How the Sauna Electrical Tool Works
Last updated 2026-10-07
What the tool shows
The tool covers the 166 models published in the InHouse Wellness Verified Sauna Database. For 125 of them the manufacturer states something about the circuit: a voltage and amperage, a breaker, a receptacle or a dedicated circuit. The tool quotes that statement in the manufacturer's own words, with its grade, its source and the date we verified it. A quote is copied from the source and is never reworded or turned into a cleaner number.
Where the manufacturer states nothing about the circuit, the tool says so and shows what is sourced: heater power, supply voltage, a stated amperage, a plug type. It links the model's manual where we hold one.
What the tool does not do
It does not calculate a breaker size, a wire gauge or any code minimum. Electrical codes differ by state and by city, and by which edition of the National Electrical Code a jurisdiction has adopted. A licensed electrician applies your local code to your home. The tool never says whether a home can or cannot run a sauna; panel details you enter become questions for your electrician.
The one calculation: heater current draw
Where the manufacturer states the heater's rated power and the voltage it runs on, the tool shows the heater's
current draw, calculated as amps = kW × 1000 ÷ volts. A 6 kW heater on 240 V draws 6 × 1000 ÷ 240 = 25.0 A.
This is the current the heater uses, not a breaker size, and it is labelled as calculated wherever it appears. For
28 models both inputs are sourced.
The tool never works backwards from volts and amps to power. A stated "240V / 30A" describes the circuit a manufacturer asks for, not what the heater draws.
Heater size: manufacturer charts, side by side
Heater makers publish their own tables of room volume per heater. The tool applies each chart separately to the room you enter, using that maker's own rule for glass and uninsulated walls, and shows every result. The charts are not averaged. They disagree, and the disagreement is information. Glass is the clearest case: for each square foot of glass, Harvia adds about 3.9 cubic feet of volume, HUUM about 3.3 and Tylö 1, while Finnleo, Saunacore and Scandia state no glass rule at all.
| Maker | Document | Heater sizes | Glass and wall rule, as stated |
|---|---|---|---|
| Harvia | Harvia KIP electric sauna heater, Instructions for Installation and Use (BY05-1516, US/UL), p. 14 (5.3 Specifications) | 3 kW, 4.5 kW, 6 kW, 8 kW | Add 1,2 m³ to the volume of the sauna for each non-insulated wall square meter (p. 16 (6.2)); log walls: multiply the cubic volume of a log sauna by 1.5 |
| HUUM | HUUM DROP user manual (H1001L02 v6, EU edition 2025), p. 4 (Table 1) | 4.5 kW, 6 kW, 7.5 kW, 8.5 kW | add 1 m³ per m² of uninsulated brick, tile or glass wall (p. 4) |
| Finnleo | Finnleo Designer SL2 heater (72-0130) and Laava Pro with SL2-C (72-0139), 72-0130 p. 2; 72-0139 p. 5 (Table 1) | 4.5 kW, 6 kW, 8 kW, 10.5 kW | No glass or wall rule stated |
| Tylö | Tylö Sense UB Series manual (72-0157, Rev B, 8/21/24), p. 9 (Table 1) | 6 kW, 8.3 kW | each square foot of glass adds one cubic foot of volume (p. 9) |
| Saunacore | Saunacore product catalogue, "Selecting a Sauna Heater" (Nov 2022), p. 46 | 2 kW, 3 kW, 4 kW, 5 kW, 6 kW, 7.5 kW, 9 kW, 10.5 kW | No glass or wall rule stated |
| Scandia | Scandia Ultra heater product pages (maximum room size only), product pages | 3 kW, 4.5 kW, 6 kW, 7.5 kW, 9 kW | No glass or wall rule stated |
Not used this round:
- Harvia Cilindro PC90: the en-US page lists 230 V 3~ / 400 V 3N~ only; not a US 240 V single-phase model.
- Tylö Sense Sport: its room ranges change with supply voltage; not applied in this round.
- Helo (formerly Amerec): no heater table read from a Helo document this round.
- Polar: no manufacturer-owned document found.
- "Sizing Your Harvia" PDF: a retailer document, conflicting with Harvia's own manual.
Metric charts (HUUM, and Harvia's glass rule) are applied in metric: the room you enter in feet is converted at 1 ft = 0.3048 m. Saunacore's method divides cubic feet by 50 and picks the next heater size up. Scandia publishes maximum room sizes only, so it sets no upper limit on heater size.
When a value is missing
A missing value is shown as missing, never as zero and never borrowed from a similar model. If a model has no rated heater power on record, the tool asks for it from the heater's spec plate or the manual; without it, no current draw is shown. A sauna sold by InHouse Wellness that is not yet in the database gets the same manual entry and is never shown as covered.
Sources and independence
Every value comes from the InHouse Wellness Verified Sauna Database, which copies each value from the manufacturer's own product page or manual and grades it. InHouse Wellness sells some of the brands listed. Results are published whether or not they favour a brand InHouse Wellness sells, and InHouse Wellness's own product pages are never used as evidence. How the database is verified. To report an error, email data@inhousewellness.com with the source that shows the correct value.
Local electrical codes vary. The manufacturer's installation manual and your local code govern, and a licensed electrician sizes and installs the circuit.
Check a model in the electrical tool · How this page is built · InHouse Wellness Verified Sauna Database