IES Publishes Research Report on Roadway LED Luminaire Dirt Depreciation

Illuminating Engineering Society

LED luminaires present new challenges for those maintaining outdoor- and roadway-lighting systems. In other luminaire types, maintenance crews often clean the luminaires when they do a bulk or single relamp (Illuminating Engineering Society of Australia and New Zealand (2012)), so the lamp life drives the cleaning schedule. However, LED-based luminaires are being marketed as lasting longer and requiring less maintenance than other luminaire types. As a result, they will be exposed longer to environmental dirt and other contaminants that can adhere to the luminaire and reduce the amount of light that reaches the road. This creates a different maintenance paradigm for LED luminaires, and their potential for dirt depreciation should be carefully investigated. The effect of dirt on luminaire output has long been studied, but past research was conducted on older designs that did not use LEDs. Complicating the problem is that LED luminaires are manufactured in a variety of ways, with different sources, lenses, and ingress protection.

This project sought to quantify luminaire dirt depreciation (LDD) in a number of different types of LED luminaires. This final report discusses project objectives, approach, and methods, presents research results, discusses the results in the context of today’s changing roadway lighting environment, and makes recommendations to stakeholders in roadway lighting regarding LDD for LED luminaires.

Download the report here: http://media.ies.org/docs/research/IES-RES-1-16.pdf

Related Articles


Changing Scene

  • LEDVANCE Expands Ontario Presence with New Specification Agent

    LEDVANCE Expands Ontario Presence with New Specification Agent

    LEDVANCE is pleased to announce the appointment of Sterling Architectural Products Ltd. (Sterling Lights) as their new specification agent in Ontario. This partnership strengthens LEDVANCE’s presence in the region and reinforces their commitment to serving the professional lighting design and specification community with innovative, reliable lighting solutions. With decades of experience and a service-driven mindset,… Read More…

  • May 29, 2025 - Eureka Wins Three 2025 Red Dot Awards for Product Design

    Eureka Wins Three 2025 Red Dot Awards for Product Design

    Eureka is pleased to announce that its Velia, Cirra, and Junction luminaires have each received a 2025 Red Dot Design Award for Product Design. It is the 11th consecutive year that Eureka products have been honored with this prestigious award, which is a testament to the company’s consistency and relentless drive to design exceptional luminaires.… Read More…


Design

  • Mac’s II Agencies: Case Study – Tesoro, Vancouver, BC

    Mac’s II Agencies: Case Study – Tesoro, Vancouver, BC

    At the crest of False Creek, Tesoro stands as a contemporary interpretation of classic luxury, offering 92 exclusive waterfront homes in the heart of Vancouver. Developed by Concert Properties, this 17-story residential tower embraces a distinctly modern character, harmonizing sleek design with timeless sophistication. The vision for Tesoro extended beyond its architectural presence—it was about… Read More…

  • LightForm: Estiluz – Versatile Solutions for Sophisticated Spaces

    LightForm: Estiluz – Versatile Solutions for Sophisticated Spaces

    For anyone seeking high-performance lighting that blends elegance with engineering, Estiluz offers an exceptional range of solutions. This Spanish brand, family-owned since 1969, creates lighting that balances form, function, and flexibility, making it ideal for both bold architectural statements and subtle design enhancements. At LightForm, they are proud to be the exclusive Canadian distributor of… Read More…


New Products

  • Cyclone Lighting Introduces New Taji Luminaire

    Cyclone Lighting Introduces New Taji Luminaire

    Cyclone Lighting is excited to announce the release of its new Taji luminaire. Taji’s captivating design features high-performance optics and enhances a variety of aesthetics. Taji’s distinctive, stylish silhouette and slender lines are a refreshing departure from the ubiquitous dome luminaire. The unique flared form maintains a slender, minimalist feel yet provides high-performance optics. The… Read More…

  • Leviton Releases New Decora Smart Wi-Fi 0-10V Dimmer for Home & Small Business Lighting Control

    Leviton Releases New Decora Smart Wi-Fi 0-10V Dimmer for Home & Small Business Lighting Control

    Leviton has announced the launch of the Decora Smart Wi-Fi 0-10V Dimmer (D2710), expanding its comprehensive Wi-Fi lighting and load control solutions that work with the My Leviton app. As the first Matter-compatible 0-10V smart dimmer, the new 120V/277V device makes it easy to add 0-10V dimming to smart platforms such as Apple Home, Amazon… Read More…