Plant diagram

Figure: 4-pipe system VAV applications

Key:

DXR2…

Automation station

 

R1

Room operator unit

YS

Supply air VAV

 

D1

Presence

YC

Chilled water cooling coils

 

D2

Window contact

YH

Hot water heating coils

 

 

 

Sequences

 

Y

Output signal

 

TR

Room temperature

SpH

Effective heating setpoint

 

SpC

Effective cooling setpoint

YH

Heating valve

 

YC

Cooling valve

Figure: Modulating heating and cooling sequence