Cree® XLamp® XQ-B LED 2’ x 2’ Troffer Reference Design Table of Contents Introduction Introduction....................................................................................1 This application note details the design of a 2’ x 2’ troffer using Design approach/objectives.........................................................2 Cree’s XLamp® XQ-B LED. This troffer is intended to be used The 6-step methodology................................................................2 in commercial and industrial applications. These applications, 1. Define lighting requirements.................................................2 that historically have used U-bend and T8 fluorescent luminaires 2. Define design goals................................................................5 typically providing 70‑80 lumens/watt, can benefit from 3. Estimate efficiencies of the optical, thermal & electrical the energy savings and high efficiency provided by a XQ-B systems...................................................................................5 4. Calculate the number of LEDs...............................................7 5. Consider all design possibilities............................................7 6. Complete the final steps: implementation and analysis......8 Conclusions..................................................................................12 Bill of materials............................................................................12 CLD-AP156 rev 0C Application Note LED‑based troffer. The XLamp XQ-B LED is designed specifically for applications that require a broad light distribution. The breakthrough lightemission pattern, where more light is directed toward the edge rather than center of the LED, and the high flux output and efficacy offered by the XLamp XQ-B LED make it a particularly strong candidate for use in a troffer. The performance of the XQ-B LED enables a troffer that provides energy savings while www.cree.com/Xlamp delivering superior light output. Reliance on any of the information provided in this Application Note is at the user’s sole risk. Cree and its affiliates make no warranties or representations about, nor assume any liability with respect to, the information in this document or any LED-based lamp or luminaire made in accordance with this reference design, including without limitation that the lamps or luminaires will not infringe the intellectual property rights of Cree or a third party. Luminaire manufacturers who base product designs in whole or part on any Cree Application Note or Reference Design are solely responsible for the compliance of their products with all applicable laws and industry requirements. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. Cree, Inc. 4600 Silicon Drive Durham, NC 27703 USA Tel: +1.919.313.5300 1 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Design approach/objectives In the “LED Luminaire Design Guide” Cree advocates a six-step framework for creating LED luminaires and lamps. All Cree reference designs use this framework, and the design guide’s summary table is reproduced below in Table 1. Table 1: Cree 6-step framework Step Explanation 1. Define lighting requirements • The design goals can be based either on an existing fixture or on the application’s lighting requirements. 2. Define design goals • Specify design goals, which will be based on the application’s lighting requirements. • Specify any other goals that will influence the design, such as special optical or environmental requirements. 3. Estimate efficiencies of the optical, thermal & electrical systems • Design goals will place constraints on the optical, thermal and electrical systems. • Good estimations of efficiencies of each system can be made based on these constraints. • The combination of lighting goals and system efficiencies will drive the number of LEDs needed in the luminaire. 4. Calculate the number of LEDs needed • Based on the design goals and estimated losses, the designer can calculate the number of LEDs to meet the design goals. 