Horticultural Lighting Technical Requirements

Technical Requirements for Horticultural Lighting V2.0

 

V2.0 Interim Application Period


Single product and family grouping application types will follow an interim application process utilizing both the application portal and email communications from April to June 2021. Update and private label applications are on hold until the end of the interim application period. The DLC will begin accepting update and private label applications in June 2021.

Please reference the Interim Application Period Guidance for V2.0 for submission details.  If you do not have a critical time frame to list your product(s), please consider delaying until approximately June 1, 2021.

 

Horticultural Technical Requirements V2.1


As a minor update to the Technical Requirements, Hort V2.1 will not contain an efficacy increase. However, V2.1 will expand the range of horticultural lighting products eligible to be qualified on the Hort QPL. 

 

    Horticultural lighting products using LEDs must comply with the provisions of this document to be eligible for listing on the DLC Solid-State Horticultural Lighting Qualified Products List (“Horticultural QPL”, “Hort QPL”). Products eligible for DLC qualification must be complete LED light fixtures. That is, they must be electromagnetic radiation-generating devices analogous to luminaires (or fixtures) as defined by ANSI/IES RP-16 sections 6.8.5 and 10.3.1.


    Definitions

    Unless otherwise noted, DLC policy nomenclature directly references the definitions from the American Society of Agricultural and Biological Engineers (ASABE) ANSI/ASABE S640: Quantities and Units of Electromagnetic Radiation for Plants (Photosynthetic Organisms), and, where applicable, the Illuminating Engineering Society (IES) ANSI/IES RP-16: Nomenclature and Definitions for Illuminating Engineering, with key deviations or interpretations noted. Each mention of the term “LED device” in this document is meant to reference LED packages, modules, or arrays.


    Eligibility

    Products designed and intended to operate with standard North American nominal AC line voltages (typically 120V – 480V) are eligible for DLC qualification. The following are further eligibility rules for horticultural lighting equipment:

    • Products that are lamps (analogous to RP-16 sections 6.8.5.3 and 6.8.5.4), light engines (analogous to RP-16 section 6.8.5.5), or identified as retrofit kits intended to replace the light sources or other structures within an existing fixture are not eligible for qualification at this time.
    • Fixtures that incorporate light sources other than LED, whether as sole-source or as LED-hybrid fixtures, are not eligible for qualification at this time.
      • Fixtures that employ externally supplied active cooling systems, including circulating liquid and ducted forced air, are not eligible for qualification at this time.
      • Fixtures that incorporate internal active cooling systems that can be measured via standardized fixture test procedures, such as on-board fans, are eligible.
    • Manufacturers must list full and complete model numbers that clearly demonstrate all qualified product options offered.
      • “Full and complete model numbers” means model numbers that include all performance-affecting and non-performance-affecting variations offered, and which do not omit any option that is available to customers in the market. In general, options that do not affect the performance of the product can be submitted as a single model number, and the multiple options can be denoted by bracketing them in the model number.
      • For example, a product that has multiple exterior paint color options or mounting options that do not affect performance may include all color and mounting options in brackets (e.g. "[WH, BLK, SLV, GRY]") within a single model number. Low and high voltage options may be submitted as a single model number (e.g. "ABC 300 [120V-277V, 347V-480V] WH") with the worst-case performance reported. Multiple driver variations may be included in single product applications, as noted above, and listed in a single model number as long as they perform nominally the same. If the drivers perform nominally differently – that is, they are not presented to customers as having the same performance other than voltage input and result in different ordering codes – then the unique drivers must be listed in separate model numbers. Options that affect the flux output, presence or lack of dimming capabilities, or spectral tuning options cannot be bracketed and submitted as a single model number.
      • DLC reviewers may check web listings and other marketing materials and reserve the right to request additional information to demonstrate the full and complete model number. A lack of clarity in model numbers will result in delayed application processing; misrepresentation of model numbers in the application process discovered outside the application process will generally be considered a violation of the DLC program and trademark rules.
      • Each model number can only represent the fixture under a single brand. If the fixture can be sold under multiple brands, model numbers must be listed separately for each brand.

