fluorescent lamp in lcd panel testing brands

Plazmo is the largest supplier of CCFL backlights (Cold Cathode Fluorescent Lamp) in North America. We currently have more 1 million CCFL backlights in stock and ready to ship.

The CCFL products we carry consist of hundreds of different sizes of raw Cold Cathode Fluorescent Lamps (CCFLs) available in diameters from 1.8mm - 6.0mm, and lengths from 40mm all the way up to 1,400mm. We also have more than 200,000 complete LCD backlight assemblies in stock in addition to the millions of CCFL backlights Plazmo has in stock.

We specialize in precision color-matching technology and use the latest in testing equipment that allows us to both analyze and produce any color CCFL backlight you want. This includes the full spectrum of white lamps commonly used in various LCD screens as well as specialty color, UV, and infrared lamps that are used in a wide range of applications.

In addition to our standard CCFL backlight offerings, we have complete engineering and manufacturing capabilities for custom designs.  We can make any type of CCFL backlight you might need. If you have an old, obsolete LCD or even a new, yet uncommon, LCD requiring a specific or custom-made backlight, we can help. We make new, specialty backlight lamps for any and all LCD applications, including straight and shaped lamps. Some of the CCFL backlight shapes Plazmo offers are: C, U, L, and M shape lamps. In short, if you don"t find the perfect solution for your LCD backlighting needs on our website,CCFLWarehouse.comorPlazmo.com, just give us a call or send us an email with your specific needs.

To go with the vast array of CCFL backlights we have in stock, we also offer the most common CCFLwire harnessesused in LCD backlighting. We stock UL-rated wire harnesses which include connector types from brands like JST, JAE, Molex, Honda, and many more. We also stock all of the components you would need to make your own, custom harnesses. Those components include High Voltage CCFL lamp wire, terminals, connectors and shrink tube, to name a few. If you need a CCFL wire harness that isn’t found atPlazmo.com, give our experts a call or send us an email. We can custom design and make practically any CCFL wire harnesses you might need. Whether you are a small LCD repair facility or a large OEM, we are CCFL backlight and LED backlight experts, and we are here to help.

Silicone end caps for CCFL backlights are a necessary component in making LCD backlight repairs. That’s why Plazmo carries hundreds of different models of silicone end caps. These include a variety of single, dual and triple LCD backlight lamp assembly varieties. However, not all of the end cap possibilities out there are available directly from our website, but we are able to help you find one that would be compatible with your needs. Send our experts an email or give us a call and we will help you find the right end cap, or, in the rare occurrence that we can not find the right end cap, we can custom manufacture the ones you need. For more information on custom CCFL silicone end caps, our contact information is below; we are here to help.

CCFLs have been used for years as a backlight source. These backlights usually have a hollow glass cylinder - 2 to 10 mm in diameter, that’s internally coated with a phosphorescent material and filled with a noble gas (most commonly argon). The tube is then sealed at both ends with an iron-nickel electrode located at each end of the tube.

CCFLs operate on high-voltage alternating current (AC). When the high voltage is applied the resulting arc ionizes the internal noble gas which produces ultraviolet energy. The ultraviolet energy excites the phosphorescent lining which then produces light in the visible range (400 to 700 nm). The phosphorus make-up determines the color temperature of the visible light output. Typically, the resulting temperature color is in the 2800 - 3200K range, which looks like a warm to standard white light.

Most systems that have LCD panels run on direct current (DC), the DC has to be converted to AC in order power the lamp. An inverter is typically used to create the high-voltage AC. In addition, CCFL backlights require constant current, not constant voltage. Also, the strike voltage or the voltage required to start the light of the CCFL is different than the sustaining voltage. The inverter that’s designed to power an LCD CCFL will typically run at about 50 kHz. The inverter has to be matched to the specifications of the CCFL, particularly the current, strike voltage, and operating voltage.

When power is applied to the inverter, it starts by ramping up the output voltage until the CCFL turns on (an arc strikes). The strike voltage may be several hundred volts higher than the sustaining voltage, just to get the CCFL to light up. After the tube strikes which is identified by current flowing, the inverter then drops the voltage until the rated current is flowing which is typically around 5 to 7 mA. For example, a CCFL may have a strike voltage of approximately 1200 V, an operating voltage of approximately 800 V, and an operating current of 6 mA. Using this example, the power draw would then be 4.8 watts. The inverter switch has built-in protection so that if the tube does not strike after it’s gotten a few hundred volts more than the normal strike voltage, the tube is considered dead.

The life expectancy of CCFLs used as backlights is now around 50,000 - 60,000 hours. CCFLs rarely exhibit catastrophic failure unlike incandescent bulbs. Rather, the tube slowly dims over time due to phosphor erosion. The useful life for all backlights is defined by when the light output from the tube reaches half of its initial brightness. Increasing the current will decrease the life expectancy, but will increase the brightness. The color temperature of the tube doesn’t usually change as the bulb gets older.

In many LCD panels, the CCFLs may be replaced when they reach the end of their useful life. CCFLs typically have low heat generation, about 6 - 8 watts per tube. The heat is spread over the surface area of the tube easing heat dissipation. Most LCDs in the embedded market use 4 tubes or less. However, when many CCFLs, more than 4, are used together in an enclosed panel, overall heat dissipation should be taken into account. The optimum ambient temperature range for the highest efficiency and brightness is 77 to 104°F (25 to 40°C). Depending on the design of the tube, it may operate at temperatures from -22 to +185°F (-30 to +85°C); however, performance may be affected at either end of the spectrum, especially the lower end. At low temperatures the brightness decreases and the strike voltage increases. The typical efficiency of CCFLs is in the range of 70 to 90 lumens-per-watt, although with the competition of LED backlights, new advances are being made to boost efficiency.

The world of LCD backlights can be a confusing one. Determining the right option for your LCD screen can be a challenge as a result. The solution you choose depends on the application, frequency of use, and perhaps your budget. However, different types of backlighting produce different results.

Whether you’re looking to replace your LCD lighting with LED or CCFL lights or just want to know which option is best for you, this brief guide will help you better understand what LCD backlighting is and what options are available.

First, let’s explore what LCD backlighting is. If you’ve made it this far, chances are you already have a general idea, but for those of you who don’t, LCD stands for Liquid Crystal Displays. Because pixels in LCDs are similar to shutters, their contrast relies on the underlying electrical current. To properly illuminate an LCD, a light source must be placed behind the color pixel panel.

