Led Lighting effect our life

Content

Chapter One

What is LED Lighting

Chapter Two

How LED Work

Chapter Three

Why we must use

Save energy

Efficiency

Long lasting

Attractive and colorful

Varieties

Chapter Four

Under LED environments

Safety and Health

Indicators and signs

Lighting

Economically sustainable

What is Led lighting

An LED lamp (or LED light bulb) is a solid-state lamp that uses light-emitting diodes (LEDs) as the source of light. LED lamps offer long service life and high energy efficiency, but initial costs are higher than those of fluorescent and incandescent lamps. Chemical decomposition of LED chips reduces luminous flux over life cycle as with conventional lamps.

Commercial LED lighting products use semiconductor light-emitting diodes. Research into organic LEDs (OLED), or polymer light-emitting diodes (PLED) is aimed at reducing the production cost of lighting products. Diode technology currently improves at an exponential rate.

LED lamps can be made interchangeable with other types of lamps. Assemblies of high power light-emitting diodes can be used to replace incandescent or fluorescent lamps. Some LED lamps are made with bases directly interchangeable with those of incandescent bulbs. Since the luminous efficacy (amount of visible light produced per unit of electrical power input) varies widely between LED and incandescent lamps, lamps are usefully marked with their lumen output to allow comparison with other types of lamps. LED lamps are sometimes marked to show the watt rating of an incandescent lamp with approximately the same lumen output, for consumer reference in purchasing a lamp that will provide a similar level of illumination.

Efficacy of LED devices continues to improve, with some chips able to emit more than 100 lumens per watt. LEDs do not emit light in all directions, and their directional characteristics affect the design of lamps. The efficacy of conversion from electric power to light is generally higher than for incandescent lamps. Since the light output of many types of light-emitting diodes is small compared to incandescent and compact fluorescent lamps, in most applications multiple diodes are assembled.

Light-emitting diodes use direct current (DC) electrical power. To use them on AC power they are operated with internal or external rectifier circuits that provide a regulated current output at low voltage. LEDs are degraded or damaged by operating at high temperatures, so LED lamps typically include heat dissipation elements such as heat sinks and cooling fins.

LED lamps have no glass tubes to break (some models have a decorative glass bulb, however), and their internal parts are rigidly supported, making them resistant to vibration and impact. With proper driver electronics design, an LED lamp can be made dimmable over a wide range; there is no minimum current needed to sustain lamp operation.

LEDs using the color-mixing principle can emit a wide range of colors by changing the proportions of light generated in each primary color. This allows full color mixing in lamps with LEDs of different colors. In contrast to other lighting technologies, LED emission tends to be directional (or at least lambertian). This can be either an advantage or a disadvantage, depending on requirements. For applications where non-directional light is required, either a diffuser is used, or multiple individual LED emitters are used to emit in different directions.

How an LED Works

How an LED works. An LED or “Light Emitting Diode” is basically as the name describes; it is a special type of diode that is specifically optimized to give off light, usually in the visual or infrared spectrum, as electricity is passed through it.

A diode is a special type of semiconductor that has many uses. One of the principle uses though is to control the direction of the flow of electricity. The most common type of diode does this by using something called “p-n junctions”. This is just a fancy way of saying “magic”.

Really though, in simple terms, think of a Dr. Pepper can divided in the middle. On one half you have made a semi conductive material that you’ve added impurities to so that it contains negatively charged carriers; basically an abundance of electrons. We then call this side an “n-type semiconductor”. On the other half you’ve done the same thing, except you’ve introduced impurities that contain positively charged carriers; basically think of it like a bunch of holes that need filled by electrons. We call this side a “p-type semiconductor”.

So we have on one side an n-type semiconductor and on the other side a p-type semiconductor. The boundary between these two is called the “p-n junction”. This is where all the magic happens. It turns out that conventional current will travel from one side to the other, but doesn’t like to go in the opposite direction. So you can use this to make sure electricity only flows in the direction you want it to in your circuit (among a lot of other things; seriously diodes are crazy useful in a variety of ways and various specialized diodes can do some other interesting things, which I won’t go into in this article, but will probably revisit at some point. Generally speaking, these p-n junctions are at the heart of almost all semiconductor electronic devices).

