Finnmark FD-4 Trinity
The Finnmark FD-4 Trinity is the only home sauna in the world that combines three
distinct modalities in a single room: full-spectrum infrared, traditional steam
heat, and red light therapy — all powered by standard 120V outlets with no
electrician required. If you have ever had to choose between infrared and
traditional sauna bathing, the FD-4 makes that compromise unnecessary.
At the core of the Trinity is Finnmark's Spectrum Plus UL-listed short-wave
infrared heater system — a distinction that matters. Short-wave infrared delivers
deep-penetrating warmth that reaches muscles and joints more effectively than
carbon panel heaters alone. The infrared system is independently verified as low
EMF by a NASA award-winning testing facility, giving bathers the confidence of
third-party validation. For full-body coverage, Spectrum Carbon 360 long-wave
panels complement the short-wave heaters — the two spectrums working together
deliver higher temperatures and a more complete infrared environment than any
single-spectrum system.
For those sessions when you want the intensity of a traditional sauna, the included
Harvia Vega Compact 1.9kW heater is wall-mounted inside the room and loaded with
stones. Pour water across them and the room fills with genuine löyly — the moist,
enveloping steam that is the hallmark of the traditional Nordic sauna experience.
The combination of infrared and steam in the same session is something no other
home sauna on the market delivers, and both run on standard 120V — no dedicated
circuit required.
Completing the Trinity is the Spectrum Red Light panel — 192 LED diodes producing
650nm red light at therapeutic intensity, adding a light therapy dimension to every
session. The entire room is built from Western Canadian Red Cedar inside — naturally
resistant to mold, bacteria, and fungus — and Thermal Plus Aspen outside, built to
resist rot, warping, and decay. Controls are managed through a built-in LCD
touchscreen Controller 2.0 with Bluetooth audio and 6" HiFi marine-grade speakers.
ETL / Intertek certified.
