Far Infrared vs Full Spectrum Saunas: What's the Difference?

The far infrared vs full spectrum sauna question sounds technical, but it comes down to one thing: how many bands of infrared the heaters produce. A far infrared cabin gives you the single band that does most of the work in an infrared sauna. A full spectrum cabin adds two more bands on top, at a higher price. Whether those extra bands are worth it depends on what you actually want from your sessions, and this guide lays that out in plain terms.

The three infrared bands

Infrared is just heat you feel but cannot see, and it is split into three bands by wavelength:

• Near infrared (NIR): the shortest wavelengths, roughly 0.76 to 1.5 microns. Often linked with skin and surface tissue, and the basis of red light and near infrared therapy panels.
• Mid infrared (MIR): the middle range, roughly 1.5 to 5.6 microns. Associated with warming a little deeper and raising circulation.
• Far infrared (FIR): the longest wavelengths, from around 5.6 microns up. This is the band that produces the deep, gentle radiant warmth and the steady sweat most people associate with an infrared sauna.

You can read a fuller technical breakdown of the infrared bands on the Wikipedia infrared entry.

What a far infrared sauna does

A far infrared sauna uses carbon or ceramic heaters that emit only the far band. That is not a limitation so much as the point: far infrared delivers the core experience, warming your body directly at a lower air temperature than a traditional sauna, so you sweat freely without the cabin feeling as fierce.

It is also the band with the most research behind it. The large majority of published studies on infrared sauna use far infrared specifically, so if you want the setting that the evidence actually covers, this is it. For most buyers, a good far infrared cabin does everything they were hoping for.

What full spectrum adds

A full spectrum sauna combines all three bands, near, mid and far, usually by adding a separate near infrared emitter (often a halogen or LED element) alongside the carbon or ceramic far infrared panels. In practice that means:

• You get the far infrared warmth as before.
• Plus near and mid infrared, which some users seek for skin or circulation reasons.
• More complex heaters, and a higher price for a cabin of the same size.

The trade-offs are real. Full spectrum units cost noticeably more than comparable far infrared cabins, the near infrared elements can run hotter and brighter, and the specific benefits of near and mid infrared are less well studied than far infrared. You are paying more for breadth that not everyone will use.

Which should you buy?

Choose far infrared if you want the classic infrared sauna experience, the best value, and the setup with the most research behind it. This suits the majority of home users and covers general relaxation and sweating comfortably. Our traditional vs infrared sauna guide is worth reading alongside this if you are still choosing a heat style.

Choose full spectrum if you specifically want near and mid infrared, for example you are interested in near infrared for skin, and you are happy to pay a premium for the extra emitters. If those goals do not apply to you, the extra bands are unlikely to justify the cost.

Either way, pay as much attention to build quality, low-EMF heaters and the timber used as you do to the infrared type. A well-made far infrared cabin beats a poorly made full spectrum one. For the wider checklist, see our home sauna buying guide and our roundup of the best home saunas in the UK.

Frequently asked questions

Is a full spectrum sauna better than far infrared? Not automatically. Full spectrum adds near and mid infrared on top of far infrared, which appeals if you specifically want those bands, but far infrared already delivers the deep radiant warmth and sweat most people are after. For general use, a good far infrared cabin is usually enough, and full spectrum mainly adds cost.

What is the difference between near, mid and far infrared? They are three bands of infrared defined by wavelength. Near infrared is the shortest and is linked with skin and surface tissue, mid infrared sits in between and is associated with circulation, and far infrared is the longest and produces the deep, gentle heat and sweating central to an infrared sauna.

Does far infrared have more research behind it? Yes. The large majority of published studies on infrared saunas have used far infrared specifically, so it is the band with the strongest evidence base. Research into the added benefits of the near and mid bands in full spectrum saunas is still developing.

Is full spectrum worth the extra cost? It depends on your goals. If you want near infrared for skin or are curious about the full range of wavelengths, the premium can be worth it. If you mainly want relaxation and a good sweat, a far infrared cabin gives you that for less, so many buyers do not need full spectrum.

Do infrared saunas get as hot as traditional saunas? No, and that is by design. Infrared saunas warm your body directly rather than heating the air, so they run at a lower air temperature than a traditional sauna while still making you sweat. Many people find the milder air easier to sit in for longer.