So how are these diodes modified to produce light? Well it turns out they don’t really need to be modified at all to produce a form of light radiation. However, standard diodes tend to be made of materials that absorb most of the light radiation given off and more importantly tend not to give off the light in human-visible form anyways.

What’s going on here is, as the electricity jumps across the p-n junction, the electrons from the “n-type” side “fill holes” in the “p-type” side. During this process, the electrons end up changing their state. During this state change, a photon is emitted. More specifically what is going on is, as electrons move around orbiting a nucleus of an atom, electrons with different orbits have different amounts of energy. Electrons with orbits farther away from the nucleus have greater energy and ones closer have less energy.

So in order for an electron to change its orbit, it needs to either lose energy or gain energy. What we are interested in with LEDs are the electrons going from a higher orbit to a lower orbit, thus losing energy in the form of a photon of light. When the electrons from the n-type side “fill the holes” in the p-type side, they then lose energy in the form of these light photons. The greater the energy release, the higher the frequency the light photon given off, thus changing the color.

If the frequency ends up being in the human visible spectrum (the range your eyes can see), then you’ll see the light being given off by the LED. If not, such as when given off in the infrared spectrum, then you won’t see it. But it can still be useful, such as in allowing you to change the channel on your TV (infrared LEDs are typically used in your TV remote control among many other places). When you press a button on your remote, you don’t see the light, but the receiver on your TV can see it and can interpret what it’s seeing from the infrared LED.

In LEDs, the light that ends up being created depends then on the material being used and the current that is run through it. The light in a standard diode has the atoms arranged so that the electron drop in energy is very short and thus the frequency of light given off isn’t visible to our eyes, rather is in the infrared. So simply put, LEDs where you can see the light are made of semiconductor materials that create a bigger drop in the electron’s orbit so that the frequency of the photon packet comes out in the human visual spectrum. They can even be designed so that the amount of electricity flowing through them will actually change the drop and so you can have a multi-color LED.

Why we must use

Save energy

Comparison to other lighting technologies

See luminous efficacy for an efficiency chart comparing various technologies.

Incandescent lamps (light bulbs) generate light by passing electric current through a resistive filament, thereby heating the filament to a very high temperature so that it glows and emits visible light over a broad range of wavelengths. Incandescent sources yield a "warm" yellow or white color quality depending on the filament operating temperature. Incandescent lamps emit 98% of the energy input as heat. A 100 W light bulb for 120 V operation emits about 1,180 lumens, about 11.8 lumens/W; for 230 V bulbs the figures are 1340 lm and 13.4 lm/W. Incandescent lamps are relatively inexpensive to make. The typical lifespan of an AC incandescent lamp is 750 to 1,000 hours. They work well with dimmers. Most older light fixtures are designed for the size and shape of these traditional bulbs. In the U.S. the regular sockets are E26 and E11, like E27 and E14 in some European countries.

Compact fluorescent lamps' lifespan may vary from 6,000 hours to 15,000 hours.

Fluorescent lamps work by passing electricity through mercury vapor, which in turn emits ultraviolet light. The ultraviolet light is then absorbed by a phosphor coating inside the lamp, causing it to glow, or fluoresce. Conventional linear fluorescent lamps have life spans around 20,000 and 30,000 hours based on 3 hours per cycle according to lamps NLPIP reviewed in 2006. Induction fluorescent relies on electromagnetism rather than the cathodes used to start conventional linear fluorescent. The newer rare earth triphosphor blend linear fluorescent lamps made by Osram, Philips, Crompton and others have a life expectancy greater than 40,000 hours, if coupled with a warm-start electronic ballast. The life expectancy depends on the number of on/off cycles, and is lower if the light is cycled often. The ballast-lamp combined system efficacy for then current linear fluorescent systems in 1998 as tested by NLPIP ranged from 80 to 90 lm/W.^. For comparison, general household LED bulbs available in 2011 emit 64 lumens/W,^. with the best LED bulbs coming in at about 100 lumens/W.

