LED Technology Basics

We’ve written this guide for anybody who wants to learn more about LED lighting and how to make an informed decision when selecting LED light fittings.
LED lighting has been widely adopted over the last 5 years and has now reached the point where it would be unthinkable to specify fluorescent or halogen in most projects.

How do white LEDs work?

Everyone is familiar with single colour indicator LEDs, red, green and more recently blue.

In fact white light LEDs are all based on blue LED emitters used in conjunction with phosphors which when struck by blue light give off white light. The composition of the phosphors can be varied to give different colour temperatures and colour rendering indices.

  • Colour temperature in Kelvin relates directly to the colour of light given off by an object heated to that temperature – LEDs are available from warm to cool white.
  • Colour rendering is a measure of how well a light fitting reproduces colours and is an assessment of its closeness to a full spectrum.

Key Concepts in LED lighting

  • Light is given off from the front only
  • There is very little heating effect from the beam, and virtually no UV
  • Most LED lighting requires a driver
  • LEDs can last longer than the building they are installed into

The life of the LED is directly linked to the junction temperature (the core operating temperature, good heatsinking is vital)

Retrofit or purpose made?

  • Purpose made: optimised for LED
  • Retrofit: compromised legacy designs

We’re still seeing a lot of LED lighting being installed using fittings designed for halogen with a LED replacement lamp. These don’t bring the full advantages of LED as they are compromised by the dimensions of the halogen lamp.

Make sure that you are using a fitting that is designed for LED from the ground up.