It’s important to note that not all LCDs use a backlight. Backlighting simply allows the viewer to see the display more clearly in low light conditions. For commercial purposes, this is important since the consumer must be able to use the screen properly regardless of the external lighting conditions.

LCD displays often run 24/7, which means they lose their brightness over time, often in 3 years or fewer. That’s why replacements are often necessary. There are two primary types of LCD backlighting replacements—CCFL and LED.

CCFL stands for Cold Cathode Fluorescent Lamps. These backlights work very much like the traditional fluorescent lamp and come in a single straight or shaped glass tube. Inside the tube is low-pressure mercury vapor. Once ionized, it emits ultraviolet light. Since humans cannot detect UV light, a coat of phosphorus inside the tube translates it into a white bright light that we can see.

LED stands for Light-Emitting Diode. LED backlights work much differently than CCFLs in that they require 10 to 18 white individual LEDs. They are laid in a uniform pattern. To make things even more complex, white LEDs are actually blue LEDs with a yellow phosphor coating that causes us to see a white light.

To control where and how light is displayed on your chosen screen, a display panel consisting of two sheets of polarizing material with a liquid crystal solution placed in between is utilized. Again, this is where an electric current comes into play. That current will pass through the liquid. The result is a pattern based on how the crystals align, depending on if the light should or shouldn’t pass through it. Crystals serve as a barrier to create the resulting light display.

Keep in mind that both CFFL and Led can be custom tuned to produce nearly any color and color temperature of light. However, they each have different advantages and disadvantages.

CCFLs are the traditional standard for backlighting. They are the tried-and-true option for backlighting any LCD display. Why? There are several reasons.

On the other hand, LED backlights are getting more traction as of late. They are relatively new and most experts consider them the backlighting preference of the future. Most new displays are only available with LED replacements. However, LEDs do come with one major downside—they cost more than CCFLs, sometimes twice as much. Keep in mind, it is typically best to stick with using the type of backlight that your OEM screen was designed to use, regardless if it is LED or CCFL. One exception is if you have customized your display for LED use.

Yet, some of the advantages of choosing an LED include superior brightness levels, no inverter is required (only a power supply), durability is better, and they can provide longer life (for more cost).

Depending on your application, other types of backlighting might also be available. LCD TVs, for example, use both full-array and direct local backlighting. Direct local dimming is similar to full-array, but there are fewer LEDs spread across a wider area than you’d see with full-array backlighting. For manufacturers, however, there is a difference. LEDs that are spaced farther apart do not have the same consistency or accuracy in lighting that full-array displays do.

If your LCD screen is dimming and not offering the same consistent bright display as it once did, it could be time for repairs. A common repair is CCFL or LED replacement. In fact, companies like Plazmo make exact OEM replacements for the original backlight in the LCD, regardless if it is LED or CCFL.

LCD repair or removing and replacing LCD backlighting is simple but does require some steps. It is far more cost effective than total replacement as well. Your LCD is unique, which means you need to carefully analyze the manufacturer’s information before you go about removing the previous CCFL backlight. You’ll likely need to remove any outer casing you encounter and possibly the screen itself, depending on the application.

You will also have to work around a copper ground or LCD controller board because these often limit access to the backlight. Noting where you removed these items and where they should go back to is important during the removal process.

Next, access the CCFL bulb. Often it has its very own spot. Remove the rubber caps from the previous bulb and add them to your replacement bulb. Run the power cable back into one end of the new bulb—potentially using a soldering tool to do so. If you don’t want to do the rebuilding of your CCFL assembly, check out our mail in repair services here.

After you finish these steps, replace the CCFL and any other components back into your display and test the result.  In the vast majority of cases, your screen will be returned to its full brightness potential, just like new.

Did replacing your bulb not do any good? Then you might be dealing with dying capacitors, inverters, or transistors. You’ll need electrical equipment like a voltmeter, to take a measurement of the electrical current flowing into important components.

Whether you aren’t quite sure which backlight your LCD repair needs, or you have not been able to find the CCFL or LED for your screen anywhere, it might be time to contact a professional. Finding the correct backlight can be challenging and getting it wrong can cause you a serious headache.

The good news is, if you opt to choose Plazmo for your replacement parts or LCD repairs, you’re in good hands. We offer affordable replacements that get your screen back to its original brightness without the high costs of buying an entirely new panel.

Give our site a browse to find the right components for your LCD display or contact us at sales@plazmo.com  if you’d like to have us do the heavy lifting for your repairs.

Monitor and optimize light levels, reduce the energy burden of buildings by significantly increasing the efficiency of the lighting system with a light meter.

Fluorescent Lamp Tester takes the guess work out of troubleshooting fluorescent light fixtures, saving you time and money. These 3-in-1 tool tests the light bulb, pins, and voltage so you can tell whether fluorescent light bulbs are working before you install or remove them. The intuitive one-button operation, 48" removable and retractable antenna, Helps detect Voltage Non Contact and the ultra-compact design, makes Fluorescent light Tester is the right tool for the right job, in electrical and facilities maintenance applications.

Need help to select the “right tool for the right job”? Our Experienced, Friendly Staff is available to take your Call – 503-406-4373, or fill out the contact us form, and one of our Sales Engineers will call you back to discuss your application needs.

We are an on-demand lighting specialty distributor. We do not have brands or items we try to sell you on, we simply listen to customers and then stock the items and brands they have requested. We have been online since 2007 and have over 75 years of lighting knowledge between our 2 head tech support managers. If it’s an item in one of our categories of items we sell we will be able to get it or suggest an alternative.

Traditional LCDs use CCFLs, or cold-cathode florescent lamps, as their backlight. While cheap, they"re not as energy efficient as LEDs. More importantly, all contain mercury, and aren"t able to do some of the fancy area-lighting of which some LED backlit models are capable. Because of these issues and the falling prices of LEDs, CCFL backlit LCD TVs will disappear entirely very soon. In 2013

Most LED LCDs on the market today are edge-lit, which means the LEDs are in the sides of the TV, facing in toward the screen. In the image at the top, the LED strips are above and to the side of this exploded-view of an LCD panel. There"s a close-up view here (full article with more images

There are a few models that are have their LEDs arrayed on the back of the TV, facing you. These are less common, though are making a comeback in the form of cheaper, but thicker, mostly low-end LED LCDs. There are a handful of high-end TVs that use full-array LED backlighting in a slightly different way, which we"ll discuss later.