5. Consider all design possibilities and choose the best • With any design, there are many ways to achieve the goals. • LED lighting is a new field; assumptions that work for conventional lighting sources may not apply. 6. Complete final steps • • • • • Complete circuit board layout. Test design choices by building a prototype luminaire. Make sure the design achieves all the design goals. Use the prototype to further refine the luminaire design. Record observations and ideas for improvement. The 6-step methodology The goal of the design is an XLamp XQ-B LED-based 2’ x 2’ troffer providing 100 lumens per watt for use in indoor commercial and industrial ceiling applications. 1. Define lighting requirements Table 2 shows a ranked list of desirable characteristics to address in a troffer. Table 2: Ranked design criteria for a troffer Importance Critical Important Characteristics Units Luminous flux lumens (lm) Luminous efficacy lm/W Electrical power watts (W) Lifetime hours Operating temperatures °C Operating humidity % relative humidity Correlated color temperature (CCT) K Color rendering index (CRI) 100-point scale Table 3 summarizes the ENERGY STAR® requirements for solid-state luminaires.1 There are no ENERGY STAR requirements for troffers. 1 ENERGY STAR Program Requirements, Product Specification for Luminaires (Light Fixtures), Eligibility Criteria, Version 1.2 Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 2 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Table 3: ENERGY STAR luminaire requirements Characteristic Requirements Light source life requirements: all luminaires The LED package(s) / LED module(s) / LED array(s), including those incorporated into LED light engines or GU24 based integrated LED lamps, shall meet the following L70 lumen maintenance life values (refer to Lumen Maintenance Requirements in the next section): • 25,000 hours for residential grade indoor luminaires • 35,000 hours for residential grade outdoor luminaires • 35,000 hours for commercial grade luminaires Lumen maintenance life projection claims in excess of the above requirements shall be substantiated with a TM-21 lumen maintenance life projection report. Lumen maintenance requirements: directional and non-directional luminaires The LED package(s) / module(s) / array(s), including those incorporated into LED light engines or GU24 based integrated LED lamps, shall meet the following • L70(6k) rated lumen maintenance life values, in situ: • L70(6k) ≥ 25,000 hours for residential indoor • L70(6k) ≥ 35,000 hours for residential outdoor, or commercial Compliance with the above shall be documented with a TM-21 lumen maintenance life projection report as detailed in TM-21, section 7. The report shall be generated using data from the LM-80 test report for the employed LED package/module/array model (“device”), the forward drive current applied to each device, and the in situ TMPLED temperature of the hottest LED in the luminaire. In addition to LM-80 reporting requirements, the following information shall be reported: • • • • • • sampling method and sample size (per LM-80 section 4.3) test results for each TS and drive current combination description of device including model number and whether device is an LED package, module or array (see Definitions) ANSI target, and calculated CCT value(s) for each device in sample set Δ u’v’ chromaticity shift value on the CIE 1976 diagram for each device in sample set a detailed rationale, with supporting data, for application of results to other devices (e.g. LED packages with other CCTs) Access to the TMPLED for the hottest LED may be accomplished via a minimally sized hole in the luminaire housing, tightly resealed with a suitable sealant if created for purposes of testing. All thermocouple attachments and intrusions to luminaire housing shall be photographed. CCT requirements: all indoor luminaires The luminaire (directional luminaires), or replaceable LED light engine or GU24 based integrated LED lamp (non-directional luminaires) shall have one of the following nominal CCTs: • • • • • 2700 Kelvin 3000 Kelvin 3500 Kelvin 4000 Kelvin 5000 Kelvin (commercial only) The luminaire, LED light engine or GU24 based integrated LED lamp shall also fall within the corresponding 7-step chromaticity quadrangles as defined in ANSI/NEMA/ANSLG C78.377-2008. Color rendering requirements: all indoor luminaires The luminaire (directional luminaires), or replaceable LED light engine or GU24 based integrated LED lamp (non-directional luminaires) shall meet or exceed Ra ≥ 80. Color angular uniformity requirements: directional solid state indoor luminaires Throughout the zonal lumen density angles detailed above, and five degrees beyond, the variation of chromaticity shall be within 0.004 from the weighted average point on the CIE 1976 (u’,v’) diagram. Color maintenance requirements: solid state indoor luminaires only The change of chromaticity over the first 6,000 hours of luminaire operation shall be within 0.007 on the CIE 1976 (u’,v’) diagram, as demonstrated by either: • the IES LM-80 test report for the employed LED package/array/module model, or • as demonstrated by a comparison of luminaire chromaticity data in LM-79 reports at zero and 6,000 hours, or • as demonstrated by a comparison of LED light engine or GU24 based integrated LED lamp chromaticity data in LM-82 reports at zero and 6,000 hours. Source start time requirement: directional and non-directional luminaires Light source shall remain continuously illuminated within one second of application of electrical power. Source run-up time requirements: directional and non-directional luminaires Light source shall reach 90% of stabilized lumen output within one minute of application of electrical power. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 3 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Characteristic Requirements Power factor requirements: directional and non-directional luminaires Total luminaire input power less than or equal to 5 watts: PF ≥ 0.5 Transient protection requirements: all luminaires Ballast or driver shall comply with ANSI/IEEE C62.41.1-2002 and ANSI/IEEE C62.41.2-2002, Class A operation. The line transient shall consist of seven strikes of a 100 kHz ring wave, 2.5 kV level, for both common mode and differential mode. Operating frequency requirements: directional and non-directional luminaires Frequency ≥ 120 Hz Noise requirements: directional and non-directional luminaires All ballasts & drivers used within the luminaire shall have a Class A sound rating. Total luminaire input power greater than 5 watts: Residential: PF ≥ 0.7 Commercial: PF ≥ 0.9 Note: This performance characteristic addresses problems with visible flicker due to low frequency operation and applies to steady-state as well as dimmed operation. Dimming operation shall meet the requirement at all light output levels. Ballasts and drivers are recommended to be installed in the luminaire in such a way that in operation, the luminaire will not emit sound exceeding a measured level of 24 BA. The DesignLights Consortium® (DLC) and the Department of Energy (DOE) Better Buildings Alliance (BBA) provide requirements for 2’ x 2’ troffers, summarized in Table 4.2,3 Table 4: DLC and BBA 2’ x 2’ troffer requirements Characteristic Minimum light output Unit lm DLC Value BBA Value 2,000 2,000 0°-180°: 1.0-1.20 90°-270°: 1.0-2.0 ≥ 75% 0-60° 0°-180°: 1.0-2.0 90°-270°: 1.0-2.0 lm/W 85 85 K < 5000 2700, 3000, 3500, 4000/4100, 4500, 5000 80 Ra > 80 and R9 > 0 L70 lumen maintenance hours 50,000 > 50,000 Minimum luminaire warranty years 5 5 Spacing criteria Minimum luminaire efficacy Allowable CCTs (ANSI C78.377-2008) Minimum CRI The spacing criteria value provides information about the uniformity of light distribution of one luminaire. It is a horizontal-spacing-tomounting-height ratio without units. The 