Sun Home manufactures the saunas and cold plunges named in this guide. Specifications and prices were checked against the sources named in the Methodology and Sources section on September 22 and 23, 2026; "not found" means the figure was not found in those sources on those dates, not that it does not exist. Figures are labeled manufacturer specification, calculated from stated inputs, or illustrative assumption where the difference matters.
Short Answer
Estimate sauna capacity from peak demand and the actual service pattern. Private cabins are limited by bookings, session length and reset time; a shared room depends on usable seats and dwell time. Include downtime and a reserve, then test the estimate against clustered arrivals. Average hourly throughput alone cannot guarantee that guests will avoid waiting.
Key Takeaways
- A bather is one person. A booking is one party occupying a private cabin. A two-seat cabin does not create two saleable bookings per cycle; measure average party size separately from time utilization.
- Private cabins are sized in bookings per hour, shared rooms in average concurrent bathers. Downtime is applied once, and empty seats inside a booking are not the same thing as unbooked time.
- With the default inputs below, one shared six-seat room serves 11.97 bathers an hour and one private two-seat cabin 1.425 bookings (1.71 bathers) an hour, so 12 bathers an hour needs eight long-cycle private cabins, five short-cycle cabins, or two shared rooms at these exact defaults.
- Round cabin counts up only at the end, from unrounded capacity. Arrivals minus capacity is excess demand over an interval, not a queue length or a wait time.
- This is a throughput worksheet, not a queue simulator. Confirm commercial suitability, cleaning obligations and permitted use of any model with Sun Home's commercial team before configuring a facility.
Definitions and Formulas
Use these definitions on both this page and the companion cost-per-session worksheet so the sale unit never changes between them.
| Symbol | Meaning | How to measure it |
|---|---|---|
| T | Session minutes (private booking length, or average dwell time in a shared room) | Booking system or timed observation |
| R | Reset minutes between private bookings (wipe-down, towel change, cool-down) | Time ten resets and average them |
| D | Unavailable fraction of operating time (cleaning closures, maintenance, no-shows that block a slot) | Fraction of scheduled hours the cabin cannot be sold |
| G | Average bathers per private booking (party size) | Booking records; 1.2 means most parties are singles with some pairs |
| S | Usable seats in a shared room | Count seats a stranger would actually take, not the nameplate capacity |
| O | Average occupied fraction of seats during active use | Headcounts during peak hours divided by S |
| B = 60 / (T + R) x (1 minus D) | Private bookings per hour per cabin | Calculated from stated inputs |
| P = B x G | Private bathers per hour per cabin | Calculated from stated inputs |
| Q = S x O x 60 / T x (1 minus D) | Shared-room bathers per hour | Calculated from stated inputs; does not simulate a queue |
| Cabins = peak-hour demand / capacity | Divide, then round up | Demand in the same unit (bathers or bookings) as the capacity used |
If O is measured across all opening hours, do not also apply a utilization factor to the same idle time. Define O within active use and treat utilization as the share of potential throughput actually sold, or state a different model explicitly.
Worked Scenarios for 12 Bathers per Hour
Every number below is calculated from the stated inputs. The inputs are illustrative assumptions; replace them with your own logs before calling the result a facility recommendation.
| Configuration | Inputs | Exact hourly capacity | Cabins for 12 bathers per hour |
|---|---|---|---|
| Shared six-seat room | T 20, O 0.70, D 0.05 | 6 x 0.70 x 3 x 0.95 = 11.970 bathers | 12 / 11.970 = 1.003, so 2 at these exact defaults |
| Private two-seat cabin, long cycle | T 30, R 10, G 1.2, D 0.05 | 60/40 x 0.95 = 1.425 bookings, or 1.710 bathers | 12 / 1.710 = 7.02, so 8 |
| Private two-seat cabin, short cycle | T 20, R 5, G 1.2, D 0.05 | 60/25 x 0.95 = 2.280 bookings, or 2.736 bathers | 12 / 2.736 = 4.39, so 5 |
| Private four-seat cabin | T 30, R 10, G 2.4, D 0.05 | 1.425 bookings, or 3.420 bathers | 12 / 3.420 = 3.51, so 4 |
The shared room at 11.97 is practically close to 12, but the displayed formula cannot round the gap away and then promise no waiting. The honest reading is that one room is at the edge of the estimate and the inputs (dwell time especially) are uncertain enough to move the answer either way.
