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Practical advice on commercial lighting from LED retrofts to lighting design

What is DLC v5.1 and how does it impact my lighting purchase?

Posted by Tad Mehringer on



A new wave of DLC requirements are in effect as of July 1, 2022. Lighting manufacturers are now required to submit all applicable products under the new set of DLC requirement updates.

What exactly does that mean? Your lighting purchase could be impacted. Let’s break down what DLC stands for and why it exists before we dive into how these changes will change your lighting.

What is DLC?

“DLC” stands for “Design Lights Consortium” and, according to the website, the designation “is dedicated to accelerating the widespread adoption of high-performing, energy efficient commercial lighting solutions. In collaboration with industry stakeholders, DLC defines high performance through technical requirements, facilitates thought leadership, and provides tools, resources, and technical expertise to members and industry.”

In layman’s terms, that means that DLC is a rating system that identifies which lighting products are generally regarded as being acceptable for their intended use through testing and manufacturer data.

Essentially, DLC is like having a “CarFax” report for LED products. That used car may look like it will perform well, but the CarFax shows what it has been through and what to expect. DLC does something similar (they don’t rate cars yet, unfortunately) in regards to lighting.

Here are a few of the categories that DLC looks at:

  • Manufacturer and brand
  • Model number
  • Luminaire efficacy
  • Light output
  • Power factor
  • Correlated Color Temperature (CCT)
  • Color Rendering Index (CRI)
  • Wattage
  • Dimming information
  • Integral controls information

The DLC label should provide certainty for decision makers. The organization's stringent standards do a lot of the vetting and due diligence for you.

What is DLC v5.1?

DLC Version 5.1 is a new set of technical requirements outlined in the Solid State of Lighting (SSL) — a policy that ensures a higher quality of light color.

DLC v5.0, passed in 2020, laid the groundwork for v5.1 with the ultimate goal of maximizing energy savings. The latest updates in DLC v5.1 focuses primarily on color performance, discomfort glare, and light distribution.

The DLC says this latest round of requirements is designed to improve satisfaction and comfort for the user. Although the efficacy (measured in lumens per watt) is the same between v5.0 and v5.1, v5.1 should enable greater energy savings because of better dimmability and controls.

Products that do not meet v5.1 requirements have already been removed from the Qualified Products List (QPL). Want to check a product to see if it's listed? You can access the QPL here.

Here is an outline of the changes and how they may affect your lighting:

1. Color maintenance requirements

Color consistency with LEDs has been a problem for quite some time. Although manufacturers have made major improvements, the new DLC policy focus on improved color rendering and color consistency over time. The requirements include enhancements for spectral quality and light distribution.

The ultimate goal is to improve productivity, performance, comfort, mood, safety, health, wellbeing, and more.

2. Dimmability

Almost all products that meet v5.1 requirements are now dimmable and must report on integrated controls. Dimmability is an essential part of saving energy and offers more comfortable light levels.

3. Improved glare performance

Once again focused on improving the experience of lighting products, DLC v5.1 also improves glare performance and reduces discomfort. The glare performance is based on light distribution and is designed to help you choose the right product when you're thinking about installation.

How DLC v5.1 will impact lighting products and rebates

The latest requirements mean that two-thirds of the current DLC list will be removed. While there are still more than 200,000 products on the list, this is a significant overhaul.

The product that's impacted the most is mogul-based HID replacement lamps (you may have heard these called corn cobs). About 80% of LED HID replacement products are now removed from v5.1.

Remember that just because a product is not on DLC's Qualified Product List does not mean the product is unsafe — it simply means it doesn't meet the highest standards for user satisfactions.

But what about rebates? Will products not on the list still qualify for rebates? This will vary from utility to utility, but typically rebates require products with the most recent DLC listing.

There may be a grace period, so it's always important to check to make sure you're selecting the right products for rebates.

Where can I find the best lighting rebates?

Navigating DLC updates and your lighting purchase

You can probably tell that the lighting industry and its certification groups want you to be informed and careful when choosing lamps or fixtures. What type of product are you installing? What is its proper rating and intended application? Where is it being used? What is the warranty and expected life?

These are all questions that DLC wants you to ask as you look at your lighting project. Through proper research and partnership, your project could offer a beneficial return for years to come.

If you're interested in learning more about how these DLC updates will affect you, please contact one of our lighting specialists

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