Cost Comparison
	Incandescent	Halogen	CFL	LED (Generic)	LED (Philips)	LED (Philips L-Prize)
Purchase price	$0.41	$4	$4	$10	$16	$30
Electricity usage	60 W	42 W	13 W	13.5 W	12.5 W	10 W
Lumens	860	570	825	850	805	940
Lumens/Watt	14.3	13.6	63.5	63	64.4	94
Color Temperature Kelvin	2700	3000	2700	3000	2700	2700
CRI	100	100	82	>75	85	92
Lifespan (hours)	1,000	3,500	8,000	25,000	25,000	30,000
Bulb lifetime in years @ 6 hours/day	0.5	1.6	3.7	>11.4	>11.4	>13.7
Energy cost over 10 years @ 15 cents/kWh	$197	$138	$43	$44	$41	$33
Total	$206	$166	$55	$54	$57	$63
Comparison based on 6 hours use per day (21,900 hours over 10 yrs)

Efficiency

Efficiency and operational parameters

Typical indicator LEDs are designed to operate with no more than 30–60 milliwatts (mW) of electrical power. Around 1999, Philips Lumileds introduced power LEDs capable of continuous use at one watt. These LEDs used much larger semiconductor die sizes to handle the large power inputs. Also, the semiconductor dies were mounted onto metal slugs to allow for heat removal from the LED die. LED power densities up to 300W/cm2 have been achieved.^.

One of the key advantages of LED-based lighting sources is high luminous efficiency. White LEDs quickly matched and overtook the efficacy of standard incandescent lighting systems. In 2002, Lumileds made five-watt LEDs available with a luminous efficacy of 18–22 lumens per watt (lm/W). For comparison, a conventional incandescent light bulb of 60–100 watts emits around 15 lm/W, and standard fluorescent lights emit up to 100 lm/W. A recurring problem is that efficacy falls sharply with rising current. This effect is known as droop and effectively limits the light output of a given LED, raising heating more than light output for higher current.

The mechanism behind droop efficiency loss was identified in 2013 as Auger recombination.

As of 2012, the Lumiled catalog gives the following as the best efficacy for each color:

Color	Wavelength range (nm)	Typical efficacy (lm/W)
Red	620 < λ < 645	72
Red-orange	610 < λ < 620	98
Green	520 < λ < 550	93
Cyan	490 < λ < 520	75
Blue	460 < λ < 490	37

In September 2003, a new type of blue LED was demonstrated by the company Cree Inc. to provide 24 mW at 20 milliamperes (mA). This produced a commercially packaged white light giving 65 lm/W at 20 mA, becoming the brightest white LED commercially available at the time, and more than four times as efficient as standard incandescents. In 2006, they demonstrated a prototype with a record white LED luminous efficacy of 131 lm/W at 20 mA. Nichia Corporation has developed a white LED with luminous efficacy of 150 lm/W at a forward current of 20 mA. Cree's XLamp XM-L LEDs, commercially available in 2011, produce 100 lumens per watt at their full power of 10 watts, and up to 160 lumens/watt at around 2 watts input power. In 2012, Cree announced a white LED giving 254 lumens per watt.

Practical general lighting needs high-power LEDs, of one watt or more. Typical operating currents for such devices begin at 350 mA.

Note that these efficiencies are for the LED chip only, held at low temperature in a lab. Lighting works at higher temperature and with drive circuit losses, so efficiencies are much lower. United States Department of Energy (DOE) testing of commercial LED lamps designed to replace incandescent lamps or CFLs showed that average efficacy was still about 46 lm/W in 2009 (tested performance ranged from 17 lm/W to 79 lm/W).

Cree issued a press release on February 3, 2010 about a laboratory prototype LED achieving 208 lumens per watt at room temperature. The correlated color temperature was reported to be 4579 K. In December 2012 Cree issued another press release announcing commercial availability of 200 lumens per watt LED at room temperature.

