Level IV – Advance Assistance

Urbana City Building

Published 02/10/2010 Site Visit: 01/14/2010 Location: 400 South Vine Street, Urbana Illinois 61801 Contact: Rodney Fletcher, City of Urbana Environmental Manager

Phone: 217-384-2381 rafletcher@city.urbana.il.us Auditor: Jean Ascoli, Report Author

Phone: (800) 214-7954, jean@sedac.org

This report was prepared as the result of work by a member of the staff of the Smart Energy Design Assistance Center (SEDAC). It does not necessarily represent the views of the University of Illinois, its employees, or the State of Illinois. SEDAC, the State of Illinois, its employees, contractors, and subcontractors make no warrant, express or implied, and assume no legal liability for the information in this report; nor does any party represent that the uses of this information will not infringe upon privately owned rights. This report has not been approved or disapproved by the Illinois Department of Commerce and Economic Opportunity nor has the Department passed upon the accuracy or adequacy of the information in this report. Reference to brand names is for identification purposes only and does not constitute an endorsement. All numerical data are order of magnitude estimates and the number of digits shown is an artifact of the calculation procedure; it is not meant to imply greater accuracy or precision.

Background: In the fall of 2009 the City of Urbana received approval of a federal grant application for $76,000 towards the initial cost of replacing all the linear fluorescent lighting in the Urbana City Building with LED (Light Emitting Diode) replacement lamps. At the City’s request, the Smart Energy Design Assistance Center (SEDAC), an affiliate of the University of Illinois, conducted an audit of the existing lighting and a review of the proposed LED retrofit.

This report represents a summary of our initial review and analysis of the lighting only. A complete building energy audit and report on the Urbana City Building, including a comprehensive list of recommended energy cost reduction measures (ECRMs) will be provided at a future date.

Existing Lighting: City staff reports that the majority of the existing lighting in the building is provided by 32-watt, four-foot T8 linear fluorescent lamps (Sylvania F032/835/EC0) in two- and three-lamp fixtures. With just a few exceptions where four-foot T12 lamps are still in use, the lighting was upgraded to T8 technology when the building was renovated and expanded approximately 15 years ago. Recently the city has started using a 28-watt T8 replacement lamp (Sylvania F028/835/XP/SS/ECO) with a longer rated life.1 All ballasts, with the exception of those in the T12 fixtures are assumed to be electronic, normal light output2, instant start ballast. The T12 fixtures are presumed to use standard magnetic ballasts. See Appendix A for a table summarizing the location, type, quantity, and energy consumption of the existing linear fluorescent lighting.

Proposed LED retrofit: SEDAC commends the City of Urbana staff for the innovative thinking and commitment to environmental stewardship which led to their proposal to replace the four-foot linear fluorescent lamps in the Urbana City Building with LED replacement-lamps.

Use of LED lighting for general space illumination is a relatively new application of LED technology. LED lamps have a lot of advantages over traditional lighting sources and this particular application (general space lighting) has a great deal of potential for the future. Unique LED characteristics sited by the U.S. Department of Energy (DOE)3 include:

• Directional light emission – directing light where it is needed. • Can be very compact and low-profile. • Breakage resistance – no breakable glass or filaments. • Cold temperature operation – performance actually improves in the cold. • Instant on – require no "warm up" time. • Rapid cycling capability – lifetime not affected by frequent switching. • Controllability – compatible with electronic controls to change light levels and color

characteristics.

Applications that may most benefit from some of these unique attributes include adjustable task lighting, under-cabinet lighting, outdoor area lighting, elevator lighting, recessed downlights, accent lights, step and path lighting, cove lighting, low temperature locations, and display lighting.

1 Rated lamp life for fluorescent lamp technology is dependent on lamp type, ballast type (instant start, rapid start or programmed start) and operating cycle (hours on, minutes between restarts). 2 Normal light output (NLO) refers to a ballast factor between 0.85 and 0.95. Ballast Factor (BF) is the ratio of lamp lumens produced when lamp(s) are operated by a given ballast to the lamp lumens produced when the lamp(s) are operated on a reference ballast. Other ballast factors available include among others, RLO (reduced light output), HLO (high light output) and VHLO (very high light output). 3 http://www1.eere.energy.gov/buildings/ssl/advantage.html

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Table 1 below shows a summary of product data for four LED linear fluorescent replacement lamps from three manufacturers. The table includes products currently under consideration by City of Urbana staff, as well as similar products identified by SEDAC for this report. These lamps are made up of multiple diodes that are mounted in a grid or strip pattern on a circuit board which is enclosed in a "light bulb" package which includes a heat sink, capacitor, metal base and plastic tube enclosure. They are designed with a bi-pin ends compatible with standard T8 and T12 fixtures. For most of the lamps the fluorescent ballast must be disconnected prior to installation.

