Plant diagram

Figure: Example for a heating/chilled ceiling application 2-pipe system

Key:

DXR2…

Automation station

 

R1

Room operator unit

Rcg

Ceiling heating/chilled ceiling valve

 

D1

Presence

CdnMon

Condensation monitor

 

D2

Window contact

Sequences

 

Y

Output signal

 

TR

Room temperature

SpH

Effective heating setpoint

 

SpC

Effective cooling setpoint

YH

Heating valve

 

YC

Cooling valve

Chovr

Changeover system

 

 

 

Figure: Modulating heating and cooling sequence with changeover system

Changeover system

The central function for chilled water supply determines whether the water system is used for heating or cooling based on heating/cooling demand of individual rooms in this supply group. The evaluated result is sent via grouping to the room segment to enable the heating or cooling sequence in the room.

The changeover determination logic counts each the segments with heating or cooling demand.

The cooling controller is disabled during heating, the heating controller for cooling.