Solid-State Lighting FAQs
Q: Once my product is qualified, how can I market it to my customers?
If your product is published on the QPL, you may market the product as DesignLights Consortium® qualified. Please refer to the DLC’s Logo Guidelines for instructions on proper marketing of a DLC qualified product.
Q: If my product PASSED, how do I know which utilities will incentivize my product?
Each DLC Member has access to the QPL and makes its decision about what products to incentivize based on its own program parameters, including cost-effectiveness tests. Manufacturers should work with utilities/energy efficiency program sponsors on a project-by-project basis to have their products be eligible for rebates. Please note that listing on the QPL is not a guarantee that the products will be eligible for incentives from DLC Members. Any incentives or other rebates are entirely at the discretion of the particular energy efficiency program sponsor.
Q: My laboratory test report indicates my product's performance meets the DLC Technical Requirements. Is my product qualified?
The DLC does not endorse any laboratory meeting the DLC Testing Laboratory Requirements. Laboratories representing the ability to qualify products and laboratory test reports indicating product performance meets DLC Technical Requirements do not represent official DLC product qualification. All decisions regarding product qualification are made by the DLC. DLC reviewers reserve the right to request documentation to clarify testing conditions or to confirm testing has been conducted by a laboratory that meets these requirements at the time of testing.
Q: What is the cost to apply? What forms of payment do you accept?
Please see the Application Fees page for more details.
Q: What if I want to update a qualified product with a new voltage operating range?
If a manufacturer wishes to update a qualifying product at a new voltage operating range (for example, to 120-277V, on a universal driver), the manufacturer will need to provide the additional data to demonstrate that the worst-case conditions in regard to efficacy and power quality pass the requirements (i.e., submitting another LM-79 at 120V if it was previously submitted with only an LM-79 at 277V). Because of the review needed to evaluate the additional test reports, the manufacturer must submit an additional application fee. The manufacturer should contact its DLC reviewer before submitting the payment to avoid creating an entirely new application.
Q: How does the DLC evaluate reported (rated) performance claims in specification sheets and/or other marketing materials?
The DLC evaluates reported performance claims based on the information manufacturers choose to report in their product specification sheets and/or other marketing materials. If the performance claims reported in specification sheets and/or other marketing material are below the Technical Requirements, the DLC reviewer will reject the application as marketing material cannot indicate that the product’s marketed performance is below any of the Technical Requirements. To avoid delays in review, please review all marketing material prior to submitting an application to ensure it accurately reflects the product submitted, and does not contain outdated or incorrect information, or typographical errors. Please note that in addition to evaluating reported performance claims in specification sheets, the DLC will also conduct a technical review of a product’s performance via the required test data detailed in the Single Product and Family Grouping application instructions.
Q: Are luminaires intended to illuminate sports fields eligible in the Architectural Flood and Spot Luminaires Primary Use Designation?
Yes, luminaires intended to provide lighting for outdoor sports fields are eligible as Architectural Flood and Spot luminaires. Products intended for illuminating sports fields may also apply under the Specialty provisions if they desire. Please review both the Architectural Flood and Spot luminaires Technical Requirements as well as the provisions for applying under Specialty designations before applying.
Q: How is the General Application determined for Outdoor Non-Cutoff and Semi-Cutoff Wall-Mounted Area Luminaires?
The General Application, or light output bin (low-, mid-, high-, or very high-output), is determined based on the total lumen output of the luminaire. Although DLC evaluates lumen output and efficacy based on the lumen output in the 0-90° zone, total lumen output and total efficacy is listed on the QPL. Therefore, the General Application is determined based on the total lumen output to be consistent with the information published on the QPL. See requirements for Non-Cutoff and Semi-Cutoff Wall-Mounted Area Luminaires under the Technical Requirements for more details on evaluation the performance of these products.
Q: Are luminaires intended to illuminate billboards eligible as Architectural Flood and Spot and Landscape/Accent Flood and Spot categories?
Yes. Luminaires intended to provide illumination to the facade of billboards are eligible as Architectural Flood and Spot or Landscape/Accent Flood and Spot Luminaires. These products are NOT eligible for the Outdoor Pole/Arm-Mounted Area and Roadway Luminaires category. Remember to review the Technical Requirements Table for each category to determine if your product would meet the listed requirements before applying.