Product Manufacturer / Product Name

See Note (1) Model Watts Lumens CRI

See Note (2)

Manufacturer’s Advertised Lamp Life See Note (3)

Cost / Lamp

See Note (4) EarthLED / DirectLEDFL 300 SuperBrite 15 1500 75 50,000 $46 (U)

LEDdynamics / Ever-LED™ TR™ E25T8-48-S3N 21 1900 85 87,600 $90 (U)

Newtek Energy Solutions / LEDGREEN™

4ft 140/ 2 Dice/LED 15 1250 70 50,000 $66 (M)

Newtek Energy Solutions / LEDGREEN™

4ft 140/ 3 Dice/LED 22 1800 70 50,000 $79 (M)

Table 1: LED Four-Foot Retrofit Lamps Notes for Table 1:

(1) The two products under consideration by City of Urbana staff to date are the EarthLED and LEDdynamics products listed above.

(2) The Color Rendering Index (CRI) is “the measure of the degree of color shift objects undergo when illuminated by the light source as compared with the color those same objects when illuminated by a reference source of comparable color temperature.”4

(3) See discussion of LED lamp life in Technology Comparison section later in this report. (4) Cost for lamps are provided for relative comparison only and are taken from manufacturer’s website (M) or

from general cost information provided to the City of Urbana (U).

A great deal has been written about the fact that no mercury is used in the manufacturing of LEDs. LED lighting products are also marketed as longer lasting and more efficient that other lighting sources. For a review of these assertions and comparison with available low-mercury, high efficiency linear fluorescent lamp technology—see the ‘Technology Comparison’ section later in this report.

Linear Fluorescent Lamps: There have been significant improvements in energy-efficient linear fluorescent lamp and fixture design in recent years. But selecting the longest lasting, most efficient system can prove challenging. There are a seemingly infinite number of choices and combinations of fixtures, lamps and ballasts on the market today. With the introduction of new low-wattage, high-performance T8 and T5 lamps, choosing the “best” linear fluorescent lighting has become quite complex.

All these elements can affect the overall energy performance of the selected lighting solution: • Nominal lamp wattage. • Mean (or design) lamp lumens. • Ballast type and efficiency. It is critical to check ballast compatibility with the fixture and

lamp selection. Ballast choice is important because it can affect lamp life, fixture energy usage (fixture wattage is dependent on the ballast efficiency factor—BEF5), and light levels (lumen output is affected by the ballast factor-BF).

4 Illuminating Engineering Society of North America 5 http://www.lightingtaxdeduction.org/technologies/ballasts.html

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• Fixture efficiency.6 Fixture efficiency is affected by the original fixture design along with the age and condition of key fixture components (e.g. back reflectors and lenses).

Table 2 below shows a summary of product data on the T8 lamp technology currently in use in the Urbana City Building. The table also includes three lamps which are discussed in this report as alternatives to the existing lamps and the proposed LED retrofit.

Product Manufacturer

/ Product Name Model

Nominal Lamp

Wattage

Lumens Initial/Mean

See Note (1)

CRI See Note (2)

Mercury (Hg)

Content Avg. Rated Life

See Note (3) Cost / lamp See Note (4)

T12 Lamps Currently in Use Sylvania / T12 Ecologic Designer SuperSaver

F34/D35/SS/ ECO 32 2800/2520 70 3.5

Magnetic Ballast: 20,000

$3.99

T8 Lamps Currently in Use Sylvania / T8 Octron 800

Ecologic F032/835/ECO 32 2950/2802 85 3.5 30,000 $3.03

Sylvania / T8 Octron 800XP

Ecologic

F028/835/XP/ SS/ECO 28 2725/2590 85 3.5 36,000 $4.49

Alternative Lamps

Philips Alto II F32T8/28W/ADV

835 EW ALTO 28 2725/2645 85 1.7 30,000 $3.20

Sylvania T8 Octron 800XP

Ecologic

F032/25W/835/XP/ SS/ECO 25 2475/2350 85 3.5 36,000 $8.19

Philips Alto II F32T8/25W/ADV835/XLL ALTO 25 2400/2330 85 1.7 36,000 $5.08

Table 2: Low-Mercury, High Efficiency Four-Foot Linear Fluorescent Lamps Notes for Table 2:

(1) Mean Lumens is defined as the lumen output of a light source at a given percentage of its rated lifetime. Mean lumen values for fluorescent lamps are typically measured at 40% of their rated lives.

(2) CRI – Color Rendering Index (CRI) is “the measure of the degree of color shift objects undergo when illuminated by the light source as compared with the color those same objects when illuminated by a reference source of comparable color temperature.”7

(3) Average rated life reported here is based on tested operation under specified test conditions at 3 hours per start, using a programmed start ballast specified by the manufacturer. Rated life at 3-hour start for these same lamps using instant start ballasts is typically 20% to 30% shorter (generally around 24,000 hours). Instant Start ballasts ignite lamps by providing a significant voltage across the lamp during starting. Instant start ballasts should be used in applications that do not require lights to be turned on and off multiple times a day. Program Start ballasts incorporate a precise starting sequence that brings the lamp up to full brightness by preheating the lamp cathode and then applying voltage across the lamp. Program Start ballasts would be recommended in a motion sensor application where the fixture will be turning on and off multiple times a day.8

(4) Cost for lamps are provided for relative comparison only and are taken from www.GoodMart.com

In addition to the fixtures using T8 lamps in use in the Urbana City Building, there are several fixtures which were not updated from the original T12 lamps and ballasts when the building was renovated in the 1990’s. These fixtures use four-foot 34-watt T12 lamps (Sylvania F34/D35/SS/ECO). There are both two- and four-lamp T12 fixtures in the building.

