Introduction

The DLC LUNA Technical Requirements are designed to mitigate negative impacts of outdoor lighting at night. By establishing requirements and reporting standards on light distribution, spectral characteristics, and controllability, LUNA identifies energy efficient luminaires that minimize light pollution, provide appropriate visibility for people, and limit negative impacts to the environment.

These goals are consistent with the IES/IDA Five Principles of Responsible Outdoor Lighting shown above. The goals are generally compatible with the following guidance from ANSI/IES TM-37-21 to reduce sky glow. TM-37-21 recommends that lighting design:

• Eliminates unnecessary lighting (most important)
• Eliminates uplight
• Reduces lumen output, both by reducing the initial lumen package and by dimming
• Controls spectral content, while considering energy use and color rendering ability, and
• Sets appropriate expectations, by considering each light source’s relative contributions in the application.

Schedule of Revisions

Definitions

The following terms are used by the DLC in the LUNA requirements documents and/or application process documentation:

• Continuous dimming: A lighting control strategy that varies the light output of a lighting system over a continuous range from full light output to a minimum light output without flickering in imperceptible steps. (NEMA LSD-64-2019)
• Light pollution: The combination of all the adverse or obtrusive effects of electric light that produces artificial sky glow, including:
  • Unnecessary, unwanted, or wasted light
  • Light that damages or degrades the nighttime environment
  • Light that negatively impacts humans and other species (ANSI/IES LP-11-20)
• Light trespass: The encroachment of light, typically across property boundaries, causing annoyance, loss of privacy, or another nuisance. Also called spill light or obtrusive light. (ANSI/IES LS-1-20)
• Rayleigh scatter: The dispersion of electromagnetic radiation by particles much smaller than the wavelength of the radiation. The amount of scatter varies inversely as the fourth power of the wavelength, resulting in short wavelengths being scattered far more than longer wavelengths. (ANSI/IES LS-1-20)
• Receptacle (ANSI C136.41-2013): Defines the mechanical and electrical interface between an outdoor LED luminaire and a photocell, typically mounted on top of the luminaire. The dimensions of the receptacle are roughly 1.5” high x 2.5” diameter.
  • NEMA 5-pin: The 5-position receptacle has three line-voltage power contacts plus two dimming/signal contacts.
  • NEMA 7-pin: The 7-position receptacle has three line-voltage power contacts plus four dimming/signal contacts. The 7-pin configuration supports field upgrades of the control capabilities of LED luminaires by adding or changing wirelessly networked controllers with sensing and communication abilities.
• Receptacle (ANSI C136.58-2019 (Zhaga Book 18)): Defines the mechanical and electrical interface between an outdoor LED luminaire and modules for sensing and communication. The data interface is defined by the digital D4i/ANSI C137.4 The specification supports field upgrades of the control capabilities of LED fixtures by adding or changing 24V modules that provide sensing and communication abilities. The dimensions are roughly 1.1” high x 1.5” diameter.
• Shield: Shields are used to minimize light trespass onto adjacent areas. A shield is an internal or external opaque structure that obstructs the backward, forward, or side light distribution in a specific solid angle produced by the shield angle and azimuth. A house-side-shield (HSS) prevents some amount of high angle light from spilling backward behind the luminaire. A front-side-shield (FSS) prevents some amount of high angle light from being emitted towards the street-side. A cul-de-sac-shield (CSS) prevents some amount of high angle light from spilling backwards and sideways. Other shield types may be offered by manufacturers – such as left-side-shields (LSS) and right-side-shields (RSS) – that do not qualify for efficacy allowances.
• Shield type subgroup: Shields typically reduce luminaire efficacy due to light absorption, so they may be eligible for an efficacy allowance based on distribution performance. Shield type sub-groups eligible for LUNA efficacy allowances are house-side shields (HSS), cul-de-sac shields (CSS), and front-side shields (FSS), provided that the zonal lumen differences between the shielded and unshielded version meet the requirements noted in the allowance section. Shield type subgroups cannot be combined. A HSS subgroup, for example, can only contain products with house-side shields, not cul-de-sac shields or front-side shields. Other shield types can be used to meet the requirement that a roadway/area/decorative product must have a shield option/accessory; however, they are not eligible for a shielding efficacy allowance.
• Sky glow: The brightening of the night sky that results from the scattering and reflection of light from the constituents of the atmosphere (gaseous molecules and aerosols), in the direction of the observer. It has two components: natural sky glow and artificial sky glow. (IES LS-1-20)

Eligibility

Only outdoor luminaires that fall into the Primary Use Designations (PUDs) listed in Table 2 are eligible for LUNA qualification under Version 1.0. At this time, replacement lamps and retrofit kits are not eligible for LUNA because the lighting distributions for these products are highly dependent on application and installation. Specialty designation hazardous luminaires are eligible for LUNA qualification as noted in Table 2, and are exempt from the dimming requirements. All product options within a LUNA qualified model number must meet the LUNA requirements. Model numbers with options that do not meet the LUNA requirements are not eligible for LUNA qualification.

Aimable luminaires, whether floodlights or area lighting with tiltable mounting brackets, may increase sky glow, discomfort glare, and light trespass, which are undesirable lighting qualities from both a light pollution perspective and for typical use cases. Therefore, floodlights are ineligible for LUNA qualification, and roadway and area lighting products with mounting brackets that allow tilt angles of more than +/- 10 degrees are ineligible for LUNA qualification. Tilt of 10 degrees or less will allow these luminaire types to be aligned parallel with the roadway surface.

Relationship between SSL V5.1 and LUNA

To attain DLC LUNA qualification, products must meet the SSL V5.1 Technical Requirements as a baseline, in addition to the LUNA Technical Requirements. Efficacy allowances are provided for cases where efficacy is compromised due to using shielding in a luminaire. In other words, LUNA creates allowances for efficacy where efficacy is compromised due to enhanced dark sky attributes, such as shielding used to minimize light trespass or uplight.

The requirements for SSL V5.1 outdoor luminaires are summarized in the LUNA Technical Requirements document in the section, Overview of SSL Baseline Requirements and LUNA Requirements. The complete SSL V5.1 Technical Requirements can be viewed on the here, and apply to indoor and outdoor luminaires, retrofit kits, and replacement lamps.

The “Overview of LUNA V1.0 Requirements” column in Table 3 of the LUNA Technical Requirements describes additional requirements that a product must meet to attain LUNA qualification.

Technical Requirements

Products must comply with the provisions of these documents to be eligible for listing under the LUNA qualification. All LUNA requirements can be found in the LUNA Technical Requirements Tables. References for the LUNA Technical Requirements can be found here.

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.

Specific Requirements for Safety Certification

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), LM-79, LM-80, LM-84.

Testing Lab Requirements

Application Fees

The DLC requires manufacturers to submit an application fee to cover the costs of application review. The specific fee amount is dependent upon the type of application submitted and (in most cases) the details of the particular product group in the application submission.