HPH Hygienic – Hygienic Buffer Tanks with Instantaneous Domestic Hot Water Preparation

HPH Hygienic is a series of buffer tanks designed to work with heating systems in which domestic hot water (DHW) is prepared in instantaneous flow-through mode. Thermal energy stored in the heating system is transferred to domestic hot water through an integrated, large-surface-area heat exchanger.

Instantaneous DHW preparation means that domestic water is heated when it is drawn, rather than being stored as hot water inside the tank. This solution reduces energy losses associated with hot water storage and can also be used in low-temperature heating systems, including systems equipped with heat pumps.

Hygienic Domestic Hot Water Preparation

One of the key design elements of the HPH Hygienic tanks is the heat exchanger used for instantaneous DHW preparation. It is made of corrugated AISI 316L stainless steel tubing, which provides corrosion resistance and properties suitable for applications involving domestic hot water.

The instantaneous method of DHW preparation reduces the need to store large quantities of domestic hot water. According to the product documentation, this solution reduces the risk of bacterial growth, including Legionella, without the need to use elevated temperatures solely for periodic disinfection of stored water.

Domestic water flows through the stainless steel heat exchanger and is heated using the thermal energy stored in the buffer tank. This combines thermal energy storage on the heating-system side with instantaneous DHW preparation.

How the HPH Hygienic Buffer Tank Works

The HPH Hygienic tank stores thermal energy on the heating-system side. When domestic hot water is drawn, cold water flows through the integrated heat exchanger, where it is heated using the energy stored in the buffer tank.

This solution separates the heating-system circuit from the domestic hot water circuit. The tank can also serve as a component for separating glycol–water circuits and can enable the connection of two heat sources operating at different working pressures.

Applications in Heating Systems

HPH Hygienic buffer tanks can be used in systems where thermal energy storage needs to be combined with instantaneous domestic hot water preparation.

The solution can be used, among others, in:

• residential buildings,
• multi-family buildings,
• public buildings,
• commercial facilities,
• installations equipped with heat pumps,
• systems using low-temperature heat sources,
• installations requiring glycol–water circuit separation.

Compatibility with Low-Temperature Heat Sources

The design of the HPH Hygienic tanks allows them to be used in systems employing low-temperature heat sources. The documentation specifically indicates heat pumps as an example.

Thermal energy supplied by the heat source can be stored in the buffer tank and subsequently used to prepare domestic hot water through the instantaneous heat exchanger.

Circuit Separation and Connection of Heat Sources

HPH Hygienic tanks can serve as components for separating heating-system circuits, including glycol–water systems.

The design also allows the tank to be used as a component connecting two heat sources operating at different working pressures. The operating parameters of the heat exchangers and tank are provided in the technical data table below.

Construction and Operation

The use of an AISI 316L stainless steel heat exchanger together with instantaneous DHW preparation provides an alternative solution to conventional enamelled water heaters.

According to the information provided in the source material, the tanks do not require annual maintenance or replacement of a magnesium anode. This reduces the scope of routine maintenance activities associated with the operation of the tank.

Key Features of HPH Hygienic Tanks

• Instantaneous DHW preparation – domestic hot water is heated during draw-off.
• AISI 316L stainless steel heat exchanger – a material offering corrosion resistance and properties suitable for domestic hot water applications.
• Reduced risk of Legionella growth – instantaneous DHW preparation reduces the need to store domestic hot water.
• Compatibility with heat pumps – suitable for systems using low-temperature heat sources.
• Circuit separation – can be used in glycol–water systems.
• Connection of different heat sources – the tank can serve as a component connecting heat sources operating at different working pressures.
• Reduced maintenance requirements – no annual magnesium anode replacement is required according to the product description.

DHW Heat Exchanger

Depending on the model, the surface area of the coil used for DHW preparation ranges from 3.5 to 8 m². The DHW coil volume ranges from 11 to 30.7 litres.

The DHW heat exchanger is made of corrugated AISI 316L stainless steel tubing. Depending on the model, its surface area and volume are matched to the nominal tank capacity.

Lower Heat Exchanger

The tanks are also equipped with a lower heat exchanger. Depending on the model, its surface area ranges from 1.2 to 4.7 m², while its volume ranges from 7.4 to 42 litres.

The operating pressure of the lower heat exchanger is 1 MPa for models 200–500 and 0.8 MPa for models 800–2000.

Connections and Installation Options

The HPH Hygienic series is equipped with a number of connections for connecting the individual circuits of the installation. Depending on the model, different nominal connection sizes and different connection heights are used.

The tanks include connections for the heat exchangers, DHW connections, an air vent connection, a drain connection, connections for an electric heating element and a temperature sensor sleeve.

Available Capacities

The HPH Hygienic series includes eight capacity variants: 200, 300, 400, 500, 800, 1000, 1500 and 2000 litres. This range allows the tank size to be selected according to the requirements of the particular heating system.

Technical Data – HPH Hygienic

Summary

HPH Hygienic is a series of buffer tanks combining thermal energy storage with instantaneous domestic hot water preparation. The use of an AISI 316L stainless steel heat exchanger, a wide capacity range from 200 to 2000 litres and the possibility of using the tank for circuit separation allow the solution to be used in various heating-system configurations.

The series includes models with different dimensions, heat exchanger surface areas, capacities and operating parameters. Detailed values for individual variants are provided in the technical data table above.

Does the HPH Hygienic tank require regular replacement of the magnesium anode?

No. According to the product description, HPH Hygienic tanks do not require annual maintenance or replacement of a magnesium anode. The use of instantaneous domestic hot water preparation and an AISI 316L stainless steel heat exchanger reduces the scope of routine maintenance associated with tank operation.