Long lasting

Low maintenance lighting

Most of LED lamps or luminaires can achieve 50,000 hours life time (running 10 hours/day, 7 days/week, they theoretically should be able to last for 14 years), but very rare manufacturers can promise a 5 year warranty of their products. The main reason that the product's life time has been shortened is the heat issue. Using high efficiency LED module (better thermal management) and well designed heat sink (efficient cooling material/structure/device) for the LED unit will significantly enhance the its performance (longer life and lower failure rate). Here is an example of how premium LED luminaires help to significantly save energy costs and maintenance costs at the same time. UK’s biggest retrofit LED deal

Lifetime and failure

Main article: List of LED failure modes

Solid-state devices such as LEDs are subject to very limited wear and tear if operated at low currents and at low temperatures. Many of the LEDs made in the 1970s and 1980s are still in service today. Typical lifetimes quoted are 25,000 to 100,000 hours, but heat and current settings can extend or shorten this time significantly.

The most common symptom of LED (and diode laser) failure is the gradual lowering of light output and loss of efficiency. Sudden failures, although rare, can occur as well. Early red LEDs were notable for their short service life. With the development of high-power LEDs the devices are subjected to higher junction temperatures and higher current densities than traditional devices. This causes stress on the material and may cause early light-output degradation. To quantitatively classify useful lifetime in a standardized manner it has been suggested to use the terms L70 and L50, which is the time it will take a given LED to reach 70% and 50% light output respectively.

LED performance is temperature dependent. Most manufacturers' published ratings of LEDs are for an operating temperature of 25 °C. LEDs used outdoors, such as traffic signals or in-pavement signal lights, and that are utilized in climates where the temperature within the luminaire gets very hot, could result in low signal intensities or even failure.

LED light output rises at lower temperatures, leveling off, depending on type, at around −30 °C Thus, LED technology may be a good replacement in uses such as supermarket freezer lightingand will last longer than other technologies. Because LEDs emit less heat than incandescent bulbs, they are an energy-efficient technology for uses such as in freezers and refrigerators. However, because they emit little heat, ice and snow may build up on the LED luminaire in colder climates.Similarly, this lack of waste heat generation has been observed to sometimes cause significant problems with street traffic signals and airport runway lighting in snow-prone areas. In response to this problem, some LED lighting systems have been designed with an added heating circuit at the expense of reduced overall electrical efficiency of the system; additionally, research has been done to develop heat sink technologies that will transfer heat produced within the junction to appropriate areas of the luminaire.

Attractive and colorful

Refractive index

Idealized example of light emission cones in a semiconductor, for a single point-source emission zone. The left illustration is for a fully translucent wafer, while the right illustration shows the half-cones formed when the bottom layer is fully opaque. The light is actually emitted equally in all directions from the point-source, so the areas between the cones shows the large amount of trapped light energy that is wasted as heat.

The light emission cones of a real LED wafer are far more complex than a single point-source light emission. The light emission zone is typically a two-dimensional plane between the wafers. Every atom across this plane has an individual set of emission cones. Drawing the billions of overlapping cones is impossible, so this is a simplified diagram showing the extents of all the emission cones combined. The larger side cones are clipped to show the interior features and reduce image complexity; they would extend to the opposite edges of the two-dimensional emission plane.

Bare uncoated semiconductors such as silicon exhibit a very high refractive index relative to open air, which prevents passage of photons at sharp angles relative to the air-contacting surface of the semiconductor. This property affects both the light-emission efficiency of LEDs as well as the light-absorption efficiency of photovoltaic cells. The refractive index of silicon is 3.96 (590 nm), while air is 1.0002926.

In general, a flat-surface uncoated LED semiconductor chip will emit light only perpendicular to the semiconductor's surface, and a few degrees to the side, in a cone shape referred to as the light cone, cone of light,or the escape cone. The maximum angle of incidence is referred to as the critical angle. When this angle is exceeded, photons no longer penetrate the semiconductor but are instead reflected both internally inside the semiconductor crystal and externally off the surface of the crystal as if it were a mirror.