0°-180° value applies along a luminaire’s length; the 90°-270° value applies along a luminaire’s width. When two overhead luminaires are at their maximum horizontal spacing, the illuminance directly beneath one is due mainly to the luminaire overhead. A low point of illumination is apt to be at the midpoint between two luminaires. The horizontal spacing between two luminaires is typically chosen so the illumination at the midpoint is equal to the illumination directly beneath one luminaire that is due only to that luminaire. For luminaires arranged in a square, a low illumination point is apt to be at the center of the square and the luminaire spacing is chosen so that the illumination at the center of the square is equal to the illumination directly beneath one luminaire that is due only to that luminaire. A larger spacing criteria value therefore suggests luminaires that can be spaced farther apart, and require fewer luminaires to achieve a given illumination, than those having a smaller spacing criteria value. Installing luminaires at their spacing criteria value does not guarantee a good lighting system. The spacing criteria value does not account for reflected illumination or for illumination from other luminaires and is an estimate and only a guideline. 2 3 Technical Requirements Table v2.0, DesignLights Consortium Qualified Products List - Non-Residential Applications BBA Model Technical Specification: High-Efficiency Troffers, A Better Building Alliances (BBA) Project, Version 4.0, Released 4/15/2013 Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 4 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design 2. Define design goals Table 5 shows the design goals for this project. Table 5: Design goals Characteristic Light output Luminaire efficacy Unit Minimum Goal Target Goal lm 4000 > 4000 lm/W 100 > 100 Power W 40 < 40 CCT K 5000 < 5000 CRI 100-point scale 80 >80 0.9 > 0.9 Power factor 3. Estimate efficiencies of the optical, thermal & electrical systems We used Cree’s Product Characterization Tool (PCT) tool to determine the drive current for the design. For the 4000‑lm target, we estimated 85% optical efficiency and 90% driver efficiency. We also estimated a 40 °C solder‑point temperature. The PCT output highlighted in Figure 1 shows that, at 56 mA, 225 XQ-B LEDs provide sufficient light output to meet the design goals. 1 LED 1 Cree XLamp XQ-B {WT} x75 Current (A) Model $ Price SYS lm tot SYS lm/W 0.052 0.054 0.056 0.058 0.060 5090.1 5269.6 4086.1 4219.2 4351.6 Flux K2 [30.6] 102.5 101.9 101.3 100.8 100.2 Tsp (ºC) SYS W 49.674 51.719 40.329 41.874 43.426 40 SYS # LED 300 300 225 225 225 Figure 1: PCT view of the number of LEDs used and drive current Troffer Housing We used a market-available 2’ x 2’ troffer housing, shown in Figure 2. Because of the troffer’s relatively large size and the low LED current, we believe that a heat sink is not needed. We mounted the LED printed‑circuit boards (PCB) directly to the housing and are confident the housing provides sufficient thermal dissipation. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 5 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Figure 2: Troffer housing Optical Requirements This LED troffer reference design uses a shallow housing, creating an optical cavity that requires efficient light recycling to achieve the 100 lm/W goal. We used an optical system consisting of reflective paper to maximize the amount of light emitted from the troffer and a polycarbonate diffuser sheet provided with the housing to cover the opening of the troffer and provide smooth light output without hot spots. The reflector sheet was made to fit the housing and accommodate the LED arrangement. Electrical Requirements Driver Because this is not an integrated lamp design, the driver form factor is not constrained and the driver can be remotely located above the ceiling. We used a constant-current driver, shown in Figure 3, located separate from the troffer. Figure 