Why We Stopped Calling Our Saunas “Full Spectrum” (And What I Learned About Infrared Physics)
Five years ago, I made a decision that probably cost us sales in the short term but was the right thing to do for our customers: we stopped using the term “full spectrum” in our marketing.
This wasn’t an easy decision. Everyone in the industry uses this term. It sounds impressive. It suggests advanced technology and comprehensive therapy. And honestly? It was helping us sell saunas.
But there was one problem: I couldn’t explain how it actually worked.
When customers asked me technical questions about how our heaters produced near, mid, and far infrared simultaneously, I found myself giving the same vague answers I’d heard from other companies: “proprietary technology,” “comprehensive wavelength coverage,” “advanced heat delivery.”
Then one day, a physicist customer asked me about Wien’s Displacement Law and surface temperatures. I had no idea what he was talking about. That moment of realizing I didn’t understand the science behind my own product—that was uncomfortable.
So I started digging into the physics. What I discovered changed everything about how we build saunas and talk about our technology. This is the story of that journey—and what I wish I’d known when I started SaunaCloud.
The Wake-Up Call: When Customers Started Asking Better Questions
Here’s what made me realize we needed to change how we talked about our saunas.
Customer #1 – March 2024:
Sarah called to ask about the difference between our “full spectrum” model and our standard far infrared model. When I gave her the standard marketing explanation, she followed up: “But what are the actual wavelengths? I’ve been reading about Wien’s Law and I’m trying to understand the physics.”
I didn’t have a good answer. That bothered me.
Customer #2 – May 2024:
Marcus, an engineer, was considering our sauna but wanted to see the technical specifications. “What’s the surface temperature of your heaters? How do they produce multiple wavelengths from a single heating element?”
I promised to get back to him with details. It took me three days to realize… I couldn’t answer his question with actual physics.
Customer #3 – August 2024:
Jennifer, a physical therapist, asked if we had third-party testing to verify our near-infrared output. “I want to recommend this to my patients, but I need to understand what wavelengths they’re actually receiving.”
These weren’t demanding customers. They were informed consumers asking reasonable questions. And I didn’t have satisfactory answers—just marketing language.
That’s when I decided to go back to school on infrared physics and figure out what we were actually building.
My Deep Dive Into Infrared Physics
I wanted to understand this correctly, so I did what I should have done when we first started using “full spectrum” terminology: I studied the actual science.
The Question That Changed Everything
I started with one fundamental question:
“If our heaters produce near, mid, and far infrared, what surface temperatures do they operate at, and how does that align with Wien’s Displacement Law?”
Learning Wien’s Displacement Law
This isn’t complicated physics—it’s taught in undergraduate courses. The formula is:
Peak Wavelength (microns) = 5268 / (Surface Temperature °F + 460)
This formula tells you exactly what wavelength any heated object produces based on its surface temperature. It’s not debatable. It’s physics.
When I plugged in the numbers, everything became clear:
To produce Near Infrared (1.4 microns):
Required surface temperature: 2,300°F+
To produce Mid Infrared (3.5 microns):
Temperature of surface needed: 845°F
To produce Far Infrared (7.9 microns):
Temperature of surface needed: 206°F
Then I measured our heaters. They operated at around 200-220°F.
According to Wien’s Law, we were producing far infrared around 7.9 microns. That’s it. No near infrared. No mid infrared (not really). Just high-quality far infrared.
The “full spectrum” claim didn’t match the physics.
What I Discovered About Our Industry
Once I understood Wien’s Law, I began examining product specifications across the industry with new eyes. I reached out to material scientists, reviewed heater specifications, and studied the actual technology being used.
Here’s what I found—not to criticize anyone, but to understand what “full spectrum” actually means in practice:
What “Full Spectrum” Actually Means in the Sauna Industry
Through my research—reading product specifications, studying heater technology, and, yes, asking questions when specifications were unclear—I discovered that “full spectrum” means different things to different companies. None of them violates the laws of physics, but the marketing doesn’t always match the reality.
