ASHRAE Journal - January 2009 - (Page 22) Existing Condition Hours/Day (Average) Average Light Level (Footcandles) Number of Bulbs Per Fixture Number of Existing Fixtures De-Lamp Number of Fixtures to Remove Number Bulbs/ Fixture to Remove Replace Bulbs or Fixtures Number of Fixtures to Modify New Number of Bulbs/Fixture Number of Timers New Ballasts? Replacement Bulb Model Recommended Controls Number of Photosensors Number of Motion Sensors Number of Bi-Level Fixtures Number of Fixtures Controlled Bulb Model 106 Hallway 133 Boiler Room 134 Transformer Room 204 Office 205 Office 206 Office 207 Hallway 211 Office EXITINC20 F32T8 F40T12 F32T8 F32T8 F32T8 EXIT INC20 F32T8 1 4 2 4 4 3 1 2 1 2 4 1 1 8 8 2 2 4 1 3 2 6 4 3 24 8 8 7 7 7 24 7 8 8 8 8 0 18 25 55 65 115 0 55 58 58 58 58 2 EXITLED2 1 1 1 2 1 1 1 1 8 8 2 2 4 3 3 3 3 3 5.6 1.7 1.7 2.2 2.2 3.3 5.6 1 1 1 1 3 2 6 4 3 3 3 3 1.6 3.2 3.8 5.1 22.2 F32T8 8 2 X 1 EXITLED2 1 1 213 Main Lobby FLOOD65 213 Main Lobby 213 Main Lobby F32T8 F32T8 213 Main Lobby FLOOD65 Table 1: Existing conditions and recommendations (from an actual commercial ofἀce energy audit). and dense-pack cellulose, have largely been developed in the residential field, but are not yet common in commercial building retrofits. In addition to these technologies, advances in modeling have made common the use of hourly energy models and interactive calculations among energy improvements. Technician accreditation is widespread, as are energy auditor training programs. There is broad dissemination of best practices and extensive ongoing applied energy conservation research. A national energy audit standard has recently been adopted.6 Evaluating “the building as a whole” has become a mantra in the residential energy field, but is not at all common in commercial buildings. Comprehensiveness has been almost universally recognized and adopted in residential energy audits. Anything short of comprehensiveness is often frowned upon. How is the room-by-room aspect of a comprehensive audit conducted in commercial office buildings? At a minimum, light levels and lighting inventories should be taken on a room-byroom basis, along with occupancy levels and schedules for occupancy and lighting use. Room-specific HVAC issues, such as distribution problems or mistaken temperature control setpoints, also can be noted. In addition, information on plug loads, such as computers and office kitchen appliances, can also be inventoried on a room-specific basis. Field data sheets should be structured to allow energy auditors, as they are standing in each room, to check off exactly what improvements will be evaluated for each 22 ASHRAE Journal particular room. Although measurements in all spaces might appear to be time-consuming, they can be completed quickly, even in large buildings, if data input is well-organized. There are time-savings during analysis, because much of the analysis can be automated. Room-specific data collection allows more accurate calculations to be performed, and, more significantly, the recommendations can be made in a fashion that guides implementation. Rather than providing general recommendations that are difficult to implement (“Replace all lighting, delamp to meet IES standards, and install photosensors on fixtures close to windows.”), room-specific recommendations allow a work scope to be given by the owner to maintenance staff or to a contractor. Tables are provided such as the ones in the previous example, which give sufficient information that might translate as: “Office 201: Replace two four-lamp fixtures with two twolamp T8 fixtures with high-efficiency electronic ballasts, and add a second light switch to allow the fixtures to be controlled independently, with a photosensor for the fixture close to the window, and an occupancy sensor to turn lights off if no occupants are detected.” Detailed reports reduce duplication of effort, as the energy auditor’s descriptions of improvements are conveyed in detail to those responsible for implementation, whether design engineers, architects, contractors, or construction managers. ashrae.org January 2009 SIR Location New Hours/ Day (Average) http://www.ashrae.org
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