The hardest part of speccing a commercial steam room is not choosing a brand — it is sizing the generator correctly. Undersize it and the room never reaches temperature during back-to-back use; oversize it and you have paid for capacity and electrical service you do not need. This guide walks through how commercial steam generator sizing actually works, then matches it to the six commercial steam systems Sauna Republic carries across Mr. Steam, ThermaSol, and Delta. Every sizing figure below comes from the manufacturer documentation on our product pages, and pricing on commercial steam is quoted per project — so the focus here is getting the spec right, not a number.
Size a commercial steam generator by the enclosure's cubic footage (length x width x height in feet), then adjust up for hard surfaces like stone or glass, high ceilings, and long pipe runs. Match that adjusted volume to the generator's kW output. For a single steam room, the Mr. Steam CX, ThermaSol PowerPak3, Mr. Steam CT Day Spa, and Delta Commercial Steam Boiler Package cover the range. For multiple rooms, the ThermaSol Day Spa Multi-Room System runs up to four rooms from one generator, and the Delta Second Room System extends a Delta boiler to a second independent room. Commercial steam runs on 208/240/480V, single or three-phase — the electrical service is part of the sizing decision, not an afterthought.
- Why commercial steam sizing is different
- How to size a commercial steam generator
- Output-to-room-volume sizing tables
- Systems for a single steam room
- Systems for multiple rooms
- Voltage, phase, and electrical service
- Completing the steam room: add-ons
- Matching the system to your facility
- Commercial steam FAQ
Why commercial steam sizing is different
Residential steam sizing is forgiving. A home shower runs one short session a day, so a generator sized loosely still performs. Commercial steam is a different problem. A spa or gym steam room cycles through clients all day, has to recover heat quickly between users, and is often built from hard, heat-shedding materials — full stone, tile, or glass enclosures with high ceilings. All of that increases the steam output a room demands.
Commercial systems are built for that duty. The generators in this guide are engineered for round-the-clock operation, offer larger kW outputs than residential units, run on commercial electrical service (208/240/480V, single or three-phase), and in several cases drive more than one room from a single unit. The trade-off is that sizing them correctly matters more — the cost of an undersized commercial room is unhappy clients and a room that never holds temperature during peak hours.
The good news is that the math is straightforward, and every commercial system on our site publishes a sizing guide. Here is how it works.
How to size a commercial steam generator
Sizing comes down to one core number — the room's cubic footage — adjusted for the things that make a room harder to heat.
1. Measure the enclosure in cubic feet. Multiply length x width x height, all in feet. A steam room that is 8 ft long, 6 ft wide, and 8 ft high is 384 cubic feet. That raw volume is your starting point.
2. Keep ceilings in range. Steam rises, so ceiling height has an outsized effect on how hard a generator has to work. Commercial guidance keeps steam-room ceilings at or below 8 feet where possible, with 10 feet as a practical maximum. Taller than that and the room needs a meaningful bump in output.
3. Adjust up for hard surfaces. Materials matter. A fully tiled or acrylic room holds heat reasonably well, but natural stone, marble, full glass, and exposed concrete pull heat out of the steam and demand more output for the same volume. The harder and more massive the surface, the larger the generator.
4. Account for the pipe run. The generator does not have to sit next to the room, but distance costs steam. Mr. Steam's guidance is a useful rule of thumb across the category: if the generator sits more than 25 feet from the steam room, add roughly one cubic foot to the room's volume for every additional foot of pipe run, so a longer mechanical-room distance is sized in rather than discovered later.
5. Match the adjusted volume to kW output. Once you have an adjusted cubic-foot figure, you match it to the generator output that covers it. That is where the per-model sizing tables come in.
None of this has to be done blind. Tell us the room dimensions, the surface materials, the ceiling height, and where the generator will live relative to the room, and our commercial steam team will confirm the exact model and electrical configuration before anything ships.
Have your room dimensions?
Send us length, width, height, surface materials, and your electrical service. We will confirm the exact commercial steam generator and configuration for your facility, and quote it per project.
Request Commercial Pricing Or call our commercial line: (302) 273-0861Output-to-room-volume sizing tables
Two of our commercial lines publish full output-to-volume charts that show how the sizing logic plays out. These are the worked examples — the other systems follow the same principle and we confirm the exact match for your room.