3: Driver Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 6 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design 4. Calculate the number of LEDs Using Cree’s PCT, we determined that 225 XLamp XQ-B LEDs produce sufficient light to meet the 4000-lm design goal. The LEDs are arranged in a 15 x 15 array that spans the length and width of the housing with even spacing between the individual LEDs. As shown in Figure 4, the LEDs in adjacent rows are symmetrically offset to aid in diffusing the light output of the luminaire. Fifteen LEDs are connected in series on each of fifteen metal‑core printed‑circuit boards (MCPCB) that are connected in parallel. Figure 4: XQ-B LED arrangement The XLamp XQ-B LED offers a wide range of color temperatures. We selected a neutral white LED for this troffer design, shown highlighted in Table 6. To show the performance available from the XQ-B LED, we selected an LED from a high‑level bin. Table 6: XQ-B order codes XLamp XQ-B LED Standard Kit Codes - White Chromaticity Kit CCT Minimum Luminous Flux (lm) @ 80 mA Code Flux (lm) Order Codes 70 CRI Minimum 75 CRI Typical 80 CRI Minimum ANSI Neutral White (3700 K – 5000 K) E3 5000 K F4 4750 K E4 4500 K F5 4250 K E5 4000 K K2 30.6 XQBAWT-00-0000-00000B0E3 XQBAWT-00-0000-00000L0E3 XQBAWT-00-0000-00000B0F4 XQBAWT-00-0000-00000L0F4 J3 26.5 K2 30.6 J3 26.5 K2 30.6 J3 26.5 K2 30.6 XQBAWT-00-0000-00000B0F5 XQBAWT-00-0000-00000H0E3 XQBAWT-00-0000-00000HXE3 XQBAWT-00-0000-00000H0F4 XQBAWT-00-0000-00000HXF4 XQBAWT-00-0000-00000B0E4 XQBAWT-00-0000-00000L0E4 XQBAWT-00-0000-00000H0E4 XQBAWT-00-0000-00000HXE4 J3 26.5 XQBAWT-00-0000-00000BXF5 K2 30.6 XQBAWT-00-0000-00000B0E5 J3 26.5 XQBAWT-00-0000-00000BXE5 J2 23.5 XQBAWT-00-0000-00000L0F5 XQBAWT-00-0000-00000H0F5 XQBAWT-00-0000-00000HXF5 XQBAWT-00-0000-00000L0E5 XQBAWT-00-0000-00000H0E5 XQBAWT-00-0000-00000HXE5 XQBAWT-00-0000-00000HWE5 5. Consider all design possibilities There are many ways to design an LED-based 2’ x 2’ troffer. This reference design aims to show that the XLamp XQ-B LED enables a 2’ x 2’ troffer offering superior performance. Table 7 contains data from the PCT for various numbers of XQ-B LEDs that indicate that troffers using different numbers of XQ-B LEDs are possibilities. Like the data in Figure 1, for the 4000-lm target, we estimated 85% optical efficiency and 90% driver efficiency. The solder point temperature estimates are given in the table. Increasing the drive current and reducing the number of LEDs to reduce cost can enable a troffer that meets the DLC and BBA requirements. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 7 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Table 7: Possible troffer implementations Number of XQ-B LEDs Current (mA) System Flux (lm) System Power (W) System Efficacy (lm/W) TSP (°C) 225 56 4070 40.5 101 40 185 70 4071 42.0 97 45 150 90 4080 44.6 92 50 130 110 4113 47.8 86 60 Because this prototype troffer uses XLamp XQ-B LEDs from the same bin, in fact, from the same reel of LEDs, color mixing is not a consideration and unit-to-unit consistency is ensured. Such a situation is less likely in a production environment. Our choice of housing determined the fixture depth and the distance from the LEDs to the diffuser. The goal of this reference design is not to design the optimum troffer, but to show the performance possible from a troffer based on the XLamp XQ-B LED. Refer to Cree’s Color Mixing and Distributed Illumination application notes for other approaches to designing LED-based luminaires that produce uniform, consistent white light. 6. Complete the final steps: implementation and analysis Using the methodology described above, we determined a suitable combination of LEDs, components and drive conditions. This section describes how Cree assembled the troffer and shows the results of the design. Prototyping Details 1. We verified the component dimensions to ensure a correct fit. 2. Following the recommendations in Cree’s Soldering and Handling Application Note for the XQ-B LED, with an appropriate solder paste and reflow profile, we reflow soldered the LEDs to the MCPCBs. We cleaned the flux residue with isopropyl alcohol (IPA). 