Internal reflections can escape through other crystalline faces, if the incidence angle is low enough and the crystal is sufficiently transparent to not re-absorb the photon emission. But for a simple square LED with 90-degree angled surfaces on all sides, the faces all act as equal angle mirrors. In this case the light can not escape and is lost as waste heat in the crystal.

A convoluted chip surface with angled facets similar to a jewel or fresnel lens can increase light output by allowing light to be emitted perpendicular to the chip surface while far to the sides of the photon emission point.

The ideal shape of a semiconductor with maximum light output would be a microsphere with the photon emission occurring at the exact center, with electrodes penetrating to the center to contact at the emission point. All light rays emanating from the center would be perpendicular to the entire surface of the sphere, resulting in no internal reflections. A hemispherical semiconductor would also work, with the flat back-surface serving as a mirror to back-scattered photons.

Varieties

Application-specific variations

Flashing LEDs are used as attention seeking indicators without requiring external electronics. Flashing LEDs resemble standard LEDs but they contain an integrated multivibrator circuit that causes the LED to flash with a typical period of one second. In diffused lens LEDs this is visible as a small black dot. Most flashing LEDs emit light of one color, but more sophisticated devices can flash between multiple colors and even fade through a color sequence using RGB color mixing.

Bi-color LEDs are two different LED emitters in one case. There are two types of these. One type consists of two dies connected to the same two leads antiparallel to each other. Current flow in one direction emits one color, and current in the opposite direction emits the other color. The other type consists of two dies with separate leads for both dies and another lead for common anode or cathode, so that they can be controlled independently.

Tri-color LEDs are three different LED emitters in one case. Each emitter is connected to a separate lead so they can be controlled independently. A four-lead arrangement is typical with one common lead (anode or cathode) and an additional lead for each color.

RGB LEDs are Tri-color LEDs with red, green, and blue emitters, in general using a four-wire connection with one common lead (anode or cathode). These LEDs can have either common positive or common negative leads. Others however, have only two leads (positive and negative) and have a built in tiny electronic control unit.

Alphanumeric LED displays are available in seven-segment and starburst format. Seven-segment displays handle all numbers and a limited set of letters. Starburst displays can display all letters. Seven-segment LED displays were in widespread use in the 1970s and 1980s, but rising use of liquid crystal displays, with their lower power needs and greater display flexibility, has reduced the popularity of numeric and alphanumeric LED displays.

Under LED environments

Safety and health

The vast majority of devices containing LEDs are "safe under all conditions of normal use", and so are classified as "Class 1 LED product"/"LED Klasse 1". At present, only a few LEDs—extremely bright LEDs that also have a tightly focused viewing angle of 8° or less—could, in theory, cause temporary blindness, and so are classified as "Class 2".The Opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) of 2010, on the health issues concerning LEDs, suggested banning public use of lamps which were in the moderate Risk Group 2, especially those with a high blue component in places frequented by children. In general, laser safety regulations—and the "Class 1", "Class 2", etc. system—also apply to LEDs.

While LEDs have the advantage over fluorescent lamps that they do not contain mercury, they may contain other hazardous metals such as lead and arsenic. A study published in 2011 states: "According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb [lead] at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), lead (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous."

Indicators and signs

The low energy consumption, low maintenance and small size of LEDs has led to uses as status indicators and displays on a variety of equipment and installations. Large-area LED displays are used as stadium displays and as dynamic decorative displays. Thin, lightweight message displays are used at airports and railway stations, and as destination displays for trains, buses, trams, and ferries.

Red and green traffic signals

One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights or lanterns (chromacity and luminance standards being set under the Convention on the International Regulations for Preventing Collisions at Sea 1972, Annex I and the CIE) and LED-based Christmas lights. In cold climates, LED traffic lights may remain snow covered.^[130] Red or yellow LEDs are used in indicator and alphanumeric displays in environments where night vision must be retained: aircraft cockpits, submarine and ship bridges, astronomy observatories, and in the field, e.g. night time animal watching and military field use.

