Does Dimming LED Lights Save Energy?

2020-07-30

LED lights are continuing to grow in popularity in commercial and residential applications across the country because of the tremendous efficacy they offer.

However, LED lighting is still relatively new to many people and there are lots of questions regarding its efficacy that aren't apparent. One question we keep getting regarding our LED lights is whether dimming LED lights saves energy and if so, what type of dimming setup is to be preferred?

As we consider dimming to be an integral aspect of choosing your LED lights, we decided to give you an overview.

The Short Answer

Yes! Dimming LED lights saves energy.

With that said, not all LED lights are dimmable. Some come with preinstalled dimmability options while some fixtures are compatible with external dimming setups. When you’re shopping for LEDs, be sure to look for the dimmability icon that suits your needs.

How does dimmable LED work?

To understand how dimming an LED light works, we'll give you a quick crash-course on how light emitting diodes (LEDs) work and how different dimmability options come with unique set of pros and cons.

There are two main ways to dim LED light: pulse width modulation (PWM) or analogue dimming.

Pulse Width Modulation (PWM)

Pulse width modulation systems work by turning LED lights on and off faster than our eyes can comprehend. By being off for about 75% of a second and on for about 25%, a dimmable LED light will appear to emit the equivalent of 25% its total potential brightness.

A similar, yet far-fetched comparison can be made to the the “flicker fusion” principle that makes movies appear to be happening in real time, even though they are a series of still images.

If you’re in a room with PWM LEDs, you won’t perceive any flashing or flickering, but you will gain more specific control over your dimmability and energy usage.

As the graphic above illustrates, PWM technology brightens or dims LED lights by decreasing the amount of time the light is on per cycle. That provides advantages, such as…

Minimal energy loss

Increased brightness range with consistent, controllable levels

Minimal stroboscopic (flashing) effect

Consistent color quality

However, this doesn’t mean PWM is perfect for everybody. It does have some disadvantages:

Dimming cycles can potentially create a buzzing sound some people can hear

The ceramic parts used in inexpensive PWM systems can vibrate in a way that distorts light and reduces precision control over dimming

Analogue Dimming

An analogue dimmer directly controls the flow of energy into the LED, raising or lowering the brightness of continually operational lights. Unlike a PWM dimmer, which rapidly switches the light on and off, an analogue system provides a continuous flow of exactly enough energy to achieve your lighting goals.

In the case of analogue dimming, an LED driver serves as a switchbox where DC voltage can be increased or choked back to control the flow of power to the light. This has a number of benefits, including…

 

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Zero output noise

Great control over LEDs with lower demand

Of course, like PWM, analogue dimming also comes with disadvantages, such as…

Color shift: as your voltage changes, the quality of your light may not remain consistent

Limited dimming range: depends on the incoming current and the quality of the driver

0-10v and 1-10v Dimming

One of the most common forms of analogue LED dimming technology on the market is known as 0-10V. 0-10V is an updated version of the protocol used to dim the fluorescent lights that were popular in larger buildings in the past.

Basically, 0-10V dimming works by scaling the output of the LED light mathematically. At a 10-volt supply, the dimmer provides 100% of the light’s pull potential. At a 0-volt supply, the dimmer provides 0% of the light’s potential.

0-10V dimming provides the some of the best advantages of analogue technology as:

Simple change-over from a legacy fluorescent system

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Affordable method

Compatibility with a wide range of dimmer switches

The drawbacks of 0-10v dimming is that it is not suitable for installations where each light requires its individual dimming percentage. When multiple LED drivers are connected to the same dimmer, they all respond identically to the dimmers current setting.

How much energy is being saved?

So to answer the initial question: When you adjust the dimmer on an LED system (using either dimming setup), your power usage goes up or down in a way that should be directly proportional to the wattage you’ve selected.

To put it simply, if you dim your LED lights 50%, they use about 50% as much energy!

 

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Dimmable LEDs provide you with the most precise, predictable control over your energy usage that’s ever been possible. You can choose exactly how much light you need in given spaces or during specific times of the day and limit your overall carbon footprint without having to turn the lights all the way off.

Not only the energy consumption levels are affected by dimming. In fact, the lifespan of LED lights can be increased by using dimmable setups. This means that by installing high-quality dimmers on your LED lights you can extend our 45000 hours lifespan guarantee even further.

All in all, by making the transition toward LED dimming, warehouses, offices and other commercial buildings can make the most of daylight harvesting and make sure to save as much energy while creating greater ambiance throughout their working spaces.