5D-i APPENDIX 5D. ADVANCED IR COATINGS

TABLE OF CONTENTS

5D.1 INTRODUCTION ........................................................................................................ 5D-1
5D.2 BACKGROUND .......................................................................................................... 5D-1
5D.2.1 HIR Technology.......................................................................................... 5D-1
5D.2.2 Silverized reflector coating......................................................................... 5D-2
5D.2.3 Alternative method...................................................................................... 5D-2
5D.3 METHOD ..................................................................................................................... 5D-2
5D.3.1 Capsules ...................................................................................................... 5D-2
5D.3.2 Modifying voltage....................................................................................... 5D-3
5D.3.3 Reflector...................................................................................................... 5D-3
5D.4 RESULTS ..................................................................................................................... 5D-4
5D.4.1 ADLT Burners ............................................................................................ 5D-4
5D.4.2 Reflector Losses.......................................................................................... 5D-4
5D.4.2.1 Commercially Available Lamps ............................................... 5D-4
5D.4.2.2 ADLT Burners .......................................................................... 5D-5
5D.5 LONG LIFE.................................................................................................................. 5D-6
5D.6 PRICE .......................................................................................................................... . 5D-6
5D.7 CONCLUSION............................................................................................................. 5D-7

LIST OF TABLES

Table 5D.1 Test Results for Burners with Advanced IR Coating ............................................ 5D-4
Table 5D.2 Test Results for Burners with A dvanced IR Coating Operating at a Reduced Operating Temperature ............................................................................... 5D-4
Table 5D.3 Test Results for Co mmercially Available HIR Lamps ......................................... 5D-4
Table 5D.4 Calculated Efficacies fo r ADLT Burner-Reflector Assemblies ........................... 5D-5 Table 5D.5 Calculated Efficacy for a Long Life (6,000 hours) IRL using an ADLT
Advanced IR burner.................................................................................... 5D-65D-1 5D.1

5D.2 APPENDIX 5D. ADVANCED IR COATINGS

INTR ODUCTION

Trial standa rd level (TSL) 5 for incandescen t reflector lamps (IRL) represents a halogen infrared reflector (HIR) lamp w ith the most efficient infrared (IR) glass coatings, reflector coatings, or filament designs. Commercially av ailable products currently meet TSL 5 by using a silverized reflector coating. One lamp manufacturer currently holds a patent on this technology which will not expire until after energy conservati on standards take effect. In this chapter the Department of Energy (DOE) presents the results of testing performed on lamps that utilize a different technology, that is potentially availa ble to all manufacturers, and may possibly be utilized to manufacture a lamp that would comply with TSL 5 without the use of the proprietary silver technology. In this appendix, DOE invest igates not only the resulting lamp efficacy when employing the advanced IR coatings, but also in vestigates manufacturing costs associated with this technology. Finally, DOE also explores the potential to use this technology to manufacture high-efficacy, long-life IRL.

BACK GROUND

5D.2.1 HIR Technology

In chapter 3 of the technical support documen t (TSD), DOE discusse s IR glass coatings as a possible design option. When a lamp contains an IR coating, it reflects more IR radiation onto the filament, so if run at the same voltage, the lamp operates at a higher temperature. This increase in operating temperature increases light output, which in turn increases efficacy. DOE concluded that this technology met the required sc reening criteria outlined in chapter 4 of the TSD and considered it as a design option.

HIR lamps that are commercially available toda y use IR coatings with alternating layers of two materials, SiO 2 and a second material of either Ta 2 O 5 or Nb 2 O 5 . Typical layer counts range from 45 to 75. In contrast , the most efficient HIR lamps have a coating made of three materials, SiO 2 , Ta 2 O 5 and TiO 2 , the latter in the high - index ru tile phase. This three material coating, described as a Hybrid TM by Advanced Lighting Technologies Inc. (ADLT) (hereafter
referred to as advanced IR coa ting), has an effective IR reflect ance significantly higher than that of the two-material coatings used in the commer cially available examples (described in section
5D.3.1 below), resulting in enhanced lumen per watt (lm/W) values.

This advanced IR coating is not a developmental product. Developed at ADLT, it has been in production on 12 Volt, single-ended bur ners in Europe for m ore than two years. However, the efficacy level achieved with this co ating on the single-ended configuration is lower
than that realized with the double-ended burne rs used in the testing described below.5D-2 5D.3 Neither the burner nor the co ating provided to DOE require s additional development. Both are separately in production at present, not patented, and av ailable to all lam p manufacturers. The additional laye rs lead to a slight increase in manufacturing time compared to the coatings currently in use in the market place.

