How to choose an efficient light – Lumens Vs Watts

Energy-efficient LED (light-emitting diodes) bulbs have caused a revolution of sorts within the lighting industry. You may be excited about the colors and smart controls of LED’s but their efficiency and long life are their true advantages.

Effectively measuring a bulb

Traditional incandescent bulbs are no more the norm – thanks to their now obsolete “wattage” measures and lack of energy-efficiency. LED bulbs come with a “lumen” rating, which is a much more accurate way to determine a lighting device’s power and capabilities. Let’s get to learning the basics and differentiating things.

The difference between Lumens and Watts.

Earlier, people misinterpreted watts for bulb brightness. When LED bulbs were not around, the brightness of incandescent bulbs was often talked about in terms of watts. Watts basically indicate the amount of electricity consumed. The measurement has little to do with actual bulb performance or its brightness levels. When only incandescent bulbs were available the difference between light outputs were similar so watts were an acceptable measure of brightness, however now we have 3 main types of bulb technology with varying levels of brightness for the same amount of watts. Thus watts almost becomes irrelevant now to determine the brightness of a bulb.

Lumens: The bulb’s actual output performance

Tells you how bright the light is and is not related to the actual power it uses. One lumen is about equivalent to the total light generated by a birthday candle.

Watts: The amount of energy a bulb consumes.

Simply put, watts refer to energy usage, not actual light output. It’s, therefore, not right to compare an incandescent bulb’s wattage with that of a completely different lighting bulb – such as CFL or LED.

Efficiency: The Watts to Lumens ratio

The watts and lumen vary per brand and bulbs, therefore, it’s important to know how much light a bulb produces for every single watt consumed. By looking at the relationship between the two specifications we can calculate the lumen per Watt. The higher the lumen per watt the more efficient and cheaper to run.

To calculate lumen per watt divide the lumens by the bulbs watts.

This bulb is 14W and gives off 800 Lm;

The Lm to W ratio is 800/14 = 57.1 Lm Per W.

Use this to compare bulbs and you will see even the same type of bulbs have different levels of efficiency. This is because not all bulbs are made to the same efficient standard.

Breakdown of different types of lights.

Each brand of light is different but if we separate just into types of lights you can easily rank the technology. The chart below sums it up quite nicely.

How Efficient does it Get?

LED is the at the top, and at the top of the top; breaking the barrier is CREE who are widely known for their LED technology, after checking online I saw this picture that shows even in the last few years their technology is getting more efficient. You probably won’t find this kind of efficiency in a regular household led bulb yet but it is a good indication of what is to come.

Bear in mind that this is the top end of the technology tree, what you can get your hand currently is unlikely to be close to these CREE standards (unless you are willing to pay a lot). Nevertheless, it is a good indication of what it to trickle down into the home led lighting market.

Why Does This Matter?

For most of us, it is about saving energy and getting the most lumens for your buck, this means choosing a bulb with a great lumen output per watt.  This is getting easier as recent industry packaging standards, manufacturers must list their bulb’s lumen output and power consumption (watts) on the box.  As old-school, incandescent bulbs are phased out you will now have to judge and buy lamps based on their lumen capacity and not watt ratings.

Need some new lights?

We have a wide range of LED lights, bulbs, and other cool stuff to help you modernize your home, so if you are looking for some efficient and smart lighting check out our bright range.