Johannes
April 15,2021
4 min read

Infrared Sauna Emissivity Explained

Understanding the concept of emissivity when buying an infrared sauna.

Should I buy an infrared sauna because of a claimed high “emissivity”?

Some of the competitors of Clearlight Infrared Saunas® have started promoting a “high emissivity”. With a high emissivity criterion, they denote a 90% or 95%+ emissivity as the benchmark for good infrared sauna heater panels.

Before criticising that claim, let’s simplify what that statement means:

“Emissivity” is a physics concept. Higher emissivity rates entail that more energy is turned into infrared that is emitted as photons. Those photons are emitted as infrared by the heater panels in your infrared sauna.

With high emissivity, less of the energy will be lost because of vibration of atoms along the electric cables.

If that sounds abstract, let’s simplify even further:

Higher emissivity ensures that electric energy from your power grid is more efficiently turned into infrared, without heat losses around the electricity cable.

Low emissivity infrared panels, on the contrary, thus ensure that your sauna runs at a high Wattage generates less infrared. In that case, you’ll get less “bang for your buck”.

At Clearlight Infrared Saunas® we do not agree that emissivity should be the benchmark of a high-quality infrared sauna. Here’s why:

First, a higher emissivity does not necessarily lead to better infrared output. On the contrary, higher emissivity only tells you heater panels put out more of infrared, not whether it’s the correct infrared wavelength. It is therefore not a measure of the actual quality of the heater or the infrared sauna, but rather measure of the heat itself. Remember, we don't want just high heat in an infrared sauna, we want good quality heat to benefit our health and wellbeing

It’s thus possible to create a sauna that only puts out near infrared while having high emissivity. In that case, you won’t get great middle and far infrared exposure.

Here’s an analogy to understand that principle:

High emissivity is like a car that’s very fuel-efficient. With an energy-efficient car, you can thus drive many miles on one gas tank. Nonetheless, you might personally want to buy a car that drives fast, looks good, or is comfortable. The same is true for infrared saunas.

Emissivity alone is thus misleading as you don’t learn anything about the specific infrared that’s emitted.

Secondly, many panels on the market already attain a 90%+ emissivity. So a claimed 98% or 99% emissivity is only a 9% improvement from 90, and not that significant. At Clearlight our heaters have an emissivity rating of about 96%, which is great per se, however it is not what truly matters when comparing brands.

At Clearlight Infrared Saunas® we consider a proper full-spectrum infrared output, with a balanced combination of near, middle, and far infrared more important than optimizing for emissivity. The same holds true for a beautiful design, lifetime warranty, and several other factors.

Conclusion? Most people don’t buy a car because of energy-efficiency reasons alone. Similarly, when they understand the concept, most people don’t want a sauna that’s marketed for high-emissivity either. It is not a true measure of the effectiveness and quality of the infrared heat. 

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