Optional reserve scenario
One optional example limits scheduled demand to 85 percent of estimated capacity. That is an illustrative reserve assumption chosen for this worksheet, not a validated waiting-time standard or an industry practice. With the long private cycle, 12 bathers an hour at 1.2 per party is 10 bookings an hour; 10 divided by (1.425 x 0.85) is 8.26, rounded up to nine cabins. Show the reserve factor you chose beside the result so the reader can change it.
Why Queues Form Below Average Capacity
- Arrivals cluster. Twelve people spread over an hour and twelve people leaving one class together at 6:30 are the same average demand with very different waiting. Count arrivals in 10-minute intervals during peak weeks, not hourly totals.
- Sessions overrun. A 30-minute booking that runs 38 minutes pushes every later slot; T should be the measured duration, not the advertised one.
- Parties vary. A private cabin booked by one person carries the same time cost as one booked by two. G converts bookings to bathers; it does not create extra slots.
- Downtime is lumpy. A 20-minute deep clean is one lost slot, not 5 percent spread evenly across the day. Schedule it outside the peak and count it in D.
Stress-test the estimate with two checks: the largest arrival count in any 10-minute window, and the number of bookings that ran long last month. If the peak window alone exceeds what the cabins can start in that window, waiting is built in regardless of the hourly average.
Data to Collect Before You Commit
- Peak-hour arrival counts by 10-minute interval for at least two weeks, including the day after any schedule change.
- Average party size for private bookings and headcounts for shared rooms.
- Actual session durations and reset durations, timed rather than assumed.
- Planned cleaning closures and maintenance windows.
- Written confirmation from Sun Home's commercial team of which models are approved for the intended commercial use, their cleaning obligations and their warranty terms.
Sun Home Formats This Worksheet Applies To
| Format | How to model it | Note |
|---|---|---|
| Nova 6 (indoor traditional, 6 seats) | Shared room: S = usable seats you would sell to strangers, O from headcounts, T from dwell time | A zero reset time means continuous circulation between scheduled cleaning closures, not that no cleaning is needed |
| Eclipse 2 (indoor infrared, 2 seats) | Private cabin: B from T and R, G from bookings | Two seats do not mean two bookings per cycle |
| Eclipse 4 (indoor infrared, 4 seats) | Private cabin with a larger G, or a small shared room | Choose one model and keep it consistent in the cost worksheet |
Bottom Line
Size cabins from measured demand in the same unit as the capacity formula: bookings for private cabins, bathers for shared rooms. Keep intermediate values unrounded, round up once at the end, add a stated reserve, and check the busiest 10-minute window before treating the count as a plan. Then confirm the model's commercial approval and cleaning obligations with Sun Home.
Frequently Asked Questions
Do two seats in a private cabin mean two bookings per cycle?
No. A booking is one party's use of the cabin for one cycle. Party size converts bookings to bathers; it does not add slots.
How does cleaning affect capacity?
Per-booking resets extend each cycle (R). Scheduled closures reduce available time (D). Apply each once and do not also discount for the same idle time elsewhere.
Why can a queue form when average demand is below capacity?
Because arrivals cluster and sessions overrun. Average throughput describes an hour; a queue forms in a ten-minute window.
How much spare capacity should we plan?
There is no validated universal figure. This worksheet's optional example limits scheduled demand to 85 percent of estimated capacity as an illustrative assumption; show the factor you used and adjust it from your own arrival logs.
Methodology and Sources
All capacity figures are calculated from the stated inputs with the formulas shown; the inputs are illustrative assumptions and no facility statistics are cited. Model seating and commercial-use notes come from Sun Home's product and commercial pages checked on September 22 and 23, 2026. Sun Home manufactures the cabins named.
- Sun Home commercial saunas and cold plunges
- Sun Home Nova
- Sun Home Eclipse help center
- Wellness center cold plunge setup (companion planning method)
Related Reading
- Commercial sauna cost per session and break-even (companion worksheet using the same definitions)
- Gym sauna benefits for post-workout recovery
- Commercial planning with Sun Home