LED lighting is the new buzzword and is seen as the go-to solution for our building lighting requirements - so what should you know about its applications and what to be wary of?
What is LED Lighting?
Light emitting diodes (LEDs) are not a new technology; they have been around for over 50 years. You may recall early digital watches and LED clocks. In recent years, there have been developments in materials used so that different colour temperature of light is produced and intensity increased.
Essentially, the LED is a semi-conductor material which produces light waves when power is applied to it. There are two main types of LED technology: LED using inorganic materials and LED using inorganic organic material (carbon), known as OLEDs.
OLEDs offer some advantages in form/size and efficiency over conventional LEDs and are particularly suited to electronic device display panels (such as tablets and PC screens). Research is continuing with both types of technology.
The range of applications of LED lighting is increasing with the development of LED technology. It now covers the majority of normal building and external lighting applications. Size, configuration, colour type, efficiency and usable life are improving with the development of the technology.
LEDs are subject to EMC compliance. All lights must have an RCM (regulatory compliance mark), including ballasts and drivers. It is important that this is sought for each type of fitting, as suppliers have been known to supply fittings which may appear similar but are actually different to fittings which carry a compliance certificate.
Design and installation
Selection of the most appropriate LED lighting should be undertaken by a specialist electrical or lighting consultant to ensure the lights selected are correctly specified and suitable for the type of task or ambience lighting required. The specialist will also ensure the lights selected provide appropriate energy saving versus cost and suitable effective life and replacement cost.
Maintenance and replacement
All forms of lighting have an ultimate lifespan, but more importantly they also have an effective rated life which is defined as 70 per cent of the original as new light output. This is the point where the human eye can detect a distinct lowering of light output. LED lighting can provide very long life to failure times, but the important figure that needs to be looked at is the effective rated life. This will be much lower, but still significantly longer than many of the lighting technologies LED is now replacing.
It is also important to note that many LED fittings are integral fittings and do not have separate replaceable bulbs. This means that if the fitting reaches the end of its effective rated life, it will need to be replaced in its entirety. Fittings with replaceable lighting strips or bulbs will generally be more expensive than integral non-serviceable fittings. Original selection should therefore carefully consider this factor for the ongoing costs of maintaining the lighting installation.
Given the long life of the fittings, one must consider circumstances where one or two fittings fail prematurely and replacement fittings cannot be sourced, effectively requiring the replacement of the fittings in the whole area to maintain consistency.
Key things to look out for when considering LED lighting as an alternative to traditional forms of lighting
A high percentage of LED lighting is imported from overseas, and the quality of the fittings can vary significantly. Ensure that lighting is sourced via an established reputable supplier.
The cost of the fitting may be misleading and you need to consider a number of factors, including its certification, energy efficiency, effective rated life, does it need full replacement or can you replace the light element/bulbs, and how many years will replacement fittings be available from the supplier?
All lighting must comply with Australian Standards. Ensure you check for compliance certificates for each and every type of fitting offered.
Light output is rated in lumens; wattage should not be used to compare light output between brand and another. The efficiency of the fitting will be expressed as lum/watt.
The light fitting beam angle is important as it can dictate how many fittings are required to provide even light distribution over an area.
Colour temperature can be important in creating the subjective mood of the space. This is often simplified in to cool white or warm white categories. Generally, colour temperatures over 5,000 K are considered cool white and those around 3,000 K are considered warm white. Colour rendition can also be an important factor for some task oriented work spaces.
Ensure all lights have RCM, including ballasts and drivers. It has been known for LED lamps to cause electrical interference with electronic equipment. Also, many transformers and dimmers commonly used for halogen lighting may not work with LEDs and can cause overheating and potential fire. It is important to check the compatibility of transformers and dimmers with the specific LED fitting.
Request an LM80 test report, which illustrates the lumen maintenance of an LED fixture and provides a life of the LEDs with what can be expected in lumen drop off.
Request an LM79 test report which includes actual fixture performance including heat, efficacy and efficiency of the luminaire (absolute luminosity).
Further information can be obtained from the Lighting Council of Australia and from established reputable local lighting suppliers.
It is recommended that advice also be sought from specialist lighting engineers and consultants before committing to large spending on this technology.