Definitions, not hidden multipliers.
Length and mass conversions follow NIST unit definitions. Geometry, load, energy, cost and scheduling calculations use the equations printed on each tool page. Heater allowances and ventilation guidance retain the manufacturer and model scope: Harvia and HUUM profiles are separate. A number in an installation manual remains an example for that product and voltage, not a universal electrical or fire-code rule.
The planning year uses 52 weeks. Room dimensions, door opening, lying length, initial rotation and the demonstration timer sequence are illustrative interface defaults. They are not certified designs, human-size standards or recommended exposure protocols. Cost scenarios use named, dated product observations or your entered quotes; a blank required scope stays visibly unquoted.
Harvia’s live calculator and its prose rough-power guidance use different heuristics. Both are named where shown. A manufacturer’s model-volume chart governs selection; no room-derived estimate predicts exact warm-up time or supplies a climate multiplier.
Keep sensitive answers on the device.
All tools calculate client-side. Health checklist answers, weights and visit logs remain in memory. They are excluded from URLs and localStorage and reset when the page reloads. Only the units preference is saved locally, with a fallback when storage is unavailable. Share actions place non-sensitive planning settings in a visible URL only when requested. Do not add private information to those settings.
CSV and PDF exports are generated on your device at your request. The tools do not upload them. The research explorer downloads a public metadata-only catalog from this site; it contains no cached abstracts, reviewer excerpts or visitor inputs. This review has no analytics, lead form or external calculation API.
A score is an inspectable judgment.
The matchmaker and infrared/traditional comparison use an editorial feature matrix. Feature ratings and user priorities each use a 0–5 scale; the weighted mean is normalized by total priority. All-zero inputs produce no ranking. Equal scores are shown as ties, with alphabetical order only for deterministic display. Heating mode and room form remain separate.
Evidence-map grades are provisional editorial judgments using the published grading policy and read abstracts. Publication counts are not independent populations or an automatic strength score. No A outcome is established by this bounded map. The myth checker retrieves fixed, reviewed claims; unmatched text receives no generated verdict.
The safety checkpoint does not establish personal suitability. Institutional exposure examples are not goal-specific treatment protocols. Hydration context is extrapolated from sports measurements and uses remaining net mass deficit. The humidity model has a stated temperature domain and fixed-room assumptions; no validated perceived-heat number is supplied.
The versioned source register.
Source snapshot: 2026-11-08.1. Sources are manufacturer instructions, official technical references, primary research and institutional guidance. Checking a URL is not medical review or code approval.
- Harvia — live sauna calculator and calculation module ↗
Public JS chunk9800-96989cff6cbf203f.js, module80743, read by HTTP
Observed implementation: multiply physical volume for log first, then add fixed glass-door and measured-area allowances. Power uses a different multiplier from support prose. Version-specific implementation, subject to future change. No source code copied into the project.
Checked 2026-11-08 - Harvia — How do I select the correct heater power? ↗
What to consider when choosing the correct power; Choosing a heater based on calculator results; updated May 11, 2026
Harvia's rough kW/m³ starting rule is not identical to selecting a model by its declared room-volume range. Prefer a model's volume-range midpoint; avoid treating the rough number as an exact universal requirement.
Checked 2026-11-08 - Harvia — What to consider when choosing sauna benches ↗
Questions on bench depth, width, roof separation, opposing benches and step height
Manufacturer ergonomic planning guidance, not an occupancy, accessibility or structural code.
Checked 2026-11-08 - Harvia — Ventilation in the sauna ↗
Separate electric-heater and woodburning-heater sections; updated January 29, 2026
The six-change hourly rate is explicitly under electric heaters. Do not silently extend that rate to a wood-burning system; its combustion air, flue, depressurization and fire requirements need a qualified designer.
Checked 2026-11-08 - Harvia — Temperature sensor installation ↗
Minimum distance between supply air valve and temperature sensor; May 4, 2026
Sensor position remains model-specific. Cooling the sensor with supply air can defeat correct temperature measurement.
Checked 2026-11-08 - HUUM CORE US installation and operation manual, v9 ↗
Printed pp.4–6: sizing, Tables1–3 and installation; pp.9–11: room and ventilation
CORE9/11 rows are consistent with P/V. CORE6 is excluded: its 240V table pairs6.5kW with25A, which does not match P/V; the208V row also conflicts. Preserve this discrepancy rather than silently correct a manufacturer's table.
Checked 2026-11-08 - Harvia Vega BC45 HCB450400S product data ↗
Room volume, power output, measurements and Electrical tables
230/400V European example; not a US208/240V selection. Product-page front/side clearance labels conflict with some Vega manual tables, so do not use this page to auto-certify a clearance envelope.
Checked 2026-11-08 - Harvia Vega BC80 HCB800400S product data ↗
Room volume, power output, measurements and Electrical tables
230/400V European example. Clearance fields are withheld from matching because of conflicting page/manual directional labels.