Automotive applications for LEDs continue to grow

Because of their long life and fast switching times, LEDs have been used in brake lights for cars' high-mounted brake lights, trucks, and buses, and in turn signals for some time, but many vehicles now use LEDs for their rear light clusters. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, up to 0.5 second faster than an incandescent bulb. This gives drivers behind more time to react. It is reported that at normal highway speeds, this equals one car length equivalent in increased time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED will appear if the eyes quickly scan across the array. White LED headlamps are starting to be used. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors.

Due to the relative cheapness of low output LEDs, they are also used in many temporary uses such as glowsticks, throwies, and the photonic textile Lumalive. Artists have also used LEDs for LED art.

Weather/all-hazards radio receivers with Specific Area Message Encoding (SAME) have three LEDs: red for warnings, orange for watches, and yellow for advisories & statements whenever issued.

Lighting

See also: LED lamp and LED-backlit LCD display

With the development of high-efficiency and high-power LEDs, it has become possible to use LEDs in lighting and illumination. Replacement light bulbs have been made, as well as dedicated fixtures and LED lamps. To encourage the shift to very high efficiency lighting, the US Department of Energy has created the L Prize competition. The Philips Lighting North America LED bulb won the first competition on August 3, 2011 after successfully completing 18 months of intensive field, lab, and product testing.

LEDs are used as street lights and in other architectural lighting where color changing is used. The mechanical robustness and long lifetime is used in automotive lighting on cars, motorcycles, and bicycle lights.

LED street lights are employed on poles and in parking garages. In 2007, the Italian village Torraca was the first place to convert its entire illumination system to LEDs.^[132]

LEDs are used in aviation lighting. Airbus has used LED lighting in their Airbus A320 Enhanced since 2007, and Boeing plans its use in the 787. LEDs are also being used now in airport and heliport lighting. LED airport fixtures currently include medium-intensity runway lights, runway centerline lights, taxiway centerline and edge lights, guidance signs, and obstruction lighting.

LEDs are also suitable for backlighting for LCD televisions and lightweight laptop displays and light source for DLP projectors (See LED TV). RGB LEDs raise the color gamut by as much as 45%. Screens for TV and computer displays can be made thinner using LEDs for backlighting.^[133]

LEDs are used increasingly in aquarium lights. In particular for reef aquariums, LED lights provide an efficient light source with less heat output to help maintain optimal aquarium temperatures. LED-based aquarium fixtures also have the advantage of being manually adjustable to emit a specific color-spectrum for ideal coloration of corals, fish, and invertebrates while optimizing photosynthetically active radiation (PAR), which raises growth and sustainability of photosynthetic life such as corals, anemones, clams, and macroalgae. These fixtures can be electronically programmed to simulate various lighting conditions throughout the day, reflecting phases of the sun and moon for a dynamic reef experience. LED fixtures typically cost up to five times as much as similarly rated fluorescent or high-intensity discharge lighting designed for reef aquariums and are not as high output to date.

The lack of IR or heat radiation makes LEDs ideal for stage lights using banks of RGB LEDs that can easily change color and decrease heating from traditional stage lighting, as well as medical lighting where IR-radiation can be harmful. In energy conservation, the lower heat output of LEDs also means air conditioning (cooling) systems have less heat to dispose of, reducing carbon dioxide emissions.

LEDs are small, durable and need little power, so they are used in hand held devices such as flashlights. LED strobe lights or camera flashes operate at a safe, low voltage, instead of the 250+ volts commonly found in xenon flashlamp-based lighting. This is especially useful in cameras on mobile phones, where space is at a premium and bulky voltage-raising circuitry is undesirable.

LEDs are used for infrared illumination in night vision uses including security cameras. A ring of LEDs around a video camera, aimed forward into a retroreflective background, allows chroma keying in video productions.

LEDs are used in mining operations, as cap lamps to provide light for miners. Research has been done to improve LEDs for mining, to reduce glare and to increase illumination, reducing risk of injury for the miners.^[134]

LEDs are now used commonly in all market areas from commercial to home use: standard lighting, AV, stage, theatrical, architectural, and public installations, and wherever artificial light is used.

