Buderus SRC plus Installations- Und Bedienungsanleitung Seite 41

6.4 Adaptive heating curve
If the Single room-dependent control type is selected, the adaptive
heating curve function is active. The flow temperature is determined
automatically and according to demand.
• Automated
Classic heating curve parameters such as the base and end point do
not need to be entered.
• Demand-controlled
The system determines the required heating curve automatically and
continuously in order to guarantee the desired set room
temperatures and operate the heat generator with the best possible
efficiency. If boundary conditions change, the system always adapts
to the new circumstances.
The flow and return temperatures play a key role in the efficiency of heat
generators. Depending on the type of heat generator, heat pump or wall
hung condensing boiler, the flow and return temperatures have a
different significance.
• The flow temperature has a major influence on the efficiency of heat
pumps.
– Reducing the flow temperature by just 1 K increases the
efficiency of an air-to-water heat pump, for example, by around 2
- 4 % (depending on the device).
– Reducing the return temperature by 1 K only increases efficiency
by around 1 % (depending on the device).
• Condensing boilers are particularly efficient if they operate in the
condensing range and thus utilise the condensing effect. To achieve
this, the return temperature must be as low as possible. Reducing the
return temperature by 5 K increases the efficiency of a condensing
boiler by around 2 % (depending on the device). The return
temperature is therefore has a particular significance.
The following is derived from this as the aim of the control for efficiency
and comfort:
• Heat pump efficiency: keep the flow temperature as low as possible
• Wall hung condensing boiler efficiency: operate in the condensate
range as far as possible
• Comfort: flow temperature as high as necessary to ensure comfort.
The set room temperatures set by the user in the respective rooms are
achieved by the system adjusting the flow temperature accordingly. If
the user increases the set room temperature from 20 °C to 21 °C, for
example, a slightly higher flow temperature is required. The flow
temperature changes at this moment from 30 °C to 32 °C, for example.
A reduction in the set room temperature from 20 °C to 19 °C, for
example, would, conversely, result in a reduction in the flow
temperature from 30 °C to 28 °C, for example.
After start-up, the system learns the optimum heating curve for each
room (individual control) individually. The starting point (heating curve
before adaptation) is always the same:
• Base point: T = 20 °C at T
VL A
• End point: maximum heating circuit temperature at T
45 °C, adjustable in the system controller Logamatic BC400)
• Design room temperature: 20 °C
Based on the data from the heat generator (e.g. current flow
temperature) and the data from the individual control (e.g. set room
temperature and measured room temperature), the heat energy
demand and therefore the required flow temperature is taught.in for
each room. Normally, the initial learning process is completed after just
a few days.
SRC plus – 6721856015 (2024/03)
= 20 °C
= -15 °C (e.g.
A
Detailed functional description
ϑ / °C
VL
50
45
40
35
30
25
20
+20 +10
0010047182-001
Fig. 17 Heating curve before and after adaptation (simplified)

Flow temperature
VL

Outdoor temperature
A
[1] Heating curve before adaptation
[2] Example of heating curve after adaptation
6
1
2
0 –10 –20
ϑ / °C
A
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