Because the light is brightest nearest the LEDs, it"s common for edge-lit LED LCDs to have poor uniformity. This is especially noticeable on dark scenes, where areas of the screen will appear brighter than others. Corners or edges can have what looks like tiny flashlights shining on the screen. Check out

Each manufacturer has a preferred method for edge-lighting, but some models may feature one type, while other models feature another type. Generally speaking, the fewer LEDs the cheaper the TV is to produce. Fewer LEDs also mean better energy efficiency, but LED LCDs are already so efficient that this is a tiny improvement. Unfortunately, specific details about where a TV"s LEDs are located (beyond "direct" or "edge"), the number of LEDs, and other useful information about the backlighting, are rarely listed on a TV"s spec sheet.

The biggest difference between all the LED back/edge-lighting methods is how effective their "local dimming" is, which as you"ll see, has become a pretty broad term.

Though TVs of this style claim to have "local dimming" you can see how this is a pretty broad definition of "local." Even if each LED is dimmable independently (highly unlikely), you"re still only able to dim columns that stretch from top to bottom. Something like this:

As you can guess, this design has LEDs on the top and bottom edges of the screen. The local dimming here is a little better, where the zones can be slightly smaller areas of the screen, like this:

This is a less common method now, as it requires more LEDs than any of the other edge-lighting methods. The local dimming can get a little more accurate, but is still limited to large-ish zones. If we used our moon example image, the result with an all-sides edge-lit would look just like top and bottom. But with regular video (that has more light sources than just the moon), it will have a more zones to work with, sort of like this:

All Sides used to be the most common edge-lighting method. But as the light guides improved, and costs had to come down (to make cheaper LED LCDs), this method became fairly rare.

Nearly all "backlit" LED LCDs use this method. The LEDs are arrayed on the back of the TV, facing you, but there is no processing to dim them individually. They work instead as a uniform backlight, like most CCFL LCDs. The least expensive LED LCDs use this method, as do most of Sharp"s

This is the ultimate LED LCD, offering performance that rivals the better plasmas. Like the "direct-lit" TVs, these have their LEDs behind the screen (the image above for direct-lit works as a visual aid for this type as well). The full local-dimming aspect means the TV is able to dim zones behind the dark areas of the screen in fairly specific areas to make the image really pop, drastically increasing the apparent contrast ratio.

However, they basically don"t exist. The LG LM9600 wasn"t great last year, and LG has yet to announce any full-array local-dimming TVs for 2013. The only other local-dimming LED LCD was the Sony HX950, which was excellent, and is still current. In his review David Katzmaier called

The two biggest-selling TV makers in the U.S. are Samsung and Vizio, and neither has sold a full-array local-dimming LED TV for the last couple years. At CES 2013, Samsung"s only such TV announced was the insanely-expensive E420i-A1, saying "Sure, black levels get darker, but the trade-off in shadow detail is one I"m not willing to make," and concluded that its "local dimming does nothing to improve picture quality."

As I mentioned at the top, there"s no easy way to tell, just by looking at a spec sheet, what kind of backlight a TV has. By extension, there"s no way to tell how good its local dimming will be. Bad local dimming can, at worst, just be marketing hyperbole. At best, it does little to improve the picture. Good local dimming, however, can make a punchy image, with lots of apparent depth and realism. Or to put it differently, the best LCDs on the market have the best local dimming, allowing them to rival plasmas on the picture quality front. The better TV reviews, like ahem those here on CNET, will talk about all this, so you"re not duped into paying for a "feature" that"s little more than a check mark on a spec sheet.

Got a question for Geoff? First, check out all the other articles he"s written on topics like Send him an e-mail! He won"t tell you what TV to buy, but he might use your letter in a future article. You can also send him a message on Twitter: @TechWriterGeoff.

An LED-backlit LCD is a liquid-crystal display that uses LEDs for backlighting instead of traditional cold cathode fluorescent (CCFL) backlighting.TFT LCD (thin-film-transistor liquid-crystal display) technologies as CCFL-backlit LCDs, but offer a variety of advantages over them.

While not an LED display, a television using such a combination of an LED backlight with an LCD panel is advertised as an LED TV by some manufacturers and suppliers.

Unlike OLED and microLED displays, LCDs cannot achieve true blacks for pixels which are illuminated by the backlight. Some LED-backlit LCDs use local dimming zones to increase contrast between bright and dim areas of the display, but this can result in a "blooming" or "halo" effect on dark pixels in or adjacent to an illuminated zone.

The local dimming method of backlighting allows to dynamically control the level of light intensity of specific areas of darkness on the screen, resulting in much higher dynamic-contrast ratios, though at the cost of less detail in small, bright objects on a dark background, such as star fields or shadow details.

A 2016 study by the University of California (Berkeley) suggests that the subjectively perceived visual enhancement with common contrast source material levels off at about 60 LCD local dimming zones.

LED-backlit LCDs are not self-illuminating (unlike pure-LED systems). There are several methods of backlighting an LCD panel using LEDs, including the use of either white or RGB (Red, Green, and Blue) LED arrays behind the panel and edge-LED lighting (which uses white LEDs around the inside frame of the TV and a light-diffusion panel to spread the light evenly behind the LCD panel). Variations in LED backlighting offer different benefits. The first commercial full-array LED-backlit LCD TV was the Sony Qualia 005 (introduced in 2004), which used RGB LED arrays to produce a color gamut about twice that of a conventional CCFL LCD television. This was possible because red, green and blue LEDs have sharp spectral peaks which (combined with the LCD panel filters) result in significantly less bleed-through to adjacent color channels. Unwanted bleed-through channels do not "whiten" the desired color as much, resulting in a larger gamut. RGB LED technology continues to be used on Sony BRAVIA LCD models. LED backlighting using white LEDs produces a broader spectrum source feeding the individual LCD panel filters (similar to CCFL sources), resulting in a more limited display gamut than RGB LEDs at lower cost.

The evolution of energy standards and the increasing public expectations regarding power consumption made it necessary for backlight systems to manage their power. As for other consumer electronics products (e.g., fridges or light bulbs), energy consumption categories are enforced for television sets.

Using PWM (pulse-width modulation), a technology where the intensity of the LEDs are kept constant but the brightness adjustment is achieved by varying a time interval of flashing these constant light intensity light sources,

A first dynamic "local dimming" LED backlight was public demonstrated by BrightSide Technologies in 2003,Sony in September 2008 on the 40-inch (1,000 mm) BRAVIA KLV-40ZX1M (known as the ZX1 in Europe). Edge-LED lighting for LCDs allows thinner housing; the Sony BRAVIA KLV-40ZX1M is 1 cm thick, and others are also extremely thin.

