Functions; Types Of Compensation; Weather Compensation; Weather Compensation With Room Influence - Siemens ALBATROS QAA73.110 Basic Documentation

Introduction
Note
Description
Prerequisites
Description
Prerequisites
Room influence
60/70
Siemens Building Technologies
HVAC Products
6

Functions

The functions described below require no settings. They are performed automatically
but have an impact on the plant.
For the rectification of faults, planning and plant maintenance, it may therefore be very
advantageous to know about their impact on plant operation.
6.1

Types of compensation

The room unit offers 3 types of compensation each of which generates the effective
flow temperature setpoint in a different way. They are the following:

Weather compensation

−

Weather compensation with room influence

−
Room compensation
−
If no outside sensor is connected and the room sensor of the QAA73.110 fails, a fault
status signal will be delivered. In that case, the room unit will change to emergency
operation "with no sensor" to generate the flow temperature setpoint based on the
current room temperature setpoint and a fixed outside temperature of 0 °C
6.1.1 Weather compensation
With this type of compensation, the building's heat losses are compensated by an
adequate flow temperature.
The colder the weather, the quicker the building cools down and the greater the heating
circuit's heat demand.
With this type of compensation, it must be ensured that the heating curve is correctly
set, because the room unit gets no feedback from the space whether the amount of
heat supplied meets the demand of the users.
The room influence (line 75) must be set to "None" and, in addition, an outside sensor
must be connected.
6.1.2 Weather compensation with room influence
Compared to pure weather compensation, this type of compensation offers enhanced
comfort because with the room influence, the room unit gets a feedback from the
space.
The room influence (line 75) must be activated for the required heating circuits and, in
addition, an outside sensor must be connected.
The room influence acts on the room temperature setpoint. The deviation of setpoint /
actual value of the room temperature is multiplied by the correction factor KORR/2 and
added to the deviation from the room temperature setpoint in the opposite direction.
Room influence acts:
• In the case of deviations of setpoint / actual value of the room temperature
• With automatic or manual changeover to a higher or lower room temperature
setpoint
Basic Documentation QAA73.110 Room unit
Functions
CE1P2284en
10.07.2002