Finnmark FD-4 Trinity Infrared & Steam Sauna | 2-Person | Cedar & Thermal Aspen
Finnmark FD-4 Trinity Infrared & Steam Sauna | 2-Person | Cedar & Thermal Aspen
- Regular price
- $7,795.00
- Regular price
- Sale price
- $7,795.00
- Unit price
- per
Found it lower? We'll match it, before or after you buy.
Send us a link to the lower price. If it is the same model, new and in stock at an authorized U.S. online retailer, we match it. Already ordered? If it was lower on your order date, claim the difference within 30 days.
Excludes sale pricing, marketplace sellers and later price drops.
Read the full price match terms →Infrared panels and a real Harvia stove, in a two person cabin.
- Spectrum Plus infrared plus a Harvia 1.9 kW stove
- Pour water on the stones for steam
- Two tier cedar benching
$0 curbside delivery
Insured in transit
Couldn't load pickup availability
How does delivery work?
How does delivery work?
Free freight to the contiguous 48. On every Finnmark sauna and the SoulCold plunge. Accessories travel by parcel and follow the store threshold, shown at checkout before you pay.
Freight, not parcel. Saunas ship palletized, as flat panels rather than a finished room. The carrier books a window, someone signs, and delivery is curbside rather than inside.
Plan for the weight. An FD-1 crate is about 349 pounds and the barrels are over 1,000. Two people, and somewhere flat and dry to stage it.
Measure the route before the truck comes. A sauna arrives as panels, so the narrowest doorway, stair turn or lift matters more than the finished footprint. Tell us first if a truck cannot reach your door.
If it arrives damaged. Note it on the paperwork before signing, photograph it, and tell us within 48 hours. If a pallet is punctured, crushed or structurally damaged, refuse it and call us while the driver is there.
Where we ship. The contiguous 48. Canada is a flat freight charge. Puerto Rico, Alaska and Hawaii are quoted case by case. No P.O. boxes.
Not included: the electrical work. Every Finnmark sauna wants a dedicated circuit of the rating on its page, and the cabins are a two person build. Professional setup and assembly is available.
What does the warranty cover?
What does the warranty cover?
Lifetime on the Spectrum Plus elements. In home use, indoors and outdoors. That is the longest heater term on any brand we carry.
Ten years on the rest. The Spectrum Carbon heaters and the LED lighting run 10 years. The cabin and the controls run 10 years indoors, 5 outdoors. Remotes and the seat cushion are 1 year.
Not covered. Anything not fitted at the factory. The optional outdoor cover is warranted by material, 5 years on the roof and 10 on the side walls.
Residential only. Finnmark's terms are written for home use, so ask us to confirm cover in writing before you order for a gym, studio or rental.
Two conditions decide most claims. Assembled and placed as the manual requires, including 3 inches of clearance all round and a dedicated circuit. And damage found on delivery reported within 48 hours, with photographs, before assembly.
The Harvia stove and the plunge are separate. The stove inside a Trinity carries Harvia's warranty. The SoulCold has its own 1 year consumer term.
Who handles it. We file the claim for you. Call with your order number, the model, and the serial number from the plate under the bench. Ask and we will send you a free copy of the full warranty before you buy.
What if I need to return it?
What if I need to return it?
30 days from purchase. On a Finnmark sauna or the SoulCold plunge. We handle it, so you do not contact the manufacturer or the distributor yourself.
What a return costs. A restocking fee of up to 5% may apply on a change of mind, and we waive it whenever we are not charged ourselves. Consumables such as the SoulCold filter packs are not returnable once opened.
Who pays the return freight. You do on a change of mind, which on a palletized sauna is the real cost to weigh up. We pay the return freight when the cause is shipping damage or our error.
Original shipping. Not refunded on a change of mind return, and we never deduct the outbound freight from your refund.
Condition. New, unassembled and resalable in the original packaging with all parts. A sauna whose panels have been screwed together cannot go back.
Damaged on arrival. A different and faster process. Note it before signing, photograph it, and report within 48 hours before assembly. Refuse a punctured or crushed pallet and call us.
To start a return. Call or email with your order number. We issue the Return Authorization number, required before anything ships back, and send the address with it.
