Horticultural Technical Requirements

Horticultural Technical Requirements V3.0

Version 3.0Effective March 31, 2023

This page includes all information and policies related to the V3.0 Horticultural Technical Requirements, effective on March 31, 2023.


Horticultural lighting products using LEDs must comply with the provisions of this document to be eligible for listing on the DLC Horticultural Lighting Qualified Products List (Horticultural QPL, Hort QPL). Products eligible for DLC qualification must be complete LED light fixtures or lamps. That is, they must be electromagnetic radiation-generating devices analogous to luminaires (or fixtures) or LED lamps (integrated or non-integrated) as defined by ANSI/IES LS-1-22.

In North America, increasing demand for locally produced food combined with the legalization of medical and/or recreational cannabis and the desire for resilient supply chains are fueling the growth of controlled environment agriculture (CEA).1 Although CEA facilities tend to be more efficient than traditional agriculture, the cumulative impact of the added electric loads must be considered. Globally, the average energy required to produce one kilogram of harvested crop is 38.8 kWh for indoor agriculture.2 Combined with the projections that show the North American CEA industry growing to $8 billion annually by 2026,3 it is imperative that CEA facilities are converted to or built with energy efficient lighting technology. The DLC Horticultural Lighting Technical Requirements are designed to help guide the industry toward sustainable growth in concert with decarbonization efforts.

Relying on industry standard nomenclature, testing, and reporting methodologies, the DLC technical requirements establish minimum performance baselines for horticultural LED fixtures. The requirements support the successful adoption of energy efficiency practices in CEA through the implementation of LED luminaires, LED lamps, and controls. Since the implementation of Hort V1.0, the average efficacy of listed products has increased by 17.5%.

Hort V3.0 further supports and accelerates the adoption of energy efficient lighting and controls in CEA. This is accomplished through the following key revisions to the previous technical requirements:

  • Increased efficacy threshold
    The Hort V3.0 PPE threshold has been increased to a minimum of 2.30 μmol × J-1, which is a 21% increase over the Hort V2.1 PPE threshold. This sets the DLC threshold for LED-based horticultural lighting at 35% above the most efficacious non-LED option, the 1000W double-ended high pressure sodium luminaire.
  • New requirements for reporting intended use of products, dimensions, and images
    To support the development of prescriptive/midstream energy efficiency incentive programs, Hort V3.0 collects and reports application (intended use of product) information of listed products to give users insights into the intended controlled environment and lighting scheme for all listed products. Additionally, product dimensions and a representative image are required and will be published on the Hort QPL.
  • Introduction of product-level controllability requirements
    To enable additional energy savings, promote interoperability, and lay the groundwork for future demand-response systems and programs, Hort V3.0 requires dimming capability for certain AC-powered luminaires, all DC-powered products, and all replacement lamps. Hort V3.0 also requires reporting of additional controllability details, including dimming and control methods, connector/transmission hardware, and integral control capabilities.
  • Introduction of a surveillance testing policy
    To protect the integrity and value of the Hort QPL for all stakeholders, the DLC will actively monitor the validity of data and other submitted information through a surveillance testing policy.

Schedule of Revisions

Version Status Effective Date Update By Delist Date Documentation
ACTIVE Mar 31, 2023 -- -- Download PDF
DELISTED Sep 1, 2021 Feb 2, 2024 Mar 31, 2024 Download PDF
DELISTED Mar 31, 2021 Feb 2, 2024 Mar 31, 2024 Download PDF
DELISTED Oct 21, 2019 Dec 31, 2021 Jan 31, 2022 Download PDF


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-45-21, Recommended Practice: Horticultural Lighting and ANSI/IES LS-1-22, Lighting Science: Nomenclature and Definitions for Illuminating Engineering, with key deviations or interpretations noted.

Each mention of the term “LED device” in the requirements is meant to reference LED packages, modules, or arrays.


Products designed and intended to operate with standard North American nominal AC line voltages (typically 120 V to 480 V) or with DC voltages below 600 V are eligible for DLC qualification. In addition:

  • Ineligible products include:
    • Products that are light engines (see definition of “LED light engine” in ANSI/IES LS-1-22) or identified as retrofit kits intended to replace the light sources or other structures within an existing fixture.
    • Fixtures and/or lamps that incorporate light sources other than LED, whether as sole-source or as LED-hybrid fixtures.
    • AC products that are dynamically configurable (i.e., having no defined configuration or set of configurations) and whose form factor may vary in the grow facility, are not eligible as an AC product and must qualify through the DC product pathway.
  • Manufacturers must list full model numbers that clearly demonstrate all qualified product options offered.
  • “Full model numbers” means model numbers that include all performance-affecting and non-performance-affecting variations offered, and that 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 may be submitted as a single model number, and the multiple options may be denoted by bracketing them in the model number.

For example, the submittal for 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 Level 1 (formerly 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 may not 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 model number. A lack of clarity in model numbers will result in delayed application processing; misrepresentation of model numbers discovered outside the application process will generally be considered a violation of the DLC program and trademark rules and may result in delisting.
  • Each model number may only represent the product under a single brand. If the product can be sold under multiple brands, model numbers must be listed separately for each brand. If brand name is not provided, the manufacturer name will be used to represent the brand name on the QPL.

Technical Requirements

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.

Safety Certification

The DLC requires specific testing and reporting to ensure that all listed products have an appropriate safety certification. All products must be certified to the applicable safety standard by a safety certification organization relevant in the United States or Canada.

Level 2 (formerly Family Grouping) Requirements

The DLC allows Level 2 (formerly Family Grouping) applications for horticultural lighting products. Level 2 applications are designed to reduce the total testing and application fees required to list groups of products that comply with the family grouping definition. Typically, parent products are based on tested data from worst-case models within a family group, and child products are based on reported data. Generally, limited testing can be provided if the worst-case models demonstrate compliance with the technical requirements.

Private Label Requirements

Private label applications allow manufacturers the option to list qualified products under multiple manufacturers and brands without having to conduct duplicate testing. Private label applications may only be submitted if the original equipment manufacturer’s (OEM) product is already DLC qualified. Private label products must be identical to the originally qualified versions.

Testing Lab Requirements

DLC applications require that product testing be conducted at an accredited laboratory appropriate for the performance being evaluated. These tests may include in situ measurement tests (ISTMT), ANSI/IES LM-79-19, ANSI/IES LM-80, ANSI/IES LM-84.

Testing Constraints

The DLC understands that in some scenarios, products that are required to be tested may be unable to test in the necessary apparatus’ as stated in the Horticultural Technical Requirements, due to size or other restrictions.