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29 Costs/Payback/Savings: Survey respondents indicated a spaces including toilets, storage closets, stairwells, hallways, payback of 0 to 5 years for lighting timers. and other areas with limited use or unpredictable use patterns (Benya et al. 2003, pp. 819; DOI 2008). Occupancy sensors may extend the life of fluorescent lamps, thereby increasing Bi-Level Switching $ the re-lamping interval and providing extra savings (Benya et al. 2003, pp. 815). A method of lighting control that provides flexibility for use and occupancy within a space is bi-level switching. In One interviewee commented that initial settings for occu- most cases, wiring allows multiple lamps to be controlled pancy sensors at a major airport were to shut off after 15 min- within a single fixture to accommodate up to four distinct utes of inactivity during nighttime hours. This had little effect lighting levels (Benya et al. 2003). Typical applications for because of cleaning crews and security sweeps. Only when bi-level switching would be staff work areas or conference reset down to two minutes were the sensors able to function rooms. as intended. This strategy saw limited implementation by survey respon- Cost/Payback/Savings: Survey respondents indicated dents. It holds potential for greater control if intelligent lighting 0- to 5-year payback and low cost. Literature cited a range controls are implemented in the future. of savings that vary depending on the area size, type of lighting, and occupancy pattern; the most current literature Cost/Payback/Savings: Bi-level switching has been noted from the DOE notes claims of up to 75%; however, "the CA as low cost by respondents. Energy Commission estimates that typical savings range from 3545%" (DOI 2008). Mounting sensors to existing Multi-level Switching/Daylight Harvesting light switch boxes can be challenging in large areas or where with Photocells $ - extensive renovations have obscured sensor mounting to movement. A subset of lighting controls tied to daylight photocell sensors called multi-level switching was noted as an energy efficiency strategy by a number of airports surveyed. With multi-level Central Automated Lighting switching, lighting levels in areas such as gate-hold, ticketing, Control $ - $$ - and other areas with typically extensive windows are reduced by switching off lamps within fixtures, balancing artificial Another type of lighting control system involves central- light with daylight, and maintaining even lighting with all ized control of all lighting fixtures within the terminal. By fixtures on. This type of improvement requires more sophisti- using central control, areas of activity can be monitored cated controls and has greater applicability where BAS exists and tracked, and neglected or problem areas identified. (Benya et al. 2003, pp. 815). In addition, some central controls can track total hours that lamps have been in service, supplying operations staff One airport indicated that airline tenants expressed con- with useful information with which to schedule re-lamping cern about implementing a daylight controlled system, but sup- programs (Benya et al. 2003, pp. 815). One settings strat- ported the project once even light levels could be maintained egy noted by PECI was to program lighting controls to through multi-level switching. periodically turn off all lights within a certain area of the building during the overnight hours (PECI 1999c, p. 25). Costs/Payback/Savings: Among most survey respon- Lighting reduction during non-peak hours and utilization dents, a payback period of 0 to 5 years and low cost was of central lighting control was a common practice among indicated. survey respondents. WEBLINK--National Lighting Product Information Cost/Payback/Savings: Literature noted that less than 1-year Program (NLPIP)--Technical and application information payback can be expected through energy savings and reduced about sensors and other energy efficient technology: staff monitoring; however, some respondents noted payback of 5 to 10 years and low to medium cost. Occupancy Sensors $ - $$ - ELECTRICAL LOADS Occupancy sensors are a specific lighting control that detects In addition to lighting, visual displays and conveyance systems movement or sound to determine when a space is occupied are prominent consumers of energy within airport terminals. and shuts off fixtures after a specific period of time if no The addition of modern baggage management and security occupancy is detected. They can be utilized in a variety of screening systems continues to increase energy costs at many

