Myth Busted: Settling the 3-Watt vs 5-Watt LED Debate

Various Light Therapy Devices

With red light therapy exploding in popularity as a treatment for hundreds of conditions, and results backed by thousands of independent studies, the market is more flooded than ever with choices in LED panels. Some are good quality; many, however, are not. 

To complicate things further, a lot of misinformation is floating around about light wattage and power output. Specifically, many companies claim to use higher wattage LED bulbs in their devices to produce more light energy and yield better results. The problem with this claim is that higher wattage LEDs don’t always produce more light energy. 

Even worse, many therapy light companies lie about the components they use. For example, they’ll claim to use a 5-watt (W) bulb, when they actually use a 3-watt bulb. And they often get away with it, because most consumers don’t know the difference. 

This blog post will give you everything you need to know in order to make an educated decision. You’ll learn: 

  • Why 3W LEDs are better than 5W LEDs for red light therapy panels;
  • Why most companies who claim to use 5W LEDs are simply lying; and
  • How to identify 3W and 5W LED bulbs just by looking at them.

Why More Wattage Isn’t Better

Power output is one of the most important specifications to look for when shopping for a light therapy panel. If everything else is equal, a more powerful therapy panel will give you better results, more quickly. 

It makes sense, then, that every light therapy panel company wants to claim that their devices are the most powerful on the market. One tactic they use in making this claim is marketing panels with higher wattage bulbs.

For example, many companies now claim to use 5W or even 10W LEDs in their panels instead of the widely accepted 3W components. 

And from a marketing angle, this makes sense: “More must be better”—right? After all, a 100W bulb is brighter than a 60W bulb. Some companies even claim to use 10W or higher LEDs, which is absolute nonsense. Here’s why:

As LED Wattage Increases, Efficiency Decreases

It’s a well-known fact that the smallest LED bulbs are also the most efficient. In fact, one widely cited study by researchers at the Massachusetts Institute of Technology (MIT) demonstrated that an extremely small LED bulb can emit even more power than it consumes. In the study, the researchers powered a small LED bulb with 30 picowatts of power, and measured an output of 69 picowatts of light⁠—an efficiency rating of more than 230 percent. 

In fact, as the researchers concluded, “The device’s wall-plug (i.e., power conversion) efficiency is inversely proportional to its output power.” In other words, as an LED’s output power increases, the efficiency decreases. 

But overall efficiency patterns don’t tell the whole story. As LED lights get larger, their efficiency curves change as well. Smaller lights typically have flatter, more even efficiency curves compared with larger LEDs. 

Let’s take a look at an example. This graph shows a simplified efficiency curve for an electric light. 

Maximum Light Output Graph

As you can see, the light output increases relatively evenly at the beginning of the curve, but rapidly increases as you get closer to the LED’s maximum light output. (Check out Figure 1a from the MIT study cited above for a more detailed example.)

This pattern is even more extreme with larger LEDs. If you compare a 3W and 5W light, for example, the efficiency curve comparison would look something like this: 

Light Output vs Power In 3w and 5w LEDs

As the diagram shows, a 3W LED is actually more efficient than a 5W LED over most of the operating range. Of course, if you power⁠—or drive⁠—a 5W bulb all the way to maximum power, it will provide more light output than the smaller LED. However, most LEDs are NOT used at maximum capacity because of one very important byproduct of light: heat. 

Light Therapy Panels Aren’t Driven at Maximum Capacity

The heat produced by an LED bulb follows the same curve as the light output. It increases exponentially near the top of the bulb’s power output. 

For this reason, every light therapy panel on the market is only driven at a fraction of their maximum capacity.  For example, a panel rated at 900 watts might only use 450 watts of electricity from your outlet⁠ (though the exact wattage used depends on the color and wavelength of light produced). You can confirm this with a kilowatt meter. As you get close to the maximum wattage rating for your panel, you’ll start to see potential issues: They’ll produce excessive heat, won’t last as long, and will require expensive internal circuitry and other components. 

So, to compare a 3W and 5W bulb accurately, you need to compare them at an absolute max of 60 to 65 percent of their total capacity, not the maximum rated wattage. And when you compare them on even terms, the 3W light actually produces more light with less heat and greater reliability. 

