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HUUM

HUUM Drop sauna heater

HUUM makes the Drop in 4 sizes, from 4.5 to 9 kW, for saunas of 106 ft³ to 459 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

4.5–9 kW

Rooms

106 ft³–459 ft³

Stones

121 lb

Sizes

4

Which size fits your sauna?

Your room's effective volume

247 ft³

71 ft³ – 530 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
DROP 44.5 kW106 ft³–247 ft³121 lb65–85 min$1.26
DROP 66 kW177 ft³–318 ft³121 lb45–60 min$1.22
DROP 77.5 kW247 ft³–388 ft³121 lb40–50 min$1.43
DROP 99 kW283 ft³–459 ft³121 lb30–45 min$1.49

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
DROP 41~ 240 V18.8 A30 A10 AWG
DROP 61~ 240 V25 A30 A10 AWG
DROP 71~ 240 V31.3 A40 A8 AWG
DROP 91~ 240 V37.5 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 Drop heat?

HUUM rates the sizes for these rooms: DROP 4 106 ft³–247 ft³; DROP 6 177 ft³–318 ft³; DROP 7 247 ft³–388 ft³; DROP 9 283 ft³–459 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 Drop need?

It depends on the size and your supply: DROP 4: 1~ 240 V: 18.8 A (30 A); DROP 6: 1~ 240 V: 25 A (30 A); DROP 7: 1~ 240 V: 31.3 A (40 A); DROP 9: 1~ 240 V: 37.5 A (50 A). A licensed electrician sizes the circuit from the heater's manual and local rules.

How long does the HUUM Drop take to heat up?

In a well-insulated indoor room at the middle of each size's range, our heat model gives: DROP 4 65–85 min; DROP 6 45–60 min; DROP 7 40–50 min; DROP 9 30–45 min to reach 176 °F. Outdoor saunas, glass and cold weather take longer.

How many stones does the HUUM Drop take?

As stated by HUUM: DROP 4 121 lb; DROP 6 121 lb; DROP 7 121 lb; DROP 9 121 lb. Use the stone size the manual specifies and re-stack the stones at least once a year, replacing crumbled ones.