VAV - Induced Heating

VAV - Induced Heating

This workflow will test a VAV box for its heating operation. 


  1. First, we display the initial conditions of the equipment. 

  2. Then KODE performs precondition checks to ensure the equipment is ready to be tested

  3. Next we will lower the setpoint to stop heating. 

  4. Finally we will raise the setpoint to start heating.


Outcome 🎯

This test will check a VAV box's ability to deliver heat when its setpoint is raised.

Recommended Schedule 📅

  1. Run weekly per floor

  2. Run when there are comfort complaints in a space or floor.

  3. Run when new VAV boxes are installed and programmed.


Device 

Point Requirements 📌

VAV

Occupied Mode

Discharge Air Temperature

Zone Temperature

Zone Temperature Setpoint

Zone Temperature Setpoint

AHU

Discharge Air Pressure

Required Preconditions

1.

AHU Pressure > Min Pressure Threshold


*Variations

  1. There is a variant of this workflow which works with occupied heating and cooling setpoints. 

  2. There is a variant of this workflow which works with network setpoint. 


Workflow Overview


Test Step

Workflow

1

Pre-condition Check

  1. VAV is Occupied

  2. AHU Pressure > Min Pressure Threshold

2

Stop Heating

  1. Control:  Lower VAV Zone Temp Setpoint

  2. Success: VAV DAT near AHU DAT or VAV Zone Temp

3

Start Heating

  1. Control:  Raise VAV Zone Temp Setpoint

  2. Success: VAV DAT greater than AHU DAT



Successful Test Example

















Failed Test Example

Tuning Parameters


Test Step

Result Description

1

AHU Min Pressure

If AHU Pressure is less than this number, the test automatically archives

2

VAV Zone Temp Setpoint Adjustment

How far below zone temp should the setpoint be set to stop heating? How far above zone temp should the setpoint be set to start heating?

3

VAV Stop Heating

After lowering the VAV setpoint, the VAV DAT should approach the zone temperature. How close does the VAV DAT need to be to verify that heating has stopped?

4

AHU Stop Heating

After lowering the VAV setpoint, the VAV DAT should approach the AHU DAT. How close does the VAV DAT need to be to verify that heating has stopped?

5


AHU Start Heating Temp


After raising the VAV setpoint, the VAV DAT should rise above the AHU DAT. How much greater should the VAV DAT be than AHU DAT to verify that heating has started?

6

Max Sequence Duration

What is the maximum length of time in seconds that a sequence should take to execute?

7

Min Sequence Duration

What is the minimum length of time in seconds that a sequence should take to execute?

8

Stabilization Time

How long in seconds should the program wait when one sequence finishes, before moving onto the next?


If you need assistance with interpreting your results, reach out to the support team at [email protected]. 


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