Intending to buy a light bulb is a forthright task. However, walking into a store and facing many types of light bulbs quickly makes the task somewhat complicated.
This is unsurprising given that light bulbs have undergone a tech revolution from incandescent to light-emitting diode (LED).
Let’s explore how the process of selecting and buying a light bulb for your home (kitchen, living room, bathroom, or bedroom) can be less frustrating.
How US & EU regulators came to the rescue
In the past when incandescent bulbs were the norm, consumers differentiated them by one key metric – Watts (the power rating).
Currently, selecting a light bulb is not as simple as that, though, at least thanks to newer bulb technology like LEDs which have higher efficiency and more defining metrics.
The US
In 2010, the US Federal Trade Commission (FTC) announced special “Lighting Facts” labels on the packaging of such new tech bulbs similar to the “Nutrition Facts” labels on food packaging.
The FTC light bulb labels provide info about a bulb’s brightness, wattage, color temperature (light appearance), lifespan, energy cost.
See image below for US light bulb info label.
The EU
The EU is not unlike the US’s FTC regarding light bulbs packaging labels, which are mandated as energy labels, albeit with a slight variance.
The energy label itself shows 3 fundamental items: bulb energy category (class A to G), the energy use per 1000 hours, and a QR code that leads to a more detailed product specifications page under the European Product Database for Energy Labeling (EPREL).
The EU also mandates imprinting other essential light bulb metrics such as brightness, power rating, color temperature, lifespan, dimmability, physical size, on-off switching cycles, & bulb start time on the packaging.
See the image below for the EU light bulb energy label.
What should you focus on during light bulb shopping?
You ought to focus less on a bulb’s power rating, and more on these three characteristics: brightness (lumens), color temperature (Kelvin), and lifespan (Years).
A quick explanation on each of these three characteristics should bring you up to speed on the best bulb you need to purchase for your residential lighting fixture.
Brightness in Lumens:
Lumens indicate a bulb’s brightness intensity or luminosity. Therefore, a brighter bulb has higher lumens while a dimmer bulb has less lumens. When incandescent bulbs were commonplace, the bulb watts (unit of energy use) – informally stood in place of brightness.
In other words, under a similar lighting system – like the incandescent system – a higher watt lamp means a higher lumen output.
Clearly, when incandescent bulbs were the standard, brightness was taken as a relative metric based on another metric (power in watts) rather than as an independent metric.
Notably, for the same lumen output, LEDs consume much lower energy compared to incandescent bulbs. It’s no wonder the US & EU regulations are in place to help you think in lumens instead of watts.
The table below demonstrates the high energy efficiency of LEDs. You can see the power requirements (watts) for both incandescent bulbs and LED lamps at fixed brightness or lumen output benchmark level:
| Incandescent bulb power (watts) | LED bulb power range (watts) | Brightness benchmark (lumens) |
| 150 | 30 | 2600 |
| 125 | 20-25 | 1850 |
| 100 | 15-19 | 1600 |
| 75 | 12-17 | 1100 |
| 60 | 8-15 | 800 |
| 40 | 6-9 | 450 |
| 25 | Up to 5 | 250 |
Color temperature in Kelvins/Light appearance
The color temperature varies on a spectrum from warm to cool and is measured in Kelvins (K) in terms of correlated color temperature (CCT).
Why is color temperature important? It defines the appearance of a lamp’s light output, and thus the mood a lit bulb sets in space.
On the one hand, warm color temperature has a golden, soft shade and falls in the 2700K – 3500K CCT range. On the other hand, cool color temperature is like natural daylight with a bluish tone, falling in the CCT range of 5000K – 6500K.
In a nutshell, the softness and allure of warmer bulbs makes them ideal for bedroom and living room spaces while the natural daylight appearance of cooler bulbs makes them ideal for task, desk, and reading applications.
Lifespan in Years
Unlike the almost faded incandescent bulbs, LED bulbs feature considerably longer lifespans and they don’t burnout, with the diode light output only fading over time, completing their useful life after a 30% brightness minimization (fading).
Therefore, the lifespan indicated on a light bulb’s packaging shows its useful life period before the brightness has faded by 30%. For context, incandescent bulbs have typical lifespans of about a year while most LEDs bulbs can last over a decade.
Now, how confident do you feel regarding purchasing a light bulb?
Having shed light on the somewhat strange language of lighting facts on light bulbs packaging, you must have strong confidence on the type of lamp you want to purchase for your home.
Without doubt, considering the three main factors, that is, lumens, color temperature, and light lifespan, your light bulb shopping should be a delight.
