When you are looking to buy lighting online, particularly LED light bulbs, we're sure you'll appreciate some advice on how to buy the right ones. That's why we've compiled a list of some of our customers' most frequently asked questions...
• What is a LED GU10?
GU10 is the lamp base or cap of a mains voltage halogen lamp. It has two legs or pins with small ‘feet’ on the end!
An LED GU10 is a retrofit energy saving replacement for halogen lamps that use the latest LED (Light Emitting Diode) technology.
Halogen GU10 LED GU10
• LED light bulbs often seem very ‘cold’ in colour. How do I choose the best shade of white to suit me?
LED light bulbs come in a variety of shades of ‘white’. The manufacturers call this “colour temperature”, which is simply a way of describing the colour of light, and is measured in °Kelvin.
Still confused? Consider a piece of metal being heated in a fire. It initially gives off a reddish glow, but as it gets hotter, the colour becomes whiter until, as it really warms up, it starts to give off a bluish glow.
The manufacturers give the different colours their own particular names, but in general the colour temperature scale with generic names of colours looks like this:
Old fashioned light bulbs (incandescent lamps) are 2700°K or “Very Warmwhite”, while fluorescent tubes used in many offices are 4000°K “Coolwhite”.
For a cosy, warm effect, you should choose “Very Warmwhite” LED light bulbs. For contemporary rooms such as gloss white kitchens and modern bathrooms, we recommend “White” or even “Coolwhite” for a crisp, bright sparkle.
• Different light outputs are given by LED light bulbs of the same wattage. How do I know how bright a particular LED will be?
The wattage of LED light bulbs, or the amount of power that they consume, was once the ultimate indicator of their light output. Alas, the use within LED light bulbs of chips of differing efficiencies makes this no longer the case, with differing optics and reflectors within LED spotlights (directional lamps) also impacting on how much light reaches the 'working surface'.
The amount of light a lamp produces is measured in “lumens”. As a rough guide, you can expect an ordinary 100 watt light bulb to produce 1,000 lumens, or 10 lumens per watt. However, most LED light bulbs now give more than 50 lumens per watt - in some cases, much more.
Most reputable manufacturers now detail the lumen output on their packaging and this will become mandatory under new rules.
• How do I select the brightness of an LED spotlight?
In the case of LED spotlights (directional lamps), the amount of light that gets to the 'working surface' can be affected by differing optics, which also control a given spotlight's beam angle. Narrow beam spotlights (10°-12°) very much concentrate the light in a narrow cone, whereas in the case of a very wide flood (60°), the light is spread over a much wider beam area at the same distance.
Those looking to buy lighting online for general domestic use are advised to choose a beam width between 30° to 36° degrees, as is customary with halogen spotlights - although these, too, can be specified in various beam widths. Manufacturers will often recommend 50° to obtain the most even light distribution in use in downlighters.
The manufacturers refer to this as luminous intensity, the amount of light in a beam, which is measured in “candelas”.
As a guide, a typical mains voltage halogen GU10 base spotlight has the following characteristics, which you can use as a benchmark for assessing LED GU10s:
35W Halogen 35° beam, 570 candelas
50W Halogen 35° beam, 900 candelas
• Can I use a dimmer switch with LED lamps?
The packaging for LED lamps will always detail whether they are dimmable or non-dimmable. However, your existing dimmer switch may not always dim 'dimmable' LED lamps smoothly, if at all. This is because traditional dimmers for tungsten lamps were usually designed to dim circuit loads of between 100 to 500 watts.
Even if a room has four 5 watt LEDs, a circuit load of only 20 watts means that your dimmer may lack the sensitivity or appropriate dimming technology to dim at what is already a low level.
However, you do have the option of replacement LED specific dimming modules. Those who have a rotary dimmer switch can simply remove the rotary knob, before unscrewing the wall switch-plate and replacing the electronic dimmer module at the back of the plate. This work should always be undertaken by a qualified electrician.
We not only recommend, but also supply the Varilight V-Pro Dimmer Module, which operates between one and 10 LEDs and is accompanied by full instructions:
• Will my LED GU10 lamp fit my existing light fitting or housing?
The older generations of LED GU10s were often larger than the halogen lamps they are meant to replace and were only suitable for fittings with open housings.
Today, LED GU10s are often labelled as “Perfect” or “True” fit and regardless of the fixture, there should be no problem with these replacing halogen lamps. They not only run cooler than halogen lamps, but also avoid the heat spots that can occur to the rear of halogen lamps close ceilings.
• Which GU10 LED light bulbs would you recommend?
Today’s state of the art GU10 LED light bulbs come from the top brands, Osram and Megaman:
7W Dimmable 500 lumens 650 candelas 2800K Very Warmwhite 35°
7W Dimmable 500 lumens 650 candelas 4000K Coolwhite 35°
7W Dimmable 500 lumens 650 candelas 6500K Daylight 35°
6W Dimmable 410 lumens 600 candelas 2800K Very Warmwhite35°
6W Dimmable 410 lumens 600 candelas 4000K Coolwhite 35°
6W Dimmable 410 lumens 600 candelas 6500K Daylight 35°
6W Non-dimmable 300 lumens 300 candelas 2800K Very Warmwhite 35°
6W Non-dimmable 300 lumens 300 candelas 4000K Coolwhite35°
6W Non-dimmable 300 lumens 300 candelas 6500K Daylight 35°
7.5W Dimmable 385 lumens 950 candelas 2700K Very Warmwhite 36°
7.5W Dimmable 390 lumens 950 candelas 3000K Warmwhite 36°
7.5W Dimmable 400 lumens 1000 candelas 4000K Coolwhite 36°
5W Dimmable 250 lumens 600 candelas 2700K Very Warmwhite 36°
5W Dimmable 250 lumens 600 candelas 3000K Warmwhite 36°
5W Dimmable 265 lumens 700 candelas 4000K Coolwhite 36°
• I want to replace existing halogen downlights or make a new installation of downlights. What should I use?
For new or replacement installations, we would always recommend light fittings with integrated LEDs, rather than the fitting of retrofit LED GU10 lamps to fixtures designed for halogen.
We recommend the KSR Firebreak LED10, which is:
• available in Warmwhite and Coolwhite light colours producing 610 lumens and 1,000 candelas respectively, comparable with a 50W halogen fitting
• fully dimmable
• water ingress protected to IP66 and can therefore be used in shower cubicles
• a fire rated downlight, which means a sealed unit in the ceiling inhibiting the potential spread of fire in a property
• supplied with a detachable bezel or rim, which allows for the easy painting of ceilings with the downlights installed
• supplied with a standard satin white bezel or rim, although there are many more different bezels or rims available to suit your requirements, including: chrome, satin chrome, black and brass
• accompanied by a 5 year warranty
Feel free to peruse our present range of LED light bulbs, which with their superior energy efficiency, longevity and 100 per cent instant light, together with increasing affordability, are becoming a particularly strong choice for those looking to buy lighting online.