User Manual

Control concept
Desigo room automation
5
102 | 353 CM110664en_07
The following illustrations show sequence control for an HVAC plant in the
room for operating modes Comfort and Economy. Sequence control acts on
heating and cooling equipment and a multi-speed fan.
Control sequences in the Comfort operating mode:
Control sequences in the Economy operating mode:
The available operating modes determine both operation and basic control
strategy in the automation and control system at three different levels:
● The room operating modes determine the operation of HVAC equipment in
a room in terms of current use by the user. The room operating modes
defined for the room are available in all HVAC control applications in the
room.
● The HVAC plant operating modes determine the operation the HVAC plant
in the room with regard to existing, physical plant processes. The HVAC
plant operating modes are defined specifically for 1 HVAC plant in the room.
● The device operating modes determine the operation of the HVAC devices
in a room by predefining their tasks and implementation method. The device
operating modes are defined specifically for each individual HVAC device.
Plant and device operating modes of a plant with heating coil,
cooling coil, and fan
Project-specific adaptations of both plant and device operating modes can be
implemented by adapting the operating mode table.
Plant operating mode Fan operating mode Heating coil operating mode Cooling coil operating mode
Off Off Off Off
Comfort Modulating Modulating Modulating
PreComfort Modulating Modulating Modulating
Neither CoolingHeating
HCSta
SpH SpC
TREff
Cool 1Heat 1 Cool 2Heat 2
AirFlReqHeat
100%
0%
TREff
FanSpd
VlvPos
Plant operating mode Comfort
VlvPos
CclChw01HclHw01
FanMultiSpd01
Speed 3
FanSpdMin=Off
Speed 2
Speed 1
AirFlReqCool
Neither CoolingHeating
SpH SpC
100%
0%
Speed 3
Plant operating mode Economy
FanSpdMin=Off
Speed 2
Speed 1
AirFlReqHeat
TREff
AirFlReqCool
VlvPos
CclChw01
HCSta
FanSpd
VlvPos
HclHw01
FanMultiSpd01
Cool 1Heat 1 Cool 2Heat 2