Whom to entrust with the room-wise heating load calculation?

I honestly find it a bit overdramatic. Simply stipulate a maximum installation distance of 10cm everywhere, 5cm in the bathroom, and lay out everything that can possibly be laid out. If you want 24 degrees in the bathroom, also lay out one wall or add an electric heater.

That's where it starts... Less than 10 cm installation distance brings no significant advantage, and less than 8 cm brings you no benefit at all. And if you want to omit the ERR, you control the temperature by designing the heating surfaces accordingly. Just as you described, that's exactly how it shouldn't be done.

That's where it starts... Less than 10 cm VA brings no significant advantage and less than 8 cm brings you nothing more. And if you want to omit the ERR, you control the temperature by designing the heating surfaces. Just as you described, that's exactly how you shouldn't do it

No, for that you take the tacos. Throttling is not bad if there is generally enough flow in the system The problem is too little heat transfer and not too much. This is countered with higher flow temperature, which is inefficient

Two things must be considered.

1. The length of the circuit. The longer the circuit, the higher the pressure loss, the less flow with a given pump power. Therefore, similarly long circuits will initially have a similar amount of water flowing.

2. The capacity of the circuit. This can vary greatly depending on pipe spacing, floor covering, room temperature, etc.

For a certain capacity, a defined volume flow is necessary if a specified temperature difference is to be achieved (which is given by the defined supply temperature/return temperature). Example: The circuit should deliver 100 watts, with a temperature difference of 3 degrees: 100 / 60 / 1.16 / 3 = 0.56 l/min.

As long as the longer circuits are to deliver less capacity than the shorter ones, everything is fine, since they automatically get less water due to the higher pressure loss.

But if a long circuit is supposed to have a high capacity, it needs a lot of water despite the high pressure loss! Ergo: For this circuit, we have to increase the circulation pump to get more pressure. As a result, we have to throttle all other circuits more. This is exactly what one tries to avoid through sensible design, as it unnecessarily costs pumping energy – forever.

Geisha Guide

Wouldn't every energy consultant have to do that? He calculates which room needs how many heating circuits and what length the circuits must have. I believe our documents even specify the [verlegeform der Schleifen].

Shouldn't every energy consultant do that? They calculate how many heating circuits each room needs and the length of the circuits. I believe our documents even specify the laying pattern of the loops.

I don't know how it is when you build KFW xy, but if you just need an energy saving certificate, then they do calculate the ht-value, etc., but for the entire building envelope. Not room by room and no design plans either. Maybe it also depends on what you "order."

It usually calculates the energy consumption but not the heating load of the building and certainly not the room heating load.