Last week, the DesignLights Consortium (DLC), delisted products that do not meet the new quality and efficiency standards. There are new 
technical requirements for indoor and outdoor Luminaries and Retrofit Kits, and there are now two categories of designation, DLC standard and DLC premium.
The measurements include:
Minimum Light Output or Lumen – This is a measure of the total quantity of visible light emitted by a source
Minimum Efficacy – This is the measure of Lumens per Watts. So for example, if the light output is 5,000 lumens and the wattage is 55, the minimum efficiency is 90.
Correlated Color Temperature (CCT) – CCT measures the color of a light source by using Kelvin (K) temperature, which indicates the warmth or coolness of a lamp’s color appearance. The lower the Kelvin temperature (2700–3000 K), the warmer the color of the light, while the higher the temperature (3600–5500 K), the cooler.
Color Rendering Index (CRI) – The CRI measures the light source’s ability to show object colors realistically compared to a familiar reference source, such as incandescent light or daylight. The higher the CRI, the better the light source renders every color in the visible spectrum. Light sources with a CRI of 85 to 90 are considered good at color rendering. Light sources with a CRI of 90 or higher are excellent at color rendering and should be used for tasks requiring the most accurate color discrimination.
Lumen Depreciation – L70 v L90 – Light sources gets dimmer over time. This dimming is called lumen depreciation. If a fixture had a lumen maintenance of 70%, that would mean it lost 30% of its brightness during its rated life. If it had a lumen maintenance of 90%, that would mean it lost just 1/10 of its brightness during its rated lifespan.
The results are then placed into two categories: DLC Standard v DLC Premium.
DLC Standard Designation
In general, for outdoor lighting, the minimum efficacy ranges from 90-100, and 65-105 for indoor lighting and the lumen depreciation L70.
The DLC Premium Designation
The DLC Premium designation is new, and is only available to complete luminaires and retrofit kits. The primary differences for the Premium designation are the significantly increased efficacy requirements, which in general range from 110-120 for outdoor lighting and 90-130 for indoor lighting. They also and the need to provide an L90 projection.
To find out more specifics about these measurements, please see the DLC’s Technical Requirements Table.
Rebates
Some utility companies offer tiered rebate programs, so it may be more cost effective to install lights that meet the DLC Premium standards. Before you install your lighting, you can check to with your local utility or the Database of State Incentives for Renewables & Efficiency (DSIRE) to find rebates. DSIRE is the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States.
Conservation Mart offers a wide range of DLC listed lighting options and our customer service team will help you figure out which products may be eligible for rebates from your utility.