Q: What will happen to already listed Non-Cutoff Wall-Pack Specialty products now that there is a specific Primary Use designation (PUD) for Non-Cutoff and Semi-Cutoff Outdoor Wall-mounted Area Luminaires? Can I continue to submit under Specialty: Non-Cutoff
These type of products are no longer eligible under the Specialty provisions with this generic end-use descriptor. For niche end-use applications of wall-mounted exterior lighting that specifically require significant amounts of light in the uplight or glare zone, DLC will consider requests for qualification of these products under the Specialty provisions on a case-by-case basis. In these cases, a specific end-use (and associated descriptor) must be identified that is distinct from the definition and intention of the non-Specialty PUD. Documentation will be required to demonstrate the marketing and use of products in these niche applications. Products currently listed as Specialty: Non-Cutoff Wall-Pack will be reviewed for compliance with the Non-Cutoff and Semi-Cutoff Outdoor Wall-mounted Area Luminaires PUD, and products that meet the requirements, will be transitioned. Products that do not meet the requirements will need to demonstrate a specific end-use and associated descriptor that is different from the definition of Non-Cutoff and Semi-Cutoff Outdoor Wall-mounted Area Luminaires PUD. If the request is denied, the products will be de-listed from the QPL.
Q: Are products that incorporate replacement lamps as the light source eligible for DLC qualification in the luminaire and retrofit kit categories?
No. At this time, products that incorporate removable or replaceable lamps are not eligible for qualification.
Q: What is the "LED Package Part number" referenced in the application form?
The LED Package Part number describes the LED, color (e.g., white), CCT (e.g., warm white), and other characteristics of the LED. Every LED must be specified with a complete LED Package Part number (e.g., XPEWHT-L1-XXX-XX-X-XX). This specific part number must be consistent throughout the application and supporting documentation, such as the LM-80 report.
Q: Can the manufacturer name listed on the QPL be different than the manufacturer name referenced throughout marketing materials?
No. The manufacturer name listed on the QPL must match the manufacturer name used in marketing materials. If a manufacturer wishes to change their manufacturer name listed on the QPL, they will be responsible for demonstrating the new manufacturer name is used throughout marketing materials, website literature, etc.
Q: My product has a small set of distinct color temperature settings. How do I know if it is eligible to be listed as white-tunable?
If a product has any functionality that enables it to change the color (i.e. CCT) of the emitted light, the intention is for it to be eligible under the requirements for color-tunable products. This includes products with a small set of color temperature settings controlled through mechanisms such as dipswitches set at the distributor or by the installer. Such products will not be deemed as non-color-tunable.
Q: Can Horizontal and Vertical Refrigerated Case Luminaires incorporate pin bases?
No. The Horizontal and Vertical Refrigerated Case Luminaire categories are intended for complete luminaires, which by definition, cannot use the existing mounting mechanism of the incumbent technology. To ensure only complete luminaires are submitted under this category, with all applicable drivers/power supplies and mounting mechanisms required of a luminaire, products that incorporate pin-bases are not eligible under these categories at this time. DLC staff reserve the right to ask for additional information about the product to verify that the product is sold as a complete luminaire.
Q: Are temporary products eligible? What makes a product temporary?
Products marketed for or intended for temporary usage/installation are not eligible for DLC qualification due to the complications in determining savings from non-permanent products. Products not specifically marketed for temporary usage, but that have a form factor similar to products that are marketed for temporary usage, are also ineligible. These types of products have typically been marketed as “work lights”, “construction lights” or “job lights”, which are designed to hang temporarily from a clip or hook or placed on the ground during construction, and are then moved to a different location.
This policy is not limited to work lights, but any products that also imply the product is not intended to be installed permanently.
Q: Can products within a white-tunable family grouping application have different tunable ranges?
No. The DLC requirements state that products within a family group of white-tunable products must have the same types of LEDs, and an identical technological approach to color output. This is intended to include a restriction that all products within a family group have the same tunable range. Therefore, as an example, if one version of a product can tune from 2700-5000K, while another version can tune from 2200-6500K, they must be submitted under separate applications, with independent testing.
Q: I'm submitting a Single/Family application, but my safety certification documentation includes a multiple listing document. What documentation and information should I submit with my DLC Single/Family application?
If submitting a Single/Family application where the safety documentation involves a multiple listing document, please submit the private labeler compliance certificate and populate the Application Form with the safety organization and private labeler safety file number. If the safety organization has not provided a private labeler compliance certificate, one will need to be obtained from the safety organization in order to proceed with the Single/Family application process.