Delta Commercial Steam Boiler Package
The Delta Commercial Steam Boiler Package sizes by adjusted room volume, with the electrical service scaling alongside the output. Ceiling height should stay at or below 8 feet (10 feet maximum).
| Output | Room volume | Voltage / phase | Breaker range |
|---|---|---|---|
| 9 kW | 0–400 cu ft | 208 / 240V · 1 or 3-phase | 30–60A |
| 12 kW | 401–500 cu ft | 208 / 240 / 480V · 1 or 3-phase | 20–80A |
| 15 kW | 501–620 cu ft | 208 / 240 / 480V · 1 or 3-phase | 25–90A |
| 18 kW | 621–740 cu ft | 208 / 240 / 480V · 1 or 3-phase | 30–100A |
| 24 kW | 741–1,000 cu ft | 208 / 240 / 480V · 1 or 3-phase | 40–150A |
| 30 kW | 1,001–1,250 cu ft | 208 / 240 / 480V · 3-phase | 45A and up |
Larger outputs are available for bigger rooms; the package is sized and wired to your facility, and is multi-room ready when paired with the Delta Second Room System covered below.
Mr. Steam CX Commercial Steam Generator
The Mr. Steam CX is the line that scales largest, with the model number tracking the room volume it covers. Adjust for wall materials and ceiling height, and add for pipe runs beyond 25 feet as described above.
| Model | Output | Room volume | Phase |
|---|---|---|---|
| CX0360 | 3.6 kW | up to 360 cu ft | 1 or 3-phase |
| CX0500 | 5.0 kW | up to 500 cu ft | 1 or 3-phase |
| CX0600 | 6.0 kW | up to 600 cu ft | 1 or 3-phase |
| CX0800 | 8.0 kW | up to 800 cu ft | 1 or 3-phase |
| CX1000 | 10.0 kW | up to 1,000 cu ft | 1 or 3-phase |
| CX1250 | 12.5 kW | 1,001–1,250 cu ft | 3-phase |
| CX1600 | 16.0 kW | 1,251–1,600 cu ft | 3-phase |
| CX2000 | 20.0 kW | 1,601 cu ft and up | 3-phase |
The CX runs a 7-inch touchscreen control and an AutoFlush cycle that drains and rinses the tank automatically to manage scale — the kind of self-maintenance feature that matters when a generator runs all day.
Systems for a single steam room
If you are outfitting one steam room, four of our commercial systems cover the range from a compact spa room to a large stone enclosure.
Mr. Steam CX — scales the largest
Next-generation commercial generator with a 7-inch touchscreen and automatic AutoFlush tank maintenance. The right choice for the biggest single rooms, scaling well past 1,600 cubic feet. Turnkey package, sized and wired to your facility.
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ThermaSol PowerPak3 — built for longevity
A split-tank design engineered for commercial duty and easy service, offered in two configurations: PowerPak3 SR at 18 kW and PowerPak3 LR at 24 kW. A strong fit for a large single commercial room where uptime and serviceability are priorities.
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Mr. Steam CT Day Spa — for space-conscious facilities
A compact commercial generator with Mr. Steam's iTempo control, built where mechanical space is tight. The practical pick when the room is commercial but the footprint for the equipment is limited.
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Delta Commercial Steam Boiler Package — turnkey, round-the-clock
A complete package with programmable management controls, built for continuous commercial duty and sized and wired to your facility. Multi-room ready, which leads to the next section.
Get PricingSystems for multiple rooms
Facilities running more than one steam room — separate men's and women's rooms, or several treatment suites — can drive multiple rooms from a single system rather than buying a generator per room.
ThermaSol Day Spa Multi-Room System — one generator, up to four rooms
Engineered for high-use commercial duty and sized by combined room volume, the Day Spa system runs as many as four independent rooms from a single generator. The efficient backbone for a multi-suite spa.
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Delta Second Room System — one boiler, two independent rooms
A complete second-room kit that extends a Delta Commercial Steam Boiler to a second, independently controlled room. The clean way to add a second steam room without a second boiler — plan it together with the boiler so the output covers both rooms.
Get PricingWhich architecture fits depends on how many rooms you are running and whether they operate on independent schedules. We will model the combined demand and confirm whether a multi-room system or separate generators is the better build for your facility.
Voltage, phase, and electrical service
Commercial steam is a meaningful electrical load, and the service is part of the sizing decision, not a detail to sort out after the order. The systems here run on 208, 240, or 480 volts, in single or three-phase, with the breaker sized to the output. As the sizing tables show, the larger outputs move to three-phase service and larger breakers — a 30 kW Delta boiler, for example, runs three-phase.
