To provide an apparatus for promoting ineffective sweating includes an air heating unit for heating air in a sweating room, a mist generator for generating mist, a blower for circulating air in the sweating room by supplying mist, and a control device. The sweating room is provided with a temperature sensor and a humidity sensor for measuring temperature and relative humidity respectively in the sweating room. The control device is provided with a dew-point temperature determination unit for determining a dew-point temperature td in the sweating room based on the temperature and the relative humidity and a temperature setting unit for setting a body temperature of a user, and controls the air heating unit and the mist generator so that the dew-point temperature td is kept higher than the body temperature. This configuration can promote comfortable ineffective sweating with the low physical burden on the user.

An arrangement for storing energy, the arrangement comprising a heat-charging mass (4) and a heat-transfer channeling (3), the arrangement also comprising a heating member (11) adapted to heat up the heat-charging mass (4). The arrangement comprises a boiler belonging to a discarded combustion power plant and converted to a thermal energy storage (2) by at least partly filling the boiler with the heat-charging mass (4).

An arrangement for storing energy, the arrangement comprising a heat-charging mass (4) and a heat-transfer channeling (3), the arrangement also comprising a heating member (11) adapted to heat up the heat-charging mass (4). The arrangement comprises a boiler belonging to a discarded combustion power plant and converted to a thermal energy storage (2) by at least partly filling the boiler with the heat-charging mass (4).

A method for operating a steam generator comprising a combustion chamber having a plurality of evaporator heating surfaces which are connected in parallel on the flow medium side is provided. An object is to provide a steam generator which has a particularly long service life and which is particularly reliable. For this purpose, a flow medium is introduced into an inlet of a first evaporator heating surface at a temperature which is lower than the temperature of the flow medium introduced into the inlet of a second evaporator heating surface.

A method for operating a steam generator comprising a combustion chamber having a plurality of evaporator heating surfaces which are connected in parallel on the flow medium side is provided. An object is to provide a steam generator which has a particularly long service life and which is particularly reliable. For this purpose, a flow medium is introduced into an inlet of a first evaporator heating surface at a temperature which is lower than the temperature of the flow medium introduced into the inlet of a second evaporator heating surface.