PRODUCT DESCRIPTION
Jump to 14 sections
The short answer
The Finnmark FD-4 Trinity is a two person sauna with infrared panels and a real Harvia stove
Everything below this model in the Finnmark range is infrared only. The Trinity adds a Harvia electric heater with stones, so the same cabin gives you a long low infrared session or a hot traditional one with steam when you pour water. That second heater is the whole product, and it is also the reason this sauna needs more than one circuit.
The room
55 × 55 in
48.8 inches square and 83.1 tall, plus the 3 inches of clearance Finnmark asks for on every side and above. Ceiling 87 inches, which is the figure that rules out most basements.
The fit
Two people
Inside is 44.5 by 45.1 inches and 75.2 tall, on two tiers of cedar bench. Sit low for infrared, sit high for the steam.
The power
Two circuits
120 volt, 15 amp, NEMA 5-15 for the infrared, and a separate circuit of its own for the Harvia. This is not a plug and play sauna.
Fit
Inside the Finnmark FD-4 Trinity: two tiers of bench and 75.2 inches of headroom
The two tier bench is what tells you this cabin was built around a stove. Heat stratifies in a traditional sauna, so the upper bench is hotter than the lower one, and you choose.
| Interior width | 44.5 in |
|---|---|
| Interior depth | 45.1 in |
| Interior height | 75.2 in |
| Upper bench | 44.5 in wide, 18.9 in deep |
| Lower bench | 44.5 in wide, 15.7 in deep |
| Door glass | 23.6 in wide, 68.9 in high, 8 mm tempered with a gasket |
| Room volume | 86 cubic feet |
Seventy five inches of interior height is nearly five more than the infrared only cabins, which is what makes the upper bench usable. The gasket on the door is there because this cabin holds steam, where the infrared models do not need to.
Where the heat comes from, and why this one is not full spectrum
Finnmark's replacement parts list for the FD-4 names three Spectrum Plus Incoloy elements at 120 volts and 300 watts each, and no carbon panels at all. The infrared only cabins below it pair carbon with Spectrum Plus, which is what their spec sheets mean by full spectrum. Finnmark titles the FD-4 sheet a combination sauna instead, and the combination it means is infrared plus traditional, not two kinds of infrared.
The traditional half is a Harvia electric heater with a bed of stones. Finnmark's spec sheet specifies a Harvia Vega Compact rated at 1.9 kilowatts. Pour water on the stones and you get steam, which no amount of infrared will give you.
Before you order
Five checks before the Finnmark FD-4 Trinity ships
The ceiling and the second circuit are the two that catch people. Both are easier to answer now than after a pallet arrives.
- Ceiling, with the clearance83.1 inches tall plus 3 inches above it is 86.1, so plan on 87 inches, which is 7 feet 3. A standard 8 foot room is fine; a finished basement at 7 feet is not, and this is the check that rules the model out most often
- Floor, with the clearanceThe cabin is 48.8 inches square and Finnmark asks for 3 inches on every side, so plan 55 by 55
- The route to the roomIt arrives flat on a pallet 80 by 36 by 52 inches. Measure the narrowest doorway or stair turn against the pallet, not the finished footprint
- Two circuits, not oneA dedicated 120 volt 15 amp NEMA 5-15 for the infrared, and a separate circuit for the Harvia. Have an electrician read Finnmark's spec sheet before you order
- A solid, dry, indoor floorFinnmark asks for a solid surface in a dry area. The removable feet adjust for floors that are not quite level
If a number is borderline, compare the cabin against the rest of the Finnmark saunas before you decide.
Construction
Three things about the Finnmark FD-4 Trinity you cannot change later
Everything else on a sauna is adjustable. These are set the day it is made.
The two timbers
Inside is Western Red Cedar, which Finnmark specifies for its resistance to mould, bacteria and fungus. Outside is Thermal Plus aspen, which Finnmark describes as treated with heat and steam. The cedar is the surface you sit against; the treated aspen is the shell that faces the room.
The stove, and the room built around it
A cabin designed for a stove is not an infrared cabin with a stove added. The FD-4 is nearly five inches taller inside than the infrared only models, the bench runs in two tiers so you can choose your height in the heat, and the door glass carries a gasket. None of that can be retrofitted.