Q: Is proof of safety certification required for Update Applications?
Yes. As of Technical Requirements V4.3, implemented on March 26, 2018, providing safety certification documentation is required for all types of Update Applications. Please refer to the Safety Certification page for more information on what safety certification documentation is required.
Q: I submitted a test report that meets the Technical Requirements, but noticed that there is incorrect information reported. Will the DLC accept a revised test report?
If the incorrect information in the LM-79 or ISTMT is first identified by the applicant, unprompted by the reviewer, the DLC will accept a revised test report. All test report revisions must follow the rules set forth by the accreditation body. If the incorrect information is first identified by the reviewer, the DLC will not accept a revised test report, and will require the product to be retested. In the event of a retest, the DLC will only reevaluate the new, retested data. Data issues encountered in LM-80 reports will be handled on a case by case basis. The DLC urges all applicants to thoroughly review all application documentation prior to submittal to ensure all information submitted is accurate.
In the event that the test report contains failing test data that is not representative of the products performance, please see the FAQ, “I believe that the test report I submitted with my application does not represent my product's performance. Will the DLC accept a new report with different performance on the same product design?”
Q: I submitted a test report that contains failing data, but believe this data does not represent my product's performance. Will the DLC accept a new report with different performance on the same product design?
No. In the event that the test report submitted does not meet the Technical Requirements, the DLC will not accept a revised test report unless a design change has been made to the product. Please note that the Self Certification Statement provided which each application includes language that the applicant certifies all model numbers submitted meet minimum requirements. In the event where a manufacturer chooses to make a design change to the product, and resubmit test data that represents that design change, the DLC will need detailed explanations of the changes made as well as assurance that the changes will be reflected in all products sold. If choosing to make a design change, the manufacturer must create and submit a new application, and pay the associated application fees for the review of the redesigned product(s). If a test report submitted does meet the Technical Requirements, but includes incorrect information, please see FAQ, “I submitted a test report that meets the Technical Requirements, but noticed that there is incorrect information reported. Will the DLC accept a revised test report?”
Q: I am submitting an application containing White-Tunable products. What performance data should I enter into the Scaled Performance Table?
When submitting an application containing White-Tunable products, the Scaled Performance Table must be populated with the performance data representative of the least efficacious setting of each product seeking qualification. For more information regarding White-Tunable applications, please refer to Testing and Reporting Requirements for Color-Tunable Products.
Q: I have a product that can be ordered with multiple luminaires mounted on a singular mounting structure. Can I qualify the options for each ordering configuration within one model number on the QPL?
Yes, under specific circumstances. Configurations of multiple luminaires mounted on a singular mounting structure can be listed in one line item on the QPL, provided that each mounting configuration includes only identical luminaires, and the configuration of luminaires is identifiable in the ordering code nomenclature. This provision is only applicable for products within the Outdoor Pole/Arm-Mounted Area and Roadway Luminaires, Outdoor Pole/Arm-Mounted Decorative Luminaires, Landscape/Accent Flood and Spot Luminaires, and Architectural Flood/Spot Luminaires Primary Use Designations.
Additionally, products that wish to utilize this listing approach must be submitted via a Family Grouping application. An example of a product design that would be eligible for bracketing includes a pole-mounted area luminaire that can be ordered in configurations of 1, 2, 3, or 4 luminaires mounted to a singular pole. In this example, the 1, 2, 3, and 4 luminaire configurations can be bracketed within a singular model number. The form of the model number should be submitted as:
- ABC-123-[1, (2, 3, 4 see notes)]
The “Notes” field on the QPL will then state:
- “Available in configurations with multiple identical heads where model number indicates 1=1 fixture, 2 = 2 fixtures, 3 = 3 fixtures, 4 = 4 fixtures”, etc… – as needed based on specific number of configurations offered using identical fixtures.
Q: How should center and end vertical refrigerated case fixtures be submitted? May they be grouped in the same application?
Because they have different light output and distribution requirements, center and end units for vertical refrigerated case lights may not be submitted in the same single product application. They should either be submitted as separate applications, or applied for under the family grouping policy. Family groups that include both center and end units must demonstrate compliance with the requirements on worst-case light output of both center and end units.
Q: Is graduated dimming acceptable for the Stairwell/Passageway Lighting category?