Pattern #1: High-Quality Far Infrared at Multiple Wavelengths
Most saunas labeled “full spectrum” actually use:
- Carbon or ceramic heaters: 200-400°F surface temp
- Actual output: Far infrared at 6.0-8.5 microns
- What this means: Excellent far infrared therapy, just not near or mid infrared
My take: This is promising technology marketed with confusing terminology. The sauna works excellently—it’s just not producing multiple spectrum bands.
Pattern #2: Far Infrared + Halogen Bulbs
Some saunas combine:
- Far infrared panels: 200°F (producing 7.9 microns)
- Halogen bulbs: 775°F (producing 4.3 microns)
- What this means: Two different far infrared wavelengths, both within the FIR band
My take: This can create a different feel due to varying wavelengths, but both are still considered far infrared. It’s like saying you have “full spectrum visible light” because you have light bulbs at two different color temperatures—they’re both still visible light.
Pattern #3: Marketing-Focused Descriptions
Some companies use “full spectrum” to mean:
- “Complete therapy”
- “Comprehensive wavelength coverage”
- “Advanced infrared technology”
These are marketing terms without a specific technical meaning.
My take: This is where the industry has gotten loose with language. It’s not technically incorrect if they’re not claiming specific wavelengths, but it’s not very clear for consumers trying to make informed decisions.
What I Realized About Our Own Marketing
Looking at our materials with fresh eyes, I realized we were doing the same thing. We called our saunas “full spectrum” because:
- Everyone else did
- It sounded advanced
- Customers expected to hear it
- It helped justify our quality and pricing
However, we couldn’t substantiate it with physics. And that wasn’t okay.
What This Research Taught Me
After months of studying infrared physics and analyzing how the industry uses terminology, here’s what I learned:
Realization #1: Physics Doesn’t Care About Marketing
Wien’s Displacement Law isn’t negotiable. You can’t market your way around thermodynamics. A heater operating at 200°F produces far infrared around 7.9 microns. That’s what physics says, regardless of what the brochure claims.
Realization #2: “Full Spectrum” Has No Standard Definition
Unlike terms like “organic” or “UL-certified,” there’s no regulatory definition for “full spectrum” in the sauna industry. Companies use it to mean whatever they want it to mean.
Realization #3: Far Infrared Is Actually What You Want
This was the biggest revelation: the core therapeutic benefits of sauna use—raised core temperature, deep sweating, cardiovascular conditioning, and detoxification—all come from far-infrared radiation in the 7-9 micron range.
Near- and mid-infrared have benefits, but they’re not necessary for sauna therapy. Far infrared does the heavy lifting.
Realization #4: I Had Been Part of the Problem
We were using “full spectrum” in our marketing because everyone else did. We genuinely believed our heaters were superior to standard far infrared heaters (they were—better emissivity, lower EMF, optimized wavelength), but labeling them “full spectrum” wasn’t entirely accurate.
I was prioritizing marketing language over scientific accuracy. That needed to change.
Realization #5: Customers Deserve Transparent Information
The customers asking detailed physics questions weren’t being difficult—they were being smart. They deserved straight answers based on actual science, not marketing speak.
What “Full Spectrum” Actually Means
Based on my investigation and examining the actual products these companies sell, here’s what you’re typically getting:
Configuration 1: Far Infrared Only
What they claim: “Full spectrum infrared”
What you get: Carbon or ceramic heaters operating at 200-400°F, producing far infrared at 6.0-8.5 microns
The truth: Standard far infrared therapy, nothing additional
Configuration 2: Far Infrared + Halogen
What they claim: “Near, mid, and far infrared coverage”
What you get: Far infrared panels (200°F) + halogen bulbs (775°F)
The truth: Both produce far infrared, just at different wavelengths within the FIR band (4.3 and 7.9 microns)
Configuration 3: Marketing Fantasy
What they claim: “NASA-developed full-spectrum technology with layered heaters.”
