Tunnel model sauna stoves are wood-burning stoves that are heated up from another room. This is a very traditional way to heat up the sauna, so that it stays clean and sauna bath is not interrupted. Many smoke saunas are planned this way, so that the person don’t need to enter the smokey sauna room. Tunnel model sauna stoves keep the sauna clean, and if the person firing up the sauna is not bathing, he or she will not be disturbing the bathing people with adding logs or checking the fire.
The sauna stove itself will be inside the sauna room, just like any stove. The firing will however happen from the outside, and the logs are put inside. It is important to push the logs long enough, so that they will heat up the sauna stove and not just the tunnel section. A hole needs to be cut to the wall, so that the tunnel section (safety distances included) will fit.
It is worth noticing, that the room where the door of the tunnel model sauna stove is, needs good ventilation. Oxygen can be delivered mechanically or naturally to the room. More info about sauna room ventilation can be found here (Saunologia).
The tunnel length is designed to fit a traditional brick wall. The tunnel section depth varies between models, and you should always check the depth in forehand. The tunnel opening must be of non-combustible material. Insulation wool can also be used. The insulation wool or or other installation material is not included along with the tunnel model sauna stove.