Heading water memory | Hot water tank

In modern buildings, these storage systems are used not only for comfort and availability, but also for energy saving and system integration. Buffer storage allows the performance of boilers, heat pumps and solar systems to be used better, load peaks can be balanced out and running times can be optimized. The correct dimensioning and design are crucial for cost-effectiveness and operational safety.

Terms and differences: service water vs. drinking water vs. hot water

The terms are often used synonymously, but are defined differently: Drinking water storage tanks are specifically designed for the storage of hygienically perfect water and must comply with strict regulations and materials that do not allow contamination. Domestic water storage tanks can also be used for applications that are not relevant to drinking water, such as heating support, garden irrigation or industrial processes. Hot water tanks generally describe the function of keeping water at the same temperature, regardless of its drinking quality.

When making the selection, it is important to clearly define the respective use, as this influences the choice of material, internal coating, material compatibility and compliance with legal requirements. In drinking water applications, anti-legionella measures, version designs with an internal coating and easy-to-clean connection points are also very important.

Types and designs of storage tanks

Storage tanks are available in monovalent and bivalent versions, as stratified charging tanks, hot water tanks with external plate exchangers or as combination tanks with integrated drinking water heating. Buffer storage for heating systems primarily serve to store thermal energy, while fresh water stations hygienically heat the drinking water using the continuous flow principle. Available volumes range from small 10-50 liter drinking water storage tanks for individual tapping points to several thousand liters in industry and commerce.

Special designs such as stainless steel tanks, enamelled steel storage tanks or plastic-lined tanks offer different advantages in terms of corrosion protection, thermal efficiency and economical manufacturing costs. Stratified charge storage tanks enable better use of different heat sources through hydraulic stratification by separating warm and cold layers and thus increasing usability.

Materials and corrosion protection

Choice of material is crucial for service life and hygiene. Stainless steel is considered particularly durable and corrosion-resistant, ideal for drinking water applications because it does not require additional protective coatings and is easy to clean. Enameled steel tanks are more cost-effective and offer good corrosion protection thanks to their glaze, but require careful processing and quality monitoring to ensure that no damage occurs.

Plastic tanks are light and corrosion-free, but are generally less resistant to temperature and pressure and may be more sensitive to chemical influences. Internal coatings and sacrificial anodes are protective measures integrated into many metal tanks, whose regular inspection is part of maintaining value and preventing material damage.

Insulation and heat losses

The quality of the thermal insulation has a significant influence on energy consumption. Well-insulated storage tanks reduce standing losses and keep the temperature stable over a longer period of time, which is particularly advantageous for irregular use and when combined with intermittent heat generators. Common insulation materials are PU foam, mineral wool or foamed plastics, which have different insulation values, environmental aspects and costs.

When planning, in addition to the insulation thickness, the operating condition should also be taken into account: frequent withdrawals require insulation solutions other than storage, which primarily work as a buffer. In addition, the shape and surface of the tank influences the insulation effect; Cylindrical containers are often cheaper in terms of construction because they have less surface area to volume ratio.

Sizing and volume calculation

The correct size of a storage tank results from the consumption profile, the number of tapping points, peak demand and the type of heat supply. A storage tank that is too small leads to a loss of comfort and frequent reheating; a storage tank that is too large causes unnecessary investment costs and can lead to problems with temperature stratification and legionella growth if the temperature is not kept sufficiently high.

For private households, there are rules of thumb for calculating volume that must be adapted individually: Example values ​​are based on the number of people and average daily consumption. For more complex systems, such as those with solar connections or heat pumps, calculations by specialist planners are recommended in order to optimally coordinate stratified charging capacities, heat losses and return temperatures.

Connection, installation and installation location

A professional connection is crucial for operational safety and hygiene. Important aspects are sufficient inlets and outlets, secure fastening, placement of thermostats and anodes, and the consideration of inspection openings. The installation location should be frost-free, easily accessible and chosen so that both short cable routes and installation are possible.

During installation, assembly and safety regulations, such as pressure relief, safety valves and suitable piping materials, must be observed. Electrical connection components for storage heating elements must comply with applicable standards and be protected from moisture to avoid failures and dangers.

Integration with heating systems: solar, heat pump and boiler

Storage systems are central interfaces for combining different heat sources. In solar systems they serve as a buffer for the time-delayed use of solar heat; in heat pumps they compensate for load peaks and improve efficiency through lower switch-on and switch-off frequencies. Conventional boilers benefit from buffer storage in that they can run in economical operating ranges and peak loads are covered.

