Traditional saunas have been heated by burning wood. But modern sauna heaters use also other heat sources for convenience and other purposes. They come from electricity, gas (standard gas lines or Propane tanks) and infrared usage. Traditional wood burning saunas have a layer of rocks on top of a burner, which reserves heat and produces stream, when water is poured over rocks. Similar effect is achieved with electric and gas sauna heaters’ top layer of rocks. Outside they look similar to wood burning heaters, but in electric heaters all electric parts are well sealed from water contact. Both gas and electric heaters are easier to use than wood burning ones, because they need no fire, nor supply of wood or fire upkeep only turning on a knob or a button. And still they have rocks to produce steam and atmosphere similar to traditional saunas. While electric and gas heaters use rocks, Infrared heaters are different, no rocks, no pouring of water. They cannot produce any steam. But for humidity specific steam generators could be used. These heaters are often used to create dry and hot saunas whereas other sauna heaters may be used for humid saunas. Generally humidity decreases human tolerance to heat and therefore less humid saunas can to be hotter than more humid ones. Because burning wood requires fire supervision and involves a risk, all other kinds of sauna heaters have become common. Where and how a sauna is used requires consideration of heating system. For example health spa sauna heater type depends on sauna usage and user preferences.
