9A-i APPENDIX 9 A. LIGHTING CONTROL S

TABLE OF CONTENTS

9A.1 LIGHTING CONTROLS ....................................................................................... 9A-1

9A.1.1 Background ............................................................................................................. 9A-1

9A.1.2 Approach ................................................................................................................. 9A-1

9A.1.2.1 The Impact of State Building Codes on Controls Penetration .............. 9A-1

9A.1.2.2 The Impact of Other Factors on Controls Penetration .......................... 9A-3

9A.1.3 Results and Conclusions ......................................................................................... 9A-3

LIST OF FIGURES

Figure 9A.1.1 U.S. Total Annual Commercial Lighting Capacity and the Capacity Projected to be Operating under Lighting Controls .................................... 9A-49A-1 9A.1 LIGHTING CONTROLS

9A.1.1 Background

Lighting controls include a range of technologies to turn lights off or down when they are

not needed or wanted . Of interest to this rulemaking are control technologies that go beyond

manual on- off switc hing , which is almost universally included in lightin g. These include manual dimmers, automatic timers, and sensor- based controls. Timers can be used to automatically adjust lighting based on occupancy schedules and daylight hours . More advanced sensor

- based controls adjust light output based on signals received from the sensors. Occupancy sensors— often referred to as motion sensors for outdoor applications and vacancy sensors for indoor applications—include infrared, ultrasonic, and, to a far lesser extent, microwave sensors. Photosensors are used to adjust light output to account for background light levels , typically from daylight.

The purpose of this appendix is to describe the assumptions and analysis the U.S. Department of Energy ( DOE ) used to project changes in the penetration of lighting controls over the analysis period of this rulemaking. DOE incorporates lighting controls in the analysis, because they can indirectly affect lamp lifetimes and

, therefore , shipments (chapter 9); controls also directly affect lamp energy use and

, therefore

, the nat ional impact analysis (chapter 10)

. There are l arge
, inherent uncertainties in the extent to which the penetration of specific controls technologies will change over time. The next section describe s the approach DOE took to estimate the penetration of ligh ting controls technologies in the building stock for the shipments and NIA analysis for this rulemaking.

9A.1.2 Approach

DOE considered the impact of state building codes and other factors in estimating the adoption of lighting controls over the analysis period, as described in the following sections.

9A.1.2.1 The Impact of State Building Codes on Controls Penetration

Federal model energy codes drive the adoption and revision of state building codes. DOE adopts different model codes for commercial and residential building s. ASHRAE Standard 90.1

is the model energy code for commercial and multi

- family high

- rise residential building s. The International Energy Conservation Code (IECC) is the model energy code for low- rise residential buildings. Both include provisions on lighting and are updated periodically. The Energy Conservation and Production Act (ECPA), as amended, requires that DOE, within one year of revision of either document, issue a determination as to whether the revised edition will improve energy efficiency compared to previous editions. 1 If DOE finds that the newest version of ASHRAE 90.1 is more energy efficient than the previous version, s tates are required by the Energy Policy Act of 1992 (EPA CT 1992) to certify that their building energy codes or standar ds meet or exceed the requirements of the new standard within two years. If the analysis shows that

the revised IECC is more energy efficient than the previous edition, EP ACT 1992 requires to certify that they have reviewed their residential building energ y code s regarding energy9A-2 efficiency and made a decision as to whether it is appropriate for that state to revise its residential building code to meet or exceed the revised code. 2

Therefore, state compliance with the model codes is compulsory for comme rcial buildings, but not for residential buildings. DOE therefore treated the two sectors different in this preliminary analysis. For the residential sector, DOE assumed that th e use of lighting controls

remains constant at today’s level. DOE seeks input from stakeholders on the validity of this assumption.

To project the future penetration of commercial lighting controls , DOE assumed tha t state building code require ments remain as they are today, with controls being installed as required for new construction and renovation. The current model energy code for commercial buildings,

ASHRAE 90.1 -2007, section 9.4.1.1, mandates that almost all interior lighting be controlled either by a timer, an occupancy sensor, or a signal from a separate system . E xceptions are made

for buildings that are less than 5,000 square feet in floor area and for health and safety; hospital operating rooms and spaces that specifically requir e 24-hour lighting. In the current building

stock , the square foota ge covered by these exceptions totals 9% of commercial floor space . Most of that is exempted because the floor area is less than 5,000 square feet

. However, DOE has determined that ASHRAE 90.1-2010 will yield significant additional savings, so it will beco me the new model code. The 2010 code eliminates the exception for commercial buildings less than 5,000 square feet, with the result that an estimated 98% of total commercial floor space would be required to include lighting controls— essentially all viable floor area. DOE does not model the adoption of the 2010 code in this rulemaking because it is uncertain if and when states will adopt

the code.