6 Fixture efficiency is the amount of light leaving a fixture compared to the amount of light generated by a given light source within the fixture. 7 Illuminating Engineering Society of North America 8 http://www.amhsllc.com/save-energy/instant-start-ballasts-vs-program-st/

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Technology Comparison

Light Quality

LED Light Quality:

• LEDs retrofit lamps are available in a full range of reported color temperatures, comparable to fluorescent lighting. However, the spectral properties of LEDs have not been subjected to the same level of study that fluorescents have and color shift has been a reported problem with some products on the market.

• The color rendering index (CRI) for the LED retrofit lamps under consideration range from 70 to 85, with the least expensive lamp (the EarthLED in Table 1) reporting a CRI of 75.

Fluorescent Light Quality:

• Spectral enhancement has been a subject of some study in fluorescent lighting and the major manufacturers have continued to improve their high performing lamps to take advantage of the research available.

• The color rendering index (CRI) for all the T8 lamps in Table 2 is 85, whereas the CRI for the T12 lamps still in use is only 70.

Light Quality Summary:

The color temperature and spectral properties of the retrofit lamps selected should be evaluated as a part of the selection process. While a CRI of 85 (in the recommended fluorescent lamps) is not as good as the color rendering that can be achieved with other incandescent lights or natural daylight, it is noticeably better than the CRI of 75 in the more affordable LED retrofit lamps.

Lamp Life

LED Lamp Life:

• The reported life for most of the LED retrofit lamps under consideration is 50,000+ hours, however LED lamps are not currently subject to uniform testing for rated life nor is there a consensus on the definition of LED lamp failure.

• According to the U.S. Department of Energy (DOE), an LED “light bulb” life testing procedure is currently under development by the Illuminating Engineering Society of North America (IESNA). Called LM-80, this testing protocol will define the useful life based on lumen depreciation. The criteria currently being considered for defining an LED lamp life is “the average number of hours that the LED would operate before depreciating to 70% of initial lumens.” According to the DOE this rating ranges from 35,000-50,000 hours for high-powered white LED lighting.9

• This lamp life rating is based on the estimated lumen depreciation of the LEDs used in a specific lighting product or fixture—but it often does not account for other potential component failure modes. For example, individual LED 'dice' may fail (rather than depreciate), thereby reducing the lumen output of an LED replacement tube. Or other components of the replacement tube, such as the capacitor, may fail with the potential outcome of complete failure—before the LED depreciation “life” has been reached.

9 U.S. Department of Energy: Solid-State Lighting: Using Light-Emitting Diodes: Measuring Light Source Life: http://www1.eere.energy.gov/buildings/ssl/life_measuring.html

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• One of the listed manufacturers stated in an email that the “average lifetime” of their product is “87,600 hours” and that they have “had the product in the field for four years now and have not had a single failure.” It should be noted that four years of continuous use (24 hours/day—365 days/year) is only 35,040 hours. This is a common problem in the industry - with 24/7 operation, testing an LED for 50,000 hours would take 5.7 years.

• The DOE began reliability testing on LED luminaires in August 2007. They report that “some luminaires maintain output levels over the first 6,000 hours of operation (7 of 26 products are producing at least 95% of their initial output), while others exhibit rapid lumen depreciation within the first 1,000 to 2,000 hours, and some products exhibit significant color shift over the first 6,000 hours of operation. No generalizable patterns can be observed yet.”10

• One advantage noted in LED systems is that frequency of on/off switching does not reportedly impact lamp life.11

Fluorescent Lamp Life:

• The life rating of fluorescent lamps is estimated through industry-standard lamp testing procedures. Typically, a large, statistically significant sample of lamps is operated until 50% have failed; that point, in terms of operating hours, defines "rated life" for that lamp.

• Typically the longest lamp life for fluorescents is reported for lamps tested using programmed start (PS) electronic ballasts selected by the lamp manufacturer, usually specific ballasts made by the same manufacturer. These are often higher quality and more expensive ballasts than those typically installed.

• There is a direct relationship between the “burn time” or frequency of “starts” (how often the lamp is turned on and off) and the rated lamp life. Typically lamp life for fluorescents is reported in 3-hour and 12-hour starts. The longer time equals a longer lamp life due to the reduced number of times the lamps are subjected to the brief jump in current needed to start the lamps.

• The life of installed fluorescent lamps varies considerably based on several factors including quality of the original manufacturing, ballast compatibility, lamp switching schedule and controls, ambient temperature conditions, etc.

• There are four-foot fluorescent lamps on the market today with greater than 35,000 hours rated life reported at 3-hour starts using programmed start ballasts.

Lamp Life Summary:

Due to the lack of standard testing procedures, statistically significant sample sizes, and length of availability for testing of the LED four-foot replacements lamps, the reported lamp life for fluorescent lamps should be considered with greater confidence than the lamp life reported for the LEDs. While reported life for the individual diodes (LEDs) within the “light bulbs” may have good test data, there is limited test data available on the projected life of the entire assemblies.

The lamp life of the best fluorescent lamps on the market today is about 70% of the lamp life reported for these LED four-foot replacements lamps, provided they are paired with the correct ballast type and on-off switching is limited to 3-hour starts. Where controls, such as occupancy sensors are used, energy will be saved but lamp life may be reduced.