    Testing Methods and Requirements

    The DLC Technical Requirements for LED-based Horticultural Lighting are as follows. Details explaining each item follow below the table.


    Table 1: DLC Horticultural Lighting Technical Requirements
    Parameter/Attribute/Metric
    Requirement
    Requirement Type
    Method of Measurement/Evaluation
    Photosynthetic Photon Flux (Φp or PPF)
    (µmol × s-1)
    n/a Reported

     (ANSI/IES LM-79) 400-700nm range, with 400-500nm, 500-600nm, and 600-700nm bins reported alongside the total

    Far-Red Photon Flux 
    (Φp,fr or PFFR
    (µmol × s-1)
    n/a Reported (ANSI/IES LM-79)
    700-800nm range

    Photon Flux
    (PFPBAR

    (µmol × s-1)

    n/a Reported (Optional)

    (ANSI/IES LM-79)
    280-800nm range

    Spectral Quantum Distribution 
    (SQD) 

    (µmol × s-1 × nm-1)

    n/a Reported

     (ANSI/IES LM-79)
    (ANSI/IES TM-33-18)
    400-800nm range

    Photosynthetic Photon Intensity Distribution 
    (IP or PPID)

    (µmol × s-1 × sr-1)

    n/a Reported

    (ANSI/IES LM-79)
    (ANSI/IES TM-33-18)
    400-700nm range

    Photosynthetic Photon Efficacy 
    (K
    p or PPE) 
    (µmol × J-1)

    ≥1.90 µmol × J-1 Required/Threshold

    (ANSI/IES LM-79)
    400-700nm range

    Photon Efficacy
    (PEPBAR

    (µmol × J-1)

    n/a Reported (Optional)

    (ANSI/IES LM-79)0
    280-800nm range

    Photon Flux Maintenance, Photosynthetic 
    (PFMP)

    Q90 ≥36,000 hours Required/Threshold

    (ANSI/IES LM-80 / IES TM-21 or IES LM-84 / IES TM-28) 400-700nm range, fixture technical specification sheet, and In-Situ Temperature Measurement Test (ISTMT)

    Photon Flux Maintenance, Far-Red
    (PFMFR)

    Report time to Q90 Reported

    (ANSI/IES LM-80 / IES TM-21 or IES LM-84 / IES TM-28)
    700-800nm range

    Driver Lifetime ≥50,000 hours Required/Threshold Driver technical specification sheet, fixture technical specification sheet, and In-Situ Temperature Measurement Test (ISTMT)
    Fan Lifetime ≥50,000 hours Required/Threshold Fan technical specification sheet, fixture technical specification sheet
    Warranty 5 years Required/Threshold Legal warranty terms & conditions

    Power Factor
    (PF)

    ≥0.9 Required/Threshold Benchtop electrical testing or ANSI/IES LM-79

    Total Harmonic Distortion, Current
    (THDi)

    ≤20% Required/Threshold Benchtop electrical testing or ANSI/IES LM-79
    Safety Certification Horticultural Lighting designation by OSHA NRTL or SCC-recognized body Required/Threshold

    ANSI/UL 8800
    (ANSI/CAN/UL 8800)

     

    Output Characteristics:

    The DLC requires testing and reporting of the following characteristics for the output of horticultural lighting devices. 

    • Photosynthetic Photon Flux (Φp or PPF), (µmol × s-1)
      This is the total output of the product over the specific range of wavelengths defined by ANSI/ASABE S640 for PPF (400-700nm). This metric is an integrated value for the entire fixture and contains no spectral or directional information.

      The DLC Horticultural QPL reports on both the total and ~100nm-wide “bins” of flux within this range to allow end users to understand the fixture’s relative proportions. Test information must provide output in these ranges specifically, in addition to the total 400-700nm output.
    • Photon Flux, Far-Red p,fr or PFFR), (µmol × s-1)
      This is the output of the product over the “far-red” band defined by ANSI/ASABE S640 (700-800nm). This metric is an integrated value for the entire fixture and contains no spectral or directional information. This metric is reported only and does not have a qualifying threshold. 

