Assortment / System Description

VAV application
Serial or parallel control strategy
18
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18 VAV application
The VAV application can be configured using a VAV application type. Each VAV
application type can also combine a radiant/chilled ceiling (beam) or radiator
application. The image below provides an overview of the VAV application type
with all possible HVAC components that can be configured for a VAV
application. The configuration enabled the applicable (required) aggregate on
the DXR2.
Figure: Application types for VAV applications
Key:
DXR2… Automation Station B4 Primary air temperature
B1 Return air temperature sensor R1 Room operator unit
B3 Supply air sensor D1 Presence
YC Chilled water cooling coils D2 Window contact
YHC Heating/cooling coils YS VAV supply air
YH Hot water heating coils or electric
heating coils
YE VAV extract air
18.1 Serial or parallel control strategy
You must select one of 2 different control strategies on all VAV applications:
● Serial fan operation: The air volume is only increased if the valve's or
reheater's positioning signal is fully open and the room temperature
exceeds or breaches an additional offset.
● Parallel fan operation: The fan speed is increased in parallel to the valve's
or repeater's positioning signal.
The two strategies are illustrates in the following example using a heating and
cooling valve.
Plant diagram