- What are the benefits of LED lamps and luminaires?
- What are lumens versus watts?
- What is the difference between 2700K, 4100K and 5100K color temperatures?
- How does the LED lamp life compare to current fluorescent lighting technologies?
- What is important to know about dimmable LEDs?
- Why does the light come on at full brightness, but the dimming range is limited?
- How does Energy Source characterize the beam spread of its lamps?
- What is the ‘beam angle’ of a lamp?
- What is ‘field angle’ and how does it differ from beam angle?
- Why is the beam angle of LED tube lamps less than a regular fluorescent lamp?
- I want to replace the fluorescent lamps in my office building with LED tube lamps, but the rated beam angle is only 120°. Will I have enough light? Will it be evenly distributed?
- An LED tube lamp specification sheet indicates a 340° beam angle. How can their LED lamp have such a wide beam angle?
- Are battery-backup systems subject to certification by UL, NEC, IBC or other regulatory bodies?
- The LM-79 report for a product I’m interested in shows an efficacy of 97 lm/W, but on DLC’s Qualified Products List (QPL) the efficacy is listed as 100 lm/W. Why are they not the same?
- Why does the LM-79 test report reflect better performance specs than those listed on DLC and Energy Star?
- Why is it that sometimes the stated “common description” wattage of a tube can deviate from rated or tested wattage data by a noticeable amount? For example, what if a product shows tested data of 17W on the LM79 report and on the DLC QPL, but also shows a DLC-rated wattage of 18W and is called an 18W product by Energy Source? What is the reason that it is not called a 17W tube?
- How does ambient temperature affect LEDs?
What are the benefits of LED lamps and luminaires?
LEDs can provide several benefits for your lighting project, including high efficacy and durability, and, with superior life over other lamp sources, their required maintenance is greatly reduced. This translates into energy savings, maintenance savings, and environmental sustainability. There is also the potential for greater optical control (more controllable source), dimming, instant on/off, and reduced rate of lumen depreciation (potential for long application life).
What are lumens versus watts?
A watt is the measure of power consumption, and is the common way incandescent light bulbs are identified — for example 60-watt, 75-watt and 100-watt. When purchasing a light bulb, however, what you really should look for is lumens, which is the measure of light output. When you purchase a 60-watt incandescent bulb, you are getting about 800 lumens. Due to the way that LEDs produce light, it is possible that an LED bulb or fixture that produces less lumens can appear just as bright if not brighter than the original light source being replaced.
What is the difference between 2700K, 4100K and 5100K color temperatures?
Correlated Color Temperature (CCT) is defined as the color of light given off by a particular light source that most closely represents the light emitted from a perfect blackbody radiator when heated to a certain temperature (K). 2700K is typically described as warm white light, 4100K is equivalent to white, and 5100K is equivalent to cool white.
How does the LED lamp life compare to current fluorescent lighting technologies?
Our LED lamps and luminaires have a rated life from 50,000 hour up to 70,000 hours, which is up to three times greater than fluorescent lighting with a typical lamp life of up to 25,000 hours.
What is important to know about dimmable LEDs?
Incandescent dimmers are designed for “resistive” loads, and typically rated for at least 600 watts. They have a requirement called “minimum holding current”, which is the minimum amount of electrical current flowing through them to keep the dimmer firing properly.
Energy Source LED Lighting lamp products have electronic drivers that are “reactive” (capacitive and/or inductive) and draw very little power. These two factors result in electrical current that is just barely above the minimum holding current for most dimmers, and below it for others. There are other factors specific to the installation site, such as neutral-to-ground integrity, power line noise coming from the utility or other loads, and source impedance. With the minimum holding current requirement barely being met, these other factors can cause the current to dip below that threshold, resulting in occasional dimmer mis-firing which can result in a faint flickering coming from the lights.
Energy Source tests its products with a variety of dimmers and makes recommendations regarding compatibility based on those results, but cannot guarantee performance.
Why does the light come on at full brightness, but the dimming range is limited?
1. Incompatible dimmer: Check Recommended Dimmer List for compatibility (Available on www.energysource.com)
2. Improper wiring/connection of dimmer: Check wiring instructions with dimmer to insure dimmer is connected properly.
3. Too many or too few fixtures on dimming circuit: Refer to Recommended Dimmer List for minimum and maximum number of fixtures recommended per dimmer.
4. Dimmer “Low End Trim” is set too high: Determine if dimmer has a “Low End Trim” adjustment, and adjust it all the way down.
5. Faulty dimmer: Replace dimmer.
6. Faulty light fixture: Replace light fixture.
How does Energy Source characterize the beam spread of its lamps?
It depends on the type of lamp. Spotlights and floodlights use beam angle to describe how the light spreads out. Streetlights define five different kinds of illumination distribution from “Type I” through “Type V.” Energy Source tube lamps, for example, use “illumination angle,” which we define from LM-79 photometric tests as the angle in which 99% of the light is included. Regardless of lamp type, though, Energy Source specs the illumination pattern of its LED lighting products based on photometric tests.
What is the “beam angle” of a lamp?
In the lighting business, the term “beam angle” has a specific meaning. It is the full angle where the light level drops to half (50%) of its highest value, which for most lamps usually falls directly underneath. A spotlight, for example, has a beam angle of only 7° to 15°, but the beam angle of an LED tube lamp could be 190°, when measured around its circumference. Regardless of the kind of lamp, though, its “beam angle” is always the point where the light intensity falls to half of its maximum, as defined by the IES.
