Buffer storage tanks by ratiotherm Optimised heat generation

Buffer storage tank for heating water & solar systems

Perfect for caching unused energy

Buffer storage tanks by the manufacturer ratiotherm serve as caches for currently unused energy from different heat sources such as boilers, heat pumps, cogeneration units, solar plants or other renewable sources.

Today, these domestic hot water buffers are integrated almost as a standard feature in every heater; they boost the efficiency of older systems as well. Because by compensating for temperature fluctuations between production and consumption, they ensure that the heating system does not have to reactivate immediately with every heat request.

This avoids the constant, particularly consumption-intensive On and Off, with clear improvement in the heater’s exhaust gas values, efficiency and service life.

The storage systems are mainly used for temporary storage of energy in the areas of solar systems, water heaters, shower water and drinking water.

Your advantages

Modern heat storage tanks for use in buffering by the manufacturer have several connections, so that they can be operated in parallel with solid fuel boilers, heat pumps, solar systems or other sources of heat supply. Various factors need to be taken into account when choosing the size of the storage tank: the number of house residents and their personal needs as well as the overall energy concept of a building. As a rule, a stratified storage tank has a size of 750 to 1000 litres, depending on the requirements of the heating system. However, it should be noted that heating and drinking water must not be mixed. That is why, with particularly efficient heat accumulators, a fresh-water station is a must, and not just for hygienic reasons. This prevents the very occurrence of the danger that e.g. bacteria such as Legionella can develop as might occur with a combinationtank-in-tank’ in which warm drinking water is standing and not moving.

Buffer storage tank for solar systems

Efficient buffer storage tanks for solar systems with solar collectors are optimally suited to be able to use energy generated on sunny days, even in the evening and at night or in longer periods of cloudy weather. In addition to the combination storage tank, there are other common types. The fresh water bufferworks in much the same way a continuous-flow heater. Here the drinking water moves in pipes through the hot heating water and is heated only on call. However, the storage tank for solar systems may be mixed considerably. The most modern, intelligent and efficient variant is the stratified storage tank, which works based on the natural principle of stratification of cold and warm water. Here, too, flowing drinking water is freshly heated on demand, eliminating fears of bacteria formation. For a perfect match of the individual components, it is advisable to purchase a system with solar power and a storage tank, preferably with the entire, hence coordinated, heating system from a single manufacturer.

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What is a buffer storage tank? 

These storage tanks involve the temporary storage of heating water in heating systems. The purpose of these storage tanks is to create a balance between the heat produced and already consumed. They can thus be used in addition to heat sources such as heat pumps as a way of generating a greater energy efficiency. Specialised companies produce systems of this type for use in efficient heating systems. The heat buffers are used in solar thermal systems, for instance.

Which functional principle is the basis for a storage tank, and why is it so important to the energy efficiency of a heating system?

With the aid of a stratified storage tank, heat not needed at the moment in a heat generator, such as a central heating system, is temporarily stored and returned to the heating system on demand. For this purpose, water contained in the stratified storage tank is heated during heating operation and is available later on, as needed, for heat loads such as radiators or underfloor heating. This achieves much more efficient operation of the heating system, as the consumption-intensive ‘Stop & Go’ is eliminated. This is also associated with a lower maintenance cost and an increased service life of the heating system. This is why buffer storage tanksare often used and deployed in the field of solar systems.

What are the advantages over conventional storage methods of the stratified storage technology ratiotherm offers, e.g. with the OSKAR° stratified storage tank?

A stratified storage tank works based on the physical principle that water naturally arranges itself in temperature layers. Since warm water is lighter than cold water, it rises. However, conventional storage tanks destroy this temperature stratification as soon as water is added to the tank, creating movement. Turbulence of water in the buffer causes the heating system to lose (PDF) energy efficiency. In the case of the OSKAR° stratified storage tank, there is a special layer insert that serves to calm the water moved by the pump. This way, it can be stored and removed without mixing. Using the various thermal layers created, the house is supplied with domestic hot water as needed. The heating system generates heat continuously and efficiently during the day. This can save energy costs of up to 15%. If additional measures for improved energy supply are implemented, for example in the form of a solar thermal system, savings of up to 40-50% are possible. This should always be considered when choosing a suitable specialised company.

Buffer storage tank of 500l, 1000l or 2000l – How much space is required for a storage tank, and how elaborate is the installation?

In general, a buffer storage tank with a capacity of 750 to 1000 litres is sufficient for an average single-family house around 140 square metres in size. The required space, accessories included, is approx. 8-10 m2. But storage tanks with volumes of 500 litres or even 2000 litres are possible as well. Ideally, the storage tank can be transported with a sack truck. With little effort, the storage tank can be placed directly alongside the boiler. Both installation and initial commissioning should be carried out by a specialist, however.

For which heating systems is the storage tank by ratiotherm particularly well-suited?

Storage tanks are often used in central heating systems that are fired using solid fuel such as logs or pellets. They achieve their best efficiency under full load, but can hardly be regulated to lower heating power without sacrificing efficiency. Once the fuel has been completely combusted, the buffer storage tank supplies the heating system in an energy-saving manner. In terms of performance, the central heating system delivers sufficient energy, even during high demand for domestic hot water. However, since demand is usually much lower than output, interval operation is required, particularly during the autumn and spring months. In this case, the storage tank absorbs the heat of a heat generator releases this again later on as needed. It also makes complete sense to use a storage tank with other systems, however, such as oil, gas or a heat pump, because this definitely contributes to improved energy efficiency in the respective heating system.