User Manual

Remarks of Siemens

This section outlines how Siemens interprets the functions and processing functions according

to EN 15232-1:2017.

3.1

Plants required for "emission control" of thermal energy such as fan coils, chilled ceilings or VAV

systems, may have different supply media (e.g. water, air, electricity). As a result, different BAC

solutions may be possible for a processing function.

1 The Siemens interpretation gives full consideration to by the processing function in the function

list of EN 15232: It includes thermostatic valves and electronic control equipment.

· Non-communicating electronic control equipment may include a local scheduler, but

experience suggests that they are often not correctly set.

· Thermostatic valves are not used for "cooling control".

3 Communication between a superposed central unit and electronic individual room controllers

allow for central schedulers, monitoring of individual room controllers as well as centralized

operation and monitoring.

4 Demand control (by use) = demand control based on occupancy information from a presence

detector or a presence button with automatic reset after a set period. Control switches from Pre-

Comfort to Comfort or the other way around using this occupancy information (see EN 15500).

Notes:

· Air quality control is considered in "Ventilation and air conditioning control"

· Occupancy information can influence "heating control", "cooling control" and "ventilation and

air conditioning control"

3.2

1 As a rule, there is only a single flow temperature setpoint per zone (heating and cooling – no

setpoint range, so that it often overheats or undercools somewhat during transition periods

(where heating and cooling are released).

2 A setpoint range is used here; one setpoint each can be preset separately for heating and cooling

activities. This eliminates to some extent overheating or underheating.

3.4

3 The pump is only enabled for demand.

With constant Dp: Pressure differential does not increase at decreasing load when maintaining a

constant pressure differential across the pump. The pump speed is reduced under part load

conditions, which lowers power consumption.

With variable Dp: Pressure differential across the pump drops as the load decreases. This

provides additional reductions in speed and electrical power under part load conditions.

4 With variable Dp following an external demand signal, the pump speed is reduced under part

load conditions as much as possible whilst ensuring, that the consumer with the largest demand

is still satisfied at any given operational situation, i.e. no underprovisioning of certain consumers.

This lowers power consumption maximally.