A heater is a device for heating up sauna, which works by continuous heating up the stones and the sauna. The stone chamber of the heater is open.
A stove is a ancient type of device for heating up sauna, which works by preheating the stones and storing the heat into the large amount of stones. A stove is enclosed, has a lid that is opened for the löyly throwing and bathing.
1. Electric heater, wall-mounted
The sauna thermostat is in the lower part of the heater and it does not measure the sauna temperature. This thermostat cuts off the heating elements, when there is enough heat, and turns them on when the temperature falls.
The regulation of the temperature is allusive: when turning the switch, the sauna will be hotter or cooler depending on the direction of the turn.
There are always certain limits for the volume of the sauna and within these limits, the temperature at height of the heater, is proportional to the temperature at the height of the bathers shoulders.
2. Electric heater, floor mounted, basic version
The sauna thermostat is mounted on the wall, about 30 cm below the ceiling. The thermostat cuts off the heating elements when there is enough heat in the sauna, and turns them on when the temperature falls.
3. Electric heater, floor mounted, two-phase heating control
With the basic versions explained above, a problem appears when the sauna is empty for longer periods. The sauna, the walls and the ceiling get hot and the heating elements are on only short periods. In this case, the stones of the heater get colder and loose their ability to give löyly.
The problem is more severe when there are long quiet periods followed by a crowd of the bathers. This can be avoided by raising the sauna temperature or increasing the ventilation to get the excess heat out and force the heating elements on.
Both of these methods waste energy, and the problem has been addressed by dividing the heating elements into two groups, one of which is on all the time, and the other turns on when the sauna thermostat asks for more heat. This lessens the problem but does not eliminate it, because the heating elements that are always on, can overheat the sauna.
4. Electric heater, floor mounted, with separate heating controls for the stones and the sauna
In addition to dividing the heating elements into two groups as described above, there are also separate thermostats for the stones and for the sauna. The sauna thermostat controls the heating elements in the air channel, whereas the stone thermostat controls the heating elements among the stones.
This gives a better control over the sauna and the stones than the former alternatives, but does not solve the problem caused by long empty periods followed by a crowd of the bathers.
5. Electric stove, type always on
This stove is carefully insulated all around, and it has a lid. When the lid is closed, the temperature of the stones is controlled by the stone thermostat. When the lid is open, the heating elements are controlled by the sauna thermostat.
Because of the low effect and the minimal thermal radiation in the sauna, the temperature in the sauna stays quite mild or moderate. The sauna is warm as long as the lid is open and there is not much regulation for the sauna thermostat.
6. Electric stove, type Magic Stove
This stove is insulated all around and there is a lid on the stove. When the lid is closed the temperature of the stones is controlled by the stone thermostat. There is a fan inside the stove. The fan circulates the air inside the stove, when the heating elements are on. This allows unlimited heating effect as the fan spreads the heat inside the stone chamber.
When the lid is opened, the fan circulates the air in the sauna through the stove to achieve the desired warmth in a minute or
two. The sauna thermostat controls the fan and the stone thermostat continues to control the heating elements. With the fan,
and the absence of thermal radiation, the temperature in the sauna can be controlled by the bathers to their liking.