Flow Balancing View

The flow balancing view is used to balance a controller that is programmed with a standard VAV application. Based on the version of the VAV application and its features, the following operations can be performed on the view.

Flow pressure zero calibration
Two point calibration
K factor calibration
Heating coil water flow calibration

Pre-requisites

The controller must be online.
The controller must be in a commissioned state.
VAV Zone Terminal Single Duct must be selected as the Application Type and Air Balance Supported must be selected.

Note: The selections must be done before downloading the program to the controller.

Select the Reheat Valve Override Supported option to calibrate the reheat valve.
Select the Peripheral Heat Valve Override Supported option to calibrate the peripheral heat valve.

Procedure

On the Nav palette, browse to Station > Config > Drivers> LonNetwork > LonDevice.
or
Browse to Station > Config > Drivers> BacnetNetwork > BacnetDevice.
Right-click ControlProgram and select Views > Flow Balancing View. The Flow Balancing View appears on the right pane.
You can type the values into the following fields.

Name	Description
Actuator Travel Time	The actuator travel time is the time required by the actuator to travel from 0% to 100% open or 100% to 0% open. This time interval depends on the actuator type and can vary from 0 to 500 seconds.
K Factor	This field allows you to manually change the K factor value from 0 to 10000.
Inlet Area	Displays the area of the duct. Either a standard diameter can be selected or a custom area can be entered in this field. The inlet area ranges from 0 to 100 sq.ft.
Measured Flow	Displays the actual air flow when measured by the balancer using an accurate device. This field is editable.
Maximum Flow Setpoint	This field allows you to set the flow setpoint from 0 to 138850 cfm for maximum flow calibration and k factor calibration. The controller seeks stable flow and when it is reached, it allows you to set the calibration source value.
Minimum Flow Setpoint	This field allows you to set the flow setpoint value from 0 to 138850 cfm. You must set the flow setpoint less than the maximum value to obtain minimum flow calibration. The controller seeks stable flow and when it is reached, it allows you to set the calibration source value.
Re-heat Valve Override	This field allows to override the value of the reheat valve in an application built for the reheat valve. This field is visible when the Reheat Valve Override Supported feature is selected in the Details View of the Control Program.
Peripheral Heat Valve Override	This field allows to override the value of the peripheral heat valve in an application built for the peripheral heat valve. This field is visible when the Peripheral Heat Valve Override Supported feature is selected in the Details View of the Control Program.
Device Mode	Displays the current device mode. This is a non-editable field.
Damper Position	Displays the current damper position. This is a non-editable field.
Sensed Flow	Displays the actual air flow that is measured by a pressure sensor. This field is non-editable.
Flow Pressure	Displays the current flow pressure. This field is non-editable.

Flow pressure zero calibration

To start zero balancing:

Click on Start Zero Balancing.

The damper is completely closed. If any flow pressure is detected that value is considered to be the flow pressure offset. After the completion of zero balancing the device mode is set to automatic operation.

Two point calibration

You can start either maximum or minimum balancing in any order. The tool does not enforce any rules on the order of balancing.

Maximum calibration

To start maximum calibration:

Click on Start Maximum Balancing.

The device adjusts the damper to try and attain the maximum flow setpoint. After the setpoint is attained, the Measured Flow field is enabled and the actual measured flow value can be entered. The device remains in manual mode (Open Maximum) after maximum balancing is complete.

Minimum calibration

To start minimum calibration:

Click on Start Minimum Balancing.

The device adjusts the damper to try and attain the minimum flow setpoint. After the set point is attained, the Measured Flow field is enabled and the actual measured flow value can be entered. The device remains in manual mode (Open Minimum) after minimum balancing is complete.

K Factor calibration

To start K factor calibration method:

Click on Start K Factor Balancing.

After a warning message, the two point calibration data is returned to factory defaults.

The device adjusts the damper to try and attain the maximum flow setpoint. After the setpoint is attained the Measured Flow field is enabled and the actual measured flow value can be entered.

After the measured flow is entered, the K factor value is calculated by the tool and displayed. The tool prompts you to write this value to the device. You can choose to calculate the K factor without using the tool and set the calculated value in the K factor field. The device remains in manual mode (Open Maximum) after K factor balancing has completed.

Heating coil water flow calibration

To override the reheat valve position:

Type the reheat value in percentage and click the Override button next to Reheat Valve Override field.

To override the peripheral heat valve position:

Type the peripheral heat value in percentage and click the Override button next to Peripheral Heat Valve Override field.

Note: Click the Auto button to set the reheat and peripheral heat valve into automatic operation.

Setting the device mode to automatic operation

To set the device to automatic operation:

Click on Set Mode to Auto when it is enabled.

While exiting the view if the device is in manual mode, then the tool prompts you to change the mode to automatic operation.

Restoring to factory defaults

To restore to factory defaults:

Click the Restore to Factory Defaults button to restore the default value of the Zero calibration values, K factor calibration values, Minimum flow calibration values and Maximum flow calibration values.