General principle of operation
In a fresh water station, the hot water is only heated when it is actually required. The energy comes from a buffer storage tank that can be previously fed from a range of different heat generation systems. It makes no difference whether the energy in the buffer storage tank comes from a regenerative energy source such as a solar system / solid fuel boiler or a fossil fuel energy source such as an oil / gas boiler.
A heat exchanger transfers heat energy from the buffer storage tank primary circuit to the drinking water secondary circuit only when hot water is actually required. The cold, fresh drinking water flows through the secondary circuit of the heat exchanger and is directly heated to the desired temperature as it flows.
The task of the electronic controller is to control the flow through the primary side buffer storage tank discharge pump as quickly and efficiently as possible. This also has the aim of achieving the lowest possible return flow temperature to the buffer storage tank in order to further increase the efficiency and yields of the solar system.
This is supported by a zone feeding function in the buffer storage tank circuit return line, which is implemented using a 3-way switching valve. On the other hand, the users should experience the maximum possible convenience and be provided with a constant hot water temperature in addition to a perfectly hygienic supply of drinking water.
Temperature changes caused by fluctuations in the consumer flow rates are quickly and automatically controlled via special control algorithms in the fresh water controller.
Cascading fresh water stations
Cascading is the connection of a number of fresh water stations to each other in order to provide a larger common water supply.
The fresh water stations can be interconnected in a variety of different ways. Parallel connection of the individual stations is especially effective. Motorised ball valves are used for interconnection.
Cascading fresh water stations is a good way of using existing standardised, low-cost fresh water stations designed for single and two-family homes to provide the larger draw-off capacities needed for apartment complexes and multi-story residential buildings.
This allows small draw-off volumes to be implemented for large buildings at very good heat transfer ratios because not all of the stations need to be operated at the same time. The reliability of the hot water supply is increased by this because the cascading makes several stations available at the same time.