LED-backlit LCDs have longer life and better energy efficiency than plasma and CCFL LCD TVs.mercury, an environmental pollutant, in their manufacture. However, other elements (such as gallium and arsenic) are used in the manufacture of the LED emitters; there is debate over whether they are a better long-term solution to the problem of screen disposal.

Because LEDs can be switched on and off more quickly than CCFLs and can offer a higher light output, it is theoretically possible to offer very high contrast ratios. They can produce deep blacks (LEDs off) and high brightness (LEDs on). However, measurements made from pure-black and pure-white outputs are complicated by edge-LED lighting not allowing these outputs to be reproduced simultaneously on screen.

Quantum dots are photoluminescent; they are useful in displays because they emit light in specific, narrow normal distributions of wavelengths. To generate white light best suited as an LCD backlight, parts of the light of a blue-emitting LED are transformed by quantum dots into small-bandwidth green and red light such that the combined white light allows a nearly ideal color gamut to be generated by the RGB color filters of the LCD panel. The quantum dors may be in a separate layer as a quantum dot enhacement film, or replace pigment-based green and red resists normally used in LCD color filters. In addition, efficiency is improved, as intermediate colors are no longer present and do not have to be filtered out by the color filters of the LCD screen. This can result in a display that more accurately renders colors in the visible spectrum. Companies developing quantum dot solutions for displays include Nanosys, 3M as a licensee of Nanosys, QD Vision of Lexington, Massachusetts, US and Avantama of Switzerland.Consumer Electronics Show 2015.quantum dot displays at CES 2017 and later formed the "QLED Alliance" with Hisense and TCL to market the technology.

Mini LED displays are LED-backlit LCDs with mini-LED–based backlighting supporting over a thousand full array local dimming (FALD) zones, providing deeper blacks and a higher contrast ratio.

LED backlights are often dimmed by applying pulse-width modulation to the supply current, switching the backlight off and on more quickly than the eye can perceive. If the dimming-pulse frequency is too low or the user is sensitive to flicker, this may cause discomfort and eyestrain similar to the flicker of CRT displays at lower refresh rates.

Competing display technologies for the best image performance; A.J.S.M. de Vaan; Journal of the society of information displays, Volume 15, Issue 9 September 2007 Pages 657–666; http://onlinelibrary.wiley.com/doi/10.1889/1.2785199/abstract?

Novitsky, Tom; Abbott, Bill (12 November 2007). "Driving LEDs versus CCFLs for LCD backlighting". EE Times. Archived from the original on 28 November 2010. Retrieved 21 November 2020.

Scott Wilkinson. "Ultimate Vizio Archived 26 August 2009 at the Wayback Machine". UltimateAVmag.com. Posted Fri 29 May 2009. Retrieved 16 December 2009.

LED TVs: 10 things you need to know; David Carnoy, David Katzmaier; CNET.com/news; 3 June 2010; https://www.cnet.com/news/led-tvs-10-things-you-need-to-know/

Method of and device for generating an image having a desired brightness; D.A. Stanton; M.V.C. Stroomer; A.J.S.M. de Vaan; US patent USRE42428E; 7 June 2011; https://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=RE42428E

Chen, Haiwei; Zhu, Ruidong; Li, Ming-Chun; Lee, Seok-Lyul; Wu, Shin-Tson (24 January 2017). "Pixel-by-pixel local dimming for high-dynamic-range liquid crystal displays". Optics Express. 25 (3): 1973–1984. doi:ISSN 1094-4087. PMID 29519046.

"Implementing directive 2005/32/EC of the European Parliament and of the Council with regard to ecodesign requirements for televisions", 2009; http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32009R0642

Controlling Power Consumption for Displays With Backlight Dimming; Claire Mantel et al; Journal of Display Technology; Volume: 9, Issue: 12, Dec. 2013; https://ieeexplore.ieee.org/document/6520956

Energy Efficiency Success Story: TV Energy Consumption Shrinks as Screen Size and Performance Grow, Finds New CTA Study; Consumer Technology Association; press release 12 July 2017; https://cta.tech/News/Press-Releases/2017/July/Energy-Efficiency-Success-Story-TV-Energy-Consump.aspx Archived 4 November 2017 at the Wayback Machine

LCD Television Power Draw Trends from 2003 to 2015; B. Urban and K. Roth; Fraunhofer USA Center for Sustainable Energy Systems; Final Report to the Consumer Technology Association; May 2017; http://www.cta.tech/cta/media/policyImages/policyPDFs/Fraunhofer-LCD-TV-Power-Draw-Trends-FINAL.pdf Archived 1 August 2017 at the Wayback Machine

Broadband reflective polarizers based on form birefringence for ultra-thin liquid crystal displays; S.U. Pan; L. Tan and H.S. Kwok; Vol. 25, No. 15; 24 July 2017; Optics Express 17499; https://www.osapublishing.org/oe/viewmedia.cfm?uri=oe-25-15-17499&seq=0

Polarisation-sensitive beam splitter; D.J. Broer; A.J.S.M. de Vaan; J. Brambring; European patent EP0428213B1; 27 July 1994; https://worldwide.espacenet.com/publicationDetails/biblio?CC=EP&NR=0428213B1&KC=B1&FT=D#

Replacing your fluorescent tube lights with LED retrofits can be a confusing and daunting process. We"ve put together this guide to demystify all of the ins and outs of replacing your fluorescent tubes with LED tube lights.

Because fluorescent fixtures are often mounted into ceilings and connected directly to mains electricity, they are relatively expensive and difficult to replace completely.

As a result, it oftentimes makes the most economical sense to simply use the same fluorescent fixture, but replace the fluorescent tube with an LED tube light.

Therefore, it is important to understand the types of fluorescent tubes that were developed, so that the correct LED tube light can be retrofitted in place.

T12 4-ft: Four-foot T12 fluorescent lamps are less efficient compared to T8 lamps. They are the same length as T8 lamps, but have a larger 1.5 inch lamp diameter.

T5 4-ft: Four-foot T5 fluorescent lamps are typically the most efficient, and some of the newest types of lamps introduced in the 2000"s in the USA. They are commonly designated T5HO (high output) and provide more brightness than their T8 counterparts. They are slightly shorter than four feet (45.8 inches). T5 lamps come in a variety of lengths such as 1-ft, 2-ft and 3-ft versions and are commonly used in non-ceiling fixtures such as table lamps.

