Plant diagram

Figure: 2-pipe system VAV applications, with changeover

Key:

DXR2…

Automation station

 

R1

Room operator unit

YS

Supply air VAV

 

D1

Presence

YHC

Heating/cooling coils

 

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