5D.2.2 Silverized reflector coating

Though aluminum is most prevalent as a re flector coating in incandescent reflector lamps, silver coatings can also be applied. Silv er coatings are generally preferred over aluminum due to their lower light loss (silver reflects about eight percent more light based on commercially available lamps). One manufactur er currently holds a patent on th e silverized reflector coating technology that will not e xpire until December 2019 1 . Therefore DOE considered the silverized reflector coating to be a proprietary tec hnology (see section VI.B.1 of the final rule Federal Register notice for a description of how DOE treats pr oprietary technologies). However, DOE is also aware of technology options th at utilize silver to enhance reflector efficienci es but may not fall under proprietary restrictions 2 (see section VI.B.2.b of the final rule Federal Register notice for a description of these other technologies ). However, DOE believes that significant uncertainty remains as to the successful implem entation of these technologies in commercial products at the scale needed to service the IR L market. Therefore, DOE maintained that a silverized reflector required propr ietary technology and thus inve stigated an alternative method
to achieve TSL5.

5D.2.3 Alternative method

DOE investigated the possibility that TSL 5 could be achieved without using a silverized reflector coating. DOE reviewed design options that me t all required screening criteria (see chapter 4 for details) and discovered the existenc e of a more efficient IR coating than that currently in use in th e lighting industry.

To prove the effectiveness of this co ating, ADLT obtained co mmercially available capsules, applied the advanced IR coating, and sent the capsules to the Lighting Research Center (LRC) in Rochester, NY for independent testing. The following sections describe the method the LRC used for testing and the results of that testing.

METH OD

5D.3.1 Capsules

ADLT provided the LRC with IR coated halo gen burners for evaluation. ADLT inform ed
DOE that when used with the two-material co ating for which they were originally designed, these burners operate at 60 W, delivering 24 lm/W. The design life and temperature are 3000 hrs5D-3 and 2880 K. They are double-ended, elliptical quartz bu rners, with length s of 4.5 cm, excluding the electrodes, and minor elliptical axes of 1.0 cm.

This shape and size readily accommodates us e in most IRL, as evidenced by products
now on the market. ADLT claims that such products exist in R 20, BR30, BR40 and PAR38 formats. In addition, outside the IRL configur ation, ADLT claims that a commercially-available A-line general service incandescent lamp inco rporates a burner of the same shape and size. These commercially available examples operate at 120V at various powers. The LRC measured the lumens and watts of these capsules according to DOE’s test procedure for testing
incandescent reflector la mps (title 10 Code of Federal Re gulations (CFR) pa rt 430, subpart B, appendix R).

5D.3.2 Modifying voltage

As me ntioned in section 5D.2.1 , IR coatings increase the operating temperature of an
HIR lam p, which in turn decreases the lifetime. According to ADLT, commercially available halogen burners with standard IR coatings have rated lifetimes of approximately 3,000 hours when operated at 120V. Because the advanced IR coating reflects more IR radiation than the standard IR coating, the lamp’s operating temperat ure increases, resu lting in a decrease of lamp lifetime. ADLT performed tests and determined th at the burners with the advanced IR coatings supplied by ADLT have lifetimes of approximate ly 1,200 hours. In order to determine the efficacy of a 3,000 hour lamp with an advanced IR coating, DOE lowered the operating voltage
of the ADLT burners such that the measured co rrelated color temperature (CCT) (representative of operating temperature) was the same as that of the commercially available lamp with the standard IR coating. DOE assumed this m odification reasonably approximated a 3,000 hour lamp.

5D.3.3 Reflector

A burner and reflector combined emit less light than the burner alone due to light losses
attributable to the reflector. Because the burners provided by ADLT are not sold com mercially as a reflector lamp assemblies, DOE calculated the potential efficacy of an IRL utilizing an advanced IR coated burner. To do this, DOE first calculated the lumen reduction due to reflectors in commercially availa ble lamps. DOE then applied these same percentage lumen reductions to the burners provided by ADLT.

The LRC bought and analyzed five existing lamps from two different manufacturers to
evaluate the lumen losses due to reflectors. It tested each burner-reflector assembly and burner (separate from the reflector) three times and averag ed the measured lumens across the three tests. Using these average lumens from the burner and the average lumens from the burner-reflector assembly, DOE then calculated the percent lumen loss due to each lamp reflector. DOE applied this percentage to calculate th e lumen loss due to a reflector fo r the burners supplied by ADLT.5D-4 5D.4 RESU LTS

5D.4.1 ADLT Burners

Table 5D.1 shows the average lumens, power, a nd efficacy of the ADLT burners at 120V, whereas Table 5D.2 below shows the same metrics with the burners operating at reduced
temp erature. As seen in the tables below, reducing the operating temperature to obtain a lifetime of 3,000 hours instead of 1,200 hours results in a decrease in efficacy of about 5.6 lm/W.

