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Everything You Need to Know About LED Lighting in 2019

By Andrew Fraser on 11.21.2018 in Scotlight Direct , , , , , , , ,

Everything You Need to Know About LED Lighting

The Light Emitting Diode (LED) has been around for over 100 years, since Captain Henry Joseph Round was the first to publish reports of electroluminescence in the journal Electrical World in 1907.

Now LEDs are everywhere, being used as all types of light sources. This article will explain why this is the case, and how you can find the right kind of lighting for your specific needs.

What is LED Lighting?

What is LED Lighting?

What LED stands for

LED stands for Light Emitting Diode.

A Light emitting diode is a two-lead light source based on a semiconductor, which emits light when activated by electricity.

LEDs have been used as general light sources since 2007.

They are considered superior to traditional light sources.

How LEDs Are Used as Lighting

LEDs are either installed in light bulbs, attached to strips or installed directly into lights.

The diodes are very small on their own, and this means that they can be easily applied to a wide variety of creative lighting solutions.

They can be bought as traditional light bulbs, and used in existing light fittings as a replacement for incandescent on fluorescent lamps.

Their general lighting uses in the home can be anything from traditional ceiling lights, bedside lights, recessed downlights, bulkheads, semi flush ceiling lights, and outdoor lighting in gardens such as outdoor wall lights and porch lights. Modern ceiling lights in hallways have also seen drastic changes with design and creativity since the rise of LED lighting.

Smaller LEDs are also used in a wide variety of electronic items including computer displays, clocks and watches, laser printers and industrial machine displays.

Besides being used as a general light source, LEDs are used for flashlights, and traffic lights.

Benefits of LED Lighting

The Benefits of LED Lighting


It is widely acknowledged that LEDs are more durable than traditional light sources.

Fluorescent and incandescent light sources can be smashed, halogen light sources can be damaged during installation, by the oil from installers hands.

Most regulatory standards require LEDs to be dropped from four metres without breaking.

LEDs Are Much More Durable

Compact Size

LEDs come in a wide variety of shapes and sizes, as they are made by many different manufacturers for a variety of applications.

In general, they are less than one square inch on the surface. Technological advancements mean they are following the miniaturisation trend of other electronic devices, and getting a lot smaller.

This means that LEDs can be used in just about any device, either as a light source, indicator or display.

Long Lifetime

LEDs impressive durability, and lack of breakable components, means that they can have a very long life-time. Much longer than traditional light sources…

  • Incandescent lights have a lifetime of 1,000 hours
  • Fluorescent lamps last for 6,000 – 15,000 hours
  • Metal-halide lamps also last for 6,000 – 15,000 hours
  • LED light sources can last between 25,000 – 50,000 hours

Expected Lifetime for lamp Bulbs

High quality LED lighting can outlast the next most durable lighting technology, the compact fluorescent (CFL) by over 10 times, and they can outlast incandescent light sources by over 50 times.

In the case of the majority of LED lights, if they were left on 24 hours a day, 7 days a week, they could last for up to 6 years!

If the same LED lights were used normally, and on for an average of 6 hours per day, they would last for 18 years or more.

(LED lights for general use have only been around for about a decade, so these ratings are mostly from intensive lab testing, they could last even longer.)

LEDs Last Longer

Low Maintenance

An upshot of the longer lifetimes of LED lights is that the need to replace lamps which have failed is greatly reduced.

This will translate into savings of time and money, and is especially important for lighting which needs to be maintained by an electrician.

This is a big advantage over other light sources, as they are more easily damaged and require replacement more often.

Reasons LED Lighting is Beneficial

Benefits of LED Lighting Video

Why You Should Change to LED?

Why You Should Switch to LED Lighting


LEDs are the most efficient light source which is widely available to buy.

LED lights are also much for efficient than their traditional counterparts…

  • Incandescent luminaires produce around 10 – 17 lumens per watt
  • Fluorescent luminaires can produce 60 lumens per watt
  • Metal-halide lamps will deliver 75 – 100 lumens per watt
  • LEDs current produce up to 150 lumens per watt, and are getting more efficient

This translates into saving an awful lot of money on electricity bills.