      The DLC Horticultural QPL reports on the total flux of this 100nm-wide band separately for end users’ informational needs.
    • Photon Flux (PFPBAR), (µmol × s-1)
      This is the output of the product over a plant’s “photobiologically active radiation” (PBAR) wavelength range (280-800nm). This metric is an integrated value for the entire fixture and contains no spectral or directional information. This metric is optionally reported only and does not have a qualifying threshold. The DLC Horticultural QPL reports on the total flux of this PBAR band specifically for end users’ informational needs. PFPBAR is intended to convey UV, PAR, and FR radiation, which are often associated with photomorphological effects in plants. PFPBAR is not an ASABE S640 defined term and is not required for DLC qualification, though it can be reported and listed if desired by applicants. 
    • Photon Efficacy (PEPBAR), (µmol × J-1)This is the output of the product over a plant’s “photobiologically active radiation” (PBAR) band (280-800nm) divided by the total electrical input watts to the fixture, including any other ancillary loads (controllers, sensors, cooling fans, etc.) used within the lighting system. This metric is an integrated value for the entire fixture and contains no spectral or directional information. This metric is optionally reported only and does not have a qualifying threshold. The DLC Horticultural QPL reports on the total flux of this PBAR band specifically for end users’ informational needs. PEPBAR is intended to convey luminaire efficacy in converting electrical energy into UV, PAR, and FR radiation, which are often associated with photomorphological effects in plants.  PEPBAR is not an ASABE S640 defined term and is not required for DLC qualification, though it can be listed if desired by applicants. 
    • Spectral Quantum Distribution (SQD), (µmol × s-1 × nm-1)
      This is the distribution of photon flux per photon wavelength over the photosynthetic and far-red range of wavelengths defined by ANSI/ASABE S640 (400-800nm). The DLC will also accept the distribution of photon flux per photon wavelengths over the PBAR range (280-800nm). When reporting either of the optional PBAR metrics (i.e. PFPBAR and PEPBAR), distribution of photon flux over the PBAR range is required. This distribution is measured and reported as integrated in all directions from the fixture and contains no granular directional information itself. This distribution must be measured and reported from an appropriately accredited facility.

      An image of this distribution must be submitted within the application in a .jpg graphical file format, at a size of 300x300 pixels or larger. This image will be accessible to users on the QPL. The DLC intends to utilize the required .xml file per ANSI/IES TM-33-18 to generate these images in the future.

      Please refer to the TM-33-18 Reporting and Photometric/Spectral Reporting Alternatives section for additional information.


    Efficacy:

    The DLC requires testing and reporting of Photosynthetic Photon Efficacy (PPE), which is the output of the fixture over the specific range of wavelengths defined by ANSI/ASABE S640 for PPF (400-700nm), divided by the total electrical input watts to the fixture, including any other ancillary loads (controllers, sensors, cooling fans, etc.) used within the lighting system.

    All products are required to have a PPE of ≥ 1.90 µmol × J-1. In both submitted applications and under surveillance testing, the DLC allows an absolute tolerance of -5% to this threshold value. The result of this is the DLC’s acceptance of any test report showing an efficacy of 1.81 µmol × J-1 or higher, and the disqualification of any product, either during submission or surveillance testing, with a test report showing an efficacy less than 1.81 µmol × J-1, at any point in the product’s specified operating voltage range. All evaluations and listings of this measurement will be rounded to the nearest hundredth.