The practical implication: confirm what electrical service your facility has, or can run, before finalizing the generator. A licensed electrician handles the connection, and your Sauna Republic specialist confirms the voltage, phase, and breaker requirement for your chosen output so the install goes in clean. Tell us your available service and we size the generator to match what you have, where possible.
Completing the steam room: add-ons
The generator produces the steam, but a finished commercial steam room needs the components that deliver and control it. Each brand has a dedicated commercial add-ons page where these are organized.
The two pieces every steam room needs are a steam head and a control. Beyond that, rainheads, aromatherapy, and multi-room sentinels are where you tailor the experience to your facility's offering. Tell us what you are building and we will spec the components alongside the generator.
Matching the system to your facility
Facility type usually points to single-room versus multi-room, and to how hard the system has to work.
Speccing a commercial steam room?
As an authorized dealer for Mr. Steam, ThermaSol, and Delta, Sauna Republic sizes the generator to your room and electrical service, specs the add-ons, and quotes the project. One steam room or several.
Request Commercial Pricing Or call our commercial line: (302) 273-0861Commercial steam FAQ
How do I size a commercial steam generator?
Measure the steam enclosure in cubic feet (length x width x height), then adjust the figure up for hard surfaces like stone, marble, or glass, for ceilings above 8 feet, and for generator-to-room pipe runs beyond 25 feet (add about one cubic foot per additional foot of run). Match that adjusted volume to the generator's kW output using the per-model sizing tables. Send us your dimensions and materials and we will confirm the exact model.
What is the difference between a single-room generator and a multi-room system?
A single-room generator serves one steam room. A multi-room system drives several rooms from one unit: the ThermaSol Day Spa Multi-Room System runs up to four independent rooms from a single generator, and the Delta Second Room System extends a Delta boiler to a second independently controlled room. Multi-room systems are sized by combined room volume, so the output has to cover all rooms running at once.
Do commercial steam generators need single-phase or three-phase power?
It depends on the output. Smaller commercial outputs run on single or three-phase 208/240V, while the larger outputs move to three-phase service (208/240/480V) with larger breakers. The sizing tables on our product pages list the voltage, phase, and breaker range per output. Confirm your facility's available electrical service early, since it influences which generator you choose.
How do ceiling height and wall materials affect sizing?
Both increase the output a room demands. Steam rises, so taller ceilings need more output — commercial guidance keeps steam-room ceilings at or below 8 feet where possible, with 10 feet as a maximum. Hard, massive surfaces like stone, marble, full glass, and exposed concrete pull heat from the steam and require a larger generator than a tiled or acrylic room of the same volume.
Can one generator run two or more steam rooms?
Yes. The ThermaSol Day Spa Multi-Room System is built to run up to four rooms from one generator, and the Delta Second Room System adds a second independent room to a Delta boiler. Both are sized by the combined volume of the rooms they serve, so the generator output covers all rooms in use. This is usually more efficient than a separate generator per room.
What add-ons does a commercial steam room need?
At minimum, a steam head and a digital control. Beyond those, facilities commonly add multi-sensory rainheads, aromatherapy systems, and multi-room control sentinels to tailor the experience. Each brand organizes these on a dedicated page: ThermaSol, Delta, and Mr. Steam commercial steam components. We spec the add-ons alongside the generator for your build.
Why isn't commercial steam pricing listed on the site?
Commercial steam is quoted per project. The price depends on the generator output, the add-ons, your electrical configuration, the number of rooms, and delivery — figures that only mean something once the system is sized to your facility. Rather than list numbers that will not reflect your actual project, we size the system and quote it. Request a quote and you will have real figures fast.
Which commercial steam brand should I choose?
All three we carry — Mr. Steam, ThermaSol, and Delta — are commercial-grade and well-supported. The choice usually comes down to room count and scale: Mr. Steam CX for the largest single rooms, ThermaSol PowerPak3 for split-tank serviceability, Mr. Steam CT for tight mechanical spaces, Delta for a turnkey round-the-clock package, and the ThermaSol Day Spa or Delta Second Room systems for multiple rooms. Tell us the facility and we will recommend the best fit.
Browse the commercial steam lineup or start a quote on the commercial pricing page, and tell us your room dimensions, materials, and electrical service so we can size it right the first time.
