Electric sauna heaters for outdoor saunas: size, power supply and app control
The heater decides how a sauna feels. For a modern outdoor sauna with large glass areas, an electric heater with app control gives even heat, no firewood or chimney, and a sauna that is warm when you arrive. This guide explains what to check.
1. Why electric for an outdoor sauna
A wood-fired stove has its charm, but it needs a chimney, fire-safety distances, firewood and someone to tend it. An electric heater is controlled to the degree, needs no flue and can be started remotely.
- Even, controllable temperature and humidity (löyly).
- No chimney, smoke or ash – simpler approval and maintenance.
- Remote start by app, so the sauna is ready when you are.
- Suits both private gardens and hospitality, where guests expect a ready sauna.
2. Sizing: room volume plus glass
Heater makers publish a room-volume range for every heater. Start with the sauna room volume: floor area × ceiling height. Glass, stone and other uninsulated surfaces lose heat faster than insulated walls, so a common rule is to add about 1.2 m³ to the calculation for every square metre of glass.
This is why a compact sauna with a panoramic glass front can need a heater rated for a room almost twice its actual volume. An undersized heater takes long to heat up and never reaches a comfortable temperature on cold days.
- Measure floor area and ceiling height of the sauna room.
- Add about 1.2 m³ per m² of glass or uninsulated wall.
- Choose a heater whose published range covers the result – not the bottom of it.
3. Power supply
Small heaters can run on a single-phase supply, but the heaters needed for glazed outdoor saunas are usually connected to a three-phase supply. The heater output decides cable size, fuse and residual-current protection, so plan the cable route from the house early.
The connection must be made by a qualified electrician according to national rules for rooms containing sauna heaters. In Norway, many homes have a 230 V IT network; check that the heater and control are approved for it.
4. App control and safe remote start
A Wi-Fi control lets you start the sauna from your phone, set the temperature and switch off from anywhere. Because nobody is in the room at start-up, the safety standard for sauna heaters (EN 60335-2-53) requires extra protection for remote operation.
In practice this means a door sensor and a control that confirms the sauna is ready to start, together with an overheat cut-out and an automatic switch-off time. Never hang towels or clothes on or near the heater.
5. Heat-up time and use all year
A correctly sized heater in a well-insulated outdoor sauna usually heats up in 30 to 60 minutes, depending on outdoor temperature and glass area. Insulated walls and roof, insulated glazing and a ventilated construction keep heat in and moisture out, so the sauna can be used in winter too.
6. How AUREFJORD does it
Every AUREFJORD sauna is specified with an electric heater and app / Wi-Fi control. Heater output, cable and fuse are matched to each model’s room volume and glass area, and listed in the written quotation, so your electrician knows exactly what to prepare.
Choosing a model?
Tell us about your site and power supply, and we will propose a model and heater.