We have planned for a 300L buffer tank for a household of 4 people. Is a legionella control circuit recommended here, or will the water volume be replaced much faster anyway due to the high flow rate?
Hi Legionella are not a problem in the buffer tank, as it is heating water. You probably mean a drinking water tank. In a household with three or more, I don't see any problems. There was also something about a DVGW worksheet with 300 liters of drinking water. Olli
Exactly, I meant drinking water storage tank. I have already read quite a bit about legionella control and most people do not consider it 100% effective. Therefore, it is probably best to choose the size of the storage tank carefully so that the contents are renewed multiple times. What happens if the heat can no longer be dissipated because no water is being used? Does the system’s fluid then overheat?
Hello The collector area should correspond to the storage volume. About five m2 for 300 liters of drinking water. Stagnation in the solar system is then usually not a problem. If there is no heat extraction from the storage and the system comes to a standstill, the temperature of the solar fluid rises until it evaporates. The additional volume is absorbed in the expansion vessel (MAG). When the system cools down, the water vapor condenses again. Olli