Checked 2026-11-08 - Harvia — FAQ about the energy consumption of sauna bathing ↗
Section2: How much energy does the heater consume?
A manufacturer example for a properly sized heater in an insulated room. Thermostat cycling means nameplate kW multiplied by clock time is an upper-bound scenario, not guaranteed consumption.
Checked 2026-11-08 - Harvia — Choosing a wood burning heater ↗
Many factors affect the heating rate; Heater location and safety distances
The manufacturer expressly declines model-specific heating times because insulation, surfaces, ventilation, chimney draft and fuel affect them. Do not invent an outdoor/climate heat-up multiplier.
Checked 2026-11-08 - Get Your Sweat On: The Benefits of a Sauna ↗
Types of saunas; Risks; Tips for using a sauna
Patient guidance: beginners may start at five minutes; general visits around 15–20 minutes. Typical traditional temperatures are descriptive. Recent heart attack/stroke or alcohol warrants avoiding use; pregnancy, heart/BP conditions, medications and other listed circumstances warrant clinician discussion. Stop if unwell. These are not outcome-specific prescriptions.
Checked 2026-11-08 - 6 Possible Benefits of Infrared Saunas ↗
October 9, 2026; What are infrared saunas? Risks; Tips
Describes 110–135°F infrared rooms and a beginner example of 110°F for five to ten minutes. Its longer experienced-user duration is not needed as an app default. Existing conditions merit clinician discussion; illness, dizziness or nausea require stopping. This is general guidance, not proof of clinical equivalence to traditional sauna.
Checked 2026-11-08 - Sauna Health Benefits: Are saunas healthy or harmful? ↗
May 14, 2020; general precautions
General precautions include avoiding alcohol, discussing heat-relevant medications, limiting visits to 15–20 minutes, gradual cooling, and avoiding sauna when ill. Symptoms during a visit mean leaving. Do not translate the text into a personal permission or treatment algorithm.
Checked 2026-11-08 - Saunas and Your Heart: Is it Safe to Use a Sauna If You Have Heart Disease? ↗
June 13, 2023; Can individuals with a heart condition use a sauna? Safety precautions
Lists unstable angina, recent heart attack, uncontrolled hypertension, decompensated heart failure, severe aortic stenosis, low BP, dehydration, fever and acute illness as reasons for individual advice. Warns people with heart disease against sudden ice-water/cold-pool immersion after sauna. Do not auto-clear a user based on time since a heart attack.
Checked 2026-11-08 - Heat and Medications – Guidance for Clinicians ↗
September 18, 2025; Heat and Medications; What Clinicians Can Do
CDC identifies medication/heat interactions and recommends individualized clinical plans. A medicine flag should prompt a clinician/pharmacist conversation; the app must not advise stopping, changing or skipping medication. This hot-weather guidance supports a precaution, not a sauna-specific drug-risk score.
Checked 2026-11-08 - National Athletic Trainers' Association Position Statement: Fluid Replacement for the Physically Active ↗
Table 2; Fluid Replacement; Rehydration After Exercise; PMID 28985128; DOI 10.4085/1062-6050-52.9.02
Sweat loss uses mass change plus drinks minus urine. With kilograms and liters, divide liters by hours for sweat rate. Short-recovery replacement is 100–150% of net fluid deficit, not necessarily total sweat produced. The statement addresses activity, so applying the measurement method to sauna is an explicit extrapolation. No universal intake prescription; avoid overdrinking and individualize with chronic disease/fluid restrictions.
Checked 2026-11-08 - Association between sauna bathing and fatal cardiovascular and all-cause mortality events ↗
Abstract, Results; original cohort of 2,315 middle-aged Finnish men; DOI 10.1001/jamainternmed.2014.8187
The baseline frequency categories were one, two to three, and four to seven visits per week. They are observational exposure groups, not assigned weekly doses or goals. Keep sessions, total minutes and temperature distinct; the tracker cannot convert these to a validated therapeutic heat dose.
Checked 2026-11-08 - NIST Chemistry WebBook, SRD 69 — Water ↗
Molecular weight; Phase change data; Antoine Equation Parameters, SI/bar table
The SI table uses Kelvin and bar: log10(P)=A−B/(T+C). Stull's coefficients cover 255.9–373 K continuously. Bridgeman/Aldrich provides narrower overlapping fits. Do not mix the calorie/atm table's A coefficient with SI/bar. Never extrapolate a chosen fit outside its documented interval.
Checked 2026-11-08 - NIST FEASST physical_constants documentation — MolarGasConstant ↗
MolarGasConstant().value()
Returns 8.31446261815324 in SI. The 2022 CODATA table also lists the molar gas constant as exact.
Checked 2026-11-08 - Equation Of State (Ideal Gas) — NASA Glenn Research Center ↗
pV=nRT
Use the ideal-gas relation for a simplified well-mixed water-vapor mass balance. Real heat/mass transfer, ventilation, evaporation and condensation require more than this model.
