Have you ever gone to purchase an LED lamp and been overwhelmed with the labeling? With so much LED lingo used on labeling it can be confusing when you find yourself thinking I just want a new bulb! So here is your guide to LED labeling hopefully it will clear up any confusion and help you find the right bulb for you.
Lumens instead of watts
Traditionally when replacing an incandescent bulb you would simply look for a 60watt bulb (as an example). But now with the production of LEDs, CFLs and Halogens the wattage you are looking for may no longer exist, and may not give a true representation of the light output from the bulb. LEDs for example are incredibly efficient, so may only need a small amount of power to achieve the same brightness. A better way to find the right brightness of bulb for you is to identify the Lumens. These are a measure of brightness given out by the bulb and are a great benchmark t use when comparing different bulbs, whether they be Halogen, CFL or LED.
A general guide for Lumens replacing watts is:
- 100 watt Incandescent – 1600 Lumens
- 75 watts -1100 Lumens
- 60 watts – 800 Lumens
- 40 watts – 450 Lumens
This is just a rough guide, look for Lumens around these amounts for your replacement bulbs, obviously if you want it to be brighter or dimmer just adjust the Lumens as needed to find the right bulb for you. You should also consider how Lumens are measured, this can sometimes vary, and Lumens can depreciate over time. All good resellers will normally include a ‘home-trial’ so that you can test the bulbs brightness in your own environment.
The Wattage will still be displayed on the labeling but this information is intended purely to inform you how much power the bulb consumes when turned on. It does not give an indication to the brightness of the bulb e.g. a 4 watt and a 7 watt LED could potentially still give the same Lumens depending on efficiency.
Colour Rendering Index (CRI)
Not all LED light packaging will include this. If it does, you can use this information to determine how well colours appear under the bulbs ‘artificial’ light, compared to natural daylight. The higher the figure the closer to daylight it is. But also note; the colour temperature may affect how well colours truly look. This article on CRI will give you more information on the topic.
Colour temperature is measured in Kelvins. It is a measurement used to show where on the colour spectrum the light produced by the bulb can be found. It is useful to know, especially with LEDs as it will ensure the colour will be right for your application.If for example you were replacing a Halogen bulb in a sitting room and you wished to retain the same warm colour, you should stick to a warm white which is normally around 3000 kelvins. Whereas in a modern kitchen may want a cooler whiter light to help highlight stark colours or design features. Cool white is typically around 5000 Kelvins.
LED Lumen Maintenance
Some products will display ‘Lumen Maintenance’. This is generally given to display how quickly the brightness of your LED will deteriorate. It will state an example ambient temperature and number of hours. The percentage shown compares the initial output of the bulb (lumens) to the brightness of the bulb after a period of use. For example a bulb may state that after 25,000 hours in a room with an ambient temperature of 25 ˚C, the bulb still outputs 95.11% of its initial brightness.
The estimated life span of a bulb is often based on it’s L70 value: This is when the bulb drops below 70% of it’s original brightness and is considered not fit for purpose. Lumen maintenance is handy to know because it will suggest whether an LED will loose some of it’s brightness very quickly- This is common place with cheaper LEDs. Whilst they may not fall below the L70 value for 25,000 hours (suggested life span) you may be loosing valuable lumens after just a few hours. This is worth considering when you are paying extra for bulb which states a very high lumen output.
Energy Efficiency rating
This has recently been updated and now ranges from ‘A++’ to ‘E’. If you purchased your bulb more than a year ago, you packaging labels may only go up to ‘A’.
This label s designed to lets you know how energy efficient your light bulb is. LED bulbs will always be in the higher ends of the energy efficiency rating; A++ being the best and E being the least efficient.
Your labeling may also feature a life span. This is the time the bulb is expected to last when used in an optimum setting. Double check your supplier though; rarely will the bulb be guaranteed for this period of time. External factors will often shorten the estimated life spans such as ambient room temperature, use of LED compatible drivers/ switches and more. You should consult your supplier for more information regarding life span.
Hopefully this will have made LED lamp labeling a bit simpler for you. Don’t be overwhelmed with the information offered to you as if understood correctly, it’s there to help you make an informed decision. Remember that inflated lumen figures re not the be all and end all, as high lumen output products may not always give that same brightness. Lifespan can often be cut short by other factors so remember to consult a lighting designer/ electrician to avoid disappointment. Now that you are armed with this extra information, you will hopefully be more likely to get it right first time and really benefit from LEDs.