ᐅ What is more economical? Charging the buffer tank more frequently or heating it up to a higher temperature?

Good day.
I am interested in understanding how to operate a buffer tank economically in combination with pellets, solar, and a domestic hot water system.
Is it better to maintain higher holding temperatures, for example around 75°C (167°F) at the top and bottom of the buffer tank, while the system recharges more frequently from the boiler at 70–75°C (158–167°F) to maintain the minimum temperature of 75°C (167°F)?

Or is it preferable to have higher minimum temperatures at the bottom of the buffer tank, around 60°C (140°F), which would still result in approximately 75°C (167°F) at the top? This would require the boiler to reheat more often (i.e., temperatures around 60°C (140°F) at both top and bottom).

Could anyone provide advice on this?
Thank you.

The heat stays inside the house in both cases. Therefore, it makes the most sense to focus on how to burn the wood with as little loss through the chimney as possible. I guess that a longer burn time is beneficial.

However, the wood stove users here would need to provide more information on this.

boxandroof schrieb:

In both cases, the heat stays inside the house. Therefore, it makes the most sense to focus on how the wood burns with as little loss through the chimney as possible. I suspect that a longer burn time is beneficial.

However, the wood stove experts here should be able to provide more input.

Thank you.
So you mean it’s better to increase the upper buffer temperature to allow more frequent refueling, rather than heating almost the entire buffer at once.
In other words, aim to maintain around 75°C (167°F) at the top, and about 60°C (140°F) at the bottom (which is sufficient for underfloor heating).

And increase the hysteresis; you can also shower very comfortably at around 45°C (113°F). If your boiler only heats up to 70°C (158°F) once a day, that saves money.

tomtom79 schrieb:

And increase the hysteresis; for example, showering comfortably at 45°C (113°F) is possible. If your boiler only heats up to 70°C (158°F) once a day, that saves money.

However, we want to maintain the domestic hot water at 60°C (140°F), or at least 58°C (136°F).
There is supposedly a regulation requiring 60°C (140°F) in multi-family buildings, even for domestic hot water...
Our main concern is to avoid fluctuations.

It is only now that it becomes clear that this is a multi-family house. However, since it is a fresh water system, you generally shouldn’t have any issues with Legionella.