    If a product contains multiple drivers:

    • All driver specification sheets must be provided.
    • For each unique driver used, manufacturers must provide electrical testing to document which driver variation results in the overall minimum Kp (PPE) or worst-case driver efficiency, as well as which variation results in the overall worst-case power quality (THDi and PF).
      • This testing must include the input current and wattage; the output voltage, current, and wattage; and the THDi and PF for each driver, at each nominal input voltage.
      • In-house (i.e. non-accredited lab) benchtop electrical testing is sufficient for demonstrating the driver variation that yields the overall minimum Kp (PPE) and minimum power quality at the applicable loading conditions and at the applicable input voltages.
      • From this electrical characterization testing, the product and conditions representing worst-case efficacy must undergo formal whole-fixture LM-79 testing by an accredited testing lab.
      • For questions about testing requirements for family grouping applications, please refer to the Family Grouping Application Requirements for LED-based Horticultural Lighting policyNote: Family grouping applications will follow an interim application process utilizing both the application portal and email communication from April to June 2021. Please reference the Interim Application Period Guidance for V2.0 for submission details.
    • Drivers that result in explicitly different nominal fixture performance (for example, if a driver change results in different flux output by the product, determined at the DLC’s discretion) are not permissible variations within a single model number and are required to submit a family grouping application for QPL listing. If alternate driver variations result in different input wattage, worst-case will be published on the QPL.

     

    Long-Term Performance:

    The DLC requires the following performance data to characterize the long-term performance of the fixture:

    • Flux Maintenance, Φp (PPF) and Φp,fr (PFFR)
      This is a characterization of the ability of the device to maintain its output within the given parameters over time. Given that device output of interest is measured in quanta of photons, and not in lumens, the DLC will use the general engineering term for quanta, “Q”, instead of the more-familiar “L” prefix used within general illumination applications.
      • The DLC requires either LED device-level or whole-fixture testing and projections in accordance with the (LM-80 and TM-21) or (LM-84 and TM-28) industry standards sufficient for a Q90 of ≥36,000 hours within the Φp (PPF) range (400-700nm).
        • The “Q” in the Q90 value is based strictly on the value shown in cell I42 of the ENERGY STAR TM-21 calculator or cell I45 of the ENERGY STAR TM-28 calculator.
      • All TM-21 or TM-28 projections must be made at the maximum ambient temperature on the fixture’s specification sheet. See In-Situ Temperature Measurement Testing (ISTMT) information below for additional details.
      • The DLC requires testing and projections to report Q90 for the Φp,fr  (PFFR) range of 700-800nm, but does not make determinations or qualifications based on this data. Please see a description of PFMFR-specific testing requirements in the “For fixtures using multiple types of LEDs” section below.
      • To support PFMP and PFMFR projections, LM-80/LM-84 information must be provided for both the 400-700nm and the 700-800nm range.
        • All new product submissions using the LM-80/TM-21 approach are required to provide LM-80 data in appropriate (PPF, PFFR) units, measured as such at all time points in the LM-80 procedure. The DLC reserves the right to request additional information for all reports referring to “photon flux” that are ambiguous (based on product SQD) about the division of said flux between the PPF and PFFR categories to determine approval.
          • Products qualified with non-PPF units that were converted into PPF units during the provisional period (i.e. prior to V1.2) will be required to provide LM-80 data in appropriate units to requalify under the V2.0 Technical Requirements.
          • Provisionally qualified products will be allowed to update their listings to remove any caveats by submitting actual data by December 2021.  The DLC will process these update applications through the month of December, 2021. Note: The DLC will begin accepting update applications for V1.2 listed products in June 2021. Please refer to the Interim Application Period Guidance for V2.0 for more information.