What you get: Far infrared with confusing technical descriptions
The truth: Creative fiction to justify premium pricing
The Real Way to Get Multi-Wavelength Benefits
After this investigation confirmed what I already suspected, here’s what I tell customers who want genuine multi-wavelength therapy:
Option 1: Optimized Far Infrared (What Everyone Actually Needs)
Get a high-quality far infrared sauna with:
- Heaters operating at a 200°F surface temperature
- Peak wavelength around 7.9 microns
- 360-degree coverage
- Ultra-low EMF
- Proper power for your space
This delivers all the core benefits: increased core temperature, deep sweating, cardiovascular conditioning, detoxification, muscle recovery, pain relief, and improved sleep.
Far infrared does the job. Period.
Option 2: Add LED Red Light Therapy (If You Want Near Infrared)
If you want legitimate near infrared benefits—collagen production, cellular energy, reduced inflammation, skin rejuvenation—add LED-based red light therapy.
Critical requirements:
- Proper wavelengths: 630-670nm (red) and 810-850nm (near infrared)
- Positioned within 6 inches of your body (distance is critical)
- Integrated into benches or backrests, NOT wall-mounted 2+ feet away
- Separate controls from far infrared heaters
- Medical-grade components with verified wavelengths
This is how you actually get multi-wavelength therapy—engineered integration of two proven technologies, each operating at its optimal parameters.
At SaunaCloud, we build our saunas with optimized far-infrared (VantaWave™ heaters at 200°F) plus LED red light panels integrated into bench seating, where they’re 2-6 inches from your body. We don’t call it “full spectrum” because that term is scientifically meaningless.
We call it what it is: far infrared for core heating + LED-based near infrared for cellular benefits.
For the complete technical breakdown of why full-spectrum claims don’t work and what actually does, read our definitive full-spectrum infrared sauna guide.
What You Should Do With This Information
If you’re shopping for an infrared sauna and considering a “full spectrum” model, here’s my advice:
Ask These Questions:
- “What is the surface temperature of your heaters?”
- If they can’t answer, walk away. If they say “proprietary,” walk away.
- “What specific wavelengths do your heaters produce at those temperatures?”
- Demand numbers, not marketing speak.
- “Can you explain Wien’s Displacement Law and how your heaters overcome it?”
- This will immediately separate companies that understand physics from those that don’t.
- “Can I see third-party test documentation of your wavelength output?”
- If they deflect to testimonials or certifications, that’s a red flag.
- “Why does this cost $3,000 more than your far infrared model?”
- Make them justify the premium pricing with technical specifications.
Red Flags to Watch For:
🚩 Can’t state heater surface temperatures
🚩 Uses “proprietary technology” to avoid explaining physics
🚩 Redirects to testimonials when asked technical questions
🚩 Claims “NASA-developed” or “medical-grade” without documentation
🚩 Instructions require rotating your body during sessions
🚩 Red light panels mounted on walls 2+ feet from seating
🚩 Defensive or hostile when questioned about specifications
What to Actually Buy:
Skip the “full spectrum” premium pricing. Get:
For most people:
A quality far infrared sauna with optimized heaters (200°F surface temp, 7.9 micron output, 360° coverage, ultra-low EMF). This delivers all the core benefits.
If you want cellular/skin benefits too:
Add LED red light therapy, positioned within 6 inches of your body—either integrated into the sauna design or as a separate panel used outside the sauna.
Explore options at our custom infrared sauna page or check out guidance for DIY builds if you’re building your own.
Why We Changed Our Approach (And Why I’m Sharing This Story)
After I understood the physics, I faced a decision: to continue using “full spectrum” because everyone else does, or to change how we talk about our saunas, even if it meant losing sales.
We chose transparency.