10 http://www1.eere.energy.gov/buildings/ssl/reliability_testing.html 11 http://www1.eere.energy.gov/buildings/ssl/advantage.html

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Environmental Hazards

LED Potential Environmental Hazards:

LED technology is marketed as a more sustainable lighting solution in part due to the absence of mercury in the lamps. However, in considering the selection of a lamp based on environmental sustainability the full life cycle of the lamp must be considered. Each four-foot lamp contains more than 100 small LED lamps plus other components including heat sinks, capacitors, metal casing, plastic tubing, etc. To date there has been little published about the comparative embodied energy in four-foot LED retrofit lamps or about other potentially hazardous materials used in the manufacture of these lamps. For example, they appear to contain significantly more aluminum than the linear fluorescent lamps they are designed to replace. For the environmental impacts of aluminum production see: http://www.enviroliteracy.org/article.php/1013.html.

Fluorescent Potential Environmental Hazards:

There are now four-foot fluorescent lamps with <2.0 mg of mercury available (see Table 2). All of the lamps listed in Table 2 are reportedly designed to pass the Federal Toxic Characteristic Leaching Procedure (TCLP) criteria for classification as non-hazardous waste in most states. TCLP test results are available upon request. Lamp disposal regulations may vary; check your local & state regulations. For more information, visit www.lamprecycle.org.

The mercury content of these lamps is only one part of the story. On average, Illinois coal-fired power plants emit 0.04 milligrams (mg) of mercury per kilowatt-hour sold.12 With 75 percent of Ameren IP electric energy supply coming from coal fired plants13, substantially more mercury is released into the environment using electricity from the central Illinois grid to power low- and no-mercury lamps over the course of their lives than the mercury contained in the lamps themselves. For any lamp, even no-mercury LED’s lamps, a 25-watt lamp operating for 25,000 hours off the current electrical grid will emit 25.0 mg of mercury into the environment.

When considering the embodied energy and potential environmental impact of fluorescent lamps the impact of the ballasts required to run the lamps must also be considered. Historically there was an additional environmental concern regarding the disposal of used fluorescent ballasts due to potential polychlorinated biphenyls (PCBs) content. However, since the late 1970s these materials have been banned in manufacture of ballasts and ballasts manufactured after 1979 that do not contain PCBs are labeled “No PCBs.”

Environmental Hazards Summary:

More information is needed about the embodied energy and materials used to manufacture the LED retrofit lamps. In any case, when selecting lamps and fixtures that will be powered with Illinois coal—the energy efficiency of the lighting system is at least as important as the material selection when addressing the problem of mercury.

Energy Efficiency

LED Energy Efficiency:

Lamp efficacy (lumens/watt) is generally the first thing considered with traditional light sources when analyzing relative energy efficiency. The LED retrofit lamps under consideration have reported lamp efficacies ranging from 82 for the lowest to 100 for the highest. It is important to

12 Emission Factors and Energy Prices for Leonardo Academy’s Cleaner and Greener® Program A White Paper by Leonardo Academy Inc. Updated: April 21, 2009 13 Illinois Commerce Commission Environmental Disclosure Statements “Sources of electricity supplied for the 12 months ending September 30, 2009 for AmerenIP” http://www.icc.illinois.gov/electricity/environmentaldisclosure.aspx

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note that there does not appear to be a standard testing protocol to provide verification for the efficacies reported. Sandia National Laboratories reports that there is “much research and development worldwide aimed at making SSL (solid state lighting) competitive with fluorescent and HID technologies in the coming decade.”14 However, the implied message is that it is not yet competitive. See Table 3 below for a summary of the reported LED retrofit lamp efficacy.

Product Manufacturer / Product Name Model Watts

Lamp Lumens

Installed Efficacy

EarthLED / DirectLEDFL 300 SuperBrite 15 1500 100

LEDdynamics / Ever-LED™ TR™ E25T8-48-S3N 21 1900 90

Newtek Energy Solutions / LEDGREEN™ 4ft 140/ 2 Dice/LED 15 1250 83

Newtek Energy Solutions / LEDGREEN™ 4ft 140/ 3 Dice/LED 22 1800 82

Table 3: Summary of LED Retrofit Lamp Efficacy

The lamp efficacy for these LEDs is not as high as the efficacy for the high performance T8’s under consideration (see Table 5 below), however due to the directional nature of their light emission, LEDs can potentially have higher “application efficiency” than other light sources in certain lighting applications.

“Application efficiency” considers the amount of light that actually reaches the intended surfaces. In the case of these LED retrofit lamps it is important to consider the design of the existing fixtures and the orientation of the lamps when installed. There are fixtures where the slots for the bi-pins are at an angle and the lamps may not be properly oriented once installed. Assuming this is not a problem, and the lights are all pointed downward, a graph of the lamp’s luminous intensity is needed to make a good comparison with other lighting sources. In other words, does the new light source ‘spread’ as well as the fluorescent lamp, giving even illumination to the entire space? This information should be reviewed for any replacement lamp under consideration.

