Fresh water station - Drinking water station
The fresh water station is used for domestic hot water heating in connection with a buffer tank. This control regulates the set tapping temperature (e.g. 46°) independently of the buffer storage temperature, which can be up to 95°C. The temperature of the buffer storage tank can also be adjusted.
A circulation pump can be controlled by the electronic control (according to pulse, time and temperature).
Hot water preparation:
The drinking water is only heated in the flow-through principle via a stainless steel plate heat exchanger when it is needed, e.g. when you let it run out of the tap. The electronic control ensures a constant hot water temperature, regardless of the buffer temperature, the quantities withdrawn or the tapping intervals.
- Fast and very accurate control processes are made possible by the use of state-of-the-art sensors.
- A flow sensor based on the vortex principle determines the flow rate.
- Accurate and fast reacting temperature sensors detect the temperatures of: Hot water, cold water and buffer flow.
The recorded signals are processed by the control system and the circulation pump is controlled accordingly (speed control).
Advantages of heating the water with this method:
- Only as much water as is needed is heated. The remaining solar energy from the buffer tank is used to support the heating system.
- In this system, no Legionella can form in the water, as no warm water is heated up for storage.
- With the fresh water station a very good temperature stratification is achieved, as the warmest water is taken from the highest point in the buffer tank - see picture below. The fresh water station takes e.g. 65° C warm water, the tap temperature is set to 46°. No matter how different the tapping capacities (= quantity of water taken e.g. via tap) are, e.g. 10l, 20l, 30l and 40l, the control regulates that the tapping temperature remains constant at approx. 46° C. The tapping temperature is controlled by the control unit. The return temperature to the buffer tank is approx. 18-20° C with a cold water inlet of approx. 10°, whereby a very good stratification is achieved.
- Compared to a combination cylinder, up to 30% less energy is required for hot water preparation if no solar energy is available.
- When solar energy is available, the storage tank can be heated up to 95°C without it calcifying quickly, as with a combination storage tank, because dead water remains in the storage tank. This means that 30 % more solar energy can also be absorbed here.