v  (1  3)  0.208 in 2.4
103
8 The rigidity of a single pier is 1/0.208  4.81, and of the three piers, 3
4.81  14.43. Therefore, the deflection of the three piers when coupled is 1  0.069 in The deflection of the whole wall, with openings, then is approximately   0.138  0.033  0.069  0.174 in And its rigidity is 1 5.12.6 Effects of Shear-Wall Arrangements To increase the stiffness of shear walls and thus their resistance to bending, intersecting walls or flanges may be used. Often in the design of buildings, A-, T-, FIGURE 5.88 Effective flange width of shear walls may be less than the actual width: (a) limits for flanges of I and T shapes; (b) limits for C and L shapes. U-, L-, and I-shaped walls in plan develop as natural parts of the design. Shear walls with these shapes have better flexural resistance than a single, straight wall. In calculation of flexural stresses in masonry shear walls for symmetrical T or I sections, the effective flange width may not exceed one-sixth the total wall height above the level being analyzed. For unsymmetrical L or C sections, the width considered effective may not exceed one-sixteenth the total wall height above the level being analyzed. In either case, the overhang for any section may not exceed six times the flange thickness

Furthermore, certain spaces within a project may have a maximum-occupancy limitation for which a notice is posted in those spaces by the applicable building authority. Examples of this type of usage include restaurants, ballrooms, convention centers, and indoor sports facilities where a large number of occupants might be gathered for the intended use. In response to the national need for energy conservation and in recognition of the high consumption of energy in buildings, the U.S. Department of Energy gave a grant to the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) for development of a national energy conservation standard for new buildings. The resulting standard, ASHRAE 90-75, establishes thermal design requirements for exterior walls and roofs. It is incorporated in some building codes. Seeking greater energy-use reduction, Congress passed the Energy Conservation Standards for New Buildings Act of 1976, mandating development of energy performance standards for new buildings (BEPS). Accordingly, the Department of Energy develops such standards, for adoption by federal agencies and state and local building codes. BEPS consists of three fundamental elements: 1. Energy budget levels for different classifications of buildings in different climates, expressed as rate of energy consumption, Btu/ ft2-yr. 2. A method for applying these energy budget levels to a specific building design to obtain a specific annual rate of energy consumption, or design energy budget, for the proposed building. 3. A method for calculating the estimated annual rate of energy consumption, or design energy consumption, of the proposed building. The design energy consumption may not exceed the design energy budget of a new building. Even without these regulations, energy conservation for buildings makes good sense, for a reduction in energy usage also reduces building operating costs. It is worthwhile, therefore, to spend more on a building initially to save energy over its service life, at least to the point where the amortized annual value of the increased investment equals the annual savings in energy costs. As a consequence, life-cycle cost, considered the sum of initial, operating, and maintenance costs, may be given preference over initial cost in establishment of a cost budget for a proposed building. Energy use and conservation are key elements in an architects approach to design. Aided by computer simulation, engineers can develop system concepts and evaluate system performance, deriving optimal operation schedules and procedures. During the initial design phase, the computer can be used in feasibility studies involving energy programs, preliminary load calculations for the selection of heating, ventilating, and air-conditioning (HVAC) systems and equipment, technical and economic evaluation of conservation alternatives. Using solar heating and cooling systems for new and existing facilities, modeling energy consumption levels, forecasting probable operating costs, and developing energy recovery systems can be investigated during the early design of a project. Architects have long been leaders in building design that is sensitive to environmental issues. Several areas of general concern for all buildings are described in the following paragraphs; they support the basic philosophy that the environment within buildings is as critical a concern as esthetics. Indoor Air Quality. Many factors, such as temperature, air velocity, fresh-air ventilation rates, relative humidity, and noise, affect indoor air quality. The fresh-air ventilation rate has the greatest influence on indoor air quality in many buildings. Fresh-air ventilation rates in a building is the flow of outside air brought into the building for the well-being of the occupants and the dilution of odors and other internally generated air pollutants. The outside air may vary in its freshness depending on the location of the building, its surrounding conditions, and the location of the fresh-air intakes for the building. Therefore, careful studies should be made by the architect to ensure the optimum internal air quality. Ventilation is required to combat not only occupant-generated odors, as has been traditionally the case, but also to provide ventilation for materials used and stored in buildings. ASHRAE Standard 62-1989, American Society of Heating, Refrigeration, and Air-Conditioning Engineers, recommends a rate of 20 cfm per person as a minimum ventilation rate for office buildings. Air-handling systems for numerous buildings provide not only this minimum recommended level but also often increased fan capacity (available when outdoor temperatures and humidity levels are favorable) through an air-side economizer control. Environmental Pollution. In response to current concern for the effect of chlorofluorocarbons (CFCs, fully halogenated refrigerants) on the earths ozone layer, the refrigerant for mechanical systems should have the lowest ozone depletion potential compatible with commercial building cooling systems. Noise Control. The acoustical environment within a building is a result of the noise entering the space from outdoors, or from adjacent interior areas, or most importantly, from the mechanical, electrical, and elevator systems of the building. This is in addition to the noise generated within the space by people and equipment. Mechanical systems should be designed to limit equipment noise and to maintain the transmission of noise via mechanical systems to occupied spaces within a range necessary for efficient and enjoyable use of the building. Occupied space noise should normally be limited to NC-35 or less if desired, through the use of stateof- the-art-distribution equipment and appropriate use of materials within the finished

FIGURE 18.20 Lucent 1100 CAT 5 power sum, modular patch panel. (Copyright
1999, Lucent Technologies, used by permission.) The following is an outline of the items needed to budget a communications facility and also serves as a list of items to consider during planning. 1. Outside plant infrastructures: a. Ductbanks: PVC encased in concrete is suggested. Include excavation, bed preparation, back fill, compaction, seeding, patching sidewalks and drives. Include innerduct in all fiberoptic ducts. b. Manholes and handholes: Include excavation, bed preparation, backfill, compaction, seeding, patching sidewalks and drives. Include ground rods for copper cables and metal strength members where required. c. Pole work. d. Right of way costs. FIGURE 18.21 Lucent modular flush-mount faceplates. (Copyright
1999, Lucent Technologies, used by permission.) FIGURE 18.22 Lucent plenum CAT 5 GigaSPEED cable. (Copyright
1999, Lucent Technologies, used by permission.) 2. Main communications room infrastructure: a. Square foot cost of base-rated room, fire-rated construction. b. Heating and air conditioning: Include humidification where needed. Include controls and monitoring. Anywhere from 2 to 5 tons of cooling is typical. c. Electric panel: 200-amp main breaker, 120/208 V, three-phase, four-wire, 42-pole is typical. Note that some installations require 240 V, in which case, a 120/240 V, single-phase panel is required. It may be necessary to provide two panels. Include transformers, shielded type, where required. d. Backup power. Some design will be required here. Any or none of the following may be required: generator, large floor-mounted UPS, rack-mounted UPSs, batteries for UPSs. Include systems monitoring. e. Lighting: fluorescent fixtures with 100% solid-state ballasts. f. Grounding: master ground bar with stand-off isolators; dedicated ground rod, bonding to steel, bonding to electrical service; grounding of cable tray, racks, and power backup system; grounding of PETs. FIGURE 18.23 Lucent MGS2000 GigaSPEED modular information outlets. (Copyright
1999, Lucent Technologies, used by permission.)