GU10 LED Bulb Guide

Factors to consider when buying GU10 LED bulbs

When replacing halogen GU10 bulbs for LED there’s a huge range to choose from, selecting the best one can be difficult. The aim of our GU10 LED bulb review is to help our customers make an informed decision when buying a replacement LED bulb. There are five main factors to consider when choosing a suitable LED replacement bulb:

• Light colour
• Spread of light (beam angle)
• Light output (luminous flux)
• Reliability
• Bulb dimensions

LED Light Colour

Most GU10 LED bulbs to emit a light colour ranging from “warm white” to “cool white”. Warm white is slightly yellow similar to the light emitted by a halogen or filament bulb. Cool white is a stark white with a slight blue tint and is rarely used for domestic lighting purposes. In between these two, we have pure white and natural white. Pure white is towards the cool end of the spectrum but gives a very clean ultra-modern look. Natural white has a hint of warmth, while still quite modern it’s not as stark as pure white.

The kelvin scale is used as a measure of light colour, warm white ranges from about 2700k to 3800k, natural white ranges from 3800k to 4800k, pure white or daylight from about 4800k to 6000k. Cool white starts from around 6000k upwards.

Integral Dichroic Glass 3.6 Watt GU10 Dimmable (50W Replacement)

Integral Dichroic Glass 3.6 Watt GU10 LED Bulb (50W Replacement)

Spread of light (beam angle)

Beam angle is extremely important – it determines how light is spread from the bulb into a given space. An important point to make is that a 90-degree beam angle (cone) is no longer what you would call a spotlight. Any bulb with a beam angle greater than 60° behaves more like a floodlight giving a different lighting effect altogether. For the non-trigonometrists amongst you, a 90-degree beam angle bulb lights a five-metre wide patch when fitted two and a half metres away. A traditional halogen GU10 bulb has a 36-degree beam angle, when fitted into a 2.5 metre tall ceiling a 1.6m wide patch is lit giving a more intense beam/spot of light.

The European DIM2 regulation states that for a GU10 LED bulb to claim it’s a 50W equivalent, it must emit a certain amount of light within a 90-degree cone. Any light outside a 90-degree cone is classed as ‘not useable’. Many early LED bulbs had surface-mounted LED’s giving a 120-degree light beam, far too wide to be classed as a spotlight. The beam angle of our LED bulbs is around 36°. The main problem with 120° SMD spotlights is they spread the light too thin. Generally, they don’t produce enough light where it’s needed and give a terrible glare that can strain the eye.

Total light output (luminous flux)

A common question is which LED GU10 bulb is equivalent to a 50-watt halogen GU10 bulb in terms of light output. The European DIM2 regulation states that to make this 50-watt equivalent claim, the LED GU10 lamp must emit at least 345 lm in a 90-degree cone. The total lumen output, including light that falls outside this cone, may be considerably higher. Our understanding is that all GU10 50W equivalent bulbs currently on the market must conform to DIM2, however, this isn’t always adhered to by some manufacturers. Our LEDs produce up to 100 lumens per watt, generally the higher the power/wattage the higher the light output. This isn’t always the case as LED’s can vary in efficiency. Therefore we state the lumens output on all our GU10 product pages. From this, you can work out how much light the replacement LED GU10 will produce compared with an old halogen.

How to ensure GU10 LED Reliability

The main cause of LED bulb failure is the driver. The driver is a small transformer that steps down the voltage from 230V AC to a much lower DC voltage for the LED’s. It’s usually located inside the back of the bulb. A poor quality driver could result in bulb failure within months. The LED chip itself rarely fails although it can happen. To ensure a decent quality driver – buy a brand-name bulb. We have tried and tested many famous brands of bulbs and even had non-branded bulbs built specifically for us. We have settled on UK-based Integral. Integral are a UK-based company with 25 years of experience in semiconductor technology and electronics. They’ve won ‘Which? Best Buy in 2015 and 2016 for GU10 LED Bulbs’. Out of the thousands of Integral GU10 bulbs we’ve sold, we’ve possibly had one or two faulty units – to the benefit of our customers and our reputation. Beware of 50,000hr bulb life claims. The best brand name drivers will only last up to 25,000 hours.

Although LEDs don’t produce much heat they can overheat in operation if they’re not cooled correctly. Cheap LED’s are less efficient, produce more heat and are more heat sensitive. Operating above 60°C can damage cheaper LED’s shortening their life, and reducing light output and efficiency. Generally the higher the wattage/power of a GU10 LED bulb, the more heat it produces requiring a more thermally efficient bulb body to keep the LEDs cool. Therefore beware of cheap higher wattage bulbs that don’t have a metallic or ceramic body.

Bulb dimensions

It’s worth checking the dimensions of the LED bulb to ensure it will fit inside the original bulb housing or light fitting. If fitted in the ceiling check the height of the ceiling void is adequate for the length of the bulb. While the diameter of the bulb face is always 50mm for GU10 bulbs the length and width of the bulb body vary. Our Integral bulbs are almost identical in shape and size providing a hassle-free installation.

Which LED bulb is the best replacement for a 50W halogen GU10?

Our Integral 4.7 Watt Dichroic GU10 LED Bulb is the closest 50W non-dimmable replacement in our opinion. Our Integral 5.6 Watt Classic Glass GU10 LED Bulb is the closest 50W dimmable replacement we offer. Both bulbs produce a very similar spread and intensity of light to a 50W halogen GU10 while being almost identical in shape and size. Our Integral GU10 bulbs also benefit from producing a similar light colour (in warm white version). They are the closest replacement bulb we have found for a Halogen GU10 50W bulb, reliable, efficient and cost-effective too.