        • Products may not be qualified and listed on the QPL without long-term performance data for flux degradation. Products that use LEDs for which no LM-80 data is available are required to undergo LM-84 testing for TM-28 projections. 
      • In-Situ Temperature Measurement Testing (ISTMT):
        • ISTMTs must be conducted and provided for the hottest LED in the fixture, and LED-device level drive current must be reported.
        • ISTMTs must be conducted and reported in the same manner as thermal testing for safety certification. Specifically, applicants must report the operating temperature of the LED at the fixture’s highest rated ambient temperature within the ISTMT report. This must be done in accordance with acceptable procedures from safety certification standards for measuring and projecting operating temperatures. For example, if a fixture is rated for operation at 40°C ambient, ISTMTs are not accepted if they only show the temperature of the LED when measured during a 25°C ambient condition. In this example, appropriate steps must be taken to characterize the LED operating temperature when the fixture is in a 40°C ambient environment, as defined by the thermal portions of the relevant safety standards.
      • For fixtures using multiple types of LEDs:
        • LM-80 reports (if being used instead of whole-fixture LM-84 data) must be provided for each type of LED device present in the fixture.
          • For DLC evaluations, LED “type” is differentiated by the nominal output of the LED device or the manufacturer of that LED device. For example, a fixture incorporating four different LEDs, with nominal emissions of 440nm, 660nm, 730nm, and a 5000K “white”, is required to provide four LM-80s and associated information for TM-21 projections, corresponding to each of these nominal designations. Some limited cross-applicability of LM-80 data is allowed within phosphor-converted white LEDs of the same series; see LM-80 applicability information below.
        • ISTMT testing must be provided on the hottest of each LED type (for example, the hottest blue, white, and red LED in the fixture, respectively).
        • Maximum LED drive current must be reported for each LED type.
        • For PFMP (400-700nm), each LED type present in the fixture that has at least 25% of its per-device flux in the PPF range must independently meet the Q90 ≥ 36,000 hours requirement, as shown by a TM-21 calculation. The DLC does not require device-level SQD data from applicants and will typically accept the applicant’s descriptions of a device’s relative PPF while reserving the right to request explanation. 
        • The DLC requires calculated PFMFR for all fixtures with a PFFR output that is equal to or greater than 5% of the fixture’s flux from 400-800nm.  For PFMFR (700-800nm), each LED type present in the fixture that has at least 25% of its per-device flux in the PFFR range must report its Q90 duration in hours. The DLC does not require device-level SQD data from applicants and will typically accept the applicant’s descriptions of a device’s relative PFFR, while reserving the right to require explanation. There is no threshold performance requirement across this far-red range; it is a reported value only.
      • LM-80 applicability:
        • For phosphor-converted “white” LEDs within the ANSI nominal chromaticity range, the DLC follows the ENERGY STAR Requirements for the Use of LM-80 Data published September 2017. Consistent with the ENERGY STAR requirements, for narrow-band emitters, the DLC generally requires an LM-80 for each distinct nominal product offered by an LED device manufacturer. Devices of the same type but with different optical codes for beam spread are allowed to cross-apply LM-80 testing. This also applies to products that are in the same series with differences in nomenclature due to marketing changes (see series provisions of ENERGY STAR requirements document). The DLC reserves the right to require additional information to approve all claims of LM-80 applicability.
    • Warranty
      Products must have a manufacturer-provided product warranty of at least five years. The warranty terms and conditions must be provided as part of the submittal for qualification. The warranty must cover the complete luminaire and must clearly explain the terms and conditions associated with the warranty. Note that “luminaire” includes light source, housing, heat sink, power supplies, and other electrical components, optics, and any other components such as cooling fans or controls (if present).

