems, fires can be contained to a single room or even smaller area In the United States, most fires are now extinguished using five or fewer sprinkler heads, limiting damage from water as well as fire Fire protection systems . dish. Low-voltage wiring is used for whole-house lighting control, for control of heating and air-conditioning systems, and for integrating security systems into the other low-voltage systems in a home will continue to operate on its own. Systems for Private Residences 317 Figure 38- 1 Touch-sensitive control panel. Communications and security systems for buildings are continually increasing. can 38 Chapter Systems for Private Residences 314 control multiple residential systems, using an annunciator to display the location and type of the alarm. We discuss these residential systems

Định dạng
Số trang	47
Dung lượng	528,5 KB