How does a high underfloor heating flow temperature affect heating costs?

Hello. First of all, many thanks for your help.

Now I would be interested in the following regarding underfloor heating with pellet heating. (Multi-family house)

- Does a high underfloor heating flow temperature (e.g. 50 degrees in a 70s KfW multi-family house) influence the reading of the individual apartment heat meters (kWh value), or "only" the consumption of the required pellets?

So, with a lower flow temperature, would the heat meter of the individual apartment be just as high with unchanged usage (i.e. room thermostat setting and weather) as if the flow was, for example, 5 degrees higher?

The heat meter only measures the flow rate during active underfloor heating, right? Regardless of whether 50 degrees or 45 degrees are flowing through. The 45 degrees would bring the room to the desired temperature just as well as 50 degrees. The flow quantity should be the same????

That the pellet boiler needs more energy (pellets) for 50 degrees than for 45 degrees flow, makes sense to me. So the amount of pellets should be higher at 50 degrees than at 45 degrees flow. And this would then affect the costs of the individual apartments. But not numerically on the heat meter, but because the basis for calculation is different.

Do I understand this correctly? Thank you

The heat quantity meters ultimately generate a distribution key, an index, to allocate the costs incurred by the central heating system. It is therefore about the relation of the measurement results to each other. Absolute values are uninteresting.

What a strange logic! It is allocated to you proportionally. More pellet consumption means higher costs, which are determined for you via the heat meter.

Whether it's running at 50 degrees or 45 degrees. The 45 degrees would bring the room to the desired room temperature just as well as the 50 degrees. The flow rate of the quantity should be the same, right????

The flow rate at 45 °C is naturally higher than at 50 °C if the room temperature is to be the same.

Such a pellet boiler surely operates internally at a completely different temperature than externally, doesn't it? That is controlled via a mixer.

Otherwise, of course, what Alex85 and tomtom79 wrote is correct. All heating costs (pellets, maintenance, etc.) are determined and then proportionally distributed to the tenants, usually depending on apartment size and consumption measurement. Therefore, the meters "only have to function the same," but it doesn't matter if the meters count kilowatt hours or apples and pears.

The heat meter only measures the flow rate with an active underfloor heating system. It doesn't matter whether 50 degrees or 45 degrees run through it. The 45 degrees would bring the room to the desired temperature just like the 50 degrees. The flow rate should be the same, right?

A heat meter measures the amount of heat ;-), not (only) the flow. It combines the flow measurement with the temperatures of the supply and return flow and thus determines the delivered amount of heat.

At the same output (room temperature), a high supply temperature either leads to a lower flow rate or a higher return temperature (or both). The amount of heat and thus the distribution of costs do not change.

So the pellet amount should be higher at 50 degrees than at 45 degrees supply temperature.

I am not sure. Combustion engines can easily produce even higher supply temperatures. Only condensing boilers, which also use the latent heat from the flue gas, are more efficient with lower supply temperatures. So it depends on the system.