The emitters
Finnmark warrants the Spectrum Plus elements for the life of the sauna. That is the longest term anywhere on the warranty sheet, and these are the parts that decide how a cabin ages.
Compare it against the other hybrid saunas we carry, or against the infrared saunas if the stove is not the point. Our infrared or traditional sauna guide covers what each kind of heat actually does.
The decision that blocks the purchase
What the Finnmark FD-4 Trinity asks of your electrical panel
Two heaters means two supplies. Any listing that calls this model plug and play is describing the infrared half and ignoring the stove.
| Circuits required | Two. One for the infrared, one for the Harvia |
|---|---|
| Infrared voltage | 120 VAC |
| Infrared circuit | Dedicated 15A, NEMA 5-15 |
| Infrared power | 1750 W, which is 14.6 amps, about 97 percent of a 15 amp breaker |
| Traditional heater | Harvia Vega Compact, 1.9 kW per the spec sheet, on a circuit of its own |
| Supply | Infrared power supply on top of the cabin, cord approximately 9 feet. The Harvia connects at floor level |
| Code | Install per the National Electrical Code, ANSI/NFPA 70. In Canada, per the applicable Canadian code |
The infrared side is settled: 120 volts, a dedicated 15 amp breaker, an ordinary three pin outlet, and at 14.6 amps that breaker has to be genuinely clear of anything else.
The Harvia circuit, and why we will not print a single figure for it
Finnmark's three documents do not agree about the stove. The spec sheet gives the Harvia as 120 volts, 1.9 kilowatts and 20 amps. The dimension drawing names it a Harvia Vega Compact Pro and gives it as either 120 volts at 14.2 amps or 240 volts at 7.1 amps, which works out nearer 1.7 kilowatts, and the same drawing labels its receptacle "120v 20a NEMA 6-15", though a NEMA 6-15 is a 240 volt outlet rather than a 120 volt one.
What all three agree on is the part that matters to you: the Harvia needs a circuit of its own, and it can be wired at either 120 or 240 volts. Take the spec sheet and the drawing to your electrician and let them settle the configuration against your panel. We would rather hand you the conflict than invent a number that turns out wrong at the wall.
Running cost
What a Finnmark FD-4 Trinity session costs to run
Worked at 1750 watts of infrared plus Finnmark's 1.9 kilowatt Harvia, so 3.65 kilowatts with both heaters running, and the US average residential rate of 18.34 cents per kilowatt hour, from the EIA Electric Power Monthly, June 2026. Your own rate is on your bill.
One hour, both heaters
$0.67
3.65 kilowatts for one hour, at 18.34 cents. An infrared only session is 1.75 kilowatts, or $0.32 an hour.
A month
$8.70
Three sessions a week, an hour each, about 13 hours a month, with both heaters on throughout.
A year
$104
The same three a week, every week. Roughly 156 hours.
Every input is above, so redo it with your own rate: kilowatts times hours times cents. In practice both heaters rarely run flat out for a full hour, because each one cycles once the cabin reaches temperature.
Scope
What arrives with the Finnmark FD-4 Trinity, and what it does not include
The Harvia stove is included. The stones, the circuits and the ladle are the things to check.
Required before it runs
- Two circuitsA dedicated 120 volt 15 amp NEMA 5-15 for the infrared, and a separate circuit for the Harvia. An electrician's job
- A second personThe manual's own warning is that a minimum of two physically able people are required for installation
- Sauna stones for the HarviaConfirm with us before you order whether your unit ships with stones, because a stove without them must not be run
Optional
- Professional setup and assemblyIf you would rather not build it yourself, see setup and assembly
- Finnmark FD-4 sauna cushionA fitted marine grade vinyl cushion for the bench
- Finnmark FD-4 sauna coverA fitted marine grade cover. Finnmark describes it as limited weather protection, not an outdoor rating
- A bucket and ladleYou cannot raise steam without one, and Finnmark does not list one in the box
| Panels | Bottom, top, back, front, left, right |
|---|---|
| Door | Glass door with gasket, and handle with screws |
| Seating | Bench support, upper and lower bench tops |
| Heating | Spectrum Plus infrared panels, Spectrum LED ceiling lights, and the Harvia traditional heater |
| Control | V2 LCD controller, 5 inch touchscreen with Bluetooth audio |
| Electrical | Power supply unit, power cable, heater cable, floor cable, interior heater connections with a wood cover |
| Fixings | Screws, removable adjustable feet for uneven surfaces |
| Paperwork | ETL certification, limited warranty |
Freight to the lower 48 carries no delivery charge. Canada is quoted at a flat rate and Puerto Rico, Alaska and Hawaii are quoted case by case, so ask us before you order to either.
