What are they?
Light emitting diode lamps (LEDs) are electronic light sources that have high energy efficiency. LED technology is advancing very rapidly and in the past five years has advanced from a curiosity to a viable replacement for most point-source lights (especially halogen downlights and compact fluorescent downlights). Although equivalent to marginally more efficient than linear fluorescents they are expensive, but should be expected to surpass this technology by 2015.
Advantages / Disadvantages
Significant energy savings can be achieved when LEDs are used for the replacement of downlights, especially halogen and compact fluorescent types.
LEDs have far better switching performance than fluorescent lamps and achieve 100% light output instantly.
There are many brands of LED available, and industry quality standards are not uniform, so some care in selection of lamps is advised.
Long life expectancy compared to FLs.
Initial cost is high compared to FLs.
LEDS are the most efficient lights source available for most applications. Indeed the rate of improvement is so great that current LED lamps may significantly outperform those bought only a few years ago.
A further efficiency benefit of LED lamps is that they can be switched on and off with no damage or reduction in lamp life. This makes them particularly competitive for situations where control can be used to reduce operating hours.
Maintenance costs are lower for LEDs because lamps have longer replacement intervals compared with FLs. Energy savings are greater compared with FLs. LEDs, as with all types of fitting, will require regular cleaning to maintain light output levels.
Retrofit / improvement opportunities
Luminaires may need to be replaced if retrofitting LEDs, which can significantly add to the replacement cost. Replacement of light fittings can generally be undertaken after-hours with minimal disruption to tenants.
All building types.
No issues. While earl LEDs had dubious colour rendering, modern LEDs have excellent colour rendering and indeed some are now designed to vary the visual warmth of the light to suit the time of day.
Lamp replacement intervals are significantly longer for LEDs than FLs.
Older LEDs may require replacement of the entire light fitting upon failure. Newer LED are available with interchangeable light sources which avoids this problem.
LEDs are available in a variety of design formats and colours. They are often distinguishable by the small dots of light emitted, which are often clustered into a fixture that resembles a halogen spotlight. However in some applications they are provided in flat panels in which no dots are visible.
Questions to ask
- Have LEDs been installed in the building and if so, where?