Here’s why I’m sharing this story publicly:
Reason #1: Customers Deserve Better Information
When someone is investing $8,000-$15,000 in a wellness product, they deserve to understand exactly what they’re getting. Not marketing language—actual physics and specifications.
Reason #2: Far Infrared Deserves Recognition
Far infrared therapy is proven, safe, and effective. It doesn’t need to be dressed up as “full spectrum” to be valuable. In fact, labeling it something it’s not undermines the legitimate science behind far-infrared therapy.
Reason #3: The Industry Can Do Better
The sauna industry has incredible potential to help people. Far infrared therapy delivers tangible benefits. LED red light therapy has thousands of studies supporting it. These are powerful wellness tools.
But when we hide behind marketing terms instead of explaining the actual science, we make it harder for informed consumers to make good decisions. We create cynicism that hurts the entire category.
Reason #4: Transparency Builds Trust
Some colleagues warned me that being this transparent about physics and what our heaters actually do would hurt our business.
The opposite happened. When we started explaining Wien’s Law, showing surface temperature specifications, and being honest that our heaters produce optimized far infrared (not all three spectrum bands), our customers trusted us more.
Educated customers become loyal customers.
Reason #5: I Want to Sleep Well
At the end of the day, I need to be able to explain to customers—and to myself—exactly how our saunas work and why we build them the way we do.
Using “full spectrum” when I couldn’t back it up with physics meant I wasn’t being sincere. Changing that felt right.
The Bottom Line: What You Should Know
After diving deep into infrared physics and rethinking how we talk about our own technology, here’s what I want you to understand:
Authentic “full-spectrum infrared saunas” don’t exist in the way they’re marketed. The physics of Wien’s Displacement Law make it impossible for a single heater to produce near-infrared (2,150°F), mid-infrared (850°F), and far-infrared (200°F) radiation simultaneously.
Far infrared therapy absolutely works. You don’t need “full spectrum” to get the benefits you’re looking for. Properly designed far-infrared radiation at 7-9 microns delivers all the core therapeutic effects: increased core temperature, deep sweating, cardiovascular conditioning, detoxification, muscle recovery, and improved sleep.
Real multi-wavelength therapy is possible—but it requires two separate technologies: far-infrared heaters for core heating (around 200°F, producing 7.9 microns) and LED red light panels for cellular benefits (630-670nm and 810-850nm, positioned within 6 inches of your body).
Ask for specifications, not marketing claims. When shopping for a sauna, request:
- Heater surface temperatures
- Peak wavelength output
- EMF testing results
- Third-party verification
Companies that understand their own technology will provide this information readily. If they deflect to “proprietary” claims or emotional appeals, that’s a signal to keep asking questions.
Transparency benefits everyone. Educated consumers make better decisions. Companies that provide transparent and honest information build stronger relationships with their customers. The whole industry improves when we prioritize science over marketing language.
— Chris Kiggins
SaunaCloud Founder
Infrared Sauna Designer Since 2014
Still Learning, Always Transparent
Related Reading:
- The Definitive Full Spectrum Infrared Sauna Guide – Complete technical breakdown
- Near vs. Far Infrared Sauna: What Actually Works – Physics explained
- Red Light Infrared Sauna: The Right Way to Combine Wavelengths – Our approach
Have Questions?
📞 800-370-0820
📧 hello@saunacloud.com
P.S. — If you’re shopping for a sauna and a company claims “full spectrum,” ask: “What are the surface temperatures of your heaters, and what wavelengths do they produce according to Wien’s Displacement Law?” Companies that understand their technology will answer directly. Companies that don’t… well, now you know what questions to ask next.
P.P.S. — The decision to stop using “full spectrum” in our marketing wasn’t easy, but it was right. Our customers appreciate the transparency, and I sleep better knowing we’re being scientifically accurate. If you’re a sauna builder or business owner reading this and reconsidering your own terminology—I respect that. The industry improves when we all commit to honest education.