Table 5D.1 Test Results for Burners with Advanced IR Coating

Reflector
& Burner Burner

Average Light Output lumens
- 2116.9 Average Power watts - 57.0 Average Efficacy lm/W
- 37.1 Average Voltage V 120

Table 5D.2 Test Results for Burners with Ad vanced IR Coating Operating at a Reduced Operating Temperature

Reflector
& Burner Burner

Average Light Output lumens
- 1513.8 Average Power watts - 48.1 Average Efficacy lm/W
- 31.5 Average Voltage V
- 107

5D.4.2 Reflector Losses

5D.4.2.1 Commercially Available Lamps

The LRC tested each commercially availabl e bu rner and burner-aluminum reflector assembly three times for repeatability and calculated an average value. The average lumens, watts, and efficacies for the five commer cially available lamps are shown in Table 5D.3

.

Table 5D.3 Test Results for Commercially Av ailable HIR Lamps

Reflector &

Burner Burner

Average Light Output lumens 993.3 1358.3 Average Power watts 61.3 61.7 Manufacturer

A Average Efficacy lm/W 16.2 22.0

Manufacturer Average Light Output lumens 978.0 1151.75D-5 Average Power watts 56.6 56.9 A Average Efficacy lm/W 17.3 20.2 Average Light Output lumens 983.7 1141.0 Average Power watts 53.6 53.7 Manufacturer

A Average Efficacy lm/W 18.4 21.2 Average Light Output lumens 780.3 975.9 Average Power watts 51.7 51.8 Manufacturer

B Average Efficacy lm/W 15.1 18.9 Average Light Output lumens 1057.0 1349.0 Average Power watts 62.1 62.3 Manufacturer

B Average Efficacy lm/W 17.0 21.7

As shown in the table above, Manufacturer A’s best reflector maintains 86.2% of the light from the capsule alone, whereas the wo rst reflector maintain s 73.1% of the light.
Manufacturer B’s best reflector ma intains 79.9% of the light from the capsule alone, whereas the worst reflector maintains 78.4% of the light. Using these percentages, it is possible to calculate a
best and worst case scenario. The best case s cenario would use the reflector that maintains 86.2% of the light, where as the worst case scenar io would use the reflector that maintains 73.1% of the light.

5D.4.2.2 ADLT Burners

Using the percentages described in the pr evious section, DOE calculated the most
efficient and least efficient burner-reflector combination that uses the ADLT burners. Table
5D.4 shows the results.

Table 5D.4 Calculated Efficacies for ADLT Burner-Reflector Assemblies

Reflector &

Burner Burner

Average Light Output lumens 1305 1513.8 Average Power watts 48.1 48.1 Best Case Scenario,
86.2% reflector Average Efficacy lm/W 27.1 31.5 Average Light Output lumens 1107 1513.8 Average Power watts 48.1 48.1 Worst Case

Scenario,
73.1% reflector Average Efficacy lm/W 23.0 31.5

As outlined in section VII.A.2 of the final rule, energy conservation standards for IRL are dependent upon the wattage of the lamp. The relevant equation that defines the minimum efficacy standard associated with TSL 5 is 6.4P 0.27 , where P is the rated wattage. If 48W were the rated wattage of the lamp in the table above , the corresponding efficacy level at TSL 5 would be 18.2 lm/W. With an efficacy of at leas t 23.0 lm/W, the ADLT burner-reflector assembly would meet TSL 5. As TSL 5 represents the highest efficacy level, the ADLT burner-reflector assembly would also meet all other TSLs.5D-6 5D.5 LONG LIFE

As discussed in section 5D.2.1 , HIR technology results in lamps operating at higher
temp eratures. This, in turn, decreases lamp lif etime because the tungsten filament evaporates more quickly. Therefore, DOE performed an anal ysis to investigate how utilizing an advanced IR coating to meet TSL 5 woul d affect long-life HIR lamps.

Using the 9 th edition of the IESNA Lighting Handbook 3 , DOE developed a relationship between lifetime, lumens, and wattage for two di fferent lamps. Using the known power, lumens, and lifetime for the 3,000 hour improved HIR lamp, DO E was able to calculate the lumens of the HIR lamp if it had the same power but a lifetime of 6,000 hours. Table 5D.5 shows the
calculated lu mens and efficacy for a 6,000 hour HIR la mp that employs an advanced IR coating.