Light meter readings taken Urbana City Building in room C201 (a test location where 15-watt EarthLED/DirectLEDFL retrofit lamps have been installed) revealed a wider range of light levels (taken at desk level) than would normally be anticipated in such a small space with two two-by-four recessed light fixtures. The measured levels on the desk surface ranged from ~35 to ~45 footcandles. If room light sources are uneven or inadequate, additional task lighting may be required, resulting in a reduction in the overall energy savings. It was also noted that the light levels in the spaces with the sample LED retrofit lamps were between 25% and 50% lower than comparable locations where the existing fluorescent lamps were in use. A nearby office with the existing fluorescent lamps had a measured light level at the desk surface of 80 footcandles.

The savings potential of the LED retrofit lamps is dependent on whether or not the lower light levels are acceptable throughout the facility. If reduced light levels are not acceptable throughout the facility, the higher wattage LED retrofit lamps may be required in some or all locations. The 21-watt LEDdynamics / Ever-LED™ TR™ replacement lamps have a reported output of 1900 lumens, a 26 percent increase over the 15-watt EarthLED / DirectLEDFL which reports 1500 lumens per lamp. However, the higher wattage LED retrofit lamps are significantly more expensive than the 15-watt lamps, so the initial cost of this option might not be fully covered by the grant received. Also the average annual replacement cost would be considerably higher for future lamp replacements (see Replacement Costs section).

Table 4 below shows the potential energy and cost savings for the 15-watt and 21-watt LED retrofit options.

14 http://ssls.sandia.gov/overview/index.html

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Retrofit Description Estimated

kWh Savings

% of current estimated linear

fluorescent usage reduced

Estimated Energy Cost

Savings All lamps replaced with 15-watt LED lamps with occupancy sensor control of 24/7 fixtures. 66,677 49% $5,994

All lamps replaced with 21-watt LED lamps with occupancy sensor control of 24/7 fixtures. 39,226 29% $3,526

Table 4: Potential Energy Savings Summary for LED Retrofit Options Notes for Table 4:

(1) Some of the LED retrofit lamps under consideration can be installed without disconnecting the fixture ballast. Ballasts can affect the total energy consumed by the lamps. The savings reported here assume fixtures where the ballast has been disconnected or, if still connected, the ballasts have a ballast factor ≤1.00.

(2) At the time of our site visit, City of Urbana staff was in the process of installing occupancy sensor control for 24/7 lighting fixtures. We estimate a potential reduction for the hours of operation of the 24/7 fixtures to a daily average of 16 hours. This will reduce the annual energy consumption of the existing lighting. The estimated savings reported in this table reflect the estimated energy savings for the proposed LED retrofit options with occupancy sensor control on the 24/7 fixtures compared to the existing lighting also with occupancy sensor control on the 24/7 fixtures.

(3) The cost savings above are calculated using an electric rate of $0.09 per kWh This is based on utility bills provided by the City of Urbana. This rate includes all fees and other charges.

(4) Lamp replacement costs are not included in cost savings calculations for this table.

Fluorescent Energy Efficiency:

In order to evaluate fluorescent lamp efficacy one must consider the wattage of the lamps and the ballast factor (BF) of the specific ballast used in the fixture:

Ballast factor is a measure of the actual lumen output for a specific lamp-ballast system relative to the rated lumen output...[Many] ballasts are available with either high [110 to 120%]…or low ballast factors (70 to 75%). It is important to note that the ballast factor value is not simply a characteristic of the ballast, but of the lamp-ballast system. Ballasts that can operate more than one type of lamp…will generally have a different ballast factor for each combination...Ballast factor is not a measure of energy efficiency. [For example, while] a lower ballast factor reduces lamp lumen output, it also consumes proportionally less input power.15

The input power (wattage) of a fluorescent fixture is calculated taking the rated wattage of the individual lamps times the number of lamps per fixture, multiplied by the ballast factor (BF). Normal light output ballasts (NLO) can have ballast factors ranging from 85 to 95 percent (.85-.95). The T12 fixtures in the Urbana City Building are assumed to use energy saving (ES) magnetic ballasts. The T8 fluorescent fixtures are assumed to use normal light output (NLO) instant start ballasts. The total fixture wattage for each existing fixture type was estimated based on total fixture wattages for similar fixtures in the 2008 Table of Standard Fixture Wattages available from Xcel Energy.16

The efficacy (lumens/watt) of all of the T8 fluorescent lamps is six to eight percent higher than the best LED reviewed. However, the efficacy of the 34-watt T12’s in fixtures with magnetic ballasts is just 70 lumens/watt, which is nearly 35 percent lower than the 25-watt and 28-watt T8 lamps being considered.

15 Definition from the Applications Team Lawrence Berkeley Lab http://ateam.lbl.gov/Design-Guide/DGHtm/ballastfactor.htm 16 http://www.xcelefficiency.com/CI/Downloads.shtml

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It should be noted that depending on the design and condition of the existing fixtures, some of the light produced by the linear fluorescent lamps may be lost within the fixture, absorbed by the lamp as heat, or escape from the fixture in a direction that is not useful for the intended application. The existing fixtures in the Urbana City Building have a standard white enamel back reflector and plastic lenses which have somewhat yellowed with age. Lens discoloration as well as dirt on the back reflector and lens will affect the fixture efficiency regardless of the lamp selected for retrofit (including the LED lamps).