3. We applied a small amount of thermally conductive compound to the back of the MCPCBs and mounted the MCPCBs on the base of the housing, securing them with screws.4 4. We soldered the MCPCB interconnect wires to the MCPCBs and fed the wires through an opening in the back of the housing. 5. We soldered the MCPCB interconnect wires to the driver and tested the troffer to make sure the LEDs illuminated. 6. We installed reflective paper (with cutouts for the LEDs) over the LEDs and on the inside walls of the housing. 7. We installed the diffuser sheet, aligning it on the top of the housing. 8. We finished the construction by securing the diffuser using the top decorative housing frame. 9. We performed final testing. Results Thermal Results Cree used a thermocouple to measure the troffer’s thermal performance. The measured TSP of 32.5 °C confirms that the thermal dissipation of the troffer’s aluminum housing is sufficient for this design. 4 Refer to Cree’s Chemical Compatibility application note for compounds that are safe to use with Cree LEDs. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 8 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Based on the measured solder point temperature, the junction temperature (TJ) can be calculated as follows. TJ = TSP + (LED power * LED thermal resistance) TJ = 32.5 °C + (.2 W * 17 °C/W) TJ = 35.9 °C Estimated LED lifetime Based on thousands of hours of long-term testing of the XLamp XQ-B LED at operating conditions similar to those of this troffer, Cree expects an L70 lifetime significantly longer than the DLC and BBA 50,000-hour L70 lumen maintenance requirements for this design. Optical and Electrical Results We obtained the results in Table 8 by testing the troffer in a 1.5-meter sphere at steady state after a 60-minute stabilizing time.5 The results meet the ENERGY STAR performance levels for a solid-state luminaire and the DLC and BBA light output requirements for a 2’ x 2’ troffer. Table 8: XQ-B 2’ x 2’ troffer steady-state results Characteristic Light output Unit Result lm 4070 0°-180°: 1.28 90°-270°: 1.28 Spacing criteria Luminaire efficacy lm/W 101 Power W 40.5 CCT K 5087 CRI 100-point scale Power factor CBCP Beam angle 83 0.9 cd 1400 degrees 114 We also tested the intensity distribution of the XQ-B troffer. Figure 5 shows that the troffer has an even intensity distribution. 5 Testing was performed at Cree’s Shanghai Technology Center. An IES file for the troffer is available. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 9 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Figure 5: Polar plot of XQ-B 2’ x 2’ troffer Table 9 shows the illuminance of the XQ-B troffer at various distances from the light source. Table 9: XQ-B 2’ x 2’ troffer illuminance Height Illuminance Eavg Emax Eavg Emax Diameter 1m 3.3 ft 37.5 fc 130.7 fc 403.7 lx 1407.0 lx 3.1 m 10.1 ft 2m 6.6 ft 9.4 fc 32.7 fc 100.9 lx 351.8 lx 6.1 m 20.1 ft 3m 9.8 ft 4.2 fc 14.5 fc 44.9 lx 156.3 lx 9.2 m 30.2 ft 4m 13.1 ft 2.3 fc 8.2 fc 25.2 lx 88.0 lx 12.3 m 40.2 ft 5m 16.4 ft 1.5 fc 5.3 fc 16.2 lx 56.3 lx 15.3 m 50.3 ft We used DIALux software to simulate the illumination of a room 30’ wide and 30’ long, with a 15’ ceiling.6 Figure 6 shows simulated false‑color illumination of the room with four troffers. The legend shows the minimum values in footcandles (fc) for the various colors in the simulation. The diagrams in the bottom show the minimum illumination values on the floor. The troffers were specified as surface mounted, evenly spaced at 7.5’ from the nearest walls and 15’ from the adjacent troffers. Simulations were done for two comparison fluorescent 2’ x 2’ troffers and the XQ-B 2’ x 2’ troffer. The fluorescent troffers simulated were included as comparison troffers in the US Department of Energy (DOE) Commercially Available Light-Emitting Diode Product Evaluation and Reporting (CALiPER) study of LED troffers.7 The simulation shows that the XQ-B troffer provides more light throughout the room than fluorescent troffer A. The XQ-B troffer illumination pattern is similar to that of fluorescent troffer B, but provides more light on the walls and ceilings. 