Table 5D.5 Calculated Efficacy for a Lo ng Life (6,000 hours) IRL using an ADLT
Advanced IR burner

Reflector &

Burner Average Light Output lumens 1188 Average Power watts 48.1 Best Case Scenario,
86.2% reflector Average Efficacy lm/W 24.7 Average Light Output lumens 1007 Average Power watts 48.1 Worst Case

Scenario,
73.1% reflector Average Efficacy lm/W 21.0

As described in section 5D.4.2.2 , the minimum efficacy requirement at each TSL varies based on the rated wattage of the lamp. If the rated wattage of the above lamp were 48W , the corresponding minimum efficacy requirement at TSL 5 would be 18.2 lm/W. As shown in Table
5D.5 , both the best case and worst case scenarios meet TSL 5. However, DOE recognizes that these efficacies do not represent lam p efficaci es under mass production. Therefore, DOE cannot conclusively determine that long-life lamps wouild be available at TSL5.

5D.6 PRIC E

To consider this advanced IR technology as an alternate technology pathwa y to achieve TSL5, DOE also analyzed potenti al manufacturing cost and pri ce impacts to this technology. ADLT provided DOE with estimates of the cost of applying the advanced IR coating described
in section 5D.2.1 to an existing capsule. It estimated the cost to the lamp manufacturer of adding the advanced IR coating to be $0.68 per burner if one million capsules were coated per year 4

. Lamp manufacturers have the option of paying ADLT to apply the advanced IR coating or acquiring a machine and coating their own lamps. ADLT expects the price to decrease to $0.20 per burner if 500 million or more cap sules were coated per year.5D-7 5D.7 To best determine the price of a lamp w ith an advanced IR coating, DOE added the
incremental cost of the advanced IR coating to th e pric e of a lamp at TSL 4 (see TSD chapter 7). TSL 4 is represented by a HIR lamp with a st andard IR coating and a 4,000 hour lifetime. ADLT estimated the cost of a standard IR coating, described in section 5D.2.1 , to be $0.50 per

burner if one m illion capsules were coated pe r year, decreasing to $0.15 per burner if 500 million or more burners were coated per year. Theref ore, based on these numbers, the incremental cost to manufacturers of the advanced coating w ould be approximately $0.18 per burner in small quantities or $0.05 per burner in large quantities.

In consideration of the current state of th e technology and its production volume, a lamp currently manufactured with this advanced IR coating technol ogy would be subject to lower volume cost estimates. In the manufacturer imp act analysis (MIA), DOE used a multiplier of 2.3 to calculate the end-user price given the cost to the lamp manufacturer. Using this multiplier, the
manufacturer cost differential between a standard IR coated lamp and an advanced IR coated lamp results in an incremental cost of $0.41 to th e end user. Adding this incremental cost to the price of a lamp at TSL 4, DOE calculates the medi um price of a PAR38 lamp with an advanced IR coating at TSL 5 to be $7.91 and calculates the medium price of a PAR30 lamp to be $7.34.

CONC LUSION

As shown in section 5D.4.2.2 , testing indicates that it is possible to achieve TSL 5 without using a silverized refl ector. An advanced IR coa ting, which, to DOE’s knowledge, would be available to all lamp m a nufacturers, can likely be used to meet TSL 5. In addition, as
shown in section 5D.5 , TSL 5 does not appear to eliminate long-life lamps from the market. Using a relationship derived from the IES NA Lighting Handbook, DOE tentatively concluded that a 6,000 lam p with an advanced IR coating could still achieve TSL 5.

In section 5D.6 , DOE calculated the cost of a lamp with an advanced IR coating by adding the incremental cost of the coating to th e price of a lamp at TSL 4. The analysis found these pr ices to be comparable with IRL that me et TSL 5 and utilize the proprietary silverized reflector technology.

Although these results show that IRL with an advanced IR coating can meet and exceed TSL5, DOE does not believe that this data is representative of the efficacy these lamps will achieve when manufactured on a large scale. Large scale production will likely result in decreased efficacy, though the magnitude of this reduction is uncertain (see section VI.B.2a of
the final rule Federal Register notice for more details). Th erefore, DOE cannot conclusively determine the performance of lamps utilizing the advanced IR coatings when manufactured on a large scale.5D-8 REFERENCES

1 Zhao, Tianji, et al. “Protected Coating fo r Energy Efficient Lamp.” U.S. Patent 6,773,141. August 10, 2004.

2 Deposition Sciences Incorporated. In Development

─ New, Improved & Enhanced Silver Coating . (Last Accessed July 7, 2009)

< http://www.depsci.com/Documents/S ubHeading/DSIannouncesEcoWhiteFINAL.pdf >

3 Rae, Mark S., ed. The IESNA Lighting Handbook, Reference & Application , 9th edition, New York, NY, IESNA 2000.

4 Boling, Norm. <bolingn@depsci.com> “FW: pric ing” 8 December 2008. Personal email. (9 December 2008).