Trane Tracer VV550 Installation, Operation And Maintenance Manual page 57

Ventilation Control actions
The controller uses the reported effective ventilation setpoint to find the reported
ventilation ratio.
Tracer Summit
The values of reported effective ventilation setpoint, reported ventilation ratio, and
reported airflow are sent to the Tracer Summit BAS for use in system ventilation control
functions. Once the system receives these values from all the zones, it determines the
required outdoor airflow setpoint by implementing Equation 6-1 from ANSI/ASHREA 62-
2001.
The communicated ventilation ratio limit tells the controllers how much outdoor air is in
the primary airflow.
Local ventilation control
If the capability of the system to deliver outdoor air is limited, local action must be taken
at the zone level to achieve proper ventilation. Since no more outdoor air is available, the
zone must provide more air into the zone to ventilate it. To do this, the zone calculates
a new increased minimum flow setpoint:
Ventilation is allowed to adjust the local minimum flow setpoint upward as much as
needed until one of the following conditions is met:
•
•
•
The minimum can be adjusted up again when one of the following conditions is met:
•
•
•
CNT-SVX17G-EN
Reported ventilation ratio = reported effective ventilation setpoint ÷ reported airflow
™
ventilation control
Zone required minimum flow setpoint = 
Reported effective ventilation setpoint ÷ Communicated ventilation ratio limit
Zone temperature drops below the heating setpoint minus 1°F (for cooling);
Zone temperature rises above the cooling setpoint plus 1°F (for heating);
Space temperature input fails.
Zone temperature rises to the heating setpoint plus 1°F (for cooling);
Zone temperature falls to the cooling setpoint minus 1°F (for heating;)
Space temperature input is regained.
Sequence of Operations
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