6 7 DIALux software version 4.11, DIALux GmbH US DOE Caliper Exploratory Study: LED Troffer Lighting Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 10 Project 1 07 / 15 / 2013 DIALux 4.11 Output Operator Telephone Fax e-Mail Page 8 of 8 XQB 07 / 15 / 2013 Project 1 Operator Telephone Fax e-Mail XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design 07 / 15 / 2013 Room 1 / False Color Rendering Operator Telephone Fax e-Mail Room 1 / False Color Rendering Room 1 / False Color Rendering DIALux 4.11 Output Project 1 Page 3 of 8 XQB Project 1 07 / 15 / 2013 07 / 15 / 2013 Operator Telephone Fax e-Mail Legend (fc) 4.64 5.57 5.57 5.57 6.50 0 0.93 6.50 0 0.93 1.86 7.43 7.43 7.43 4.64 7.43 7.43 7.43 7.43 5.57 7.43 5.57 5.57 DIALux 4.11 by DIAL GmbH 11.15 6.50 5.57 7.43 7.43 7.43 Room 1 / Summary fc 30.00 ft 11.15 11.15 9.29 13.012.79 1.86 3.72 4.64 5.57 13.01 6.50 7.43 fc 0 9.29 Page 8 1.86 0.93 4.64 3.72 2.79 fc 9.29 13.01 13.01 11.15 DIALux 4.11 Output 11.15 5.57 9.29 9.29 Page 8 9.29 fc 7.43 11.15 Page 8 of 8 11.15 9.29 9.29 9.29 Page 8 9.29 11.15 DIALux 4.11 by DIAL GmbH 11.15 9.29 7.50 Page 8 11.15 9.29 7.43 0.00 7.43 9.29 0.00 30.00 ft Figure 6: Illumination simulation - left: XQ-B troffer 0.00 fluorescent troffer A, center: fluorescent 30.00 ft troffer 0.00B, right:7.50 0.00 6.50 5.57 9.29 DIALux 4.11 by DIAL GmbH 5.57 22.50 11.15 11.15 6.50 30.00 ft 9.29 9.29 9.29 9.29 9.29 6.50 6.50 0.93 DIALux 4.11 by DIAL GmbH 7.43 7.43 7.43 7.43 2.79 7.433.72 7.43 5.57 0 6.50 7.43 9.29 11.15 9.29 11.15 5.57 5.57 2.79 9.29 6.50 6.50 Room 1 / Summary 3.72 4.64 5.57 1.86 30.00 ft 4.64 Operator Telephone Fax e-Mail Operator Telephone Fax e-Mail 0.00 22.50 30.00 ft Height of Room: 15.000 ft, Mounting Height: 15.000 ft, Light loss factor: Values in Footcandles, Scale 1:118 Height of Room: 15.000 ft, Mounting Height: 15.000 ft, Light lossHeight of Room: Values 15.000 in Footcandles, Scale ft, Mounting Height: 15.000 ft, Light loss factor: factor: 1:118 to be 2.493’ 0.80workplane was specified Table0.80 10 shows the illumination values throughout the0.80 room for the simulations in Figure 6. The Surface E [fc] E [fc] E [fc] u0 [%] Eav [fc] the room EminSurface [fc] Emax [fc] troffer Eav [fc] av min max [%] [%]A u0 above the floor. Table 10 also shows that the XQ-BSurface troffer puts more light throughout than fluorescent and more light on Workplane the walls and Floor ceiling Ceiling the fluorescent troffers. Walls (4) / 6.21 than troffer 20 fluorescent 5.61 80 50 1.39 3.43 3.66 Workplane B.Floor The3.58 ratios 1.01 Ceiling Walls1.35 (4) show 7.54 / that 6.94 20the 1.64 80 5.39 50 0.58911 XQ-B troffer 0.639 9.65 0.728 2.19 / 5.14 5.40 13 Workplane produces of 5.79 Floora uniformity12 1.63 2.61 Ceiling 2.17 7.88 Walls (4) 0.510 / light 20 nearly 0.600 0.745 80 / 50 11 identical 9.52 to 2.51 6.22 Emin 5 5 1 2 Workplane: UGR LengthwaysAcross data to luminaire Table 10: Illumination from axis simulation Workplane:Across to luminaire axis Workplane: UGR LengthwaysHeight: 2.493 ft Left Wall 16 17 Height: 2.493 ft Left Wall 17Height: 18 2.493 ft Grid: 32 x 32 Points Lower Wall 16 17 64 x 64 Points Grid: 64 x 64 Points Lower Wall 17Grid: 18 Emax Emin Boundary Zone: 0.000 ft (CIE, SHR = 0.25.) Troffer Surface (fc) Emax/Emin Emax/Eavg 0.000 ft BoundaryEav Zone: 0.000 ft (CIE, SHR =Eavg/Emin 0.25.) Boundary Zone: (fc) (fc) Illuminance Quotient (according to LG7): Walls / Working Plane: 0.559, Ceiling / Working Plane: 0.224. Quotient (according LG7): Walls / Working Plane: 0.604, Illuminance Quotient (according to LG7): Walls / Working Plane:Illuminance 0.487, Ceiling / Working