All fluorescent tube lights use a device called a ballast to regulate the lamp"s brightness as it warms up. These devices are necessary for fluorescent lamps, and differ from incandescent lamps which can be connected directly to mains electrical circuits.

Fluorescent lamp fixtures typically house the ballast inside the fixture, and is not accessible without removing the fixture from the ceiling. Alterations to the fluorescent lamp ballast should be done only by those comfortable and knowledgeable with electrical work.

LED lamps, on the other hand, operate differently from fluorescent lamps, and do not utilize a ballast (but do utilize electronic components that make up the LED driver).

Early LED tube lights required removing or bypassing the fluorescent ballast. Now, many LED tube lights are designed to be compatible with fluorescent ballasts, allowing for a simple replacement of the fluorescent tube, without re-wiring the fixture. Below, we discuss the common terms used for each of these configurations.

Commonly designed "UL Type A" - these LED tube lights are designed to be compatible with fluorescent ballasts. They are the most straightforward to implement, since it does not require rewiring the fluorescent fixture.

Ideal for: Consumers not comfortable with or preferring to avoid electrical wiring work, lighting installations where electrician labor costs are high

Disadvantages: Fluorescent ballasts can fail, requiring continued maintenance and eventual replacement or bypass of the ballast; potential issues with fluorescent ballast compatibility; lower overall electrical efficiency due to ballast.

LED tube lights that have  a "UL Type B" specification are not compatible with fluorescent ballasts. They cannot be used with the fluorescent ballast, and must be connected directly to mains electricity. The LED driver, however, is integrated into the LED tube itself.

In a single-ended configuration, only the two pins on one end of the tube are used (one pin = live; one pin = neutral), and the two pins on the other end are not electrically functional, and only used for holding the lamp in place.

For single-ended configurations, the direction in which a lamp is installed is important - incorrect configurations can lead to a lamp that does not illuminate, or a potentially hazardous fire risk. Single-ended configurations will typically have a sticker label on one end of the tube with the words "AC INPUT" or similar. Some single-ended configurations can accept power from either end.

In a double-ended configuration, the two pins on each side of the tube are the same polarity. Therefore, the lampholders on one end of the tube must be connected to [neutral], while the other must be connected to [positive].

UL Type C LED tubes are relatively uncommon, but offer the most flexibility and efficiency for a lighting system. Unlike a UL Type B LED tube, these do not have the LED driver integrated into the LED tube, and therefore requires a separate LED driver device to be connected between the LED tube and mains electricity.

Ideal for: lowest maintenance costs as LED drivers can be replaced without replacing the whole LED tube; more LED driver options such as 0-10V dimming and other IoT connectivity.

Tombstones are the "sockets" or lampholders that the LED tube lights will be installed into, providing both the mechanical support as well as electrical current.

Scenario ii) is called non-shunted, while scenario iii) is called shunted. "Shunting" refers to the joining of two separate circuits into one. The result of shunting is that both tombstone contacts connect to the same electrical polarity.

In general, fluorescent fixtures that have never been altered for LED or instant-start ballasts have non-shunted tombstones, while those that have been altered for LED or instant-start ballast may have shunted tombstones.

Sometimes, tombstones are externally shunted, as shown in the photo above, where the wire inputs are only open on one side. In some cases, however, tombstones can be internally shunted, where the wire inputs on both sides are open, but are connected inside the tombstone.

Since some tombstones are internally shunted, visually checking the tombstones does not provide a conclusive result. We strongly recommend testing the two tombstone contacts with a voltmeter to determine whether a closed or open circuit exists. A closed circuit will indicate shunted tombstones.

If your LED tube light is single-ended, it is NOT compatible with shunted tombstones. This is because each of the two contacts in the tombstone must be opposite polarity for a single-ended LED tube light to work. In a shunted tombstone, however, this is not possible as there will be an internal short circuit.

If you have shunted tombstones, you will need to rewire or replace them and connect them to match the single-ended LED tube light manufacturers" wiring diagram.

If your LED tube light is double-ended, it is likely compatible with both shunted and non-shunted tombstones. The reason is that the two pins on each end of the LED tube light expect the same polarity, so whether or not they are shunted should have no influence on the final resulting circuit.

Keep in mind this section discusses whether or not the tombstone itself is shunted vs non-shunted - be sure to connect the wires into the tombstone correctly to match the manufacturers" wiring diagram to ensure safe installation.

We recommend looking for LED tubes that are compatible with any of the potential electrical configurations in a fluorescent fixture - for example, Waveform Lighting"s T8 3-in-1 LED tubes.

Commonly characterized as the core photoelectric specifications, it"s also important that the emitted light qualities are similar or exceed your current fluorescent tube lighting.

Most fluorescent tube lights have a correlated color temperature (CCT) of 4000K or 5000K, as they have been considered to be most suitable for retail and office environments, respectively. Many fluorescent lamp phosphor developments over the years, however, have enabled a wide range of color temperatures.

Similarly, LED tube lights are also available in a wide range of color temperatures. Generally, the color appearance will be similar between an LED tube light and fluorescent tube light with the same color temperature rating.

Luminous flux, measured in lumens, measures the total amount of light emitted from a lamp, and is the best measure to determine the brightness of a lamp.

The best way to make an apples-to-apples comparison is to compare the luminous flux value of the fluorescent lamp with the LED tube light. Generally, a 35W T8 fluorescent lamp emits about 2500 lumens.

One thing to note about LED tube lights is that they tend to direct light downward, rather than a full 360 degrees in a fluorescent lamp. Therefore, when installed in a ceiling fixture, an LED tube light may provide more useful lumens, since the light is directed downwards rather than back into the fixture as in a fluorescent lamp.

CRI measures the extent to which objects" color appear true and accurate under a light source. Most fluorescent lamps have a CRI rating of 80 or so, and the majority of LED tube lights also come in at around 80 CRI as well. 80 CRI is acceptable for most applications, but for enhanced color quality and environments where color perception is important, look for a higher CRI rating in an LED tube light.

Finally, we"ll talk a bit about the cost considerations for making an LED tube light purchase. In recent years, LED tube lights have come down in price to a level that competes with fluorescent lamps, so the purchase price of the lamps makes LED tube lights a very appealing option.