All Stairwell/Passageway Lighting must be capable of at least bi-level dimming. Graduate dimming is acceptable, as long as the controls dim the fixture to a lower-power state when the space is not occupied. Documentation of dimming and controls must be provided with the application.
Q: What occupancy sensors are acceptable for the Stairwell/Passageway Lighting category?
All occupancy sensors for the Stairwell/Passageway Lighting category are acceptable, as long as they meet the following requirements:
- Luminaires that include integral controls for occupancy sensing and bi-level dimming.
- Luminaires that operate off remote occupancy sensors, including wireless options, where a remote sensor(s) is sold packaged together with a luminaire(s) under a single model number or ordering code.
- Luminaires that operate off remote occupancy sensors, including wireless options, where the luminaire and sensor are sold separately, but the luminaire has features enabling communication with a remote sensor(s).
Q: What if I upgrade components in my product?
If a manufacturer wishes to update the listed performance of a qualified product, the manufacturer must provide new test data for the updated product and pay the associated application fee. This will require DLC review. If the manufacturer wishes to have the originally qualified and updated products both listed on the DLC QPL, a new part number for the updated product must be provided to avoid duplicate model numbers on the QPL. If model numbers are not changed, the listing will be for the upgraded product only. Multiple products with identical model numbers may not be listed under the same product category on the QPL.
Q: Why am I required to submit an explanation of the ordering code/model number breakdown in the Application Form?
Understanding the available options for a product is necessary to ensure worst case performance has been identified and tested. As such, an explanation of the ordering code/model number breakdown must be included in the relevant section of the Application Form and must match the spec sheets and other marketing materials submitted with the application. DLC reviewers reserve the right to request additional information or clarification of ordering codes or model number breakdowns. Please note that omitting or submitting an insufficient ordering code/model number breakdown explanation is one of the most common reasons application reviews are delayed.
Q: What types of signatures does the DLC allow?
Acceptable forms of signatures include either a wet signature or verified digital signature. The signature must be affixed to the document, unable to be moved. Wet signatures must be written on a print-out of the document with a pen, then scanned and submitted. Verified digital signatures must authenticate the electronic user and capture the user’s intent to sign the document. Software may not auto-sign on a signee’s behalf.
Q: What are the color temperature requirements for a white-tunable product to be listed on the QPL?
There are no color temperature limitations regarding the color-tunable feature for standard product listing on the QPL. However, the existing Technical Requirements specific to the product type must be met. For instance, outdoor products are not limited to a color temperature range but must be capable of light output at ≤ 5700K (per the nominal ANSI binning descriptions). Please consult the Technical Requirements for color temperature specific to the General Application and Primary Use Designation under which the product will apply.
Q: I believe that the drive current information presented in my Application Form does not correctly represent my product's performance. Will the DLC accept revised drive current information on the same product design?
In situations where the originally-provided drive current information impacts whether or not the product will meet the lumen maintenance requirements, revised drive current information will typically not be accepted, unless the product is redesigned, retested, and resubmitted. The DLC reserves the right to review changes to drive current that impact eligibility on a case-by-case basis to determine whether revisions without a redesign are acceptable. This supports efforts to maintain the integrity of the product data listed on the QPL.
Please note that in all situations, it is expected that the drive current information within the Application Form accurately represents that product's performance. The Self Certification Statement provided with each application includes language that the applicant certifies all model numbers submitted meet minimum requirements and that the information provided in the application is accurate.
In the event where a manufacturer chooses to make a design change to the product and resubmit test data that represents that design change, the DLC will need detailed explanations of the changes made as well as assurance that the changes will be reflected in all products sold.
Q: What is the difference between the Outdoor Pole/Arm-Mounted Area and Roadway Luminaires, Outdoor Wall-Mounted Area Luminaires, and Architectural Flood and Spot Luminaires category?
The Outdoor Pole/Arm-Mounted Area and Roadway Luminaires and Outdoor Wall-Mounted Area Luminaires category are designed for luminaires intended to light up general areas. The Architectural Flood and Spot Luminaires category is designed for luminaires intended to light up specific items/objects/elements. The floodlight category cannot be used to qualify area lights that would not meet the zonal lumen requirements of the Outdoor Pole/Arm-Mounted Area Luminaires or Outdoor Wall-Mounted Luminaires category. See examples of these Primary Use Designations on the Product Eligibility page.
Q: Can I test a prototype for my DLC submission?