Plane: to 0.207. Luminaire Parts List Workplane 7.54 6.21 List 3.66 2.1 1.7 Luminaire Parts 1.2 List Luminaire Parts No. 1 Pieces 4 Designation (Correction Factor)Floor A FINELITE,Troffer INC. FINELITE HPR-x-2X2-2T8Ceiling DCO 2' X 2' FLUORESCENT RECESSED LUMINAIRE WHITE REFLECTOR, Walls& FROSTED PLASTIC SIDE LENSES FROSTED .080 CENTER LENS (1.000) [W] (Luminaire) 3.58 (Lamps) [lm] P1.9 6.94 5.61[lm] No. Pieces Designation (Correction Factor) 1.6No. 1.2 Pieces Designation P [W] Factor) (Luminaire) [lm] (Lamps) [lm] (Correction 1.64 Lighting 2SP G B 2U316 1.39Lithonia 1.01 1.6 1.4 1 1 5.39 4 Troffer Air Handling, 2'x2', 2 Lamp, 3.43 1.35 4.0 2.5 A12 GEB Specification 2329 2700 Premium 30.0 T8 U6, Pattern #12 Acrylic Lens, Ballast (1.000)2.4 11 Electronic 5.4 Total: 9316 Total: 10800 120.0 4 *Modified Technical Specifications 3776 1.6 5300 53.0 13 Floor 12 9.65 5.79 2.1 Ceiling 2.61 2.19 1.63 1.6 1.3 1.2 Walls 7.88 5.14 2.17 3.6 2.4 1.5 Workplane 13 11 5.9 2.2 1.9 1.2 11 9.52 5.86 1.9 DIALux 4.11 by DIAL GmbH 1.6 1.2 4.11 Output2.51 Ceiling DIALux2.88 1.76 1.6 1.4 1.1 2.45 3.9 2.5 1.5 Total: 1.7 15104 Total: 1.2 21200 212.0 Specific connected load: 0.13 W/sq B ft = 0.21 W/sq ft/10 fc (Ground area: 900.02 sq ft) Troffer Specific connected load: 0.24 W/sq ft = 0.22 W/sq ft/10 fc (Ground area: 900.02 sq ft) DIALux 4.11 by DIAL GmbH XQ-B Troffer Floor Walls 9.52 6.22 Page 3 To Specific connected 2.0 1.2load: 0.16 W/sq ft = 0.16 W/sq ft/10 fc (Ground area Workplane DIALux 4.11 by DIAL GmbH (Lu EVERFINE K2 5000K (Type 1)* (1.000) 1.2 Page 3 Page 3 of 8 Table 11shows luminous flux and power values from the simulation. The XQ-B troffer is not only brighter than the fluorescent troffers but is also 41% more efficient than troffer A and 55% more efficient than troffer B. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 11 XLamp ® XQ-B LED 2’ x 2’ Troffer Reference Design Table 11: Luminance and power data from simulation Lumens (lm) Troffer 1 Troffer Power (W) 4 Troffers 1 Troffer 4 Troffers Efficacy (lm/W) Troffer A 2329 9316 30 120 78 Troffer B 3776 15,104 53 212 71 XQ-B Troffer 4071 16,283 37 148 110 Conclusions This reference design illustrates the excellent results produced by a high-performance troffer based on the Cree XLamp XQ-B LED. The design uses commercially available components to produce a 2’ x 2’ troffer that meets the DLC and BBA light output requirements for the form factor. The troffer provides significantly more than 4000 lm of light output with excellent efficacy of better than 100 lm/W. The lighting-class performance of the Cree XLamp XQ-B LED makes it an attractive design option for an LED-based troffer. Bill of materials Table 12: Bill of materials for XQ-B 2’ x 2’ troffer Component Order Code/Model Number Company Web Link Driver LP40W-48-C0830 XHG Tech www.xhg-tech.cn LED XQBAWT-00-0000-00000H0E3 Cree, Inc. XQ-B product page Reflective paper Micro Cell PET Furukawa Electric www.furukawa.co.jp/foam/english/mcpet/index.htm Thermally conductive compound Black Ice 712 Timtronics www.timtronics.com/electricallyconductive.htm Reliance on any of the information provided in this Application Note is at the user’s sole risk. Cree and its affiliates make no warranties or representations about, nor assume any liability with respect to, the information in this document or any LED-based lamp or luminaire made in accordance with this reference design, including without limitation that the lamps or luminaires will not infringe the intellectual property rights of Cree or a third party. Luminaire manufacturers who base product designs in whole or part on any Cree Application Note or Reference Design are solely responsible for the compliance of their products with all applicable laws and industry requirements. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree® and XLamp® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. Other trademarks, product, and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 12