If, however, the LED tube light you selected is not a UL Type A lamp, you will incur electrical rewiring labor costs. For a large or commercial installation, these costs may be significant depending on the complexity of the rewiring necessary for the fluorescent fixture. Typically, it can take a trained electrician 15-25 minutes per 4-lamp fluorescent fixture.

If we assume it takes an hour for an electrician charging $100 per hour to complete the rewiring of 3x 4-lamp fluorescent fixtures, we can calculate a labor cost of more than $8 per lamp. You can see how labor costs quickly add to the initial costs of the project - adding to the appeal of UL Type A compatible LED tube lights.

Calculate the amount of electricity and maintenance costs that LED tube lights will save, and determine the payback period. Generally, the shorter the better!

Also, consider the warranty terms of the manufacturer. Ideally, the payback period is shorter than the warranty, as that way, you are insured against any premature product failures that jeopardize the cost savings of going with LED tube lights.

(1) Contents. Fluorescent lamp ballasts that are “covered products,” as defined in this part, and to which standards are applicable under section 325 of the Act, shall be marked conspicuously, in color-contrasting ink, with a capital letter “E” printed within a circle. Packaging for such fluorescent lamp ballasts, as well as packaging for luminaires into which they are incorporated, shall also be marked conspicuously with a capital letter “E” printed within a circle. For purposes of this section, the encircled capital letter “E” will be deemed “conspicuous,” in terms of size, if it is as large as either the manufacturer"s name or another logo, such as the “UL,” “CBM” or “ETL” logos, whichever is larger, that appears on the fluorescent lamp ballast, the packaging for such ballast or the packaging for the luminaire into which the covered ballast is incorporated, whichever is applicable for purpose of labeling.

(2) Product labeling. The encircled capital letter “E” on fluorescent lamp ballasts must appear conspicuously, in color-contrasting ink, (i.e., in a color that contrasts with the background on which the encircled capital letter “E” is placed) on the surface that is normally labeled. It may be printed on the label that normally appears on the fluorescent lamp ballast, printed on a separate label, or stamped indelibly on the surface of the fluorescent lamp ballast.

(3) Package labeling. For purposes of labeling under this section, packaging for such fluorescent lamp ballasts and the luminaires into which they are incorporated consists of the plastic sheeting, or “shrink-wrap,” covering pallet loads of fluorescent lamp ballasts or luminaires as well as any containers in which such fluorescent lamp ballasts or the luminaires into which they are incorporated are marketed individually or in small numbers. The encircled capital letter “E” on packages containing fluorescent lamp ballasts or the luminaires into which they are incorporated must appear conspicuously, in color-contrasting ink, on the surface of the package on which printing or a label normally appears. If the package contains printing on more than one surface, the label must appear on the surface on which the product inside the package is described. The encircled capital letter “E” may be printed on the surface of the package, printed on a label containing other information, printed on a separate label, or indelibly stamped on the surface of the package. In the case of pallet loads containing fluorescent lamp ballasts or the luminaires into which they are incorporated, the encircled capital letter “E” must appear conspicuously, in color-contrasting ink, on the plastic sheeting, unless clear plastic sheeting is used and the encircled capital letter “E” is legible underneath this packaging. The encircled capital letter “E” must also appear conspicuously on any documentation that would normally accompany such a pallet load. The encircled capital letter “E” may appear on a label affixed to the sheeting or may be indelibly stamped on the sheeting. It may be printed on the documentation, printed on a separate label that is affixed to the documentation or indelibly stamped on the documentation.

(b) General service lamps. Except as provided in paragraph (f) of this section, any covered product that is a general service lamp shall be labeled as follows:

(1) Principal display panel content. The principal display panel of the product package shall be labeled clearly and conspicuously with the following information:

(ii) The estimated annual energy cost of each lamp included in the package, expressed as “Estimated Energy Cost” in dollars and based on usage of 3 hours per day and 11 cents ($0.11) per kWh.

(2) Principal display panel format. The light output (brightness) and energy cost shall appear in that order and with equal clarity and conspicuousness on the principal display panel of the product package. The format, terms, specifications, and minimum sizes shall follow the specifications and minimum sizes displayed in Prototype Label 5 in appendix L of this part.

(3) Lighting Facts label content. The side or rear display panel of the product package shall be labeled clearly and conspicuously with a Lighting Facts label that contains the following information in the following order:

(ii) The estimated annual energy cost of each lamp included in the package based on the average initial wattage, a usage rate of 3 hours per day and 11 cents ($0.11) per kWh and explanatory text as illustrated in Prototype Label 6 in appendix L of this part;

(iii) The life, as defined in this part, of each lamp included in the package, expressed in years rounded to the nearest tenth (based on 3 hours operation per day);

(iv) The correlated color temperature of each lamp included in the package, as measured in degrees Kelvin and expressed as “Light Appearance” and by a number and a marker in the form of a scale as illustrated in Prototype Label 6 to appendix L of this part placed proportionately on the scale where the left end equals 2,600 K and the right end equals 6,600 K;

(vi) The ENERGY STAR logo as illustrated in Prototype Label 6 to appendix L of this part for certified products, if desired by the manufacturer or private labeler. Only manufacturers or private labelers that have signed a Memorandum of Understanding with the Department of Energy or the Environmental Protection Agency may add the ENERGY STAR logo to labels on certified covered products; such manufacturers or private labelers may add the ENERGY STAR logo to labels only on those products that are covered by the Memorandum of Understanding;

(viii) For any general service lamp containing mercury, the following statement: “Contains Mercury For more on clean up and safe disposal, visit epa.gov/cfl.” The manufacturer may also print an “Hg[Encircled]” symbol on the label after the term “Contains Mercury”; and

(4) Standard Lighting Facts label format. Except as provided in paragraph (b)(5) of this section, information specified in paragraph (b)(3) of this section shall be presented on covered lamp packages in the format, terms, explanatory text, specifications, and minimum sizes as shown in Prototype Labels 6 in appendix L of this part and consistent in format and orientation with Sample Labels 10, 11, or 12 in appendix L. The text and lines shall be all black or one color type, printed on a white or other neutral contrasting background whenever practical.

(i) The Lighting Facts information shall be set off in a box by use of hairlines and shall be all black or one color type, printed on a white or other neutral contrasting background whenever practical.

(5) Lighting Facts format for small packages. If the total surface area of the product package available for labeling is less than 24 square inches and the package shape or size cannot accommodate the standard label required by paragraph (b)(4) of this section, manufacturers may provide the information specified in paragraph (b)(3) of this section using a smaller, linear label following the format, terms, explanatory text, specifications, and minimum sizes illustrated in Prototype Label 7 in appendix L of this part.

