Page 204 - Alternative Energy Systems in Building Design
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180  ENERGY CONSERVATION


                     global warming will increase the national expenditure to such a degree that govern-
                     ments will be prevented from meeting society’s needs for transportation, irrigation,
                     heating, and many other energy-dependent services. On the other hand, environmen-
                     talists argue that protection of nature and the prevention of global warming warrant the
                     required expenditure to prevent inevitable climatic deterioration.
                       Advances in technology, the increased output efficiency of solar photovoltaic (PV)
                     modules, and the reduction in cost of PV modules that would result from mass pro-
                     duction will make solar power installation quite economical within the next decade.
                     National policies should take into consideration that technologies aimed at reducing
                     global warming indeed could be a major component of the gross national income and
                     that savings from decreased fossil-fuel consumption could be much less than the
                     expenditures for research and development of solar power and sustainable-energy
                     technologies.
                       In the recent past, some industry leaders, such as DuPont, IBM, Alcan, NorskeCanada,
                     and British Petroleum, have expended substantial capital toward the reduction of
                     carbon dioxide and greenhouse gas emissions, which has resulted in billions of
                     dollars of savings. For example, British Petroleum has reduced carbon dioxide emissions
                     by 10 percent in the past 10 years and, as a result, has cut $650 million over 10 years
                     of expenses. DuPont, by reducing 72 percent of its greenhouse gas emissions, has
                     increased its production by 30 percent, which resulted in $2 billion per year of savings.
                     The United States at present uses 47 percent fewer energy dollars than it did 30 years
                     ago, which results in $1 billion per day of savings.



                     Computerized Lighting Control


                     In general, conventional interior lighting control is accomplished by means of hard-wired
                     switches, dimmers, timers, lighting contactor relays, occupancy sensors, and photoelec-
                     tric eyes that provide the means to turn various light fixtures on and off or to reduce lumi-
                     nescence by dimming.  The degree of interior lighting control in most instances is
                     addressed by the state of California Title 24 energy regulations, which dictate specific
                     design measures required to meet energy-conservation strategies, including

                     ■ Interior room illumination switching
                     ■ Daylight illumination control or harvesting
                     ■ Duration of illumination control by means of a preset timing schedule
                     ■ Illumination level control specific to each space occupancy and task environment
                     ■ Lighting-zone system management
                     ■ Exterior lighting control

                     Figures 5.2 through 5.10 depict various wiring diagrams and lighting-control equip-
                     ment used to increase illumination energy-consumption efficiency.
                       In limited spaces such as small offices and commercial retail and industrial envi-
                                                                  2
                     ronments (where floor spaces do not exceed 10,000 ft ), lighting control is undertaken
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