Setup
Assembling the Finnmark FD-4 Trinity
It arrives as panels and goes together without specialist tools, with one extra step the infrared cabins do not have.
The manual's tool list is a screwdriver and a level. Panels lock to each other and are fixed with two screw lengths Finnmark supplies. The order is back panel, left side, bench support, right side, then the front wall and the top. The manual notes that the interior and exterior receptacles on the right panel are not used during assembly.
Step five on this model is the Harvia heater installation, which the infrared cabins do not have, and it is the step where the second circuit has to already exist. Finnmark's own warning is blunt: a minimum of two physically able individuals are required, and the manual says in capitals not to attempt the install without proper professionals or without proper tools and safety equipment. At 437 pounds of panels plus a stove, this is a model where paying for assembly is worth pricing. We do not publish an assembly time, because Finnmark does not state one.
Before the first session
Wipe the inside down with a damp cloth to clear any sawdust. Then run the cabin to burn off factory dust before anyone uses it. Check the Harvia's stones are in place and loosely stacked so air can move through them before you switch the stove on for the first time. The serial number plate, which you will want if you ever make a warranty claim, sits underneath the bench.
Delivery day
What to check when your Finnmark FD-4 Trinity is delivered
It moves by freight at 485 pounds and comes off the truck at the curb. Ten minutes of checking there is the difference between a replacement panel and an argument.
Before delivery
Have both circuits finished and your second person booked for the day itself, not for the week after.
At the truck
Walk around the pallet before you sign. Photograph any crushed corner, tear or water mark, and write what you see on the delivery paperwork before you sign.
Before you build
Open the crate and check the glass door, each panel face and the stove while the packaging is still there, and tell us straight away if anything is marked. Our return policy sets out how long you have.
Reference
Finnmark FD-4 Trinity infrared and traditional sauna specifications
| Capacity | 2 person |
|---|---|
| Exterior | 48.8 in W x 48.8 in D x 83.1 in H |
| Interior | 44.5 in W x 45.1 in D x 75.2 in H |
| Electrical | Two circuits. Infrared 120 VAC, 1750 W, dedicated 15A, NEMA 5-15. Harvia on its own circuit |
| Heaters | Three Spectrum Plus Incoloy elements, plus a Harvia Vega Compact traditional stove |
| Steam | Yes, from the Harvia's stones. The infrared only models cannot do this |
Full specification tables
| Upper bench | 44.5 in W x 18.9 in D |
|---|---|
| Lower bench | 44.5 in W x 15.7 in D |
| Door glass | 23.6 in W x 68.9 in H, 8 mm tempered with a gasket |
| Room volume | 86 cubic feet |
| Clearance required | 3 in minimum, top and all sides |
| Ceiling required | 87 in, which is 7 ft 3 |
| Product weight | 437 lb (198.22 kg) |
| Shipping weight | 485 lb (219.99 kg) |
| Pallet | 80 in x 36 in x 52 in |
| Placement | Indoor, freestanding, solid dry floor |
| Interior wood | Western Red Cedar |
|---|---|
| Exterior wood | Thermal Plus aspen, heat and steam treated |
| Infrared emitters | Three Spectrum Plus Incoloy, 120V, 300W each. No carbon panels |
| Traditional heater | Harvia Vega Compact, 1.9 kW per Finnmark's spec sheet |
| Bench | Two tier Canadian cedar |
| Lighting | Spectrum LED with colour chromotherapy. Finnmark specifies a 650 nm red setting |
| Glass | 8 mm tempered with a gasket |
| Control | V2 LCD controller, 5 in touchscreen, Bluetooth audio |
| Maximum temperature | 170 F on the infrared side |
| Infrared voltage | 120 VAC |
|---|---|
| Infrared power | 1750 W. 14.6 amps, about 97 percent of a 15 amp breaker |
| Infrared circuit | Dedicated 15A, NEMA 5-15 |
| Harvia circuit | Its own circuit. Finnmark's documents give either 120 V or 240 V; your electrician settles it |
| Model and part | FD-4, part number FD-KN004 |
| Certification | ETL Listed to UL-875, and cETL to CAN/CSA-C22.2 No. 164. The FD-4 is named on both certificates |
| Warranty, home use | Lifetime on the Spectrum Plus elements, 10 years on the cabin, the controls and the LED, 1 year on the remote. The sheet's preamble limits cover to residential use, and states terms can be changed on a quote or invoice. We will send you the full warranty document free on request |
| Delivery | Freight, no delivery charge to the lower 48. Canada quoted flat, PR, AK and HI by quote |
| Assembly | Screwdriver and level. Two people minimum. Finnmark publishes no assembly time |
The range
The Finnmark FD-4 Trinity against the rest of the Finnmark indoor rooms
Three infrared only cabins, then the two Trinity models. The line that matters is the stove, not the size.