(6) Bilingual labels. The information required by paragraphs (b)(1) through (5) of this section may be presented in a second language either by using separate labels for each language or in a bilingual label with the English text in the format required by this section immediately followed by the text in the second language. Sample Label 13 in appendix L of this part provides an example of a bilingual Lighting Facts label. All required information must be included in both languages. Numeric characters that are identical in both languages need not be repeated.

(i) The lamp"s average initial lumens, expressed as a number rounded to the nearest five, adjacent to the word “lumens,” both provided in minimum 8 point font; and

(1) Any specialty consumer lamp that is a vibration-service lamp as defined at 42 U.S.C. 6291, rough service lamp as defined at 42 U.S.C. 6291(30), appliance lamp as defined at 42 U.S.C. 6291(30); or shatter resistant lamp (including a shatter proof lamp and a shatter protected lamp) must be labeled pursuant to the requirements in paragraphs (b)(1) through (7) of this section.

(2) Specialty consumer lamp Lighting Facts label content. All specialty consumer lamps not covered by paragraph (c)(1) of this section shall be labeled pursuant to the requirements of paragraphs (b)(1) through (7) of this section or as follows:

(i) The principal display panel of the product package shall be labeled clearly and conspicuously with the following information consistent with the Prototype Labels in Appendix L:

(B) The estimated annual energy cost of each lamp included in the package, expressed as “Estimated Energy Cost” in dollars and based on usage of 3 hours per day and 11 cents ($0.11) per kWh; and

(C) The life, as defined in this part, of each lamp included in the package, expressed in years rounded to the nearest tenth (based on 3 hours operation per day).

(iii) If the lamp contains mercury, the lamp shall be labeled legibly on the product with the following statement: “Mercury disposal: epa.gov/cfl” in minimum 8 point font.

(iv) If the required disclosures for a lamp covered by paragraph (c)(2) of this section will not be legible on the front panel of a single-card, blister package due to the small size of the panel, the manufacturer or private labeler may print the statement “Lighting Facts see back” on the principal display panel consistent with the sample label in Appendix L as long as the Lighting Facts label required by paragraph (b)(3) of this section appears on the rear panel.

(3) Specialty Lighting Facts label format. Information specified in paragraph (c)(2) of this section shall be presented on covered lamp packages in the format, terms, explanatory text, specifications, and minimum sizes as shown in the Prototype Labels of appendix L and consistent in format and orientation with Sample Labels in Appendix L of this part. The text and lines shall be all black or one color type, printed on a white or other neutral contrasting background whenever practical.

(i) The Lighting Facts information shall be set off in a box by use of hairlines and shall be all black or one color type, printed on a white or other neutral contrasting background whenever practical.

(iii) For small package labels covered by (c)(2)(iv) of this section, the words “Lighting Facts see back” shall appear on the primary display panel in a size and format specified in appendix L of this part.

(4) Bilingual labels. The information required by paragraph (c) of this section may be presented in a second language either by using separate labels for each language or in a bilingual label with the English text in the format required by this section immediately followed by the text in the second language. All required information must be included in both languages. Numeric characters that are identical in both languages need not be repeated.

(d) For lamps that do not meet the definition of general service lamp or specialty consumer lamp, manufacturers and private labelers have the discretion to label with the Lighting Facts label as long as they comply with all requirements applicable to specialty consumer lamps in this part.

(1) Any covered incandescent lamp that is subject to and does not comply with the January 1, 2012 or January 1, 2013 efficiency standards specified in 42 U.S.C. 6295 or the DOE standards at 10 CFR 430.32(n)(5) effective July 14, 2012 shall be labeled clearly and conspicuously on the principal display panel of the product package with the following information in lieu of the labeling requirements specified in paragraph (b):

(2) The light output, energy usage and life ratings of any product covered by paragraph (c)(1) of this section shall appear in that order and with equal clarity and conspicuousness on the product"s principal display panel. The light output, energy usage and life ratings shall be disclosed in terms of “lumens,” “watts,” and “hours” respectively, with the lumens, watts, and hours rating numbers each appearing in the same type style and size and with the words “lumens,” “watts,” and “hours” each appearing in the same type style and size. The words “light output,” “energy used,” and “life” shall precede and have the same conspicuousness as both the rating numbers and the words “lumens,” “watts,” and “hours,” except that the letters of the words “lumens,” “watts,” and “hours” shall be approximately 50% of the sizes of those used for the words “light output,” “energy used,” and “life,” respectively.

(1) The required disclosures of any covered product that is a general service lamp or specialty consumer lamp shall be measured at 120 volts, regardless of the lamp"s design voltage. If a lamp"s design voltage is 125 volts or 130 volts, the disclosures of the wattage, light output, energy cost, and life ratings shall in each instance be:

(i) At 120 volts and followed by the phrase “at 120 volts.” In such case, the labels for such lamps also may disclose the lamp"s wattage, light output, energy cost, and life at the design voltage (e.g., “Light Output 1710 Lumens at 125 volts”); or

(ii) At the design voltage and followed by the phrase “at (125 volts/130 volts)” if the ratings at 120 volts are disclosed clearly and conspicuously on another panel of the package, and if all panels of the package that contain a claimed light output, energy cost, wattage or lifeclearly and conspicuously identify the lamp as “(125 volt/130 volt),” and if the principal display panel clearly and conspicuously discloses the following statement:

This product is designed for (125/130) volts. When used on the normal line voltage of 120 volts, the light output and energy efficiency are noticeably reduced. See (side/back) panel for 120 volt ratings.

(2) For any covered product that is an incandescent reflector lamp, the required disclosures of light output shall be given for the lamp"s total forward lumens.

(3) For any covered product that is a compact fluorescent lamp, the required light output disclosure shall be measured at a base-up position; but, if the manufacturer or private labeler has reason to believe that the light output at a base-down position would be more than 5% different, the label also shall disclose the light output at the base-down position or, if no test data for the base-down position exist, the fact that at a base-down position the light output might be more than 5% less.

(4) For any covered product that is a general service lamp or specialty consumer lamp and operates at discrete, multiple light levels (e.g., 800, 1600, and 2500 lumens), the light output, energy cost, and wattage disclosures required by this section must be provided at each of the lamp"s levels of light output and the lamp"s life provided on the basis of the shortest lived operating mode. The multiple numbers shall be separated by a “/” (e.g., 800/1600/2500 lumens) if they appear on the same line on the label.