Fluorescent lamps emit light in all directions. Therefore, the light from properly spaced linear fluorescent fixtures tends to be evenly distributed within the space. This appeared to be the case with the existing fluorescent lighting in the City Building. Light level measurements taken at the time of the site visit showed fairly even distribution and adequate to high footcandle levels in the offices and public spaces measured. Some reduction in light level could potentially be acceptable. See Appendix C for currently recommended footcandle levels.

Product Manufacturer / Product Name Model

Estimated Input

Watts per Lamp

Mean Lumens

Installed Efficacy

Sylvania / T12 Ecologic Designer SuperSaver F34/D35/SS/ECO 36* 2520 70

Sylvania / T8 Octron 800 Ecologic F032/835/EC0 29.5* 2802 95

Sylvania / T8 Octron 800XP Ecologic F028/835/XP/ SS/ECO 24.5* 2590 106

Philips Alto II T8 F32T8/28W/ADV835

EW ALTO 24.5* 2645 108

Sylvania T8 Octron 800XP Ecologic F032/25W/835/XP/

SS/ECO 22* 2350 107

Philips Alto II T8 F32T8/25W/ADV835/X

LL ALTO 22* 2330 106

Table 5: Summary of Linear Fluorescent Lamp Efficacy

The City of Urbana is already in the process of installing motion occupancy sensors in areas of 24/7 lighting. Program Start ballasts are highly recommended in a motion sensor application where fluorescent fixtures will be turning on and off multiple times a day to avoid shortening the lamp life.

Another low cost method for reducing the fluorescent lighting energy load is de-lamping fixtures with three or more lamps. It is recommended that some trial locations be selected and a single lamp be removed from the three-lamp fixtures and one or two lamps be removed from the four-lamp fixtures in the building.

We analyzed the following package of alternative lighting upgrades:

• Upgrade all fixtures (including all existing T12 fixtures) to the low-mercury, high lumen 28-watt T8 lamps.

• Complete installation of occupancy sensors to control 24/7 lighting. We estimated a potential reduction for the hours of operation of the 24/7 fixtures to a daily average of 16 hours.

• Install program start ballasts in all fixtures (not only those which will be controlled by occupancy sensors).

• De-lamp three-lamp fixtures to two-lamp (33% reduction), and four-lamp fixtures to three-lamp (25% reduction). If reduced light levels are not acceptable, consider fixture replacement or installation of reflectors made of high-reflectance material to improve light distribution when implementing de-lamping strategies.

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If all of these strategies are implemented the overall energy savings are estimated to be about 52,277 kWh—saving approximately $4.699 annually—a 37 percent savings compared with the existing fluorescent lighting with occupancy control on the 24/7 fixtures. Another option for consideration would be use of 25-watt T8 lamps such as those shown in Table 2. Use of 25-watt lamps throughout, with or without de-lamping (depending on light levels), could achieve similar savings at or below those described above for the 28-watt T8 lamps. However, there are greater limitations on operating temperatures and availability of these newer low-wattage fluorescents, so we typically recommend the 28-watt lamps.

Fluorescent Energy Efficiency:

Energy Efficiency Summary:

Table 6 below summarizes the energy savings analysis of the LED lamp replacement options with occupancy sensor control of the 24/7 lighting as well as the suggested fluorescent lighting upgrades. These savings are in comparison with the current fluorescent lighting also with occupancy sensor control of the 24/7 lighting.

Retrofit Description

Estimated kWh

Savings

% of current estimated linear fluorescent usage

reduced

Estimated Energy Cost

Savings All lamps replaced with 15-watt LED lamps with occupancy sensor control of 24/7 fixtures. 66,677 49% $5,994

All lamps replaced with 21-watt LED lamps with occupancy sensor control of 24/7 fixtures. 39,226 29% $3,526

All lamps replaced with 28-watt T8 fluorescent lamps with programmed start ballasts, combined with strategic de-lamping and occupancy sensor control of 24/7 fixtures.

52,277 39% $4,699

Table 6: Potential Energy Savings Summary for Retrofit Options Notes for Table 6:

(1) The cost savings above are calculated using an electric rate of $0.09 per kWh This is based on utility bills provided by the City of Urbana. This rate includes all fees and other charges.

(2) Lamp replacement costs are not included in cost savings calculations for this table.

The originally proposed 15-watt LED retrofit lamps represent the greatest energy savings potential, however they require accepting 25-50% reduced light levels in all locations (including where there are two-lamp fixtures currently). The reported lumen output of the 21-watt LED retrofit lamps is likely not adequate to make lamp removal an option—therefore they represent a smaller overall energy reduction than the recommended package using 28-watt fluorescent lamps with de-lamping.

Replacement Costs

Appendix B shows a summary of the replacement cost analysis performed and reported below.

LED Replacement Costs:

Assuming that the lower light levels are acceptable everywhere and the least expensive LED 15-watt lamps listed in Table 1 are purchased, the replacement cost for 1334 lamps at $46 each is approximately $61,365. Also assuming the lamps will last the reported 50,000 hours, the average annual replacement cost based on estimated hours of operation, would be $4,362.