In addition to the mandatory general lighting provisions of section 9.4.1.1 described previously , ASHRAE 90.1 -2007 includes additional requirements for lighting controls in some

smaller spaces , such as individual offices, which may be superimposed on controls required under the general provisions. DOE did not attempt to account for the effect of multiple layers of controls or improvements in control technolog ies that may take place over time. This appendix calculates only the lighting capacity ( in teralumens) covered by controls. Given the lack of data on whether multiple levels of controls would be adopted and which controls will be adopted in

which area s, the energy use calculations in c hapter 10 assume that controls yield a fixed 30% energy savings if controls are required for the floor area

. 3

Compliance rates are the largest source of uncertainty in the analysis. Given that all of the

most populous states are currently compliant with the federal requirement to adopt the model code or better, future changes in the level of state compliance should do little to change the

results of the energy an alysis. The level of builders’ complian ce with state code s is less clear

. This preliminary analysis assumes a 75 percent overall compliance rate , and DOE is considering incorporating an uncertainty analysis on compliance rates into it analysis in the NOPR phase of this rulemaking . DOE is seeking data on current compliance rates.

Using the assumptions described above, DOE estimated the national commercial lighting capacity ( in teralumens) covered by lighting controls for each year of the analysis, based on the

floor space projected to be operating under lighting controls, using a computational model9A-3 developed for by Sturges (2012). 4 Th e model estimates the commercial floor area incorporating controls, accounting for the current variation in standards adopt ed by the states, the relevant floor area in each state, the breakdown of floor area by application, and the code requirements for each floor area application. Because the analysis period in Sturges ’ study extended only until 2030, for this rulemaking DOE extrapolated Sturges’ projection to the end of the analysis period (2046). The results of the analysis are described in section 9A.1.3

.

9A.1.2.2 The Impact of Other Factors on Controls Penetration

In addition to lighting controls installed as a result of state building codes, some fraction of building owners install controls for other reasons. For the commercial sector, DOE computed the current lighting capacity installed fo r other reasons from the difference between the current total lighting capacity under controls and the lighting capacity under control s as a result of building codes, based on Sturges’ model. DOE’s 2010 Lighting Market Characterization (LMC)

estimates that 30% of commercial lighting was governed by lighting controls in 2010. 5 The LMC

estimate d that 30% of commercial lighting is governed by lighting controls. T he building codes analysis estimated that state codes would have resulted in only 12% of floorspace having implemented lighting controls at the beginning of the analysis period. Assuming that floorspace fractions equate approximately to lighting fractions, an estimated 18% of commercial lighting is assumed to be using lighting controls for other reasons. DOE held th at fraction fixed throughout the analysis period.

9A.1.3 Results and Conclusions

Figure 9A.1.1 shows DOE’s projection of the teralumen hours of capacity expected to be operating under controls as a result of building codes, and for other reasons. Total lumen capacity is also included in the plot to facilitate comparison. As shown, by the end of the analysis period approximately 75% of com mercial floor space is expected to be operating under lighting controls, assuming that today’s building codes remain frozen in place and a 75 percent compliance rate. If ASHRAE 90.1-2010 is adopted by the states, there will be some increase in lumen capac ity covered by controls, because the lighting controls exception for small buildings will be eliminated. The magnitude of that increase will depend on which states adopt the

standard and when. However

, a larger uncertainty appears to be the rate at which b uilders comply with state code requirements . Currently, DOE is assuming a 75% compliance rate. DOE is considering including an uncertainty analysis in the NOPR that assumes 50% and 100% compliance rates. DOE seeks feedback and data to better inform its ana lysis.9A-4 Figure 9A.1.1 U.S. Total Annual Commercial Lighting Capacity and the Capacity Projected to be Operating under Lighting Controls

REFERENCES

1 http://www.energycodes.gov/regulations

2 http://www .energycod es.gov/regulations/determinations

3 Williams, A., B. Atkinson, K. Garbesi, E. Page, and F. Rubinstein (2012). Lighting controls in commercial buildings. Leukos 8(3): 161-180. http://www.ies.org/leukos/samples/1_Jan12.pdf

4 Sturges, A, "Modeling the Market Penetration of Advanced Lighting Controls in the U.S Commercial Sector" (master's thesis, Duke University, Nicholas School of the Environment, 2012). Available online at http://dukespace.lib.duke.edu/dspace/handle/10161/5278

5 U.S . Department of Energy

- Energy Efficiency & Renewable Energy Building Technologies Program. 2010 U.S. Lighting Market Characterization. January 2012. Washington, D.C.

< http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/2010- lmc

- final

- jan -2012.pdf >