Checked 2026-11-08 - NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity or field of science ↗
Temperature entries
Celsius=(Fahrenheit−32)/1.8; Kelvin=Celsius+273.15. Conversion does not establish a safe personal sauna temperature.
Checked 2026-11-08 - RNLI Water Safety — The Dangers Of Cold Water Shock ↗
Cold water shock explanation
Sudden cold-water exposure can disrupt breathing and cardiac function. A contrast timer supplies timing functions, not an endorsed cold-immersion protocol or protection from cold shock.
Checked 2026-11-08 - EIA Electric Power Monthly, Table 5.3 ↗
Year 2026, August, Residential column; release October 23, 2026; technical notes
U.S. residential average 18.16 cents/kWh for August 2026. Latest available monthly observation on review date; 2026 values preliminary. National average revenue per kWh is a proxy and differs from a household's marginal tariff.
Checked 2026-11-08 - Virginia Cooperative Extension: Estimating Appliance and Home Electronic Energy Use ↗
Estimating Energy Consumption
Energy is watts multiplied by operating hours divided by 1000; multiply kWh by the utility rate for cost. Heater cycling requires actual energized time or an explicitly user-supplied duty factor.
Checked 2026-11-08 - Almost Heaven Auburn 2–3 Person Indoor Sauna ↗
Main price; selected Traditional/Hemfir, 6 kW KIP with dials; Features and Specifications
Displayed base price $4,577. Includes heater and stones; existing floor used. Traditional cabin example only. Verify selected finish and availability at checkout. Do not reuse the page's medical or 100%-humidity marketing.
Checked 2026-11-08 - Almost Heaven Pinnacle 4 Person Barrel Sauna ↗
Main price; default rustic cedar/glass door/no window/6 kW KIP with dials; Specifications
Displayed promotional price $5,302.50; displayed regular comparison price $7,575. Heater and stones included. These are two prices for one base model, not a statistical project-cost range. Older collection prices differed; direct current product page takes precedence.
Checked 2026-11-08 - Almost Heaven Harmony Infrared 2–3 Person Sauna ↗
Main price and Size: 2 Person; Features
Displayed two-person promotional price $5,162.49 and comparison price $7,374.99. Clear hemlock and carbon-panel heating. Product page says 120 V, dedicated 20 A outlet; no actual wattage was read, so do not equate outlet capacity with operating power.
Checked 2026-11-08 - Almost Heaven Timberline Outdoor Sauna — Harvia Collection ↗
Main price; Medium Scala 4 Person / 8 kW KIP with dials selected
Displayed promotional price $9,963.10 and comparison price $14,233. Nordic spruce outdoor cabin; heater and stones included. A premium-cabin example, not a quote for a bespoke project.
Checked 2026-11-08 - Almost Heaven Professional Assembly ↗
Transparent, tailored pricing; FAQ electrical-work exclusion
Assembly starts at $1,400, with a tailored final quote. Electrical work and installation of electric heaters are excluded. Debris removal is an add-on. Site must be level, accessible and prepared.
Checked 2026-11-08 - Thermory: Ten Types of Wood We Use for Saunas ↗
General thermal modification; species sections aspen, red cedar, Canadian hemlock, alder, Scots pine, Norway spruce, radiata pine
Manufacturer descriptions, not clinical or independent performance ratings. Species and grade matter. Short selector attributes below preserve application distinctions.
Checked 2026-11-08 - Osmo: Sauna panelling ↗
Recommended panelling and Bench Slats sections
Lists selected spruce/aspen/hemlock panelling; describes abachi's low heat conductivity for bench slats. Relative heat-transfer description is not a skin-burn guarantee.
Checked 2026-11-08 - Finlandia Sauna: Wood Types ↗
Western Red Cedar; Western Hemlock; knotty spruce and abachi paragraphs
Supplier describes Western hemlock as without aroma/resin and cautions against knotty spruce bench contact. Its allergy-friendly marketing is not used as medical clearance. Eastern/Canadian hemlock in Thermory's guide has a different aroma description.
Checked 2026-11-08 - NIST Handbook 44 (2026), Appendix C conversion tables ↗
Appendix C: exact international inch, foot, pound and SI prefixes
Unit definitions, not engineering or medical guidance.
Checked 2026-11-08
Open a tool’s complete method
- Sauna room designer
- Heater size calculator
- Bench & ceiling height planner
- Ventilation planner
- Wood species selector
- Total cost estimator
- Running cost calculator
- Cost per session calculator
- Electrical requirements checker
- Session planner
- Safety screener
- Weekly heat dose tracker
- Hydration & sweat-loss estimator
- Contrast therapy timer
- Temperature & humidity converter
- Sauna type matchmaker
- Infrared vs traditional decision tool
- Study explorer
- Evidence map
- Myth checker