Understanding Lumens: Brightness in Lighting
In the past, lighting, and light bulbs (correctly called lamps) were labelled and sold based on the load they carried, the wattage – i.e., a 100W lamp was brighter than a 60W lamp, which was brighter than a 40W lamp.
These days, with the use of LED and other energy-efficient technologies, these wattage rating are no longer applicable to decide which lamp is the brightest.
Most lamp manufacturers (like Osram or Philips) have LED lamps that give as much light as the old 60W and 100W equivalents. We measure this amount of light in a metric called lumen.
What are Lumens?
Lumens are, without getting too technical – the measurement of how much light leaves a light source. There are other measurements for how much of that light reaches a surface, or in which direction, but that’s another article. Higher lumens = higher brightness.
Lumens are preferred by lighting specialists to compare lamps, as technology is still changing and lighting is continually getting more and more energy efficient. It’s used to compare a lamp from 2010 with a lamp today, with a lamp 5 years from now, to compare how the wattages have changed, without the lamps getting less bright.
An example – a 100W incandescent (old-school) light bulb might give you between 1000 & 1200 lumens, but a 100W LED (from 2023) can give you as much as 12 000 lumens. That’s right – more than 10x as much light for the same amount of energy.
That’s working with an LED that’s rated 120lumens/W. It’s becoming more commonplace for household LEDs to have upwards of 120lumens/W, and higher quality, commercial grade lights, are nearing 200lumens/W.
This means for your home, you don’t need a bright 100W LED lamp, you can have a 10w LED and have as much light, if not more than you might be used to, for 10% of the electricity used previously.
Some people might have difficulty with LEDs that are so very bright – you can always opt for the dimmable options and reduce the light-levels when it suits you. (Dimming lights uses even less electricity, so check on this option when shopping).
How do I know how many lumens I need?
Good question – and this is always relative to the task being performed in the space, or the general use of a space. You would need more lumens in a kitchen or bathroom (think 800-1000 per lamp), but less in a bedroom or living area (450-600 lumens per lamp). In a study or office, you might want a combination of lower light generally, but a brighter desk lamp where you’re working.
If you’re working as an architect or designer and must meet building regulations with certain lighting criteria, contact Mask. Design to assist you with a formal lighting design & plan, and we can work out which and how many lights you need where, to balance your clients’ budget, and the optimal brightness & use of the space.
hello@mask-design.co.za
+27 64 908 8411
