What Is an Infrared Sauna? Near-, Far-, and Full-Spectrum Explained
Published
Summary
An infrared sauna uses radiant heaters instead of a conventional sauna heater and stones as its main heat source. "Near infrared," "far infrared," and "full spectrum" describe the wavelengths a product is designed to emit, but those labels do not tell you whether the sauna will fit your room, electrical service, or daily routine. For a home installation, cabin size, emitter placement, power requirements, controls, and indoor or outdoor rating matter just as much as the spectrum label.
How an infrared sauna heats you
A traditional sauna heats the room air and surrounding surfaces with a heater and stones. An infrared sauna relies more heavily on radiant heat coming from panels or other emitters inside the cabin.
That difference changes what you should look at when comparing products. The location of the emitters matters. Panels behind your back, beside your body, near your legs, or in front of you do not create the same exposure pattern. In a compact one-person cabin, the panel layout can matter more to comfort than a broad marketing term such as "full spectrum."
What do near, far, and full spectrum mean?
Infrared covers a range of wavelengths. Products may be described as near infrared, far infrared, or full spectrum depending on the emitters they use and the wavelength ranges the manufacturer says they produce.
Those labels are useful for understanding how a product is built, but they are not universal construction standards. Two saunas carrying the same "full spectrum" label may use different emitter types, placements, power levels, and control systems.
If the distinction matters to you, read the specifications for the exact model rather than assuming the category name tells the whole story.
Electrical requirements can differ even within the same category
Many residential infrared cabins run on ordinary 120-volt household power. Finnleo sells its S-Series as ready to plug into a standard 15- or 20-amp outlet, but the manuals assign a specific rating to each model (the S-810 and S-820 are 15-amp rooms, the S-825, S-830, and S-840 are 20-amp) and say the sauna should go into a dedicated outlet of the correct rating, because sharing a circuit can trip the breaker or overheat the wiring.
So a familiar plug does not mean any outlet in the house will do. Check the amperage and circuit requirement in the manual before buying.
Indoor and outdoor models are not interchangeable
A wooden cabinet is not automatically an outdoor sauna.
If the sauna will sit on a patio, deck, or in another exposed location, use a model specifically designed for those conditions. Outdoor products may have different requirements for weather protection, temperature exposure, base preparation, and electrical installation.
An indoor infrared sauna should stay indoors unless the manufacturer explicitly approves another use.
What should you compare before buying?
The specifications that decide whether a cabin fits are exterior and interior dimensions, seating position, emitter layout, voltage and amperage, required circuit, controls, warranty, service access, and whether the sauna is rated for your intended location.
After that, compare the heating system itself: how many emitters there are, where they sit, and what wavelength range the manufacturer states for each type.
Sources
- finnleo.com/infrared-saunas/s-series
- finnleo.com/hubfs/Finnleo%20Downloads/71…m%20w%20IL2%2002-08-2023.pdf
Specifications, prices and installation requirements are as the makers published them on these pages on the date above and can change. Check the current manual and the retailer before you buy.