Balancing airflow sequence, Dual duct – KMC Controls BAC-8007 Installation Guide User Manual
Page 69
Balancing airflow
sequence
Balancing airflow is the process of calibrating the internal airflow sensor to a
known standard. In the field, airflow is measured with an airflow hood or
other measuring instrument and then compared to the airflow measurements
from the sensor in the controller. The balancing process uses an STE-8001 or
STE-8201 as the technicians setup tool for initiating the balancing sequence
and entering actual flow measurements.
When the balancing sequence starts, all other functions of the controller are
locked out.
At the start of the sequence, the controller drives the damper open until the
airflow reaches the highest value of either the cooling or heating maximum
airflow setpoints. An airflow measurement is made with an airflow hood and
the actual airflow value is entered into the controller. Once the actual airflow
is entered, the controller drives the damper closed to the lower value of
either the cooling or heating minimum airflow. Another measurement is made
with the flow hood and that measurement is entered into the controller.
After the minimum airflow measurement is entered, the programming in the
controller calculates airflow correction factors which are used to adjust
measurements from the internal airflow sensor. Balancing is complete and the
controller is returned to normal operation.
See the topic
for the procedure to balance the
airflow with an STE-8001.
Dual duct
A dual duct installation consists of separate primary heating and cooling
ducts, both with control dampers and airflow monitoring. For this type of
installation a SimplyVAV BAC-8007 controls the cooling air (primary) damper
and a TSP-8001 actuator controls the heating air (secondary) damper.
As the space temperature rises above the cooling setpoint, the primary
airflow is modulated from the Cooling Minimum flow to the Cooling
Maximum Flow.
As the space temperature falls below the heating setpoint, the secondary
airflow is modulated from the Heating Minimum flow to the Heating
Maximum Flow.
Between the heating and cooling setpoints, both the primary airflow and
secondary airflow are modulated to maintain the Dual Duct Minimum
airflow.
See the topic,
for an application drawing.
SimplyVAV
Section 7: Sequences of operation
Revision E
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