(5) A manufacturer or private labeler who distributes general service fluorescent lamps, general service lamps, or specialty consumer lamp without labels attached to the lamps or without labels on individual retail-sale packaging for one or more lamps may meet the package disclosure requirements of this section by making the required disclosures, in the manner and form required by those paragraphs, on the bulk shipping cartons that are to be used to display the lamps for retail sale.

(6) Any manufacturer or private labeler who makes any representation, other than those required by this section, on a package of any covered product that is a general service fluorescent lamp, general service lamp, or specialty consumer lamp regarding the cost of operation or life of such lamp shall clearly and conspicuously disclose in close proximity to such representation the assumptions upon which it is based, including, e.g., purchase price, unit cost of electricity, hours of use, patterns of use. If those assumptions differ from those required for the cost and life information on the Lighting Facts label (11 cents per kWh and 3 hours per day), the manufacturer or private labeler must also disclose, with equal clarity and conspicuousness and in close proximity to, the same representation based on the assumptions for cost and life required on the Lighting Facts label.

(1) Any covered product that is a general service fluorescent lamp or an incandescent reflector lamp shall be labeled clearly and conspicuously with a capital letter “E” printed within a circle and followed by an asterisk. The label shall also clearly and conspicuously disclose, either in close proximity to that asterisk or elsewhere on the label, the following statement:

(ii) For purposes of this paragraph, the encircled capital letter “E” shall be clearly and conspicuously disclosed in color-contrasting ink on the label of any covered product that is a general service fluorescent lamp and will be deemed “conspicuous,” in terms of size, if it appears in typeface at least as large as either the manufacturer"s name or logo or another logo disclosed on the label, such as the “UL” or “ETL” logos, whichever is larger.

(2) Instead of labeling any covered product that is a general service fluorescent lamp with the encircled “E” and with the statement described in paragraph (e)(1) of this section, a manufacturer or private labeler who would not otherwise put a label on such a lamp may meet the disclosure requirements of that paragraph by permanently marking the lamp clearly and conspicuously with the encircled “E.”

(3) Any cartons in which any covered products that are general service fluorescent lamps and general service lamps are shipped within the United States or imported into the United States shall disclose clearly and conspicuously the following statement:

(1) Contents. Metal halide ballasts contained in a metal halide lamp fixture covered by this Part shall be marked conspicuously, in color-contrasting ink, with a capital letter “E” printed within a circle. Packaging for metal halide lamp fixtures covered by this part shall also be marked conspicuously with a capital letter “E” printed within a circle. For purposes of this section, the encircled capital letter “E” will be deemed “conspicuous,” in terms of size, if it is as large as either the manufacturer"s name or another logo, such as the “UL,” “CBM” or “ETL” logos, whichever is larger, that appears on the metal halide ballast, or the packaging for the metal halide lamp fixture, whichever is applicable for purposes of labeling.

(2) Product labeling. The encircled capital letter “E” on metal halide ballasts must appear conspicuously, in color-contrasting ink (i.e., in a color that contrasts with the background on which the encircled capital letter “E” is placed) on the surface that is normally labeled. It may be printed on the label that normally appears on the metal halide ballast, printed on a separate label, or stamped indelibly on the surface of the metal halide ballast.

(3) Package labeling. For purposes of labeling under this section, packaging for metal halide lamp fixtures consists of the plastic sheeting, or “shrink-wrap,” covering pallet loads of metal halide lamp fixtures as well as any containers in which such metal halide lamp fixtures are marketed individually or in small numbers. The encircled capital letter “E” on packages containing metal halide lamp fixtures must appear conspicuously, in color-contrasting ink, on the surface of the package on which printing or a label normally appears. If the package contains printing on more than one surface, the label must appear on the surface on which the product inside the package is described. The encircled capital letter “E” may be printed on the surface of the package, printed on a label containing other information, printed on a separate label, or indelibly stamped on the surface of the package. In the case of pallet loads containing metal halide lamp fixtures, the encircled capital letter “E” must appear conspicuously, in color-contrasting ink, on the plastic sheeting, unless clear plastic sheeting is used and the encircled capital letter “E” is legible underneath this packaging.

LEDstands for light emitting diode. LED lighting products produce light up to 90% more efficiently than incandescent light bulbs. How do they work? An electrical current passes through a microchip, which illuminates the tiny light sources we call LEDs and the result is visible light. To prevent performance issues, the heat LEDs produce is absorbed into a heat sink.

The useful life of LED lighting products is defined differently than that of other light sources, such as incandescent or compact fluorescent lighting (CFL). LEDs typically do not “burn out” or fail. Instead, they experience ‘lumen depreciation’, wherein the brightness of the LED dims slowly over time. Unlike incandescent bulbs, LED “lifetime” is established on a prediction of when the light output decreases by 30 percent.

LEDs are incorporated into bulbs and fixtures for general lighting applications. Small in size, LEDs provide unique design opportunities. Some LED bulb solutions may physically resemble familiar light bulbs and better match the appearance of traditional light bulbs. Some LED light fixtures may have LEDs built in as a permanent light source. There are also hybrid approaches where a non-traditional “bulb” or replaceable light source format is used and specially designed for a unique fixture. LEDs offer a tremendous opportunity for innovation in lighting form factors and fit a wider breadth of applications than traditional lighting technologies.

LEDs use heat sinks to absorb the heat produced by the LED and dissipate it into the surrounding environment. This keeps LEDs from overheating and burning out. Thermal management is generally the single most important factor in the successful performance of an LED over its lifetime. The higher the temperature at which the LEDs are operated, the more quickly the light will degrade, and the shorter the useful life will be.

LED products use a variety of unique heat sink designs and configurations to manage heat. Today, advancements in materials have allowed manufacturers to design LED bulbs that match the shapes and sizes of traditional incandescent bulbs. Regardless of the heat sink design, all LED products that have earned the ENERGY STAR have been tested to ensure that they properly manage the heat so that the light output is properly maintained through the end of its rated life.

LEDs are “directional” light sources, which means they emit light in a specific direction, unlike incandescent and CFL, which emit light and heat in all directions. That means LEDs are able to use light and energy more efficiently in a multitude of applications. However, it also means that sophisticated engineering is needed to produce an LED light bulb that shines light in every direction.

Common LED colors include amber, red, green, a