No. The DLC is interested in the performance of the production-ready product seeking qualification. As such, test data on prototypes will not be accepted for DLC submissions. Testing must be on production-ready models that are identical in design and construction to those that are being or will be sold.
Q: How many points within each ANSI CCT quadrangle must be reported in Table 1: Data Reporting Format For White-Tunable Product Submissions?
For white-tunable product submissions, manufacturers must report the performance for their least-efficacious product within their group according to Table 1 in the requirements. Performance must be reported for one point within each ANSI quadrangle the product is able to tune to. The language in the policy is not intended to state that performance must be reported for the highest CCT and lowest CCT within each quadrangle, but rather one point in each quadrangle from the lowest CCT to the highest CCT the product can tune to.
Q: Can I test and include a bracketing worst-case product in a Family Grouping Application solely for submitting to the DLC, even though I do not intend to sell this product variation?
Yes. Production-ready models that are identical in design and construction to the other product variations in the family, but differ in a measurable parameter to represent a worst case performance metric (i.e. worst case thermal member), can be included in a Family Grouping application if the corresponding test data is provided. For example, this is commonly seen in products with a higher LED drive current than what is intended to be offered to customers to represent the worst case thermal member. A description of the testing rationale is required, and may require additional details during the review.
Note that there may be additional implications if any of the products described above cannot be procured for Surveillance Testing purposes. For instance, if one of these worst-case brackets is selected for Surveillance Testing but cannot be procured by the DLC, then the product will be de-listed in accordance with the Surveillance Testing Policy. In this situation, the remaining family members would need to be re-bracketed or the entire family may be de-listed. It is up to each manufacturer to weigh the advantages and disadvantages associated with including non-procurable worst-case product brackets.
Q: My electrical testing shows a higher wattage at an input voltage for which I did not measure light output. Can the DLC use the electrical measurements to calculate worst-case efficacy?
Manufacturers should always be considering worst-case across all product variations, including input voltage, before submitting test data to the DLC. However, in the event that the electrical testing demonstrates a higher wattage at a different voltage than the photometric testing was conducted, the DLC will allow worst-case efficacy to be calculated from taking the lumen output from the photometric testing and dividing by the higher wattage from the electrical testing. This calculation approach is permitted to reduce testing burden rather than requiring the manufacturer to retest light output at the worst-case operating voltage. This approach is only allowed when the only variable between the LM-79 lumen output test and the electrical test is input voltage, and is based on the premise that the driver output (and therefore lumen output) will not significantly change with input voltage. If using the calculation approach, the DLC reserves the right to ask additional questions to confirm the input voltage is not impacting the drive current to the LEDs before moving forward with the review. The calculated efficacy will be listed as the Measured Efficacy on the QPL. If the manufacturer chooses to retest at the worst-case operating voltage instead of conducting the calculation, the retested values will supersede any calculations.
Q: I tested my product in a way that I believe is technically sound, but may go against specific DLC policies. Will the DLC accept my test results if I can successfully demonstrate they are technically sound?
No. To remain fair and consistent across manufacturers submitting applications to the DLC, the DLC must strictly enforce its policies and cannot make ad hoc exceptions, even if there is a sound technical justification for the alternate approach to testing. In situations where the testing does not follow DLC policy, the DLC will require the product be retested according to policy, or may decide that the product is ineligible if retesting according to policy is not a viable option.
Policy revisions occur periodically. For more information on past and present policy development efforts, please see Policy Development. The DLC is very open to suggestions for policy revisions; if you have a suggested revision to a policy, please submit the request to email@example.com for consideration during policy development cycles.
Please note that clarifications to existing policies can be found via this FAQ page.
Q: How should luminaire efficacy be reported?
Luminaire efficacy should be reported as the total luminous flux from the fixture divided by the total input power. Luminous flux is based on the photopic luminous efficiency function (V lambda), not scotopic or mesopic efficiency.
Q: My laboratory testing on the identified "worst case" showed better performance than the scaled performance of other family members. Will this testing be acceptable?
It is the manufacturer’s responsibility to determine the “worst case” product of the group/sub-group. The worst-performing product can be identified through engineering analysis and/or in-house testing of all family members. If engineering analysis is used to identify worst case, the tested value associated with the worst-case product may be higher than scaled values indicating the performance of other family members. If this is the case, the manufacturer must provide an explanation that addresses the variance between scaled values and tested values, and the reviewer must understand the manufacturer’s scaling method before the application process may continue.