The wood stove and rocks that characterize traditional Finnish saunas are still around, and lots of people refuse to give up the rustic sauna experience. Wood burning is only one way to heat a sauna, though, and the more-modern methods are the ones in widest use today.
Besides the wood stove, your primary choices are:
- Electric -- Kind of like a very heavy-duty space heater, this is one of the cheaper options. Extra safety measures may be required due to the presence of electricity and water in the environment.
- Gas -- The type of approach used in natural-gas home heating and another wallet-friendly option. Fluctuating gas prices can affect costs in the long run.
- Infrared -- A whole new way to sauna, infrared light waves target the bodies in the room, heating them directly instead of heating the air. A more expensive way to go.
There's no right choice here. Heat source is a matter of preference and logistics. Be aware, though, that a gas heater requires a gas line running to the sauna, and if that means installing one from scratch, you're looking at a significant increase in cost.
Finally, don't overlook the importance of the controls.