    Warranty terms and conditions can vary widely from manufacturer to manufacturer. The DLC explicitly defines a warranty period of five years and does not have specific requirements for warranty claim terms (e.g. labor, recommissioning, etc.) other than those listed above. The DLC does not verify or validate a manufacturer’s terms, conditions, or process for customer warranty claims. The DLC does not monitor field failure rates of qualified products or warranty policy redemption or history among manufacturers. Industry stakeholders are urged to review warranty terms and conditions as part of the purchasing decision process.

    • Driver ISTMT
      Applicants must supply a technical specification sheet for the driver(s) they use in their product, showing the lifetime of the driver based on operating temperature and the temperature measurement point (TMP) for monitoring the operating temperature of the driver. In-situ temperature measurement testing must be conducted, and a report must be provided with the application showing an operating temperature consistent with the driver specification sheet information and demonstrating that the driver will have a lifetime of at least 50,000 hours when operating at or above the highest rated ambient temperature on the fixture’s specification sheet.

    As noted in the ISTMT description within the flux maintenance section, driver ISTMTs must be conducted and reported in the same manner as thermal testing for safety certification. Specifically, applicants must report the operating temperature of the driver at the fixture’s highest rated ambient temperature within the ISTMT report. This must be done in accordance with acceptable procedures from safety certification standards for measuring and projecting operating temperatures. For example, if a fixture is rated for operation at 40°C ambient, ISTMTs are not accepted if they only show the temperature of the driver when measured during a 25°C ambient condition. In this example, appropriate steps must be taken to report the driver operating temperature when the fixture is operating in a 40°C ambient environment, as defined by the thermal portions of the relevant safety standards.

      • For products that may use multiple drivers, specification sheets for each driver must be provided with the details above. Testing must be conducted on each driver at its appropriate worst-case input voltage. If a product uses multiple drivers from the same manufacturer product line or series, then the single worst-case thermal ambient environment of the product line or series requires a driver ISTMT. The DLC will operate with the expectation that the operating condition at the highest wattage in the driver manufacturer’s product line or series is the worst-case thermal ambient environment, but the DLC may ask the manufacturer to provide detailed evidence to document the worst-case driver thermals.
    • Fans
      Products that employ on-board cooling fans must provide a technical specification sheet for each fan type employed in the product, family group, or sub-group, as applicable. The fan specification sheet must state the lifetime of the fan and a reference operating temperature rating for that lifetime claim. The lifetime must be at least 50,000 hours, at an operating temperature at or above the fixture’s highest rated ambient temperature.

    If the product is available with multiple fan models:

      • If fan model variations result in substantively different component temperature or wattage consumption by the fixture (determined at the DLC’s discretion), a family grouping application is required with model numbers to represent the different fan variations. DLC reviewers will examine fan model power levels and flow rate to determine this distinction. Products that offer fan variations without substantively different component temperature or wattage consumption by the fixture are allowed to qualify using bracketed variations within a single model number. Note: Family grouping applications will follow an interim application process utilizing both the application portal and email communication from April to June 2021. Please reference the Interim Application Period Guidance for V2.0 for submission details.
      • Multiple fan variations require a similar testing and reporting plan to multiple driver variations, as noted in the efficacy section.

     

    Electrical Performance/Power Quality:

    The DLC requires testing and reporting of the following items to characterize the electrical performance of the fixture:

    • Power Factor
      Products must have a measured power factor of ≥0.90 at any rated input voltage at full output or non-dimmed state.
    • Total Harmonic Distortion, current (THDi)
      Products must have a measured THDi of ≤20% at any rated input voltage at full output or non-dimmed state.

    For products with driver variations, including input voltage variations, electrical testing of each product must be performed, sufficient to characterize the power quality of each driver, at its applicable nominal input voltages and maximum designed output power. Testing to demonstrate that products are compliant with the power factor and total harmonic distortion requirements may be done on an in-house or benchtop setup for practical simplicity, and results must be documented and included in the application materials. Please see the efficacy section regarding the use of this electrical testing for worst-case efficacy driver variation determination. Please refer to the Family Grouping Testing Requirements for LED-based Horticultural Lighting policy for specific testing and reporting requirements for product families. Note: Family grouping applications will follow an interim application process utilizing both the application portal and email communication from April to June 2021. Please reference the Interim Application Period Guidance for V2.0 for submission details.

     

    Safety:

    Products must be certified by an OSHA NRTL or SCC-recognized body to ANSI/UL 8800 (ANSI/CAN/UL 8800) which is applicable for horticultural lighting products by that safety organization.