| FinnmarkFD-1 | FinnmarkFD-2 | FinnmarkFD-3 | FinnmarkFD-4You are here | FinnmarkFD-5 | |
|---|---|---|---|---|---|
| Capacity | 1 person | 2 | 3 to 4 | 2 person | 4 |
| Width | 37 in | 48 | 72 | 48.8 in | 75 |
| Depth | 37.8 in | 43.5 | 46 | 48.8 in | 64 |
| Height | 78.3 in | 78.3 | 78.3 | 83.1 in | 84 |
| Bench tiers | One | One | One | Two | Two |
| Carbon panels | Yes | Yes | Yes | No | No |
| Traditional stove | No | No | No | Harvia 1.9 kW | Harvia 4.5 kW |
| Steam | No | No | No | Yes | Yes |
| Infrared voltage | 120 V | 120 | 240 | 120 V | 240 |
| Circuits | One | One | One | Two | Two |
| Shipping weight | 349 lb | 441 | 536 | 485 lb | 654 |
Pick the FD-4 when you want both kinds of heat in a two person footprint and have the ceiling for it. If the stove is not the point, the Finnmark FD-2 seats the same two people on one household circuit, in a cabin nearly five inches shorter. If four people need the steam, that is the Trinity XL. The infrared only Finnmark FD-3 seats three to four for less, on a single 240 volt line.
The stove inside this cabin is one we stock on its own: the Harvia Vega Compact 1900.
The rest of the range: Finnmark FD-1, Finnmark FD-5 Trinity XL, Finnmark SoulCold.
Evidence
The Finnmark FD-4 low EMF reading, and what the certificates say
Two documents on this sauna are worth reading in full. Here is what each actually says.
The low EMF survey, in full
A third party laboratory in Tempe, Arizona measured Finnmark's Spectrum+ heaters in December 2019 under project PR108242, at three positions on each heater. With everything switched off, the room itself read 0.5304 milligauss. Running, the readings ran from 0.6881 milligauss up to a maximum of 1.1708 milligauss at the third position. So the heater added between 0.2 and 0.64 milligauss over what the room was already producing. The laboratory describes every result as magnitudes lower than the ICNIRP Occupational 2010 test limit.
The 1.1708 maximum is the laboratory's own headline figure, from position three; position one at 100 Hz read 0.7328. Three caveats: the limit is the occupational one rather than the general public one, the survey tested heaters rather than an assembled cabin, and pages four and six of the log name the customer as Influence Sauna rather than Finnmark Designs. The survey covers the Spectrum+ elements, which are the only infrared emitters in this cabin.
What the certificates actually say
The FD-4 is named on both Intertek certificates we hold, as ETL Listed to UL-875 and cETL to CAN/CSA-C22.2 No. 164. Those two certificates name the FD-1, FD-2, FD-3 and FD-4 and no others, which is why we do not call the FD-5, FD-6 or FD-7 listed. The Harvia stove carries its own ETL listing, named on Finnmark's dimension drawing. Separately, Finnmark identifies its Spectrum Plus elements as UL component recognised under file E65554, which covers sheathed heating elements as a component rather than a finished sauna. That record names the tradename BKR, not Finnmark and not Spectrum Plus. We do not describe any Finnmark cabin as a UL listed sauna, because that is not what that record says.
