Stratified storage tank Oskar°
Stratified storage tank Oskar°

Stratified storage tank Oskar°

A good idea knows no limits

Heat storage is now regarded as one of the most important components of a heating system in connection with the energy revolution. ratiotherm addressed this issue more than 25 years ago and developed the Oskar° stratified storage tank with patented stratification technology. The biggest difference to a conventional buffer tank is that the natural stratification (warm water rises, cold water sinks) can be fully utilised by calming the water in the tank.

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Our proven products in this sector

The heating water driven by the pump displaces the standing water when it enters the inner chamber and pushes it into the stratification chamber. By increasing the volume of the chamber due to the patented, helical design, the speed is reduced on the way there. The water calmed in this way now drifts into the appropriate layer due to its temperature. There it exits through corresponding openings in the layer insert into the actual storage volume.


The Oskar° stratified storage tank can optimally organize various heat sources and heat consumers through the stratified storage of the water.

  • Oskar° is sorting

    Oskar° sorts the water according to different temperatures

    It makes use of one of the natural properties of water - without the need for complex and susceptible control technology. Because water automatically arranges itself in temperature layers, because warmer water is lighter than colder water and thus rises upwards. This temperature stratification is quickly destroyed, however, if uncontrolled inflowing water swirls the contents of the storage tank again and mixes the layers. This effect is prevented by the Oskar° stratified tank with its intelligent and patented stratification system, which does not impair the water that has already been pre-sorted according to temperature, i.e. the existing strata. In addition, the Oskar° stratified tank has no "disturbing factors" such as internal heat exchangers which, to put it simply, bring thermal unrest into the tank and destroy the stratification in the tank.

  • Oskar° is economical

    The economic use

    Where only warm water is needed, e.g. in underfloor or wall heating systems, it is sufficient to tap the layer with the warm water. So the solar system can be used even if it produces only 40° C hot water on cloudy days. Where particularly hot water is required, for example at the heat exchangers for hygienic drinking water heating, Oskar° simply taps into the top temperature layer. In this way, savings of up to 30% and more are possible without loss of comfort.

  • Oskar° is flexible

    Oskar° gets the most out of your heating system

    No matter whether you want to generate warm water for heating, bathing and cooking with a solar system, pellets, wood chips, oil, gas, heat pumps, combined heat and power plants or a combination of these energy sources. And regardless of whether you prefer conventional radiators with high flow temperatures or want to use underfloor or wall heating that operates at lower temperatures: Oskar° is always your perfect partner - whether new construction or renovation. And it will remain so in the future when new types of heat generators and heat consumers come onto the market.


    The Oskar° stratified storage tank is available not only for every requirement, but also with a wide variety of add-on modules and combinations tailored to it. For example, for hygienic DHW heating (hot water preparation), for the use of renewable energies or for energy-saving heat generation and distribution.

  • Oskar° fits anywhere

    On-site welding or individual adaptation

    Oskar° can be supplied for narrow stairwells and narrow doors less than 80 cm wide, in parts for on-site welding. Our specialists weld the storage tank in the boiler room and carry out a corresponding pressure test, as in the factory. The tank can then be fully assembled.


    Adjustments in height or diameter are also possible without problems - always an individual solution. Even the connections can be varied, whether at the side or at the rear.


    Thanks to this flexibility, Oskar° has already proven itself 1000 times over.