    For illustrative and reference purposes, practices of acceptable safety organizations are described below:

    • UL
      Fixture manufacturers who use UL for safety certification purposes are required to be listed on the UL Certification Directory under the designation IFAU.
    • ETL/Intertek
      Fixture manufacturers who use ETL for safety certification are required to be listed on the ETL Certification Directory, specifically as Horticultural Fixtures.
    • CSA Group
      Fixture manufacturers who use CSA for safety certification are required to be listed under CSA Group's Classes defined for horticultural lighting equipment in Canada and the US.
    • TÜV SÜD
      Fixture manufacturers who use TÜV SÜD for safety certification are required to be listed on the TÜV SÜD Certification Directory, specifically as a light fixture for use on horticulture purposes.
    • SGS
      Fixture manufacturers who use SGS for safety certification are required to be listed on the SGS Certification Directory, specifically as horticultural lighting equipment.
    • Other safety organizations
      To be added to the DLC’s approved list of safety organizations who certify horticultural lighting equipment per ANSI/CAN/UL 8800 requirements, please contact horticulture@designlights.org.

     

    Special Considerations for Spectrally-Tunable Products

    Spectrally-tunable products (those with varying output channels beyond simple, single-axis dimming of the whole product) are eligible with the following conditions:

    • The threshold-qualifying state to be tested must be the manufacturer-designed state with the highest power consumption (“maximum power”).  This may or may not be the same as an “all channels on” condition, since fixtures may not be designed to use all their channels simultaneously. Test reports must specifically indicate that the product is operated in this “maximum power” condition during the testing, with a description of the control narrative to ensure that the power state is at its maximum designed level.
    • In addition to the “maximum power” condition, applicants must perform PPF testing for each control channel, in which the channel under test must be set to the maximum designed output, while all other channels must be set to their minimum designed output for this state. The test report must present an identifying name of this channel and setting, the PPF (400-700nm total and 400-500nm, 500-600nm, and 600-700nm “bins” PPF) and PFFR (700-800nm) for each of the single-channel scenarios, and a description of the control narrative to achieve each setting. For each channel tested, a corresponding graphic for the SQD produced in that setting must be provided in the application. Refer to the SQD section for reporting requirements.
      • The flux output of each specific channel testing is displayed on the DLC Horticultural QPL, with the per-channel test outcomes and identifying information for each setting. These data are intended to support standardized communication of information about the product’s spectral tuning range, aiding product selection and user acceptance.
    • Applicants must provide user-facing documentation narrating the control protocol and input parameters employed in controlling the output.
    • For PFMP and PFMFR evaluation:
      • Provisions for products utilizing multiple types of LEDs must be followed as described in the For fixtures using multiple types of LEDs section.
      • ISTMT testing must be provided on the hottest of each of the LED types. For each unique LED type, ISTMT testing must occur at the operating mode that produces the highest operating temperature in the fixture, for this LED type. 
      • The DLC asks any applicants considering LM-84-based maintenance testing on a spectrally-tunable fixture to contact horticulture@designlights.org to discuss their proposed testing plan.

     

    Tolerances

    The DLC accepts measurement tolerances to most metrics listed in the Technical Requirements. Please refer to Table 2 below for additional tolerance information.

    Table 2: DLC Horticultural Lighting Technical Requirements Tolerances

    Parameter/Attribute/Metric

    V2.0 Tolerances

    Photosynthetic Photon Efficacy

    -5%

    Power Factor

    -3 percentage points

    Total Harmonic Distortion

    +5 percentage points

    ISTMT Temperature Measurements

    1.1°C or 0.4%, whichever is greater

    LM-80 Drive Current

    -5%

     

    Tolerances are intended to account for all testing variation, rounding, and significant digits. The requirement values and tolerances will be interpreted by DLC review staff as exact requirements. While test labs will be expected to follow the requirements of their accreditation and relevant test standards, DLC staff will not employ additional “rounding” to interpret values below the absolute thresholds as passing. For example, if a horticultural lighting product is required to have a PPE of 1.9 with an efficacy tolerance of -5%, any value for efficacy less than 1.81 will be interpreted as a failing value. It is the applicant’s responsibility to check all data presented in an application before submission to ensure compliance with the DLC requirements.