LEDs are increasingly finding uses in medical and educational applications, for example as mood enhancement^{[citation needed]}, and new technologies such as AmBX, exploiting LED versatility. NASA has even sponsored research for the use of LEDs to promote health for astronauts.

Economically sustainable

LED light bulbs could be a cost-effective option for lighting a home or office space because of their very long lifetimes. Consumer use of LEDs as a replacement for conventional lighting system is currently hampered by the high cost and low efficiency of available products. 2009 DOE testing results showed an average efficacy of 35 lm/W, below that of typical CFLs, and as low as 9 lm/W, worse than standard incandescents.^[137] However, as of 2011, there are LED bulbs available as efficient as 150 lm/W and even inexpensive low-end models typically exceed 50 lm/W. The high initial cost of commercial LED bulbs is due to the expensive sapphire substrate, which is key to the production process. The sapphire apparatus must be coupled with a mirror-like collector to reflect light that would otherwise be wasted.

Conclusion

LED Lighting Could Improve Your Home

1. LED lighting can and will save you money

Operating costs are reduced by 85% compared with incandescent equivalents. This reduced energy consumption directly affects your electricity bills. Since LED lighting has an extremely long lifespan, you will be buying replacement bulbs less often than when you had conventional lighting, highlighting LED lighting's cost effectiveness! Check out our LED energy saving calculations to see how much you could save.

2. LED lighting is a lot more convenient than conventional lighting

Its extremely long life span means changing light bulbs and light fixtures is one less thing to worry about in the upkeep of your home. Your standard bulb will last from 10-15 years resulting in very low maintenance.

3. LEDs result in less risk of fire

A worryingly large proportion of house fires are caused by lighting fixtures. However, LED lights remain cool so there is practically no heat generated and therefore present a reduced fire hazard than that associated with standard incandescent bulbs. Again – one less thing to worry about. What's more, LED bulbs do not contain any glass components, meaning they are less vulnerable to breakage and smashing - ideal when you've got little ones running about.

4. LEDs contain no hazardous substances

LEDs do not contain mercury. Mercury is hazardous to human health, yet fluorescent lights use mercury in order to create light. LEDs, however, do not. This makes them less of a risk to use around children or in lamps that may be easily knocked over.

5. Food stays fresher for longer with LED lighting

Most of us have fruit bowls in our kitchen - and many of us have this fruit bowl under direct lighting (as seen in the photo above). Conventional lighting emits heat, so this can lead to rapid deterioration of fresh fruit. However, LED lighting does not emit heat or any UV rays so your food stays freshers for longer.

Take a look at our LED lamps or LED tube lighting here, both ideal for the home.

Posted in How LED lighting could improve our lives, LED lighting, Energy Efficiencyand tagged with led lights and house heat, led tube lighting, led tube lights, are led lights suitable for the home, why are leds more convenient, domestic led lighting, led lighting for the home, led lighting in the home, advantages of led lighting by Ellie McKeon.

LED Lighting Could Improve Your School, College or University

1. Money saved can be spent on what's important

Operating costs are reduced by 85% with LED lighting compared with incandescent equivalents. Cutting your electricity costs means more of your budget can be spent on what’s important – classroom resources, assistants and educational tools.

2. Similarly to businesses, LED lights will improve work ethic in the class room

LED lights do not create a nauseating flickering which has been associated with incandescent and fluorescent lights. These forms of light produce a flickering which has been said to cause headaches, make people feel nauseous and less motivated in the work place - a term which has become known as "flicker vertigo". What's more, if lights are too dim people tend to feel drowsy and lathargic. LED lights have a very high lumen output that can prevent this.

3. Less vandalism

When adolescents are surrounded by a run-down environment, studies have shown that they are more likely to vandalize as said environment is not worthy of respect. LED lights have an extremely high quality of light, so the students will be proud and respectful of their environment.

4. Health and Safety

From a health and safety perspective, LED bulbs are safer than other types of lighting. They remain cool so there is virtually no heat generated and therefore a much-reduced fire hazard than that associated with standard incandescent bulbs.

5. Education, education, education

Installation of LED lighting could educate the students about the environment, energy efficiency and eco-friendliness and the science behind the energy efficiency.

