Which Beam Angle?
Every light source from an LED to a simple wax candle has got a beam angle. A beam angle is a measurement of how the light is distributed. GU10 LEDs and recessed downlights have a fairly narrow beam of around 40 degrees, anything within 5 degrees of this is the industry standard. A wax candle or traditional light bulb would have a beam angle of 360 degrees as the light shines all the way around but is less intense.
By selecting a light with a wider beam angle you don't get any extra light, it is just spread out further. The brightness (measured in lumens) remains the same but the beam intensity (measured in candelas) increases. The downside to a wider beam angle is that it's not as intense and the centre of the beam of light wouldn't go as far. Choosing the right beam angle can make a big difference in a room but you don't always have the option so if you know which beam angle you want from start this can often limit your options to just a few LED downlights.
A narrow beam angle of 25 degrees is known as a spot. Wider beam angles of 60 degrees are known as as flood and even wider beams are known as wide flood beams.
One of the best examples of using a wider beam such as 60 degrees would be in a lounge area. Lounges don't need to be as bright as other rooms and are usually illuminated to around 150 lux as you are only performing basic tasks like watching the TV or reading. In comparison a kitchen should be around 300 lux as you need to see what you are doing more clearly. By using a wider beam you can space out your downlights further apart, rather than having the 1 metre apart you can go to 1.2 or 1.5 metre distances.
If you were to select wider beam angles in a kitchen and the downlights were only 1 metre apart it would be pointless especially if the room has dark walls or cupboards. The wider spread of light would get directed onto the surfaces and you would loose some of the light due to the low reflectance levels.
A good example of using a more narrow beam angle of 25 degrees would be in a room with high ceilings. Anything over 2.4 metres is classed a high
If you're looking for an integrated LED downlight with a choice of beam angles the Aurora M10 is worth looking at. It's got a 40 degree beam as standard but the new replaceable beam angle attachment is available in 24 or 60 degrees. This attachment can be used to replace the 40 degree and gives designers and consumers more options. You could even have a mixture of beam angles in the same room! Why not install 40 degrees in the centre of the room and a border of 24 degree beams all around the edges?
If you're unsure about which beam angle to choose, selecting anything from 35 to 45 degrees will work fine in the majority of room types but it does depend on the application and spacing of the lights.