LED Lighting Q&A

What is LED?

LED stands for Light Emitting Diode. Diodes are a semiconductor device that will conduct electricity in only one direction. The device is made-up of layers of silicon and seeded with atoms of phosphorus, germanium, arsenic or other rare-earth elements. The layers of the device are called the die and the junction between the materials is where the light is generated. Different materials and designs have different coloured lights and intensities. LEDs are now bright enough to be considered for applications that traditionally used incandescent bulbs.

Technical advances have dramatically improved the reliability and the performance of LEDs since they were invented in the 1960s. The lifetime for the new generation of LEDs is about 100,000 hours of use, or 30 to 40 years of normal operation. As they are a semiconductor device, they are also very rugged and are not subject to fail when dropped or vibrated as are incandescent or fluorescent lights.

The original LEDs only emitted light of one frequency or colour of light. These were blues, greens, yellows, oranges or reds and they were unsuited for domestic lighting. Recent innovations in materials, doping and die structure have developed high brightness LEDs that emit light in all visible frequencies to produce white light. With Spectrum Lighting working on new technology with LED, we now can provide the same output in light as incandescent or fluorescent light.

What are the benefits of using LED lighting ? 

Everyday residential and commercial property owners are making the decision to replace their existing downlights with LED downlights and reaping the benefits of this change. Here are the top ten benefits for installing LED downlights and highlights why this lighting source is the most attractive option in the lighting market today.

 

1. Efficiency

LEDs consume very little energy compared to other forms of lighting, benefiting the environment as well as reducing electricity bills. A standard 50W halogen lamp converts only 10% of its electricity into light and the rest into heat. In contrast, LEDs turn 85% of their electricity into light and only require a fifth of the power that halogen needs to do this.

2. Superior product life

Once an LED downlight is installed it can last up to thirty years, which is fifteen times longer than halogen. Not only does this solve the annoyance of regularly replacing light bulbs, it also reduces the embedded energy involved with making and packaging the product.

3. Mercury & heavy metal free

LED lights are free from all harmful materials, including mercury and lead, which are both found in CFLs. This makes Self Sufficient Homes’s lights safe to use as well as safe to recycle.

4. Great light quality

Self Sufficient Homes have an extremely high light quality,, which makes the light appear as close to natural light as possible. This differs from other forms of lighting such as CFLs that emit a blue, artificial light.

5. UV free

Self Sufficient Homes’s lights contain no UV light protecting objects sensitive to UV light, such as paintings, as well as repelling insects, a necessity for Australian summers.

6. Cradle to cradle

Easily separated, as a result, recycling the light allows all the materials to be converted into new products without leaving anything behind.

7. Instant start up

Once an LED is switched on, its full brightness appears instantly no matter what temperature or environment the light is illuminating.

8. Fire free

Meeting Australian standards our bulb’s lower temperature minimizes any risk of fires as well as allowing a safer, easier installation.

9. Unaffected by the ON/OFF cycle

CFL’s life expectancy is greatly reduced by the ON/OFF cycle each and every time you turn a light on and off you reduce the life expectancy of that bulb because of the design in that mercury must be heated to illuminate.

10. Unidirectional Light

LED lights are extremely more effective in recessed lighting because of the unidirectional light beam.

What do all the technical terms mean?

Lumen Rating

The lumen (lm) also known as the luminous flux rating of an LED lamp is basically a measure of amount of light the LED lamp can produce. The greater the lumen rating, the more light the lamp will emit. The lumen rating is a useful figure for comparing LED lamps to conventional light sources. Note that it is possible for LED’s to have different lumen ratings even though they are of similar wattage. An LED that has a higher lumen rating for the same wattage is a more efficient LED.

Light Quality (CRI)

Colour Rendering Index (CRI), CRI is a measure of the ability of a light source to render colours, compared to a reference source (incandescent or daylight), on a scale of up to 100, with 100 being identical to the reference source. The higher the CRI, the better the fixture’s ability to show the true colours of nearby objects.  Higher CRI is required in art galleries, museums and hairdressers, where the selected lights are very critical for not losing any of its original colours for its objects. The higher CRI value is also important for shopping centres and retail outlets.

Efficacy

Capacity or power to produce a desired effect

Colour Temp

Colour Temperature is a measurement in Degrees Kelvin that indicates the hue of a specific type of light source. Higher colour temperatures (5,000 K or more) are cool (blueish white) colours, and lower colour temperatures (2,700–3,000 K) warm (yellowish white through red) collars.

IP Rating

IP stands for Ingress Protection. It is the degree of protection provided against the intrusion of solid objects, dust, accidental contact and water.

The first digit indicates the level of protection that the enclosure provides against access to hazardous parts and the ingress of solid foreign objects. (Dust, solid objects, accidental contact)

The second digit indicates protection of the equipment inside the enclosure against harmful ingress of water

Wattage

Watts (W) is the unit of measurement for power consumption. LED lamps come in different power ratings like traditional light sources. There is a vast array of different wattages ranging from 1W all the way up to 25W or greater in the Domestic LED market. The greater the wattage, the more energy the LED bulb will consume and generally the brighter the light source will be.

Beam Angle

The beam angle of a LED lamp refers to the measure of the spread of the light source and is simply stated in degrees. This is a great feature of LED lamps as the individual LED’s can be arranged in a manner to alter the angle of the light beam. To make the most of your LED lamps, it is best to purchase a lamp with a specific beam angle depending on its use.

Luminous efficacy – unit: lm/W

Luminous efficacy is a property of light sources, which indicates what portion of the emitted electromagnetic radiation is usable for human vision. It is the ratio of emitted luminous flux to radiant flux. Luminous efficacy is related to the overall efficiency of a light source for illumination, but the overall lighting efficiency also depends on how much of the input energy is converted into electromagnetic waves (whether visible or not).

Lifetime

This does not actually refer to the end of the LED life. A good quality LED bulb will not burn out or die like a regular bulb. LED light bulbs will eventually lose their brightness but technically can last way beyond the stated lifespan. On average, the LED lifespan is between 30,000 and 70,000 hours, depending on operating conditions.  At the end of their rated lifetime, they will operate at approximately 70% of the original brightness.

Operating Temp

The range quoted is the operating temperature as quoted by the manufacturer for the light source only. Once this light source is placed into a fixture or fitting this can have a dramatic effect on the actual operating temperature as well as the LED longevity, light quality and power used. For example, compact fluorescent bulbs draw more and more power as their operating temperature increases. Halogens down lights are notorious for extremely high operating temperatures (+350 degrees Celsius) resulting in increased room temperature and increased cooling costs.