Take a look at our LED lights perfect for schools.

Posted in How LED lighting could improve our lives, LED lighting, Energy Efficiencyand tagged with flicker vertigo, the science behind led lighting, led lighting for a school, advantages of led lighting by Ellie McKeon.

LED Light Could Improve Your Area

1. More of the council's budget can be spent on what is important

Operating costs are reduced by 85% compared with incandescent equivalents. Cutting electricity costs means more of the council’s budget can be spent on what is important – education and policing. The dimmable feature allows the facility to only use as much electricity as needed.

2. LED lights are extremely eco-friendly

LEDs do not contain mercury or lead, and do not give off poisonous gases if damaged. As mentioned above, they consume 85% less electricity than incandescent equivalents. The government is putting more and more pressure on councils to go green, and LED street lights should be one of the first avenues a council takes in its journey to becoming green.

3. Long life-span

The extremely long lifespan of LED lights of approximately 10-15 years (three times the lifespan of current street lights) means very low maintenance and less need for inconvenient and expensive replacement.

4. Crime deterrent

Studies have shown that improved lighting can lead to a significant 30 per cent decrease in crime. LED street lights could make the general public feel safer and deter crime by improving visibility on the streets; 50% say better lighting used in the area they live has made them feel safer. What’s more, driving at night could be safer and easier. In addition, since they contain no glass components, they are not vulnerable to vibration or breakage like conventional bulbs; LEDs are thus better suited for use in areas like sports facilities and high-crime locations.

5. Good for wildlife

LED light is less attractive to nocturnal insects. Nocturnal insects are attracted to ultra violet, blue and green light emitted by conventional light sources. LEDs emit a much smaller amount of light in the UV, blue and green range. This is beneficial for the wildlife, for example bats, which are a protected species. With normal street lighting, insects - which are a bat's main source of food - stray away from their natural habitat leaving the bats with no food or forcing them to leave their natural habitat which hugely disrupts their flight cycle.

Convinced? Take a look at our LED streetlights.

Posted in How LED lighting could improve our lives, LED lighting, Energy Efficiencyand tagged with led lighting for a town, led lighting makes people feel safe, led streetlights, advantages of led lighting by Ellie McKeon.

LED Lighting Could Improve Your Business

1. LED lights will save you money

We've said it once, we'll say it again - operating costs are reduced by 85% compared with incandescent equivalents. If your business is retail and you like to have your shop window lights on during the night, then it’s important to save as much on energy costs as you can. Since retail premises usually have far more lighting than a home, and have to have it switched on most of the time, the savings in electricity bills by switching to LED lighting will be that much more noticeable. What's more, as LEDs do not produce heat, air conditioning costs are reduced.

2. LED lighting could improve work ethic

LED lights do not create a nauseating flickering unlike incandescent bulbs, which produce a flickering which has been said to make people feel nauseous and less motivated in the work place. See your workforce's motivation and alertness increase after installing LED lighting.

3. If your business is retail, LED lighting could help improve sales

I don’t care what Hollister say - it is crucial that your products are brightly lit. The quality of LED is so high that it’ll make your products look highly appealing. From a point of sales perspective, LED’s high quality of light creates a beautiful environment that is more likely to increase sales; good quality lighting allows for a better presentation and exhibition of goods as they are perfectly rendered in their natural colours.

4. From a health and safety perspective, LED bulbs are safer than other types of lighting.

They remain cool so there is virtually no heat generated and therefore a much-reduced fire hazard than that associated with standard incandescent bulbs.

The end

About the Author

Wilson was born in Hong Kong in 1950, but he has spent most of her life in Science , Surrey. She always wanted to be a writer and wrote her first studies when she was nineteen , filling countless exercise books as the grew up. She started work at a publishing company and then went on to work as a journalist on Famous magazine.

The right of Wilson to be identified as the author of this work has been asserted in accordnace with the Copyright, Designs and Patents Act 2013.

All rights reserved. No part of this publications may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publishers.

LED light Bulbs

2013年8月18日星期日