Far Infrared vs Full Spectrum Sauna: Which Infrared Type Is Right for You?

If you've decided on an infrared sauna over a traditional model, the next question is which type of infrared. The market splits into two main categories: far infrared (FIR) saunas and full spectrum infrared saunas. The difference comes down to the wavelengths of light each uses — and those wavelengths determine how heat penetrates your body and which benefits you get the most of.

Here's the breakdown so you can match the right sauna to your specific goals.

Understanding the Infrared Spectrum

Infrared light sits just beyond visible red light on the electromagnetic spectrum. It's invisible to the human eye but you feel it as heat. Unlike traditional saunas that heat the air around you, infrared saunas use radiant heat that penetrates your skin directly — warming your body from the inside rather than cooking you from the outside.

The infrared spectrum divides into three distinct bands, each with different wavelengths and penetration characteristics.

Near Infrared (NIR): 700–1,400nm

Near infrared has the shortest wavelengths in the infrared range and the shallowest tissue penetration — roughly 1–2mm into the skin. That sounds limited, but the skin is where NIR does its best work.

NIR light has the most research backing in the area of photobiomodulation (light therapy). It stimulates mitochondrial function in skin cells, promoting collagen production, wound healing, and cellular repair. This is the same wavelength range used in red light therapy panels and dermatological treatments for skin rejuvenation, acne, and scar reduction. For a deep dive on the research behind photobiomodulation, see our complete Red Light Therapy 101 guide.

If your primary goals are skin health, anti-aging, or wound healing support, near infrared is the most relevant wavelength.

Mid Infrared (MIR): 1,400–3,000nm

Mid infrared penetrates deeper than NIR — reaching into soft tissue, joints, and muscles. This wavelength range is particularly effective for increasing circulation, reducing inflammation in joints and connective tissue, and providing pain relief.

MIR is the least studied of the three bands individually, but its benefits are well-established in the context of thermal therapy for musculoskeletal conditions. Research on infrared therapy for arthritis, joint stiffness, and chronic pain frequently involves mid-infrared wavelengths.

If you deal with joint pain, arthritis, or chronic inflammation, mid infrared wavelengths are especially relevant to your recovery.

Far Infrared (FIR): 3,000nm–1mm

Far infrared has the longest wavelengths and the deepest tissue penetration — up to 1.5 inches (4cm) into the body. This is the wavelength that heats you most efficiently at the core level, producing the deepest sweat and the most significant cardiovascular response.

The majority of infrared sauna research — including studies on cardiovascular health, detoxification, blood pressure reduction, and chronic fatigue syndrome — has been conducted using far infrared saunas specifically. The landmark Finnish cardiovascular studies that showed reduced risk of cardiac events in regular sauna users involved deep heat exposure consistent with FIR penetration depths.

Far infrared is also where the detoxification research is most relevant. A study published in the Journal of Environmental and Public Health found that sweat induced by far infrared exposure contained higher concentrations of heavy metals (including lead, mercury, and cadmium) compared to sweat from exercise alone. The deeper tissue penetration appears to mobilize stored toxins more effectively.

FIR saunas are the most common type of infrared sauna on the market, typically the most affordable, and have the deepest body of research supporting their health benefits.

Full Spectrum Infrared: All Three Combined

Full spectrum infrared saunas incorporate emitters that produce near, mid, and far infrared wavelengths simultaneously. The idea is straightforward: instead of choosing one wavelength band, you get all three in a single session.

A full spectrum session targets multiple tissue depths at once — NIR working on the skin surface, MIR reaching joints and soft tissue, and FIR penetrating deep into the core. This makes full spectrum the most versatile option, covering the widest range of therapeutic benefits in each session.

The trade-off is that full spectrum saunas are typically priced higher than dedicated FIR models, and some practitioners argue that a dedicated FIR sauna delivers stronger deep-tissue heating because 100% of its output is concentrated on far infrared wavelengths rather than splitting energy across three bands.

Infrared Wavelength Comparison

Which Should You Choose?

Choose a far infrared sauna if: Your primary goals are cardiovascular health, deep detoxification, post-workout recovery, or general wellness. FIR has the most research backing, the deepest tissue penetration, and is typically the most cost-effective option. If you're buying your first infrared sauna and want the most proven benefits per dollar, far infrared is the move.

Choose a full spectrum sauna if: You want maximum versatility and the widest range of therapeutic benefits in each session. Full spectrum makes sense if skin health is important to you alongside the deep-tissue benefits, or if you have multiple recovery goals spanning different tissue depths. The premium price is justified if you'll use and benefit from all three wavelength ranges.

Skip near-infrared-only or mid-infrared-only units. Standalone NIR or MIR saunas are rare in the consumer market, and for good reason — far infrared or full spectrum covers those benefits while adding deeper penetration. If you specifically want concentrated NIR for skin therapy, a dedicated red light therapy panel is a more targeted (and more affordable) solution than a NIR sauna.

What About EMF Levels?

One concern that comes up frequently with infrared saunas is electromagnetic field (EMF) exposure. All electrical devices produce some level of EMF, and since you're sitting inside an infrared sauna for extended periods, it's a fair question.

Quality infrared sauna manufacturers — including Golden Designs, whose models we carry — use low-EMF carbon fiber heating panels that keep exposure well below safety thresholds established by international standards (ICNIRP guidelines). When shopping, look for saunas that publish their EMF readings and test below 3 milligauss (mG) at the seating position.

Both FIR and full spectrum saunas can be low-EMF — this is a manufacturing quality issue, not a wavelength issue.

The Bottom Line

Far infrared saunas are the proven workhorse — deepest penetration, most research, best value. Full spectrum saunas add versatility by covering all three infrared bands in one unit, at a higher price point. Both are excellent investments in your health and recovery.

At Peak Flow Fitness, we carry both far infrared and full spectrum models from Golden Designs, one of the most respected names in home infrared saunas. Every model features low-EMF carbon heating panels, Canadian hemlock or red cedar construction, and capacities from 1-person to 6-person units.

Explore our infrared sauna collection and find the right model for your space and recovery goals.

Related reading: Infrared Sauna Benefits · Which Sauna Should I Get? · Traditional vs Infrared Sauna · Red Light Therapy 101