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30 respondent terminals. Implementing controls that allow reduc- tions in energy consumption based on loads or temporary shut down during off hours can mitigate impacts of expanded systems. Visual Information Displays The communication of flight and baggage information at air- ports is done primarily by electronic displays. These displays are often in large composite assemblies in custom cabinets. At many airports surveyed, cathode ray tube (CRT) displays were once common but have largely been replaced by energy effi- cient liquid crystal displays (LCDs) or wide-screen plasma display technology. In addition to passenger displays, energy efficiency upgrades can also be made to staff computer displays and entertainment and advertising systems. FIGURE 11 Information display. Flight information display retrofit with LCD monitor. Display Shutdown $ Turning off information displays and staff computer monitors found longer payback of 11 to 13 years on replacement of when not in use can reduce energy use and has been identified CRT with LCD using 2005 costs (Ng 2005). LCD costs con- as a low to no-cost strategy for airports. tinue to drop; therefore, a shorter payback may be expected. Displays on staff and tenant workstations can be shut down or placed in sleep mode during off hours. Visual information Conveyance Systems: Controls for Baggage displays for baggage systems can be automatically or manually Conveyors, Escalators, and Moving Walks shut down between flights, depending on the level of automa- tion available. Manual shutdown is typical at most airports A number of practices that increase energy efficiency were surveyed. BAS can be utilized for flight information display noted by interviewees for conveyance systems, including the system and baggage displays. installation of high-flexibility, low-friction belts for baggage conveyors and shutting down service on escalators or moving walks when use patterns dictate. In addition, some airports Display Retrofit $ - have installed motor controls on moving walks that are load- sensitive, adjusting motors to meet demand. These controls Retrofit of CRT and other outdated visual displays used for reduce horsepower output and heat generated by the motor, flight information display system, baggage, parking, and adver- which can extend service life and save energy (CAP 2004). tising with energy efficient display technology has been done Another way to reduce time on for systems such as moving at a majority of surveyed airports. Respondents noted the retro- walks is to use motion sensors (CAP 2003a, p. 22). fit of CRT displays with flat-screen, LCD (see Figure 11), light emitting diode (LED), or plasma displays. Cost/Payback/Savings: Literature notes a savings of 30% to 40% yearly energy consumption for upgraded conveyor Benefits of flat screen displays include lower power con- belts and motor controls. Interviewees noted that quantifying sumption, lower weight, reduced heat, and better image con- energy savings when making an improvement can be difficult trast (EPA and DOE n.d.c). LCD displays have been found to when systems are replaced owing to the complex of modern use up to 50% less energy than CRT and generate less heat, baggage screening systems. thereby reducing cooling loads (EPA and DOE n.d.c.). There are also claims that improved flight information Chapter Summary displays can "lessen fuel consumption and costs associated with delayed flight departures" by facilitating more rapid gate The following practices were identified within the litera- information updates on screens that are easier to read, thereby ture and survey data as practices that reduce energy costs getting passengers to the gate and onto the aircraft faster and improve energy efficiency within small airport termi- (Ackerman 2009, p. 26). nal electrical and mechanical systems (see Table 2). Cost/Payback/Savings: Survey respondents reported a Seek out opportunities to replace carbon-based energy payback of 0 to 2 years and low cost. Literature sources sources with renewable energy sources.

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31 TABLE 2 ENERGY EFFICIENCY PRACTICES--ENERGY USE AND SYSTEMS Notes: 1. Payback--time indicated refers to years required for improvement to return cost savings equivalent to project costs. 2. Cost information is based on energy rates for 2009 at respondent airport locations. 3. Cost can be defined as total project cost and not cost per square foot. 4. Percentage--value given represents a yearly reduction in energy or operations costs for that system or process. Document and manage energy use with metering Utilize heat recovery and economizers to save energy systems. costs. Seek improved energy rate structure and reduce peak Reduce energy used by lighting systems by replacing load charges through communication with and pro- bulbs or fixtures and improving controllability with con- grams by utility providers. trols and sensors. Optimize existing heating and cooling systems with Reduce energy use by major equipment by retrofitting improved controls or retrofit with new, more efficient with more efficient systems and implementing load sens- systems. ing controls.