    Supporting Documentation

    Test Reports

    The DLC requires that all testing be conducted at appropriately accredited laboratories except where noted otherwise. Specifically:

    • Testing of flux, intensity, and electrical characteristics must be conducted at laboratories that are accredited to ISO 17025 and the appropriate reference test standard by accreditation bodies that are signatories to the ILAC-MRA.
    • Labs conducting testing of device-level and/or fixture-level photon flux maintenance must also follow the DLC requirements for LM-80/LM-84 labs.
    • Labs conducting In-Situ Temperature Measurement Testing (ISTMT) must meet at least one of the following:
      • Approved by OSHA as Nationally Recognized Testing Laboratories (NRTLs)
      • Approved through an OSHA NRTL data acceptance program or OSHA Satellite Notification and Acceptance Program (SNAP)
      • Accredited for ANSI/UL 1598 or CSA C22.2 No. 250.0-08, including Sections 19.7, 19.10-16, by an accreditation organization that is an ILAC-MRA Signatory

    TM-33-18 Reporting and Photometric/Spectral Reporting Alternatives

    The DLC requires all applicants to submit accompanying .xml files per ANSI/IES TM-33-18 for each parent or single product to represent the spatial and spectral distribution of the tested fixture.

    • The .xml file must be based on measured data from an accredited lab, accompanying the LM-79 testing requirements for spectral and spatial measurements.
    • The .xml file must include the spectral power distribution data, with an interval resolution of 5nm or smaller over the photosynthetic and far-red range of wavelengths defined by ANSI/ASABE S640 (400-800nm). The DLC also requires the distribution of photon flux per photon wavelengths over the PBAR range (280-800nm) in the case that applicants provide PFPBAR and PEPBAR  data. Spectral data in 1nm intervals are acceptable. The spectral measurement represents the integrated flux in all directions from the fixture, without directional spectral information. Per TM-33-18, the data is reported in W/nm, not spectral quantum distributions. All DLC developed and interim manufacturer submitted SQD images will report in µmol × s-1 × nm-1.
    • The .xml file must also include the Photosynthetic Photon Intensity Distribution (PPID), reported in µmol × s-1 × sr-1, over the photosynthetic wavelengths defined by ANSI/ASABE S640 (400-700nm). PPID is the distribution of photosynthetic photon intensity per unit solid angle leaving the fixture. Each measurement is integrated across the 400-700nm range leaving the fixture and contains no granular spectral distribution information (i.e. color over angle).

      To facilitate time for accredited labs to develop or purchase TM-33-18 reporting software, the DLC offers a 9-month grace period for applicants to provide .xml files compliant with TM-33 reporting for parent products. If TM-33-18 reports are not available, applicants must submit LM-63 and TM-27 (i.e. .ies and .spdx files, respectively) for parent products or single products.
    • For manufacturers choosing to submit .ies and .spdx files instead of .xml files in the interim period, they must resubmit data compliant with TM-33-18 reporting requirements by December 31, 2021, or the products will be delisted.
    • The .ies files must contain [_OTHER] keywords to describe the units of intensity values and a conversion factor relating photosynthetic photon intensity to luminous intensity (conversion factor = PPF/lumens).

    Additional Application Details

    In addition to the test data noted in the sections above, the DLC requires the following for all submissions:

    • A completed web-based application form
    • Specification sheets (or “cut sheets”) for the product that include maximum ambient temperature
    • Specification sheets for all drivers and fans employed in the product, including lifetime-at-temperature information
    • Safety certificates of compliance as issued by the relevant safety body, attested to by the DLC self-certification statement
    • If demonstrating flux maintenance at the device-level, a completed TM-21 calculator must be provided for each LED device present in the fixture, with the applicable LM-80 and ISTMT information for that LED device. If demonstrating flux maintenance at the fixture-level, a completed TM-28 calculator must be provided for the fixture, with the applicable LM-84 information accompanying it.

    The DLC will only accept applications for products with testing on the product submitted, with only limited variations permitted as detailed in the sections above. Given the multiple options within product families, the DLC offers the Family Grouping Application Requirements for LED-based Horticultural Lighting policy, which describes a method to determine “worst-case” product family members. Note: Family grouping applications will follow an interim application process utilizing both the application portal and email communication from April to June 2021. Please reference the Interim Application Period Guidance for V2.0 for submission details.