Skip to content

HUUM

HUUM Core sauna heater

HUUM makes the Core in 3 sizes, from 6.5 to 10.5 kW, for saunas of 177 ft³ to 565 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 17, 2026

Output

6.5–10.5 kW

Rooms

177 ft³–565 ft³

Stones

88 lb

Sizes

3

Which size fits your sauna?

Your room's effective volume

371 ft³

106 ft³ – 671 ft³

Effective 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

ModelOutputRoom rangeStonesHeat-upPer session
CORE 66.5 kW177 ft³–318 ft³88 lb30–40 min$1.10
CORE 99 kW283 ft³–459 ft³88 lb25–35 min$1.44
CORE 1110.5 kW353 ft³–565 ft³88 lb25–35 min$1.63

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

ModelSupplyCurrentFuse / breakerCable
CORE 61~ 240 V27.1 A30 A10 AWG
CORE 91~ 240 V37.5 A50 A8 AWG
CORE 111~ 240 V43.8 A50 A8 AWG

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

Other heaters for the same rooms

Questions and answers

What size sauna does the HUUM Core heat?

HUUM rates the sizes for these rooms: CORE 6 177 ft³–318 ft³; CORE 9 283 ft³–459 ft³; CORE 11 353 ft³–565 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 HUUM Core need?

It depends on the size and your supply: CORE 6: 1~ 240 V: 27.1 A (30 A); CORE 9: 1~ 240 V: 37.5 A (50 A); CORE 11: 1~ 240 V: 43.8 A (50 A). A licensed electrician sizes the circuit from the heater's manual and local rules.

How long does the HUUM Core take to heat up?

In a well-insulated indoor room at the middle of each size's range, our heat model gives: CORE 6 30–40 min; CORE 9 25–35 min; CORE 11 25–35 min to reach 176 °F. Outdoor saunas, glass and cold weather take longer.

How many stones does the HUUM Core take?

As stated by HUUM: CORE 6 88 lb; CORE 9 88 lb; CORE 11 88 lb. Use the stone size the manual specifies and re-stack the stones at least once a year, replacing crumbled ones.