plug-in lighting, the total interior lighting calculated using this equation is in the middle range of residential lighting energy use found in other lighting references, as shown in Figure 16, including Huang and Gu (2002), the 1993 RECS (DOE 1996), an FSEC study (Parker et al. 2000), default lighting for Visual DOE software (Eley Associates 2002), a lighting study conducted by Navigant for DOE (Navigant Consulting 2002), and two other studies in Grays Harbor, Washington (Manclark and Nelson 1992), and Southern California Edison (SCE 1993).
Annual Indoor Lighting (kWh)
Benchmark Huang & Gu FSEC Visual DOE RECS 93 Navigant Grays Harbor SCE
1500 2000 2500 House Size (ft2)
Figure 16. Comparison of Benchmark lighting equation to other references
The Benchmark lighting budget is based on an assumption that 86% of all lamps are incandescent, and the remaining 14% are fluorescent. This is consistent with the source data set from 161 homes monitored by Tacoma Public Utilities (TPU) for the Bonneville Power Administration, which was the basis for the Navigant study. Although the core data set used in this study is the most complete and comprehensive residential lighting data set that we have identified, it is nevertheless limited in terms of geographic location, number of homes, length of study, percentage of fixtures monitored, and type of homes studied. The Navigant report includes an appendix providing information about the characteristics of the homes monitored in the TPU study.
The Benchmark and Prototype lighting calculations have two options. The first option is a simpler method that is relatively consistent with previous Benchmark protocols. The second is more complicated, and uses a more sophisticated room-by-room analysis approach that factors in the amount of hard-wired lighting compared to the total lighting needed based on Illuminating Engineering Society of North America (IESNA) illumination recommendations, and adjusts plug-in lighting accordingly. If the project is a multi-family housing complex, Option 2 must be used.