a heat storage stove has a large heat (stone) capacity and can take much longer to heat. Heat storage-type Smoke sauna Smoke sauna (Finnish savusauna, Estonian suitsusaun, Võro savvusann) is one of the earliest forms of the sauna. It is simply a room containing a pile of rocks, but without a chimney. A fire is lit directly under the rocks and after a while the fire is extinguished. The heat retained in the rocks, and the earlier fire, becomes the main source for heating the sauna. Following this process, the ashes and embers are removed from the hearth, the benches and floor are cleaned, and the room is allowed to air out and freshen for a period of time. The smoke deposits a layer of soot on every surface, so if the benches and back-rests can be removed while the fire is alight the amount of cleaning necessary is reduced. Depending on size of the stove and the airing time, the temperature may be low, about , while the humidity is relatively high. The tradition almost died out in Finland, but was revived by enthusiasts in the 1980s. These are still used in present-day Finland by some enthusiasts, but usually only on special occasions such as Christmas, New Year's, Easter, and juhannus (Midsummer). Smoke saunas are popular in the southern Estonia and smoke sauna tradition in Võrumaa was added into UNESCO Intangible Cultural Heritage Lists in 2014. Heat storage-sauna The smoke-sauna stove is also used with a sealed stone compartment and chimney (a heat storage-stove) which eliminates the smoke odour and eye irritation of the smoke sauna. A heat storage stove does not give up much heat in the sauna before bathing since the stone compartment has an insulated lid. When the sauna bath is started and the löyly shutter opened a soft warmth flow into the otherwise relatively cold () sauna. This heat is soft and clean because, thanks to combustion, the stove stones glow red, even white-hot, and are freed of dust at the same time. When bathing the heat-storage sauna will become as hot as a continuous fire-type sauna () but more humid. The stones are usually durable heatproof and heat-retaining peridotite. The upper part of the stove is often insulated with rock wool and firebricks. Heat-storing stoves are also found with electric heating, with similar service but no need to maintain a fire. Continuous heat-type Continuous