SAWO
SAWO Nimbus sauna heater
SAWO makes the Nimbus in 7 sizes, from 9 to 24 kW, for saunas of 283 ft³ to 1,483 ft³. Slide to your room size to see which one fits, how fast it heats and what it needs from your fuse box.
Updated Oct 18, 2026
Output
9–24 kW
Rooms
283 ft³–1,483 ft³
Stones
110 lb–220 lb
Sizes
7
Which size fits your sauna?
Your room's effective volume
636 ft³
Best fit: NIM-150
Work out your effective volumeEffective volume = inside volume, plus 1.2 m³ for every m² of glass, tile or stone; × 1.5 for solid log walls (Harvia's rule, used by most planners).
Sizes and specifications
| Model | Output | Room range | Stones | Heat-up | Per session |
|---|---|---|---|---|---|
| Nimbus NIM-90NIM-90NS-P | 9 kW | 283 ft³–494 ft³ | 110 lb | 30–40 min | $1.56 |
| Nimbus NIM-105NIM-105NS-P | 10.5 kW | 318 ft³–530 ft³ | 110 lb | 25–35 min | $1.58 |
| Nimbus NIM-120NIM-120NS-P | 12 kW | 353 ft³–636 ft³ | 110 lb | 25–30 min | $1.79 |
| Nimbus NIM-150NIM-150NS-P | 15 kW | 459 ft³–812 ft³ | 165 lb | 25–35 min | $2.30 |
| Nimbus NIM-180NIM-180NS-P, NIM-180NS-V12-P | 18 kW | 600 ft³–1,024 ft³ | 165 lb | 25–35 min | $2.71 |
| Nimbus NIM-210NIM-210NS-V12-P | 21 kW | 777 ft³–1,236 ft³ | 220 lb | 25–35 min | $3.34 |
| Nimbus NIM-240NIM-240NS-V12-P | 24 kW | 918 ft³–1,483 ft³ | 220 lb | 25–35 min | $3.67 |
Heat-up and cost are our heat model's estimate for each size in a room at the middle of its range: indoor, insulated walls, 68 °F around the sauna, heated to 176 °F, one hour of bathing, electricity at $0.18/kWh (United States average).
Electrical connection
| Output | three-phase 400 V (per phase) | single-phase 230 V |
|---|---|---|
| 9 kW | 13 A | 39.1 A |
| 10.5 kW | 15.2 A | 45.7 A |
| 12 kW | 17.3 A | 52.2 A |
| 15 kW | 21.7 A | 65.2 A |
| 18 kW | 26 A | 78.3 A |
| 21 kW | 30.3 A | 91.3 A |
| 24 kW | 34.6 A | 104.3 A |
Current is computed from the output; fuse and cable are shown where the maker or dealer states them. A licensed electrician sizes and installs the circuit following the heater's manual and local rules.
Where to see it
Prices and availability come from the shop or maker and change; their page is what counts. Shop offers are added as retailers join.
Sources
- sawo.com/nimbus-ns/maker · read 2026-10-18
Other heaters for the same rooms
Questions and answers
What size sauna does the SAWO Nimbus heat?
SAWO rates the sizes for these rooms: Nimbus NIM-90 283 ft³–494 ft³; Nimbus NIM-105 318 ft³–530 ft³; Nimbus NIM-120 353 ft³–636 ft³; Nimbus NIM-150 459 ft³–812 ft³; Nimbus NIM-180 600 ft³–1,024 ft³; Nimbus NIM-210 777 ft³–1,236 ft³; Nimbus NIM-240 918 ft³–1,483 ft³. Use your room's effective volume: add 1.2 m³ for every m² of glass, tile or stone, and multiply by 1.5 for solid log walls.
What fuse or breaker does the SAWO Nimbus need?
It depends on the size and your supply: Nimbus NIM-90: 3~ 400 V: 13 A, 1~ 230 V: 39.1 A; Nimbus NIM-105: 3~ 400 V: 15.2 A, 1~ 230 V: 45.7 A; Nimbus NIM-120: 3~ 400 V: 17.3 A, 1~ 230 V: 52.2 A; Nimbus NIM-150: 3~ 400 V: 21.7 A, 1~ 230 V: 65.2 A; Nimbus NIM-180: 3~ 400 V: 26 A, 1~ 230 V: 78.3 A; Nimbus NIM-210: 3~ 400 V: 30.3 A, 1~ 230 V: 91.3 A. A licensed electrician sizes the circuit from the heater's manual and local rules.
How long does the SAWO Nimbus take to heat up?
In a well-insulated indoor room at the middle of each size's range, our heat model gives: Nimbus NIM-90 30–40 min; Nimbus NIM-105 25–35 min; Nimbus NIM-120 25–30 min; Nimbus NIM-150 25–35 min; Nimbus NIM-180 25–35 min; Nimbus NIM-210 25–35 min to reach 176 °F. Outdoor saunas, glass and cold weather take longer.
How many stones does the SAWO Nimbus take?
As stated by SAWO: Nimbus NIM-90 110 lb; Nimbus NIM-105 110 lb; Nimbus NIM-120 110 lb; Nimbus NIM-150 165 lb; Nimbus NIM-180 165 lb; Nimbus NIM-210 220 lb; Nimbus NIM-240 220 lb. Use the stone size the manual specifies and re-stack the stones at least once a year, replacing crumbled ones.