VAV - Heating Operation

VAV - Heating Operation

Testing Procedure

Pre-Conditions Check

Before testing is started, it must be verified that the VAV is in operation.
  • Verify that VAV is “Occupied”.
  • Verify that it’s parent AHU is “Occupied
  • Verify fan is running by checking that duct pressure is more than 0.4psi [Pressure Min Threshold]
If any of these conditions are not met, STOP the workflow and ARCHIVE.

Setup Testing Conditions

In order to ensure that testing is accurate, sources of heating must to be eliminated or minimized. If this condition is applicable and not verified, then the testing will be aborted.
Stop Active Heating
  • Verify that discharge temp drops to 10△°F [Heating AHU - Delta] below original discharge temp AND
  • Verify that zone temp is less than 5△°F [Heating - Delta] above discharge temp

Damper Testing

Close the Damper
  • Command Damper to “CLOSED”
  • Pass if VAV discharge flow is less than 30cfm [Max Allowed Flow].
Open the Damper
  • Command Damper to “OPEN”
  • Pass if discharge airflow is greater than 100cfm [Min Flow Indication]. OR
  • Pass if discharge airflow is 20% [Relative Flow Tolerance] greater than discharge airflow setpoint.

Test Heating

Start Heating
  • Verify that discharge temp rises to 10△°F [Heating AHU - Delta] above original discharge temp AND
  • Verify that zone temp is greater than 5△°F [Heating - Delta] above discharge temp

Tuning Parameters

DisplayHint
Damper Close Command [%]To what percentage do we want to test the closing operation.
Close Damper Weight [2]What is the weight on the overall test that we want to assign to this sequence. All sequences will sum up their weights and than each weight will be divided by this total.
Damper Open Command [100%]To what percentage do we want to test the opening operation.
Open Damper Weight [2]What is the weight on the overall test that we want to assign to this sequence. All sequences will sum up their weights and than each weight will be divided by this total.
Heating Stop Command [%]To what percentage do we want to test the closing operation.
Stop Heating Weight [4]What is the weight on the overall test that we want to assign to this sequence. All sequences will sum up their weights and than each weight will be divided by this total.
Pressure Min Threshold [0.4psi]How much should the duct pressure be minimally.
Heating AHU - Delta [10△°F]The threshold tolerance for heating. Delta (DAT VAV - DAT AHU).
Heating - Delta [5△°F]The threshold tolerance for heating. Delta between ZT and DAT.
Max Allowed Flow [30cfm]Max allowed Flow when fully closed damper.
Min Flow Indication [100cfm]Minimum Flow to indicate open damper.
Relative Flow Tolerance [20%]How much below the setpoint in % do we allow the flow to be when we have a fully open damper.
Reaction Time [300sec]How long to wait for the actuators to fully do their job.
Stabilization Time [60sec]How long to wait for the system to come to stability after we have given it an actuator command and the conditions have been fullfiled.
Measure After [60sec]How long to wait in seconds to start checking the feedback readings.
AHU Fan Min Threshold [5%]How much should the ahu discharge fan be minimally in percentage.
DAT Heating Threshold [70°F]How much should the DAT maximally be for our VAV to be able to provide reheat.
Sec Loop Valve Req [10%]How much should the Valve minimally be in (%) to run the heating test.
Heating Start Command [100%]To what percentage do we want to test the opening operation.
Start Heating Weight [4]What is the weight on the overall test that we want to assign to this sequence. All sequences will sum up their weights and than each weight will be divided by this total.

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