The correct hydraulic integration, stratified charging strategies and control are crucial for the system components to work together optimally. Especially in hybrid systems, the coordination of temperature zones, charging strategies and return temperatures is important in order to make the best possible use of the energy source and maximize the overall efficiency.

Hygiene, Legionella prevention and temperature management

Drinking water hygiene is a central issue in hot water storage. To prevent the growth of Legionella and other microorganisms, common measures are temperatures above 60 °C at certain points, regular thermal disinfection or the use of connection technology such as fresh water stations. Avoiding stagnant pipe sections and ensuring sufficient circulation are also important.

Modern control systems monitor temperature trends and can trigger automatic heating cycles if necessary. Combined systems must function in such a way that minimum hygienic requirements are met without wasting energy unnecessarily. Regular inspections by qualified personnel and the documentation of measures increase operational safety.

Maintenance, inspection and service life

Regular maintenance extends the service life and ensures functionality. This includes visual inspections, checking seals and connections, checking and, if necessary, replacing sacrificial anodes as well as cleaning contents and inspection openings. Many manufacturers specify maintenance intervals; In addition, aerial use or pipe cleaning may be necessary, especially with higher water hardness or in industrial applications.

The service life depends on material quality, water quality and maintenance intervals. High-quality stainless steel containers can last for decades, while cheaper coatings require more frequent inspection or renovation. Professional documentation of all maintenance measures supports warranty claims and creates transparency about the condition of the system.

Standards, regulations and approvals

Numerous national and European standards as well as health regulations that regulate materials, construction and verification apply to drinking water storage tanks. Products should be tested according to recognized standards and provided with appropriate certificates. Approvals and declarations of conformity help with selection and ensure legally compliant installation and operation.

For commercial or public institutions, there are often further requirements, for example with regard to documentation, regular inspections and certain technical devices for legionella prevention. Specialist planners and certified installation companies know the relevant specifications and can recommend the appropriate design.

Accessories, measurement and control technology

Accessories increase comfort, safety and efficiency: thermometers, thermostatic mixing valves, circulation pumps with time and temperature control as well as electronic controls are often part of the standard scope of delivery or can be retrofitted. Modern remote monitoring and smart controls enable the monitoring of temperatures, fill levels and energy flows, which is particularly economical for larger systems.

When selecting accessories, attention should be paid to compatibility with the storage and heating system. Measurement and control technology influences user-friendliness and operating costs: Intelligent controls reduce standstill losses, optimize charging cycles and can thus have a positive influence on the service life of the entire system.

Environmental aspects and recycling

The choice of materials and product lifespan have a direct influence on the environmental balance. Long-lasting and recyclable materials such as stainless steel conserve resources; Insulation materials should be as free as possible from environmentally harmful additives. When disposing of the components, it is important to separate them and return them correctly to the recycling cycle in order to preserve valuable materials and avoid pollutants.

The energy efficiency of the storage unit also contributes to the ecological assessment: lower heat losses mean less heating energy and therefore fewer CO2 emissions. When combined with renewable heat generators, an efficient storage share increases the share of renewable energy in total consumption and thus improves the climate footprint of a system.

Purchasing criteria and decision factors

Several criteria play a role when purchasing: the required volume, material and coating, thermal insulation, connection options, space requirements and the planned integration into existing systems. In addition, the service network, availability of spare parts and manufacturer guarantees are important decision points that determine long-term operational reliability and costs.

It is recommended to obtain an offer and technical data sheet, check for relevant certificates and, if necessary, seek advice from a specialist company. Individual requirements, such as frequent withdrawal profiles or combination with solar systems, should be taken into account when selecting in order to minimize later retrofits and operating costs.

Common problems and easy troubleshooting

Typical problems include inadequate temperature maintenance, dripping connections, unusual noises or discoloration in the water. Many faults can be located by checking the connections, checking pressure and safety valves and inspecting the electric heating elements. Regular inspection can detect minor defects early on and prevent major damage.

If there are hygiene problems, measuring the hot water temperature, checking the circulation and, if necessary, thermal disinfection are sensible first steps. More complex errors, such as anode wear or coating defects, should be repaired by qualified personnel in order to exclude consequential damage and hygienic risks.

Conclusion and recommendations for planning and purchasing

Selecting the right memory requires careful consideration of technical, hygienic and economic aspects. Planning, professional installation and regular maintenance are key to reliable, energy-efficient and hygienic operation. Anyone who knows the specific requirements of their application and coordinates them with a qualified provider or installer will usually make a sustainable and economical decision.

When making your selection, consider both short-term investment costs as well as long-term operating costs and environmental aspects. A well thought-out combination of material quality, insulation, control and accessories creates comfort, reduces energy costs and increases safety in drinking water and hot water preparation.