Fluorescent Replacement Costs:

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Assuming that the lower light levels are acceptable and de-lamping of three- and four-lamp fixtures occurs, the total number of lamps will be reduced from 1334 to 963, and at a replacement cost of $4.50 each, the total replacement cost would be approximately $4,335. We have included the cost to replace ballasts for the fluorescent lamps using programmed start ballasts, assuming one ballast for every two lamps. Assuming the lamps will last the reported 36,000 hours, the average annual replacement cost based on estimated hours of operation, would be $2,246.

Replacement Cost Summary:

The cost for maintaining the recommended energy-efficient, high-performance fluorescent lighting system is 48% less than for the LED 15-watt replacement lamps being considered by the City of Urbana.

Conclusions and Recommendations: The City of Urbana is to be commended as an early adopter of T8 fluorescent lighting in the Urbana City Building and for its consideration of adopting another innovative technology—LED retrofit lighting. Our study of the LED retrofit option reveals that the technology is not necessarily optimal for retrofit into office spaces where even distribution and higher light levels are generally required. However, the technology has some distinct advantages over fluorescent lighting in specific applications, including cold temperature operation17 and situations where frequent switching is desired to reduce hours of lamp operation. We therefore recommend a hybrid upgrade strategy where LED technology is used to its best advantage. The following is a summary of our recommendations:

Limited LED Retrofit—one-for-one LED lamp retrofit is suggested for the following locations: • Atrium/Lobby Space: Retrofit the two-lamp 24/7 fixtures in the lobby (20) and atrium

space (12) with 15-watt LED retrofit lamps. • Stairwells: Retrofit the two-lamp and four-lamp 24/7 fixtures in stairwells (both T8 and

T12) with 15-watt LED retrofit lamps. • Restrooms and Locker rooms: Retrofit the two- and three-lamp fixtures in all restrooms

with 15-watt LED retrofit lamps. • Corridors: Retrofit all the corridor lighting fixtures (both T8 and T12) on all levels with 15-

watt LED retrofit lamps. Where corridors are interior to office suites, be sure to match color temperature of the adjacent fluorescent lighting.

Completion of T8 and T12 Upgrades to 28-watt, high performance, low-mercury lamps: • Upgrade all remaining T8 and T12 fixtures to 28-watt high performance lamps with

electronic ballasts.

Strategic De-lamping of Remaining Fluorescent Fixtures. • Experiment with de-lamping three- and four-lamp fluorescent fixtures in offices and

storage spaces. In spaces where light levels exceed the recommended minimums for the space usage type, remove one lamp in three-lamp fixtures and two lamps in four-lamp fixtures and test light levels and occupant comfort. Purchase and install new high-performance reflectors for fixtures where de-lamping results in lower light levels than desired.

Expanded controls: • Add occupancy sensor on/off control to all 24/7 fixtures • Add occupancy sensor on/off control to all restroom and locker room fixtures (including

those that are not on 24/7 circuits).

17 LED performance increases as temperatures drop: http://www1.eere.energy.gov/buildings/ssl/cold_operation.html

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• Add occupancy sensor on/off control to all storage room fixtures (including those that are not on 24/7 circuits).

• Add daylight dimming control to the lobby and atrium fixtures as the skylight provides significant lighting in the space during most daytime hours.

Reminder: In fixtures which are to retain fluorescent lamps, upgrade controlled fixtures with programmed start ballasts.

We estimate that his combination of lighting upgrade strategies will result in a savings of 59,153 kWh, saving $5,317. This equals a 44% reduction of the current linear fluorescent usage with occupancy control of 24/7 fixtures. These savings are based the following assumptions:

• Replacement of approximately 250 lamps with 15-watt LED retrofit lamps • 33% reduction in operation hours for 24/7 fixtures through added occupancy or daylight

dimming control. • 10% reduction in operation hours for non-24/7 fixtures in restrooms, locker rooms and

storage rooms through added occupancy sensors. • Successful de-lamping of all three-lamp fixtures to two-lamps and four-lamp fixtures to

three-lamps, installing new reflectors as needed to maintain desired light levels and distribution—where fixtures are upgraded with 28-watt T8 lamps (no de-lamping with LED replacements).

These are fairly conservative assumptions. Greater savings may well be realized if occupancy sensor installation results in greater reduction in operation hours.

Additional Retrofit suggestions:

• Consider retrofitting the fixtures in the Fire Station apparatus bay with 15-watt LED retrofit lamps. (These fixtures did not appear to be included in the drawings and fixture take-off information provided by the city – however it appears to be an excellent location to take advantage of the improved cold temperature performance of the LED lamps. The day of the site visit we observed the existing fluorescent lighting was quite dim—likely due to the cold temperatures outside and the high-bay doors standing open.

• Consider replacing all metal halide and compact fluorescent lamps in corridor recessed fixtures with LED replacement lamps made for that application.

• Consider purchasing low-wattage LED task lighting (under cabinet strip lighting or desk lamps) for office spaces where de-lamping is used to reduce overall space lighting.