It is estimated that switching your home over to LED lighting from incandescent could save as much as £240 per year. Source – The Telegraph

The reduction in energy usage also has a positive impact on the environment.

The LEDs are in production, the more efficient they will become, according to Haitz Law.

Haitz’ Law and the Efficiency Curve

LEDs follow an efficiency curve which is similar to Moores law for processing power.

It is named after Roland Haitz (Haitz’ Law), it states that the cost of each lumen produced will fall by a factor of 10, and the lumen output of LED lighting will increase by a factor of 20 over the same period.

The similarities with Moore’s law continue, as both depend on the process optimisation of semiconductor devices. (Moore’s law observes that the number of transistors in a dense integrated circuit can double about every two years, also due to process optimisation).

LED lighting achieved 100 lumens per watt by 2010, and by 2020, 200 lumens per watt will be achieved, according to Haitz.

A graph representing Haitz Law

A graph representing Haitz Law

However, Philips have already achieved this level of efficiency. In 2017 they unveiled a prototype of their TLED product. Designed as a direct replacement for fluorescent lamps, it can produce 200 lumens per watt.

Safe Disposal

LED lights contain less toxic waste.

They do not contain arsenic, lead, mercury or any of the harmful gasses which can be found in traditional light sources.

It is therefore not as hazardous to dispose of LED lights.

Less Harmful Light

LEDs emit less radiation than traditional light sources.

The harmful radiation emitted by traditional light sources comes from UV emissions and infra-red light.

UV emissions and infra-red light can be harmful to health, especially after long term exposure.

Lower Temperature

LEDs emit a little heat, however it is only a fraction of what is produced by traditional light sources.

They give off approximately 20 – 50% less heat when fully illuminated.

This is because they use less electricity, do not give off infra-red radiation, and are usually combined with modern heat sinks. Items such as Wall Lights in the UK have also seen benefits from this as the lower temperature has increased the life span of a light fittings lamp holders as with conventual lamp bulbs the high heat burned the lamp holders components on the inside.

Check out this video of a chocolate bunny under LED and traditional lighting to see the difference for yourself

More Effective

LEDs give off less glare than traditional light sources.

Glare can damage our vision and cause headaches, especially after long-term exposure

We are all exposed to a lot of artificial light, as we light our homes, but reduced glare is especially beneficial for office workers, as well as the users of roadways and public spaces.

Why you should switch to LEDs

How Does LED Lighting Work?

How Does LED Lighting Work?

Basically, LED lighting works by changing electrical energy into light.

It is better to understand how LED lighting works as a light source, instead of as an electronic component.

LEDs have found their way into all forms of lighting such as indoor wall lights, picture lights, and ceiling spotlights. Besides the enhanced efficiency and lifetime of the lamps, they open up a large variety of options which lend themselves to a variety of jobs.

LEDs are providing amateur and professional interior designers with a wide range of options to choose from when working on their projects. This greater flexibility enables designers to use LED Lighting in a varitety of ways such as bedroom ceiling lights and in contemporary ceiling lights.

When choosing LED lighting, buyers must make choices between different colour temperatures, beam angles, optical distribution, colour rendering and other considerations for each job.

This can be tricky, so here’s a guide to these terms…

Colour Temperatures

Colour temperature is specified as a number on the Kelvin scale (K)

There are a few standard colours used in the majority of lighting, these are…

  • 2200K The warmest white on the typical scale, found in cosy bars, snugs and in the home
  • 2700K Again still warm white, used in hotels and homes
  • 3000K Still warm white, used in shops, cafés and other locations on the high street
  • 4000K Known as cool white, used in workplaces and bathrooms where attentiveness is required
  • 5000k Very cool white, used in hospitals situations where attention to detail is required

The Colour Spectrum

Many other colours besides white can be produced using LED lamps, though usually not the same lamps as for white lighting.

These are known as RGB LEDs, which means red, green and blue. These LEDs can be operated using a touch-screen colour wheel or software application to produce over 16 million hues of light.