What we do not have
No owner reviews of our own yet, because this is a new listing for us, and no independent test of a finished FD-4 cabin as opposed to its heaters. Finnmark publishes a logged heat-up run for the two person FD-2 but not for this model, and none at all for the traditional side.
Buyer questions
Finnmark FD-4 Trinity, questions buyers ask before ordering
Can the Finnmark FD-4 Trinity plug into a normal outlet?
The infrared half can: a NEMA 5-15 at 120 volts, on a dedicated 15 amp circuit with nothing else on it. The Harvia stove needs a second circuit of its own, so taken as a whole this is not a plug and play sauna, whatever a listing elsewhere says. Finnmark's documents give the stove as either 120 or 240 volts, so have an electrician read the spec sheet and settle it against your panel before you order.
Is the Finnmark FD-4 Trinity a full spectrum sauna?
No, and Finnmark does not call it one. Its replacement parts list names three Spectrum Plus Incoloy elements and no carbon panels, and Finnmark titles the spec sheet a combination sauna rather than a full spectrum sauna. The combination it means is infrared plus traditional heat. For carbon and Spectrum Plus in the same cabin you want the FD-1, FD-2 or FD-3.
Does the Finnmark FD-4 Trinity make steam?
Yes. The Harvia is a traditional electric stove with a bed of stones, so pouring water on the stones raises steam exactly as it would in a Finnish sauna. That is the whole reason to choose a Trinity over an infrared cabin. You will want a bucket and ladle, which Finnmark does not list in the box. The door glass carries a gasket on this model because the cabin is built to hold that steam.
What ceiling height does the Finnmark FD-4 Trinity need?
87 inches, which is 7 feet 3. The cabin is 83.1 inches tall and the manual asks for 3 inches of clearance above it. A standard 8 foot room is fine. A finished basement at 7 feet is not, and this is the check that rules the model out most often, so measure to the lowest thing above the spot, including ducting and joists.
Can I put the Finnmark FD-4 Trinity outside or on a covered porch?
It is built as an indoor sauna. The manual says the cabin contains electronics and is intended for indoor use, and that placing it outside without a cover will void the warranty. Finnmark's fitted cover is described as limited weather protection, not full protection. A basement, garage, spare bedroom or new extension suits it, provided the ceiling clears 87 inches. For a covered porch, call us first.
Why does the Finnmark FD-4 Trinity have two benches?
Because heat stratifies once there is a stove in the room. The air at head height on the upper bench is considerably hotter than the air at the lower one, so two tiers let you choose your intensity without changing the setting. The upper bench is 44.5 by 18.9 inches and the lower is 44.5 by 15.7. The infrared only models have one bench because infrared heats you rather than the air.
What is the warranty on the Finnmark FD-4 Trinity?
Lifetime on the Spectrum Plus elements, ten years on the cabin, the controls and the LED lighting, one year on the remote, and nothing on parts not fitted at the factory. The full terms, including the residential use condition, are in the specification table above. Ask us and we will send you the warranty document free before you buy.
How is the Finnmark FD-4 Trinity delivered, and will it fit through my door?
By freight, with no delivery charge to the lower 48, as flat panels on a pallet 80 by 36 by 52 inches. That pallet is the measurement that matters for a stair turn, not the 48.8 inch finished width. The driver brings it to the curb at 485 pounds, so plan a second pair of hands and somewhere flat and dry to stage it. Canada is a flat quote; Puerto Rico, Alaska and Hawaii are quoted case by case.
Am I buying from an authorized Finnmark dealer?
Yes. Recovery Room Direct is a factory authorized Finnmark Designs dealer, so your FD-4 carries the full factory warranty rather than a reseller term. It also means the specification here comes from the manufacturer's own documents rather than from copied listings, which is why this page tells you where those documents disagree. Finnmark sets a minimum advertised price and enforces it, so if you find an authorized dealer advertising below it, our price match covers it.
One last thing
Before you order the Finnmark FD-4 Trinity: the 87 inch ceiling and the second circuit
One measurement and two circuits decide this purchase. Tell us your ceiling height and what your panel has spare, and we will tell you whether the Trinity works in that room or whether an infrared cabin suits it better.
ChaddySauna specialistMon to Sat, 9am to 6pm ET
