User Manual

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Source: „Centre Scientifique et Technique du Bâtiment (CSTB)", Frankreich
Siemens achieved very solid values with their certified single room controllers. For example with
Desigo DXR2.E09T (for fan coils) with motoric actuators control accuracy for heating and cooling of
0.1 K was achieved.
Impact of actuator on energy savings
It is well known that characteristics (time constants, adjustment response, characteristic curve, etc.)
for field devices have a direct impact on control accuracy.
In other words, different levels of control accuracy can be achieved with the same individual room
controllers and temperature sensors, but using different valve actuators (motor, thermal modulating,
thermal on/off) and thus different energy savings can be realized. On the flip side, the variously
equipped control circuits cause differences in the costs of the control circuit.
The chart below illustrates that a higher investment in motor driven valves makes sense versus
thermally driven valves (in the comparison with the previous chart, curve "natural gas heating
H3"/Southern France):
· The amortization period for the investment is shorter
· Then operating costs are lower as a result of larger energy savings
· And the impact on the environment declines in line with the energy savings
Cost reduction from utilizing motoric valves (see curve „ gaz heating H3“, Southern France above)