3W vs 5W at 65% power input

Overall, 3W lights are the superior option for three reasons: 

  1. They run cooler than a 5W LED that produces the same light output;
  2. Lower heat also leads to better reliability and safety, and lower cost than a comparable 5W LED; and
  3. 3W LEDs actually produce more light energy under real-world conditions. 

The Truth About 5W Panels Being Sold Today

Despite the science, many companies are still jumping on the 5W therapy light bandwagon. They’ll take a common panel size⁠—say, 900W⁠—and just use fewer bulbs to make up the overall wattage number. Instead of using 300 3W LEDs like we do in our BIO and BIOMAX series, they’ll use 180 5W bulbs. 

Remember that the label describes the maximum power consumption of the lights. It’s not a rating of what the panel will consume during everyday usage. As we mentioned earlier, a 900W panel will only consume a max of 585W. 

In fact, all of the panels we’ve seen using 5W LEDs consume less power than comparable 3W models. They also produce less light energy, also known as irradiance. We know because we’ve tested comparable models using a simple solar power meter.  

We run the tests by turning each panel on and measuring irradiance at a few standard distances from the panel, including six inches and 12 inches. Here are the results: 

Table of Irradiance measurements

As you can see, while 5W bulbs might sound great from a marketing perspective, they actually produce less irradiance than 3W panels during daily usage. Irradiance is the most important measure of a light panel’s power because it’s the light energy that your body will actually absorb. Your cells don’t care what your panel is made of. They simply respond to energy. 

By the way, you don’t have to take our word for it. You can run these tests at home. Here’s the power meter we use: Tenmars TM-206

Irradiance Measurements

Beware Fake 5W Panels

Despite the fact that 5W bulbs aren’t as effective as 3W bulbs, some companies are claiming to use 5W bulbs, but using 3W bulbs instead. You’ll typically see this from small LED resellers who have caught on to the therapy light trend and want to cash-in without investing in research and development. 

These resellers just find specs that sound impressive, and count on the ignorance of consumers when shipping the product. But we’d like to show you the difference. Check it out for yourself in the photographs below.

The biggest giveaway between 5W and 3W bulbs is the design of the light-producing semiconductor chips. Most light therapy LED bulbs come in two variations: single- and dual-chip. (Some LEDs have more, but we haven’t seen them used in a therapy panel.) The chip is basically the source of light; power runs through it and creates light waves. 

You can tell the difference between a single- and dual-chip LED simply by looking at them. Here are two examples: 

Single vs Double Chip Design

Look at the rectangles in the middle of each bulb. The bulb on the left has a single chip, while the bulb on the right has two. 

Either design can be used to create a 3W or 5W bulb, but 5W bulbs typically use a dual-chip design. That’s because dual-chip designs can produce a lot of power in a relatively small form factor. For reference, a 5W double-chip bulb can be about the same size as a 3W single-chip bulb. The only possible way to have a 5W single-chip bulb is to increase the size of the casing, or “package.” There is no other option. 

We’ve examined every therapy panel on the market, and many panels that claim to use 5W bulbs use small, single-chip LEDs. There is no way they could possibly produce 5 watts of energy from each bulb. 

Wattage Doesn’t Matter. Irradiance Does. 

You will never see PlatinumLED claiming to have the highest wattage lights, because those numbers don’t matter. 

PlatinumLED has always been driven by quality and value, and for this reason, we design and manufacture our own lights. Unlike our competition, we are not resellers. We design and manufacture every panel with our customers’ benefits in mind.

This is why you can trust PlatinumLED as the global leader in LED therapy lights. When we say we offer the highest irradiance, it’s because we use lights that are scientifically proven to deliver the maximum light energy output safely and effectively. 

When we say that our BIOMAX panels offer the most widely studied wavelengths with the greatest therapeutic value, it’s because we researched the benefits and deliberately chose each specific wavelength, delivered in a specific ratio for maximum benefit.

When we say that we use 3W bulbs, it’s because they’re proven to work and to give you the longest-lasting panels and the best light output.

The same cannot be said by a company claiming to offer panels that feature nonexistent 5W LED bulbs. If they’re not truthful about that, what else aren’t they telling you? Remember the wise principle, caveat emptor … which means "let the buyer beware.”