Building automation – impact on energy efficiency - Siemens ...

Remarks of Siemens
This section outlines how Siemens interprets these functions and processing
functions according to EN 15232:2012.
4.1
4.1
4.2
This deals exclusively with air renewal in the room.
Note:
As per EN 15232, the parts "Heating control" and "Cooling control" apply to
room temperature control.
This function affects the air flow in a single room system (e.g. movie theater or
lecture hall) or in the reference room of a multi-room system without room
<strong>automation</strong>.
This function affects the air flow of each room <strong>automation</strong> as part of a multiroom
system. For that, supply air pressure control in the air handling unit is required
(refer to Processing function 3 per interpretation 4.2).
Processing functions 0 to 2 affect the air flow in the air handling unit as part of a
multi-room system without room <strong>automation</strong>. These are, however, already contained
in the function as per interpretation 4.1.
Processing function 3 was planned as air flow provisioning for a multi-room system
with room <strong>automation</strong>.
4.3
4.4
4.5
4.6
4.7
Control of exhaust air side icing protection of heat recovery (heat exchanger).
Control of heat recovery in the central air handling unit.
Cooling and ventilation with a portion provided by passive energy (renewable
and free, may however require auxiliary energy, e.g. electrical energy for
pumps). This reduces the percentage of active energy (that has to be paid for).
If the air system serves only one room and is controlled according to indoor
temperature of this room one should use "Heating and cooling control" even if
the control acts on the supply temperature. In the other cases one shoud differentiate
at least the available types of control.
This temperature control shall be considered with particular attention if the
system principle does not prevent simultaneous heating and cooling.
1. The prerequisite for dew point control is an air washer that has a humidification
efficiency of at least 95 %, i.e. one that can almost achieve the saturation
of the escaping air. If the temperature of this practically saturated air is
also controlled, its water vapor content is fixed. Therefore, the required effort
in terms of control equipment is relatively small. This solution is appropriate
in applications where the air that has been cooled to the dew point is
largely reheated by internal heat sources in the conditioned space. If this is
not the case, direct humidity control is – for energy efficiency reasons –
preferable in conventional air conditioning systems
2. In the case of water spray humidification, humidification efficiency that is
considerably lower than that of the dewpoint air washer is sufficient. This
means that a correspondingly lower priced device can be used. It is, however,
important that the humidifier is controllable within a sufficiently large
output range.
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