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Sizing a sauna heater

Sizing a Sauna Heater

 

As a general rule of thumb, a sauna heater needs 1 Kw to heat 50 cubic foot of room space.  This is a general rule and an outdoor sauna or a sauna built on outside walls may need to have the heater oversized. As an example a 6'x7'x7' sauna room should require a 5 Kw heater.  (252 cubic feet divide by 50 = 5.04).

Because a sauna is heating air, you will find most sauna minimize the ceiling height.  A 6-7' ceiling is almost always standard.  Never build a sauna in an 8 foot room as a good portion of the heat will be up in the ceiling where it is not used.

Electric Sauna heaters turn off once the desired room temperature is met.  This means that a larger heater simply works less than a smaller heater so there is virtually no energy savings by purchasing an under sized sauna heater.  If in doubt always go up a size.

 Heater Sizing Chart

SIZE (Watts)

VOLTS

PHASE

AMPS

FUSING

WIRE

MIN
(Cubic

MAX
Feet)

4000

240

1

16.7

30

10

100

150

5000

240

1

20.8

30

10

150

250

6000

240

1

25

40

8

200

300

6000

208

3

16.6

30

10

200

300

7500

240

1

31.3

40

8

290

375

7500

208

3

20.9

30

10

290

375

9000

240

1

37.5

50

8

360

450

9000

208

3

25

40

8

360

450

12000

240

1

50

60

6

450

650

12000

208

3

33.4

50

8

450

650

15000

240

1

62.5

80

4

600

800

15000

208

3

41.7

60

6

600

800

18000

208

3

50.3

60

6

800

1000

Standard residential voltage for North America is 240 volts, single (1) phase.