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Appendix A – Summary of Existing Four-Foot Linear Fluorescent Lighting

Location

Current Hours of

Operation No. of

Fixtures Lamps/ Fixture

Lamp Type

Lamp Wattage

Subtotal no. lamps

Ballast Type (*assumed)

Fixture Wattage

Subtotal kWh

Subtotal kWh

w/Occ Control

First Floor 8,760 6 2 T8 32 12 Electronic *Instant Start NLO 59 3,101 2,067

First Floor Lobby 8,760 20 2 T8 32 40 Electronic

*Instant Start NLO 59 10,337 6,892

First Floor 8,760 18 3 T8 32 54 Electronic *Instant Start NLO 87 13,718 9,146

First Floor Stairwells 8,760 4 2 T12 34 8 *Standard Magnetic 72 2,523 1,682

First Floor 2,700 6 2 T8 32 12 Electronic *Instant Start NLO 59 956 956

First Floor 2,700 96 3 T8 32 288 Electronic *Instant Start NLO 87 22,550 22,550

No. of Fixtures per Floor: 150 No. of Lamps per Floor: 414 Subtotal kWh/year per Floor: 53,185 43,293

Second Floor 8,760 3 2 T8 32 6 Electronic

*Instant Start NLO 59 1,551 1,034

Lobby Atrium

8,760 12 2 T8 32 24 Electronic *Instant Start NLO 59 6,202 4,135

Second Floor 8,760 4 4 T12 34 16 *Standard Magnetic 144 5,046 3,364

Second Floor 8,760 30 3 T8 32 90 Electronic *Instant Start NLO 87 22,864 15,243

Second Floor 2,700 2 2 T8 32 26 Electronic *Instant Start NLO 59 2,071 319

Second Floor 2,700 130 3 T8 32 390 Electronic *Instant Start NLO 87 30,537 30,537

No. of Fixtures per Floor: 181 No. of Lamps per Floor: 530 Subtotal kWh/year per Floor 66,518 54,631

Appendix A – Summary of Existing Four-Foot Linear Fluorescent Lighting (cont.)

Location

Current Hours of

Operation No. of

Fixtures Lamps/ Fixture

Lamp Type

Lamp Wattage

Subtotal no. lamps

Ballast Type (*assumed)

Fixture Wattage

Subtotal kWh

Subtotal kWh

w/Occ Control

Basement 8,760 9 2 T8 32 18 Electronic *Instant Start NLO 59 4,652 3,101

Basement 8,760 14 3 T8 32 42 Electronic *Instant Start NLO 87 10,670 7,113

Basement 2,700 30 2 T8 32 60 Electronic *Instant Start NLO 59 4,779 4,779

Basement 2,700 68 3 T8 32 204 Electronic *Instant Start NLO 87 15,973 15,973

Basement 2,700 11 2 T12 34 22 *Standard Magnetic 72 2,138 2,138

Basement 2,700 11 4 T12 34 44 *Standard Magnetic 144 4,277 4,277

No. of Fixtures per Floor: 143 No. of Lamps per Floor: 390 Subtotal kWh/year per Floor 42,489 37,382

Total No. Fixtures: 474 Total No. Lamps: 1,334 Total kWh/year: 162,191 135,307

Appendix B: Summary of Retrofit Replacement Cost Analysis

Description

Annual Hours of

Operation Assumed Lamp

Life Number of

Lamps

Assumed Ballast

Life

Cost / Lamp (incl. $2.00 labor ea.)

Cost / Ballast

(incl. $7.00 labor ea.)

Averaged Annual

Operational Cost

LED 15-watt Lamps 5840* 8.5 years (50,000 hrs) 310 N/A $47.50 N/A $1,732

LED 15-watt Lamps 2700 18.5 years (50,000 hrs) 1024 N/A $47.50 N/A $2,629

1334 $4,362

Fluorescent 28-watt Lamps with Programmed Start (PS) Ballasts

5840* 6.2 years

(36,000 hrs: 3-hour starts, PS Ballasts)

244 10 years $6.00 $35.00 $663

Fluorescent 28-watt Lamps with Programmed Start (PS) Ballasts

2700 13.3 years

(36,000 hrs: 3-hour starts, PS Ballasts)

719 10 years $6.00 $35.00 $1,583

963 $2,246

Notes for Replacement Cost Analysis: (1) This analysis assumed a 33% reduction in the annual usage hours for the 24/7 fixtures based on the installation of occupancy sensors as discussed. (2) Cost basis for LED’s uses pricing provided to the City of Urbana for EarthLED / DirectLEDFL /300 SuperBrite 15-watt replacement lamps. This is for comparison only

and is not considered an endorsement of this product. (3) Cost basis for T8 28-watt fluorescent lamps is taken from www.Goodmart.com for the Sylvania lamps currently being installed by the city (F028/835/XP/ SS/ECO).

This is for comparison only and is not considered an endorsement of this product. (4) Cost basis for the ballasts is taken from www.Goodmart.com for the Sylvania QUICKTRONIC PROStart T8 Fluorescent PSX/XPS Programmed Start ballast. This is

for comparison only and is not considered a ballast recommendation. The manufacturer should always be consulted when selecting high performance ballasts to match a particular lamp selected.

Appendix C – Recommended Minimum Interior Light Levels Please note: The “Light Level” ranges in the following table are minimum recommended footcandle (FC) levels for the given functional areas. Whereas the “Lighting Power Density” ranges in the table are maximum watts per square foot that should be necessary in designing

the lighting to attain the minimum light levels.