What is ‘field angle’ and how does it differ from beam angle?
Like “beam angle,” “field angle” also has a precise meaning defined by the IES. It is the full angle where the light level drops to 10% of its maximum.
Why is the beam angle of LED tube lamps less than a regular fluorescent lamp?
This is a classic case of comparing apples to oranges. LEDs and fluorescents use completely different technologies to get light from one place to another. Fluorescent tubes emit light all over the place, while LEDs direct the light to where it’s needed. If a user doesn’t mind wasting 40% of his electricity to generate fluorescent light that shoots everywhere except where he needs it, then he probably drives a Hummer, too. The whole idea of LED lighting is efficiency and durability. He can enjoy the same amount of light for half the electricity, or twice as much light with the same amount of electricity, or he can keep paying those outrageous maintenance and utility bills for outdated “legacy” lighting.
I want to replace the fluorescent lamps in my office building with LED tube lamps, but the rated beam angle is only 120°. Will I have enough light? Will it be evenly distributed?
Yes, and yes. Seeing is believing, as they say, so the best way to know for sure is to try it. Install LEDs in a few of your light fixtures and see how they look. An Energy Source representative can help you choose the right LED tube lamp for your application. But if you don’t want to do that, the next best option is to have a computer-generated lighting layout done, which evaluates the light level and distribution based on the measured light output (IES files) of the lamps you plan to use. Contact Energy Source Tech Support at firstname.lastname@example.org for a custom lighting layout for your space.
An LED tube lamp specification sheet indicates a 340° beam angle. How can their LED lamp have such a wide beam angle?
Read the spec sheets carefully and ask to see a photometric chart of the light output. Chances are the angle is referencing the lamp’s “field angle” or some other method to measure the light spread.
Are battery-backup systems subject to certification by UL, NEC, IBC or other regulatory bodies?
Absolutely! Most building codes mandate a certain level of safety certification for any fixture in a structure. For U.S. commercial lighting, battery-backup systems should meet UL 924 requirements. Other governing standards, including the National Electrical Code (NEC), exist to evaluate real-life performance, such as: light levels and duration (NFPA 70), fire-resistance (NFPA 1), and life-safety codes (NFPA 101).
The LM-79 report for a product I’m interested in shows an efficacy of 97 lm/W, but on DLC’s Qualified Products List (QPL) the efficacy is listed as 100 lm/W. Why are they not the same?
DLC allows for a tested LM-79 efficacy of up to 3% below the efficacy stated on the QPL. The scenario described above conforms to DLC’s allowable -3% tolerance. For a fuller description of DLC’s performance tolerances, please refer to “Table 5: Tolerances” on their Technical Requirements page at: https://www.designlights.org/content/qpl/productsubmit/categoryspecifications. This webpage provides a comprehensive treatment of DLC’s product specifications and is a valuable resource for most questions regarding their requirements. We’ll let you in on a little secret: We refer to it all the time!
Why does the LM-79 test report reflect better performance specs than those listed on DLC and Energy Star?
We send prototypes to various certification organizations in an effort to expedite the release of each new product. The performance of production samples often exceeds the prototypes due to consistency in manufacturing. DLC does not prohibit a product’s performance specs from exceeding their requirements, so long as the total lumen output is within 10% of what is reported on their website. Please refer to “Table 5: Tolerances” on the DLC Technical Requirements page at: https://www.designlights.org/content/qpl/productsubmit/categoryspecifications.
Why is it that sometimes the stated “common description” wattage of a tube can deviate from rated or tested wattage data by a noticeable amount? For example, what if a product shows tested data of 17W on the LM79 report and on the DLC QPL, but also shows a DLC-rated wattage of 18W and is called an 18W product by Energy Source? What is the reason that it is not called a 17W tube?
This scenario is understandably confusing. To help clarify the issue, let’s break it down into the three different terms: “common description specs,” “tested specs,” and “rated specs.” The “common description specs” are what you see in the product’s name. For example, you may see something like, “18W 4000K 2600 Lumen Milky Tube Lamp.” These specifications are based on the circuit, driver, and LED designs used in the tube lamp, and they represent the theoretical performance of the tube. Conversely, “tested specs” are actual data that are found by a third-party laboratory when evaluating a random sample of our product. These results are packaged in a document called an LM79 report. In reference to the previously mentioned product, you may see specs like, “16.9W 4112K 2578 Lumen Milky Tube Lamp.” Remember that the tested specs are taken from a random sample, and naturally variances can occur. Finally, we get to “rated specs.” DLC allows us to submit our “rated data” when applying for a listing. The rated data often corresponds with the original designed specs. This practice is universally acceptable as long as the tested specs are within a certain margin of error from the rated specs. Though the tested and rated data don’t match identically in our example, they are within DLC tolerances; thus, they can be listed along with the rest of the family under the “rated data” umbrella.
How does ambient temperature affect LEDs?
LED fixtures must be designed with junction temperature thermal management as a key component and use the correct LEDs. These products will then be robust enough to operate in most ambient temperature applications. Unlike fluorescent sources, cold temperatures do not impact the performance of LEDs.