With standard RGB it is difficult to make some colours such as pink or brown, but with some additive colours these can also be made. These LEDs are known as RGBW (W = White) or RGBA (A = Amber)

Colour spectrum wheel

Colour Spectrum Wheel
Example of colour spectrum wheel

Light Distribution

LEDs differ from incandescent light sources in how they emit light. Where incandescent lamps without reflectors or diffusers will light from 180° around the luminaire, LEDs have a very distinct cut off, where the difference between light and dark is visible, and usually, need the help of attachments to create the required effect.

These come in a variety of angles and types…

Beam angles can be anything from 10° to 80° for LED downlights and kitchen spotlights.

Colour Rendering

Colour rendering is another important consideration when applying LED lighting to interior design projects. There is a Colour Rendering Index (CRI), which is a numerical value up to one hundred.

LEDs typically start at CRI 70, and the highest are CRI 95.

CRI 70 can be used for street lighting and is a vast improvement on the orange colour we grew up with, created by the High Pressure Sodium lamps which were once widely used.

CRI 80 is ok for offices and other applications where colour detail is important but not of the highest importance.

CRI 90 to CRI 95 should be used in retail especially, where the colours of garments and other products need to be vibrant in order to boost sales.

Other important things for professionals working with LED lighting include;

Individual Colours

The individual colour rendering values. These are also a numerical value up to one hundred. Each colour is represented by the letter R and a corresponding number.

For example, the most difficult colour for LEDs to reproduce is red, and this has the code R9. Good quality LEDs will have an R9 value closer to 100, while poorer versions may be closer to 50. This is again particularly important for retail lighting.

LEDs Come In Different Colours


LED lighting can produce a lot of glare, especially if it is not diffused or distributed in the right way. This is particularly important for office workers, who spend a lot of time looking at screens which increase glare.

There are values to measure this by as well. It is known as the Unified Glare Rating (UGR)

In office lighting, a value of UGR <19 is required, while more general applications require UGR <25

Colour Stability

The output colour of LED lighting can vary over time. Therefore, the colour stability is assigned a value as well, know as a MacAdam Ellipse, or Standard Deviation Colour Matching (SDCM).

The majority of quality LEDs have a value of 3 SDCM, some can be as low as 2 SDCM, while 5 SDCM is on the lower end of the scale, it is still acceptable for applications such as street lighting.

LEDs are Contributing to a Greener Planet

Reducing Energy Dependency

Reducing our energy dependency is one of the biggest challenges facing humanity. Finding renewable energy sources has been the focus of energy innovation over the last few decades, but reducing the amount of energy we consume is also extremely important.

LEDs play a part in this.

Consider that according to the U.S Energy Information Administration (EIA), in the United States in 2017 273 billion kilowatthours (kWh) of electricity was used for lighting in the commercial and residential sector.

Altogether that’s about 10% of the total energy consumption for the United States in a given year.

By 2020 LEDs are estimated to account for 61% of the global lighting market.

LEDs use approximately 20% of the energy of conventional incandescent light sources.

If the United States can switch entirely to LED lighting over the coming twenty years, the energy consumption used for lighting can be reduced by 50%.

Cutting Pollution

That will help to avoid 1.8 billion metric tons of carbon emissions from the US alone, significantly reducing pollution.

As stated earlier in this article LED light sources last 10 times longer than incandescent light sources.

That’s 10% of the waste!

LEDs Are Less Wasteful

Managing Toxic Waste

Incandescent lamps also contain a small amount of mercury, which is harmful to the environment and people as well.

In relation to the environmental impact, one disadvantage LEDs have compared to compact fluorescent (CFLs) is the large aluminium heat sinks they use for heat dissipation.

This means that they actually generate more waste than CFLs, however this anomaly can be solved by recycling the aluminium or using recycled aluminium for the heat sinks. There are LED lamps which use 80% recycled aluminium recovered from industrial sources currently available.

Two main advantages to be gained by using LED lighting.

  • Low energy consumption
  • Longer life

Ultimately, compared to incandescent light sources, there will be significantly less LED lamps which need to be manufactured, packaged, distributed, used and have their waste dealt with at the end of their life.

LEDs Consume Much Less Energy