How Much Does It Cost to Run an Outdoor Sauna in Australia?

Running an outdoor sauna costs far less than most people expect. A typical two-hour session costs around $2.15 to $2.80 in the 2 person Sauna Lite and $3.20 to $4.20 in the 4, 6 and 8 person models at average Australian electricity rates. This guide explains where those figures come from and how to estimate the cost for your own home and routine.

Kilowatts and kilowatt-hours

A sauna heater is rated in kilowatts (kW). That number tells you how much power it draws while the elements are on. Your electricity bill charges for energy in kilowatt-hours (kWh). One kilowatt-hour is one kilowatt used for one hour. A 6kW heater running flat out for one hour uses 6kWh.

A simple worked example

To estimate the cost of a session, multiply the energy used by your electricity rate. Here is the arithmetic for one hour at full power.

• 6kW heater: 6kWh x $0.35 per kWh = $2.10
• 9kW heater: 9kWh x $0.35 per kWh = $3.15

The $0.35 rate is only an example. Check the usage rate on your own bill and use that figure instead.

Why a session usually costs less than the full rating

A sauna heater does not run at full power for the whole session. It works hardest while the room heats up. A Nova Sauna reaches 85°C in about 40 minutes. Once the room is hot the thermostat switches the elements on and off to hold the temperature. Thick walls lose heat more slowly, so the heater cycles less often. Every Nova Sauna uses 38mm thermally modified timber, which is 27% thicker than the 30mm panels many other saunas use.

What changes your running cost

• Heater size: the 2 person Sauna Lite uses a 6kW or 4.5kW heater. The 4, 6 and 8 person models use 9kW heaters.
• Session length: longer sessions and longer warm-ups use more energy.
• Target temperature: heating to 110°C takes about 60 minutes compared with about 40 minutes to 85°C.
• Your tariff: peak, off-peak and time-of-use rates can differ a lot.
• The weather: a sauna heats faster on a warm afternoon than on a cold winter night.

Solar power and timing

If your home has solar panels, running the sauna in daylight can use your own power instead of power from the grid. If you are on a time-of-use plan, a session in a cheaper period will cost less. A heater with a control panel and WiFi makes this easy because you can schedule the sauna to heat at the right time from your phone.

Estimate your own cost

1. Find your heater size in kW.
2. Find your usage rate per kWh on your electricity bill.
3. Multiply the two to get the cost of one hour at full power.
4. Multiply that by the length of your session in hours.
5. Remember that thermostat cycling brings the real cost of a session below that figure.
6. Multiply by the number of sessions you plan each week to estimate a weekly cost.

Your running cost checklist

• Know your heater size in kW
• Check your electricity usage rate
• Choose a well insulated sauna with thick walls
• Use solar or off-peak periods where you can
• Close the door while the sauna heats up