As LED lighting increasingly becomes the solution of choice, it’s important to understand how it works and what makes the difference between good LED lighting systems and disappointing ones. Duncan Chamberlain, director of Philips Lighting explains.
Switching on a light is an everyday ritual that we often don’t consider as significant. Most of us certainly don’t appreciate that something as simple as the quality of a lightbulb can completely transform our homes and the way we enjoy them. The humble lightbulb, once a commodity, has been transformed by the digital age.
Not all LEDs are equal
In terms of delivering the required light output, energy performance and operational life it’s important to be aware that not all LED light sources offer the same peace of mind.
For example, variation in colour temperature between individual lamps can result in an unsightly patchwork of colours across the installation. Consequently, how the manufacturer’s quality control procedures ensure a consistent colour temperature is important.
White LED lighting is actually the result of using a blue LED to excite a phosphor that, in turn, emits white light – the same principle as fluorescent lighting. Varying the chemical make-up of the phosphor coating enables different colour temperatures. This means that the consistency of both the light from the blue LED and the phosphor coating are both extremely important. And while you don’t need to know the minutiae of the quality control mechanisms you do need the assurance that colour temperature will be consistent. A good indication of a manufacturer’s confidence in the consistency of colour temperature is the information on the packaging of the lamp. A precise colour temperature (e.g. 2,700K) indicates high quality control, whereas a range (e.g. 4,000-4,500K) indicates poor quality control.
When using LED, consider the colour temperature that is right for the requirements of a space. Opt for a warm white to create a soft and relaxing environment but use cool white for task lighting, such as lighting your desk or a kitchen workspace, where it can actually reduce strain on your eyes by providing bright and clear lighting.
Lumens and watts
One of the major differences between LED light sources and more traditional lamps is the lack of correlation between wattage and light output – so lumen output is more meaningful. Also, LEDs are directional so there is less dependency on the optics of the luminaire and less of the light output is wasted inside the luminaire. Therefore the light output ratio is usually higher with LED lighting so that the required lux levels can be achieved with a lower lumen package.
As a guide most manufacturers will provide information on lumen output but it has been known for some companies to quote the light output of the raw LED before it has been incorporated into the lamp – giving a misleadingly high figure that will not be realised when the lighting is installed.
Are LEDs really capable of delivering beautiful light or are they only for the energy conscious?
Just as sunshine can transform your day and lift your spirits, so good lighting can have a similar impact on your home. With the development of LED technology, the lowly light bulb is now doing much more than turning on and off, it’s impacting our mood, the way we express ourselves and our general sense of well-being. LED technology has resulted in incredibly flexible lighting, enabling the creation of light settings that are unique to you.
Good lighting is about creating layers of different lighting effects, with requirements varying from room to room. Tailor the lighting in each room, by applying the appropriate mix of ambient lighting, task lighting for close-up work and accent lighting to highlight special features. As a first step though, consider the light effect you wish to create. This could be achieved just by choosing the right bulb. For example frosted or white coated LED bulbs provide a diffused light compared to clear ones which generate a sparkling natural white light, ideal for use in chandeliers.
But LEDs can do so much more than just give you white light. With LEDs you can adapt both the colour and brightness in order to achieve the effect you want. With dimmable LED bulbs, you can control the amount of light to create the perfect atmosphere. And smart LEDs make it possible to easily personalise your lighting via your smart phone or tablet. The digital age of lighting and the magic of the internet have combined to create a whole new world of possibilities. New lighting innovations are reinventing how you can interact with light through apps, using the extra functionality of LEDs to create flexibility that just wasn’t possible with older technology. You can now control, dim and bathe your house in all the colours of the rainbow. There are also four pre-programmed settings that adjust the lighting to help you relax, read, concentrate or boost your energy. LED tape that you can fix to any surface using the included adhesive back is also popular. You can cut it to size and stick it almost anywhere, so it’s ideal for under-shelf or under-table lighting, inside an alcove, or above a bed to add ambiance. Lighting is clearly no longer just for illumination.